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Title: Smithsonian Institution - United States National Museum - Bulletin 240 - Contributions From the Museum of History and Technology
Author: Anonymous
Language: English
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Copyright Status: Not copyrighted in the United States. If you live elsewhere check the laws of your country before downloading this ebook. See comments about copyright issues at end of book.

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Transcriber's Notes

This volume was compiled by Tom Cosmas from 11 Papers from The
Smithsonian Intitute's Bulletin 240 CONTRIBUTIONS FROM THE MUSEUM OF
HISTORY AND TECHNOLOGY: which were previously published on Project

  Paper 34 == The 1893 Duryea Automobile In the Museum of History and
    Technology, by Don H. Berkebile

  Paper 35 == The Borghesi Astronomical Clock in the Museum of History
    and Technology, by Silvio A. Bedini

  Paper 36 == The Engineering Contributions of Wendel Bollman, by
    Robert M. Vogel

  Paper 37 == Screw-Thread Cutting by the Master-Screw Method since
    1480, by Edwin A. Battison

  Paper 38 == The Earliest Electromagnetic Instruments, by Robert A.

  Paper 39 == Fulton's "Steam Battery": Blockship and Catamaran, by
    Howard I. Chapelle

  Paper 40 == History of Phosphorus, by Eduard Farber

  Paper 41 == Tunnel Engineering: A Museum Treatment - Robert M. Vogel

  Paper 42 == The 'Pioneer': Light Passenger Locomotive of 1851, by
    John H. White

  Paper 43 == History of the Division of Medical Sciences, by Sami
    Khalaf Hamarneh

  Paper 44 == Development of Gravity Pendulums in the 19th Century, by
    Victor Fritz Lenzen and Robert P. Multhauf

The following applies to all of the Papers:

  Italic emphasis denoted as _Text_. Bold emphasis as =Text=.
  Whole numbers and fractions: shown as 1-1/2, 3-1/4, etc.
  Superscripts are ^{3} and subscripts are _{4} unless otherwise noted.
  All footnotes and any list of corrections were placed at the end of
  each individual Paper. Numerous minor typographical error were corrected.
  All obvious typographical errors corrected. Formatting inconsistancies
  and spelling were standardized. Paragraphs split by illustrations were

       *       *       *       *       *


  PAPER 34


  _Don H. Berkebile_

                                    EARLY AUTOMOTIVE EXPERIENCE      5

                                            CONSTRUCTION BEGINS      6

                                  DESCRIPTION OF THE AUTOMOBILE     16

[Illustration: FIGURE 1.--DURYEA AUTOMOBILE in the Museum of History and
Technology, from an 1897 photograph. The gear-sprockets were already
missing when this was taken, and the chain lies loosely on the pinion.
Shown at the right, the Duryea vehicle following the recent restoration
(Smithsonian photo 34183).]

  _Don H. Berkebile_

  The 1893 Duryea Automobile
  _In the Museum of History and Technology_

     _During the last decade of the nineteenth century a number of
     American engineers and mechanics were working diligently to develop
     a practical self-propelled vehicle employing an internal-combustion
     engine as the motive force. Among these men were Charles and Frank
     Duryea, who began work on this type of vehicle about 1892. This
     carriage was operated on the streets of Springfield, Massachusetts,
     in 1893, where its trials were noted in the newspapers. Now
     preserved in the Museum of History and Technology, it is a prized
     exhibit in the collection of early automobiles._

     _It is the purpose of this paper to present some of the facts
     discovered during the restoration of the vehicle, to show the
     problems that faced its builders, and to describe their solutions.
     An attempt also has been made to correlate all this information
     with reports of the now almost legendary day-to-day experiences of
     the Duryeas, as published by the brothers in various booklets, and
     as related by Frank Duryea during two interviews, recorded on tape
     in 1956 and 1957, while he was visiting the Smithsonian._

     THE AUTHOR: _Don H. Berkebile is on the staff of the Museum of
     History and Technology, in the Smithsonian Institution's United
     States National Museum._

Of the numerous American automotive pioneers, perhaps among the best
known are Charles and Frank Duryea. Beginning their work of automobile
building in Springfield, Massachusetts, and after much rebuilding, they
constructed their first successful vehicle in 1892 and 1893. No sooner
was this finished than Frank, working alone, began work on a second
vehicle having a two-cylinder engine. With this automobile, sufficient
capital was attracted in 1895 to form the Duryea Motor Wagon Company in
which both brothers were among the stockholders and directors. A short
time after the formation of the company this second automobile was
entered by the company in the Chicago Times-Herald automobile race on
Thanksgiving Day, November 28, 1895, where Frank Duryea won a victory
over the other five contestants--two electric automobiles and three Benz
machines imported from Germany.

In the year following this victory Frank, as engineer in charge of
design and construction, completed the plans begun earlier for a more
powerful automobile. During 1896 the company turned out thirteen
identical automobiles, the first example of mass production in American
automotive history.[1] Even while these cars were under construction
Frank was planning a lighter vehicle, one of which was completed in
October of 1896. This machine was driven to another victory by Frank
Duryea on November 14, 1896, when he competed once again with
European-built cars in the Liberty-Day Run from London to Brighton. The
decision to race and demonstrate their autos abroad was the result of
the company's desire to interest foreign capital, yet Frank later felt
they might better have used their time and money by concentrating on
building cars and selling them to the local market. Subsequently, in the
fall of 1898, Frank arranged for the sale of his and Charles' interest
in the company, and thereafter the brothers pursued separate careers.

[Illustration: FIGURE 2.--WORKMEN IN THE DURYEA FACTORY in Springfield,
Mass., working on some of the thirteen 1896 motor wagons. (Smithsonian
photo 44062.)]

Frank, in 1901, entered into a contract with the J. Stevens Arms and
Tool Company, of Chicopee Falls, Massachusetts, which built automobiles
under his supervision. This association led in 1904 to the formation of
the Stevens-Duryea Company, of which Irving Page was president and Frank
Duryea was vice president and chief engineer. This company produced
during its 10-year existence a number of popular and well-known models,
among them a light six known as the Model U, in 1907; a larger
4-cylinder called the Model X, in 1908; and a larger six, the Model Y,
in 1909. In 1914 when Stevens withdrew from the company, Frank obtained
control. The following year he sold the plants and machinery, liquidated
the company, and, due to ill health, retired.

Charles, in the meantime, located in Reading, Pennsylvania, where he
built autos under the name of the Duryea Power Company.[2] Here, and
later in Philadelphia under the name of the Duryea Motor Corporation and
other corporate names, he continued for a number of years to build
automobiles, vacuum cleaners and other mechanical devices. Until the
time of his death in 1938, he practiced as a consulting engineer.

[Illustration: Department of the Interior
  April 1, 1887
  Admit Mr. Charles E. Duryea
  to this Office on all business days
  between the hours of 2 and 4 P.M.
  until otherwise ordered.

  Chief Clerk


FIGURE 3.--ADMITTANCE CARD of C. E. Duryea to the
U.S. Patent Office, 1887. (Gift of Rhea Duryea Johnson.)]

Early Automotive Experience

Born in 1861 near Canton, Illinois, Charles E. Duryea had learned the
trade of a mechanic following his graduation from high school, and
subsequently turned his interests to bicycle repair. He and his brother
James Frank, eight years younger, eventually left Illinois and moved to
Washington D.C., where they were employed in the bicycle shop of H. S.
Owen, one of that city's leading bicycle dealers and importers. While in
Washington, Charles became a regular reader of the Patent Office
Gazette,[3] an act which undoubtedly influenced his later work with
automobiles. A short time later, probably in 1889, Charles contracted
with a firm in Rockaway, New Jersey, to construct bicycles for him, but
their failure to make delivery as promised caused him to go to Chicopee,
Massachusetts, where he contracted with the Ames Manufacturing Company
to do his work. Moving there in 1890, he obtained for his brother a
position as toolmaker with the Ames Company. Thus, Frank Duryea, as he
was later known, also became located in Chicopee, a northern suburb of

[Illustration: FIGURE 4.--CHARLES E. DURYEA, about 1894, as drawn by
George Giguere from a photograph. (Smithsonian photo 48335-A.)]

During the summer, 1891, Charles found the bicycle business left him
some spare time, and the gasoline-powered carriages he had read of
earlier came constantly into his mind in these periods of idleness.[4]
He and Frank studied several books on gasoline engines, among them one
by an English writer (title and author now unknown);[5] this described
the Otto 4-stroke cycle as now used. Some engineers, however, were
concerned because this engine, on the completion of the exhaust stroke,
had not entirely evacuated all of the products of combustion. The
Atkinson engine, patented in 1887, was one of the attempts to solve this
as well as several other problems, thus creating a more efficient cycle.
This engine was designed so that the exhaust stroke carried the piston
all the way to the head of the engine, while the compression stroke only
moved the piston far enough to sufficiently compress the mixture. The
unusual linkage necessary to create these unequal strokes in the
Atkinson engine made it seem impractical for a carriage engine, where
compactness was desired.

[Illustration: _Agents Want{d}_


Pneumatics not enough; springs necessary for comfort & safety Sylph
spring frame saves muscle & nerves & is perfection. All users delighted.
Investigate. We also make a 30 lb. rigid Sylph. Cata. free.

Rouse-Duryea Cycle Co. _Mfrs._ 16 G st., Peoria, Ill.

FIGURE 5.--ADVERTISEMENT of Duryea bicycle company,
_Scientific American_, September 9, 1893.]

Going to Hartford, Connecticut, possibly on business relating to his
bicycle work, Charles visited the Hartford Machine Screw Company where
the Daimler-type engine was being produced,[6] but after examining it he
felt it was too heavy and clumsy for his purpose. Also in Hartford he
talked over the problem of a satisfactory engine with C. E. Hawley, an
employee of the Pope Manufacturing Company, makers of the Columbia
bicycle. Hawley, searching for a way to construct an engine that would
perform in a manner similar to the Atkinson, yet would have the
lightness and compactness necessary for a carriage engine, suggested an
idea that Charles believed had some merit. This idea, involving the use
of what the Duryeas later called a "free piston," was eventually to be
incorporated in their first engine.[7]

[Illustration: FIGURE 6.--J. FRANK DURYEA, about 1894, as drawn by George
Giguere from a photograph. (Smithsonian photo 48335.)]

Construction Begins

Back in Chicopee again, Charles began planning his first horseless
carriage. Frank later stated that they leaned heavily on the Benz
patents in their work;[8] but while the later engine and transmission
show evidence of this, only the Benz manner of placing the engine and
the flywheel seem to have been employed in the original Duryea plan.
Charles reversed the engine so that the flywheel was to the front,
rather than to the rear as in the Benz patent, but made use of Benz'
vertical crankshaft so that the flywheel rotated in a horizontal plane.
Previously most engines had used vertical flywheels; Benz, believing
that this practice would cause difficulty in steering a propelled
carriage, explained his reason for changing this feature in his U.S.
patent 385087, issued June 26, 1888:

     In motors hitherto used the fly-wheels have been attached to a
     horizontal shaft or axle, and have thus been made to revolve in a
     vertical plane, since the horizontal shaft is best adapted to the
     transmission of power. If, however, in this case we should use a
     heavy rotating mass, corresponding to the power employed and
     revolving rapidly in a vertical plane, the power to manage the
     vehicle or boat would become very much lessened, as the flywheel
     continues to revolve in its plane. I therefore so design the
     apparatus that its crank shaft x has a vertical position and its
     fly-wheel y revolves in a horizontal plane.... By this means the
     vehicle is not only easily controlled, but also the greatest safety
     is attained against capsizing.

To the Duryea plan, Benz may also have contributed the idea for
positioning the countershaft, though its location is sufficiently
obvious that Charles may have had no need for copying Benz. Charles
wisely differed from Benz in placing the flywheel forward, thus
eliminating the need for the long driving belt of the Benz carriage. Yet
he did reject the bevel gears used by Benz, which might well have been
retained, as Frank was later to prove by designing a workable
transmission that incorporated such bevel gears. The initial plan, as
conceived by Charles, also included the details of the axles, steering
gear, countershaft with its friction-drum, the 2-piece angle-iron frame
upon which the countershaft bearings were mounted, and the free piston
engine with its ignition tube, since hot-tube ignition was to be
employed. No provision was made, however, for a burner to heat the tube;
nor had a carburetor been designed, though it had been decided not to
use a surface tank carburetor. The plans called for no muffler or
starting arrangement.[9] Many engines of the period were started simply
by turning the flywheel with the hands, and Charles felt this method was
sufficient for his carriage.

[Illustration: FIGURE 7.--DRAWING SHOWING PRINCIPLE of the Atkinson
engine; this feature is what the Duryeas were trying to achieve with
their free-piston engine, by substituting the free piston for the
unusual linkage of the Atkinson. (Smithsonian photo H3263-A.)]

[Illustration: FIGURE 8.--DRAWING OF 1885 BENZ engine, showing
similarity in general appearance to Duryea engine. From Karl Benz und
sein Lebenswerk, Stuttgart, 1953. (Daimler-Benz Company publication.)]

The Ames plant customarily had a summer shutdown during August; thus,
during August of 1891 Charles and Frank had access to a nearly empty
plant in which they could carry on experiments and make up working
drawings of the proposed vehicle. It cannot now be conclusively stated
whether any parts were made for the car during August or the remainder
of the year. It is more likely that the brothers attempted to complete a
set of drawings. Frank Harrington, chief draftsman at Ames, may have
helped out at this time; from Charles' statement of April 14, 1937, it
is learned that he did prepare drawings during 1892.

[Illustration: C. BENZ.


No. 385,087. Patented June 26, 1888.

FIGURE 9.--ILLUSTRATION FROM U.S. patent 385087, issued to Carl Benz,
showing the horizontal plane of the flywheel, a feature utilized by the
Duryeas in their machine.]

The first contemporary record of any work on vehicles is a bill, dated
January 21, 1892, for a drawing made by George W. Howard & Company. This
drawing was made in the fall of 1891 by Charles A. Bartlett, a member of
the Howard firm and a neighbor of Charles Duryea, according to a
statement by Charles in the _Automobile Trade Journal_ of Jan. 10, 1925.
He was then also of the opinion that this drawing may not have had
anything to do with the carriage they were about to assemble, but a
notation found by Charles at a later date has led him to believe that it
possibly concerned a business type vehicle he had discussed with an
unidentified Mr. Snow.

By early 1892 Charles needed capital to finance his venture, an old
carriage to attach his inventions to, a place to work, and a mechanic to
do the work. On March 26, he stopped by the Smith Carriage Company and
looked over a selection of used buggies and phaetons. He finally decided
on a rather well-used ladies' phaeton which he purchased for $70. The
leather dash was in so deplorable a state it would have to be recovered
before the carriage went onto the road, and the leather fenders it once
possessed had previously been removed; yet the upholstery appeared to be
in satisfactory condition, and the candle lamps were intact.

[Illustration: FIGURE 10.--PHANTOM ILLUSTRATION of Benz' first automobile.
(From _Carl Benz, Father of the Automobile Industry_, by L. M. Fanning,
New York, 1955.)]

Two days later, Charles was able to interest Erwin F. Markham, of
Springfield, sufficiently to obtain his financial aid in the project. A
contract was drawn up between the two men, which stated that Mr.
Markham was to put up $1000 for which he received a five-tenths share of
the venture. When the $1000 had been used, he then had the option to
continue his aid until the project had been carried to a successful
climax, and retain his half share, or to refuse further funds and
relinquish four of his five-tenths interest in the business.[10] Had he
eventually chosen the latter, Charles would obviously have had to seek
assistance elsewhere.

[Illustration: FIGURE 11.--THE HOWARD & CO. BILL showing the first work
performed toward a motor vehicle. While this may not refer specifically
to the machine now in the museum, it is evidence of early work.]

[Illustration: FIGURE 12.--THE SHOP OF JOHN RUSSELL & SONS. It was on
the second floor of this building that Charles and Frank Duryea built
their first motor vehicle. (Courtesy of the _Springfield Union_.)]

That same day, March 28, Charles found working space and machinery
available at John W. Russell & Sons Company in Springfield.[11] The
Russells had recently completed a large government order of shells for
the famous dynamite guns later used on board the cruiser _Vesuvius_ in
the Spanish-American War, and this left an entire second floor,
approximately 35 × 85 feet, virtually unoccupied, according to an
affidavit of William J. Russell of April 30, 1926. Now ready to begin
the actual work, Charles hired his brother Frank to start construction.
Frank started about the first of April, receiving a raise of about 10
percent over the salary he had received at Ames. Before the vehicle was
completed a number of other men performed work on some of the parts,
among them William Deats who had been hired by Charles primarily to work
on bicycles in the same area, but who occasionally assisted on the
carriage. Russell Company records show time charged against Charles
Duryea by six other Russell employees: W. J. Russell, P. Colgan, C. E.
Merrick, T. Shea, L. J. Parmelee, and A. A. Poissant.

[Illustration: FIGURE 13.--J. FRANK DURYEA looking over the Russell shop
lathe on which he turned parts for the first Duryea vehicle. Photo taken
about 1944. (Courtesy of the _Springfield Union_.)]

It is Frank Duryea's remembrance that he started work on Monday, April
4. He first removed the body, with its springs, and placed it on a pair
of wooden horses where it remained until the summer of the following
year. The next step was to remove the rear axle and take it to a
blacksmith shop where the old axle spindles were cut off and welded to a
new drop-center axle. Following this the front axle spindles were
removed, the ends of the axle slotted, and a webbed, C-shaped piece
carrying the kingpin bearings was fitted into each slot, braced from
underneath by short brackets which were riveted and brazed in place. The
old spindles then were welded to the center of offset kingpins which in
turn were mounted in their bearings in a manner similar to that in which
the frame of the Columbia high-wheeled bicycle was mounted in its fork.
Arms welded to the lower end of the kingpins were connected by the tie
rods to an arm on the lower end of the vertical steering column, located
on the center of the axle.

[Illustration: FIGURE 14.--A PORTION of the Russell shop records showing
charges made against Charles Duryea during 1893-1894.]

While work on the running gear advanced, some progress was made in the
construction of the engine. Patterns for the castings were fabricated,
most of them by Charles Marshall on Taylor Street,[12] and castings were
poured. The body or main casting of the engine resembled a length of
cast-iron pipe: it had no bosses or lugs cast on, nor any water jacket,
for they thought the engine would be kept cool merely by being placed in
the open air. The front end of the engine was secured to the vehicle by
four bolts which passed through the halves of the bearings and onto four
projections on the open end of the engine. As the crankshaft of this
engine was retained in constructing the present engine, it is logical
to assume that the bearings were the same also. The head was cast as a
thick disc, with both intake and exhaust valves located therein, and was
bolted onto the flanged head end of the engine.

Inside the cylinder was the strange arrangement previously suggested by
C. E. Hawley. To the connecting rod was attached a rather ordinary
ringed piston, over which was fitted a free, ringless piston, machined
to fit closely the cylinder bore. This floating piston could move freely
a distance equal to the compression space. The intention was that on the
intake stroke, suction would open the intake valve, which had no
positive opening arrangement, and draw in the mixture which then was
compressed as in a regular Otto engine. Fired by the hot-tube ignition
system, the force of the explosion would drive both pistons down,
forcing the outer one tight against the head of the smaller one, and at
the end of the stroke the longer wall of the outer piston would strike
an arm projecting into the cylinder near the open end, moving forward
the exhaust valve rod to which the arm was attached, thus pushing open
the valve in the head.[13] On the exhaust stroke the unrestrained outer
piston moved all the way to the head, expelling all of the products of
combustion and pushing the exhaust valve shut again. With a bore of four
inches or less, this engine, Charles believed, should develop about
three horsepower and run at a speed between 350 to 400 revolutions per

As no ignition system had yet been provided, they prepared a 4-1/2-inch
length of one-quarter inch iron pipe, closed at one end, and screwed the
open end into the head. Heating this tube with an alcohol burner would
cause ignition of the mixture when a portion of it was forced into the
heated tube toward the end of the compression stroke. No attempt was
made at this time to use the electrical make-and-break circuit used in
their second engine, as the free piston would have wrecked the igniter
parts on the exhaust stroke, and the push rod located on the end of the
piston would have prevented the piston from closing the exhaust valve.

After keying the flywheel to the lower end of the crankshaft, Charles
and Frank decided to make an attempt to run the engine. Carrying it
into a back room, probably during July or August, 1892, they blocked it
up on horses. A carburetor had not yet been constructed, so they
attempted to start the engine by spinning the flywheel by hand, at the
same time spraying gasoline through the intake valve with a perfume
atomizer previously purchased at a drugstore in the Massasoit House.
Repeated efforts of the two men to start the engine resulted in failure.

[Illustration: FIGURE 15.--CONJECTURAL drawing of the free-piston engine
used in the Museum vehicle prior to the present engine. (Drawing by A. A.

In the belief that the defects, whatever they might be, could be
remedied after the engine was installed, the Duryeas went ahead and
mounted the engine in the carriage. To do this they shortened the
original reach of the carriage, allowing the engine itself to become the
rear continuation of the reach. The four ears on the front, or open end
of the engine, were bolted to the centrally located frame, with the
bearing blocks in between. This frame, the same one now in the vehicle,
was constructed of two pieces of angle iron, riveted and brazed
together. Greater rigidity was obtained by a number of half-inch iron
rods running from the frame to both front and rear axles. Because of the
absence of any mounting brackets on the engine casting itself, a wooden
block with a trough on top to receive the body of the engine was fitted
between the engine and the axle, while two U-shaped rods secured it with
clip bars and nuts underneath.

Beneath the flywheel was mounted the friction transmission of Charles'
design. This consisted of a large drum, perhaps 12 inches in diameter,
equal in length to the diameter of the flywheel and keyed to a shaft
directly under the center of the crankshaft and parallel to the axles.
(Diameter of drum estimated by examination of existing features.) In
view of the four projections of the frame extending downward and just in
front of the jackshaft position, it is likely that these supported the
four jackshaft bearings. Being a bicycle manufacturer, Charles saw the
need for a differential or balance gear. Accordingly, he purchased from
the Pope Manufacturing Company a very light unit of the type formerly
used on Columbia tricycles, and installed it somewhere on the jackshaft.
A small sprocket on each end of the shaft carried a chain from the
larger sprockets clamped to the spokes of each rear wheel. The lower
surface of the flywheel had been machined so as to form a friction disc,
with a one-quarter inch depression 3 inches in diameter turned in the
center. The drum was positioned so that its upper surface was
one-quarter inch below the face of the flywheel. Hanging loosely around
the drum was an endless belt, one and one-half inches wide, first made
of rather soft rubber packing material. The belt lay on the drum surface
between the fingers of a shipper fork. While it lay under the 3-inch
depression in the center of the flywheel, the belt and the drum were at
rest, but when it was moved away from that depression the belt wedged
itself tightly between the drum and flywheel, the resulting friction
causing the drum to turn and setting the vehicle into motion. The
farther the belt was moved toward the outer edge of the wheel, the
faster the drum and the vehicle moved.

In September 1892, Charles, who had contracted with a Peoria, Illinois,
firm to have bicycle parts manufactured, decided to move to that city.
Departing on the 22d of September, he did not return to Springfield for
over two years, and thus was not able to participate in the completion
and testing of the carriage. At the time of his departure several units
on the carriage were incomplete. A carburetor had not been built, nor
had a satisfactory burner or belt-shifting device. Charles had
experimented with various shifting levers just before leaving
Springfield: however, as he reported later, he did not succeed in
designing a workable mechanism.[15] Frank Duryea, now left to finish the
work unassisted, continued the experiments with the belt shifter. He
finally worked out a fork mounted on a carriage that was supported by
two rods, each of which slid in two bearings. Although the short
distance between the two bearings caused the shifter carriage to bind
occasionally, the device was thought to be sufficient and was installed
just in front of the frame. Connected to a system of cables, arms, and
rods, possibly similar to the present cam-bar shifter, the shipper-fork
carriage was moved from side to side by raising or lowering the tiller.

[Illustration: FIGURE 16.--DRAWING of the carburetor used on both Duryea
engines, 1893-1894, showing sight feed on left and choke mechanism on
right. (Smithsonian photo 13455.)]

Turning now to an efficient burner for heating the ignition tube, Frank
started with an ordinary wick-type kerosene lamp with a small metal
tank. Wishing to use gasoline in the lamp, he found it necessary to
fabricate a number of burner units before he found a type that gave him
a clean blue flame. He then found the flame to be very sensitive to
drafts and easily extinguished, and devised a small shield or chimney to
afford it some protection.

Early in October, while still working with the burner, Frank developed a
severe headache. He felt the fumes of the lamp had probably caused it,
and went to his room in the home of a Mr. and Mrs. Patrick on Front
Street in Chicopee. After he noticed no improvement, a doctor's
examination showed he had typhoid fever, and on October 5 he was
admitted to the Springfield Hospital. Here he remained for one month,
being discharged on November 5. Returning to his room he was informed
that because of the fear that he might be a typhoid carrier, the
Patricks preferred him to find other lodgings. He readily accepted the
invitation of Mr. and Mrs. D. H. Nesbitt of Chicopee to take a room with
them. After several weeks recuperation in their home, he left
Springfield to visit his mother in Wyoming, Illinois.

After a restful visit at home Frank Duryea returned to Springfield and
finished the work on his burner. Now only the lack of a carburetor
prevented a trial of the vehicle. He recalls that he studied several
gasoline-engine catalogs and in one of them, a Fairbanks catalog he
believes,[16] he saw a design that seemed to suit his needs. He decided
to simplify the construction and operation of his carburetor and had a
small bronze casting made to form the body of it. Inside was a gasoline
chamber with two tapped openings, one to receive a pipe from the
2-gallon gasoline tank mounted above the engine, the other taking a pipe
to the overflow tank underneath the engine, thus maintaining the
gasoline level without the use of a float valve. This latter tank had a
hand pump on one end so that the overflow gasoline could at times be
pumped again into the main tank. Gasoline passed from the carburetor
chamber through a needle valve, adjusted by a knob on top, then through
a tiny tube that entered the pipe leading to the intake valve. It is not
certain whether this intake pipe was at first fitted with the choke
arrangement later used with the second engine.

Frank, hoping at last to be rewarded for his efforts by the sound of
explosions from the engine, was ready to give the carriage an indoor
trial. Standing astraddle of the reach and facing to the rear, he spun
the flywheel with both hands, taking care not to get his hands caught
between the wheel and the frame. His efforts were in vain, as there was
complete failure to obtain ignition. He then made a new ignition tube,
nearly twice as long as the original 4-1/2-inch tube, and turned down
its wall as thin as he thought safety allowed. The thinner wall did not
conduct the heat off so rapidly and thus kept the tube hot enough to
permit ignition. After this slight change, he was able to get a few
occasional explosions but he does not now believe that the engine ever
operated continuously. Each explosion was accompanied by a loud knock,
due, undoubtedly, to the movement of the free piston. Had the engine
operated continuously, it is likely that the action of the free piston
would have shortly wrecked the engine. Further efforts appeared
unwarranted until alterations could be made.

                     BEYOND OUR CONTROL


                                                   EXPERT IN PATENT SUITS.
                                                   GAS ENGIN, AUTO, ETC.
                                                   THINGS ACCOMPLISHT

                            PHILADELPHIA, PA.
                            3528 N. 18TH ST.

  Dear Mr Mitman                                  24 Nov 1920

On the train I had some time to puzzle over that car. Been working
nights to make up time lost in the day so did not hav much.

I made a sketch for you but did not show the spring that holds the
circuit breaker in contact with the spark point. That thin finger was
part of it. A spring was wound spirally--not helically--around the
projecting end of the breaker pivot and the end of the spring hookt over
the thin finger. See sketch herwith.

Just how the central end of the spring wire was fastened to the square
of the pivot I do not kno. We did in some cases bore a hole thru and
simply stick the spring thru but this put most of the action right at
the bend in the wire and it broke quickly. So in other cases we fitted a
light grooved spool or pulley and wound the spring around this and so
avoided a sharp bend. If this was used it has been lost with the spring.
A couple generations of boys playing in that barn was too many.

The Haynes steering sketch also worries me. If that vertical post came
up thru that slot in the floor the crank had to be long as the sketch
shows in order to get over to the driver conveniently. Then if he tried
to make a complete circle with it he could not reach far enuf forward to
do it easily. And he had to make a turn or two be cause H shows bevel
gears of about same size so the post had to make same number of turns
the worm made. Sketch herewith to illustrate my thought.

  Yrs for the historical facts
         Chas. E. Duryea

FIGURE 17.--LETTER EXPLAINING the circuit breaker spring and the brass
projection on top of the ignition chamber. Mr. Mitman was, at the time,
curator of engineering in the U.S. National Museum.]

The two pistons were first pinned together into a single unit which was
probably ringless, since it is believed the walls of the outer piston
were too thin to admit rings. Because the piston no longer struck the
exhaust valve, a short rod had to be screwed into the pistonhead; this
pushed the valve shut at the completion of the exhaust stroke. The
remaining problem, the opening of the exhaust valve, was solved by
screwing a device to the side of the cylinder which operated from the
sidewise motion of the connecting rod. This device shifted a small
spacer between the piston and the striker arm of the exhaust-valve rod,
permitting the piston to push open the exhaust valve. On alternating
strokes the spacer shifted back out of the cylinder; therefore, no
contact was made between piston and striker arm. Sometime in February
1893, the altered engine was successfully started.

At last the transmission could be tested. Will Russell had come upstairs
to watch the trial, and according to a statement by him, given April 30,
1926, Frank, standing to the right of the engine and behind the rear
axle, reached forward and with the combination tiller-belt-shifter,
moved the belt into driving position. The carriage started forward, but
as it approached the wall of the building Frank discovered that he could
not get the belt back into the neutral position. In desperation, he
grasped the rear axle with both hands and was dragged a short distance,
attempting to stop the machine, before it struck the wall. He had,
however, sufficiently retarded it so that no damage was done.

This short trial demonstrated some of the weaknesses in the friction
transmission. Since the speed of the surface of the flywheel, in feet
per second, increased in proportion to the distance of the point of
contact from the center, the outer edge of the belt attempted to run
faster than the inner edge. This conflict of forces not only put an
undue load on the motor causing a great loss of power, but it also
created a tendency for the belt to work towards the outer edge of the
flywheel. Conversely, when the operator desired to return the belt to
neutral, it strongly resisted any efforts to slide it toward the center
of the wheel, as Frank had learned from the wall-bumping incident.
Furthermore, the rubber belt on the friction drum had worn so badly
that it had to be replaced at least once during the brief experiments.

[Illustration: FIGURE 18.--IGNITION CHAMBER, switch, and breaker contacts
of the present Duryea engine.]

At this point, Frank and Markham felt that the carriage was anything but
satisfactory. While they were trying to decide what steps should be
taken next, Frank added one last improvement to the engine. Fearing that
the uncooled cylinder might suffer damage from the excessive heat, he
constructed a copper water jacket in two halves, drew them together
around the cylinder with clamping rings and soldered the seams. Asbestos
packing sealed the end joints where the jacket contacted the cylinder.
Thinking back, Frank does not recall that he ever used a water tank with
this engine, though he does remember adding water through the upper
jacket opening. The engine was run only for a few brief periods
following this addition.

Obviously this collection of patchwork could not fulfill their needs for
an engine. First, it would be next to impossible to start if the body
was placed on the running gear, as the flywheel then would be
practically inaccessible. The absence of rings on the piston caused a
further loss of power to the already overloaded engine. The flywheel was
too light. The absence of any form of governor left the operator with no
control over the engine speed. Ignition was poor, partly owing to the
hot-tube arrangement, and partly to the excessive distance between the
engine and the carburetor. Frank wrote his brother Charles on February
6[17] that in his opinion the mixing chamber was so far from the engine
that the gasoline could not be drawn into the cylinder as liquid, and it
was too cold to vaporize and go in as gas. Thus he had difficulty in
getting the engine started. When it did start the explosions were
unmuffled. Less important to him than these defects, however, was the
awkward and unsightly wooden engine mount.

Description of the Automobile

Sometime in the early part of March, Frank convinced Markham that he
could construct a new and practical engine, using only previously tried
mechanical principles.[18] Drawing up new plans for this engine, he took
them to Charles Marshall who began work on the patterns for the new
engine castings. After the patterns had been delivered to the foundry,
Frank left Springfield for a short vacation in Groton, Connecticut,
where he visited with his fiancée. On May 17, 1893, several weeks after
his return to Springfield, they were married.

The engine castings were undoubtedly received from the foundry prior to
Frank Duryea's marriage, and the work of machining and assembling the
parts went on through the spring and summer. This engine, still on the
carriage in the Museum of History and Technology, is cased with a water
jacket, and has bases on top to support the front and rear bearings of
the starting crankshaft, and a base with port on the upper right side
where the exhaust-valve housing was to be bolted. On the underside are
two flanges, forming a base for seating the engine on the axle. A
separate combustion chamber is cast and bolted to the head. Inside this
chamber are located the igniter parts of Frank's electric ignition
system. The fixed part, an insulated electrode, is screwed into the
right side of the chamber and is connected with the ignition switch
outside, to which one of the ignition wires is attached. A breaker arm
inside is pinned to a small shaft extending through the top of the
chamber. Around the breaker-arm shaft is a small coil spring (originally
a spiral spring, according to the letter of Charles Duryea shown in fig.
17), anchored below to a thin brass finger extending toward the right
side of the car, and above to a nut screwed tightly onto the shaft. This
nut is also the terminal for the other ignition wire. The action of the
spring keeps the breaker arm and the electrode in constant contact until
the push rod on the end of the piston strikes the arm and separates the
two parts. Breaking contact then produces the ignition spark. Since the
mechanism would spark at the end of both the exhaust and compression
strokes, the battery current is conserved by a contact strip, on the
underside of the larger exhaust-valve gear, by means of which the flow
of current is cut off during the greater part of the cycle.

On the left side of the combustion chamber is bolted the housing
containing the tiny intake valve. A comparatively weak spring seats this
valve in order that the suction created by the piston can easily pull it
open. Clamped onto the valve housing is the intake pipe, enclosing the
choke and carrying the carburetor on its forward side. The choke
consists of two discs which block the pipe, each with four holes at the
edges and one in the center. Turning one disc by means of a small handle
outside, so that the four outer holes cannot coincide with those in the
other disc, decreases the flow of air and causes all air to rush through
the center hole, where the tiny carburetor tube passes through. The
present carburetor was transferred over from the first engine. When
Frank later installed the engine on the carriage he noticed the close
proximity of the intake pipe to the open end of the muffler. Believing
that the fumes might choke the engine, he attached a long sheet-metal
tube to the intake pipe so that fresh air would be drawn in from a point
farther forward on the vehicle.

Moving to the right side of the engine brings the exhaust-valve assembly
into view. This valve is contained in a casting bolted over the exhaust
port in the side of the cylinder, and from the casting a pipe leads to
the muffler underneath. The valve is pushed open by a rod connected to a
crank which is pinned to the lower end of a shaft carrying an iron gear
on top. This gear is in mesh with a fiber gear, keyed to the upper end
of the crankshaft, with half the number of teeth. This ratio permits the
opening of the exhaust valve on every other revolution.

The crankshaft of the first engine was retained for the new engine, thus
giving the two engines the same stroke of 5-3/8 inches, but the bore was
increased slightly to 4-3/8 inches. With this larger bore and with the
engine speed increased to 500 rpm, Frank rated this engine at 4 hp.[19]
A heavier flywheel, with a governor resting in the upper recess, was
pressed onto the crankshaft. As the operator of the vehicle had no
control over the carburetor once he climbed into the seat, this governor
was necessary to maintain regular engine speed. Its function was to move
a slide on the exhaust-valve unit to prevent the valve from closing.
Thus the engine, with the suction broken, could not draw a charge on the
next revolution. During the recent restoration of this carriage it was
found that while most parts are still intact, nearly all of the
governor parts are missing. A description of them must therefore be
based on the recollections of Frank Duryea, along with certain evidences
seen on the engine.

[Illustration: FIGURE 19.--UNDER SIDE of exhaust valve mechanism showing
electrical contacts that give spark only on every other revolution.]

Just on top of the flywheel, and surrounding the crankshaft, rest two
rings, 3-7/8 inches in diameter. Into the opposing surfaces of these
rings are cut a series of small inclined planes, appertinent to each
other. On the outer circumference of the upper ring two pins pass
through a pair of lugs mounted in the flywheel, causing the ring to
rotate with the flywheel, yet permitting vertical movement. Underneath,
the other ring is allowed to turn slightly when, by means of two
connecting links, the arms of the governor push against them. These two
arms, each constructed like a right angle and pivoted at the apex, are
arranged directly opposite each other far out in the flywheel recess. As
a weight on one angle of the arm presses outward by centrifugal force
against a spring, the other angle presses inward against the connecting
link mentioned above. The turning of the lower set of inclined planes
against the fixed set above raises the upper ring and the fork resting
on it. The upward movement of this fork, which is a continuation of an
arm pivoted to a bracket midway between the crankshaft and the slide
carrying the exhaust valve stop, causes the other end of the arm to
drop, pulling the slide down with it. In this manner the closing of the
exhaust valve is blocked, preventing the intake of the next charge, and
therefore the engine misses one or more explosions until it slows to its
normal speed.

A starting shaft is mounted above the engine casting by a cast-iron
bracket on either end. The front end of the shaft has a bevel gear which
is held by a coil spring behind the front bracket, just out of contact
with a bevel gear pressed onto the upper end of the crankshaft. The
short rear portion of the shaft is a tube which slides over the main
shaft. Fitting the removable handcrank to the squared end of the hollow
shaft and turning the crank clockwise, will advance the forward section
of shaft through the medium of a pair of inclined collars. With the
bevel gears now engaged the engine may be cranked. When ignition begins,
the inclined collars slide back down each other's surfaces, the shaft is
again shortened, and its bevel gear springs free of the one on the

[Illustration: FIGURE 20.--PISTON AND CONNECTING ROD of second engine.
Screw on rod is where oil is poured into connecting rod to lubricate wrist
pin and crankshaft.]

While Frank worked on his engine, he realized that certain parts of the
old running gear would need to be altered or replaced. In view of the
heavier and more powerful engine, he felt the old wheels, probably
having compressed band hubs, were inadequate. He procured a set of new,
heavier wheels[20] with Warner-type, cast-iron reinforced hubs. The
angle iron frame, apparently sturdy enough to carry the added weight,
was retained, but it was decided to install a heavier rear axle.[21] The
front axle assembly was at first allowed to remain unchanged, as was the
steering apparatus. A short time later when the engine and friction
transmission were bolted in place on the running gear, Frank saw that
the rigidity of the framework had an undesirable effect. When the
vehicle passed over any unevenness in the shop floor, the framework was
distorted and caused the jackshaft bearings to bind tightly enough on
the shaft to prevent its being turned by hand. In order to provide the
3-point suspension necessary to eliminate this distortion, Frank
attached the forward parts of the framework to an extra wooden spring
bar, installing between this bar and the front axle a vertical fifth
wheel of the type ordinarily used in a horizontal position in any light

Frank next calculated that with the faster running engine the speed of
the vehicle would be about 15 miles an hour, too much for the heavily
loaded wheels. As he intended to make use of the original transmission,
he decided to decrease the speed by increasing the size of the friction
drum. He accomplished this by sliding a heavy fiber tube over the
original drum, bringing its diameter to approximately 14 inches. The
original shipper fork carriage was improved by separating the original
bearings to a greater distance, and eliminating one of the two bearings
on one end. This permitted a smooth and free operation of the small
sliding carriage.

In August 1893, possibly as a result of indoor experiments, Frank
discovered that the chains running from the small 5-tooth[22] jackshaft
sprockets to the large, bronze, wheel sprockets were tight at some times
and loose at others. This caused considerable unnecessary noise. The
difficulty apparently was the result of the sprockets being cast and not
machined. The patternmaker had said he believed he could make the
pattern accurately enough so that no machining of the castings would be
necessary. Nice castings were produced, but "these sprockets were the
reason why an unusual construction was put on the crankshaft [meaning
jackshaft]," explained Frank Duryea during an interview at the National
Museum on November 9, 1956. Elaborating further, in reply to the queries
of E. A. Battison, of the Museum's division of engineering, Duryea told
of the problem and the solution when he explained that the sprockets had
places where the shrinkage was not even. The hot metal, contracting as
it cooled, did not seem to contract uniformly, creating slightly unequal
distances between teeth. This resulted in the chain hanging quite loose
in some places and in others the tightness prevented adjustment. He
contacted Will Russell, foreman of the Russell shop, where the
automobile was made, and Russell showed him a device, built by George
Warwick, who had made the Warwick bicycle. It was an internal-cut gear,
according to Duryea's description, with sprocket teeth on its periphery.
With sprockets outside and normal teeth inside, the wheels were about 6
inches in diameter, externally.

These little internal-gear sprockets were hung on double-shrouded
pinions secured to each end of the jackshaft. A solid disc or housing
fitted against both ends of the pinion to prevent the internal gear
from working off sideways. Duryea explained the function of these
unique little parts: "as soon as tension came on that ring gear that we
talked about, it not only tightened the chain hanging on this sprocket
on the upper side, but it tightened it on both sides. [The sprocket]
rocks right out: both sides of the chain are tight."

This feature is one rarely encountered elsewhere, and Duryea, later in
the interview said, "To tell you the truth, I think I was just a little
bit ashamed about the thing, because I had to pull it off. I didn't like
the looks of it after I got it on."

Two small tanks, each with a capacity of approximately two gallons, were
mounted over the engine in the positions they still occupy, the one on
the left for gasoline,[23] the other for water. The small fitting under
the gasoline tank has a thumbscrew shutoff and a glass-sight feed tube,
leading to the carburetor. The water tank, an inch longer than the
gasoline tank, communicates with the water jacket of the engine through
two pieces of half-inch pipe, entering the jacket from above and below.
The overflow tank, holding just over a gallon, is suspended between the
rear axle and the flywheel.

A number of mufflers were constructed for the engine.[24] The first
experimental one was built of wood, being a box 6 × 6 × 15 inches with a
hole for the exhaust pipe in one end and a series of small holes in the
opposite end. Inside, Frank arranged metal plates which were somewhat
shorter than the depth of the box. Every other one was attached to the
bottom of the box; the intermediate plates were fastened to the top.
This contrivance muffled the sound considerably, but, as might be
expected, soon began to smoke. There can be little doubt that it was
replaced before any of the outdoor trials began. Another type consisted
of a cylindrical metal shell, perhaps six inches in diameter and ten or
twelve inches long. Here a series of perforated baffle plates were
inserted, with alternating solid plates having parts of their external
edges cut away. Two bolts running the length of the muffler held on the
cast-iron heads in a manner quite similar to the Model-T Ford mufflers
of later years. Though partially satisfactory, Frank, in a November 6,
1957, interview, complained that it made a metallic sound. Perhaps this
was the muffler he used from September to November 1893.

by the Duryeas in their vehicle. (Smithsonian photo 46858.)]

On August 28 Frank wrote to Charles saying the carriage was almost ready
for the road and that he hoped to take it out for a test on the coming
Saturday, "off somewhere so no one will see us...."[25] There is no
evidence showing whether the amount of remaining work permitted the
proposed trial on September 2. The body was finally replaced on the
running gear, at which time it was found necessary to raise the seat
cushion several inches by the insertion of a framework made of old
crating boards. This allowed sufficient room between the seat and the
frame to suspend the batteries and coil. Six no. 2 Samson batteries were
contained in this space, three on each side, in rows parallel to the
side of the vehicle. The Samson battery consisted of a glass jar
containing a solution of ammonia salts and water, with a carbon rod in
the center, housing a zinc rod. It is difficult to understand why they
used Samson batteries rather than dry cells; perhaps they were concerned
with the mounting cost of the machine and were making use of parts
already on hand.[26] A coil, possibly from an old gaslight igniter
system, accompanied the Samson batteries under the seat. This original
coil is now missing.

The iron dash frame, previously recovered and provided with a rain apron
to be pulled up over the knees in the event a heavy rain blew in under
the carriage top, was bolted back in place. Frank and Mr. Markham gave
the carriage a quick painting; later Frank admitted, "the machine never
had a good job of painting."[27] Before the motor wagon actually got
onto the road, a reporter on the _Springfield Evening Union_ got some
statistics on it and an item appeared on September 16, giving the first
public notice of the machine.

[Illustration: NO USE FOR HORSES.

Springfield Mechanics Devise a New Mode of Travel.

Ingenious Wagon Now Being Made in This City for Which the Makers Claim
Great Things.

A new motor carriage, which, if the preliminary tests prove successful
as is expected, will revolutionize the mode of travel on highways, and
do away with the horse as a means of transportation, is being made in
this city. It is quite probable that within a short time one may be able
to see an ordinary carriage in almost every respect, running along the
streets or climbing country hills without visible means of propulsion.
The carriage is being built by J. F. Duryea, the designer and B. F.
Markham, who have been at work on it for over a year. The vehicle was
designed by C. E. Duryea, a bicycle manufacturer of Peoria, Ill., and he
communicated his scheme to his brother, who is a practical machanic in
this city.

The propelling power is furnished by a two-horse power gasoline motor
situated near the rear axle and which, when started, runs continuously
to the end of the trip, notwithstanding the number of times the carriage
may be stopped. The speed of the motor is uniform, being about 500
revolutions a minute, and is so arranged that it gives a multiplied
power for climbing hills and the lower the rate of speed the greater
power is furnished by the motor. The slowest that the carriage can be
driven is three miles an hour and the speed can be increased to fourteen
or fifteen miles an hour. The power is transferred from the driving
wheel of the motor, which runs horizontally with the main shaft by an
endless friction belt running on a drum wheel. The belt is controlled by
a lever within easy reach of the driver and is shifted along the drum
wheel to increase or decrease the speed. The driving wheel is about
twenty inches in diameter, having in its center a depression to which
the belt is shifted to stop the carriage.

The carriage can be reversed by shifting the belt from the end of the
drum, which gives the forward motion to the opposite side beyond the
depression in the driving wheel. The power which has been transferred to
the driving shaft from the motor is in turn transferred to the two rear
wheels of the carriage by a combination gear and sprockets. An endless
chain connects the sprockets on the carriage wheels to the sprocket
wheels on the driving shaft. All of the motive power is located under
the body of an ordinary phaeton, the hight of which is not increased by
the machinery. The motor is started by a crank which is easily applied
to a shaft in the rear of the carriage and the gasoline is ignited in
the cylinder by electricity. An automatic device stops the flow of
gasoline into the cylinder when the motor ceases running. The gasoline
is carried in tanks, which hold about two gallons, and which will run
the carriage for about eight hours. The wagon is guided by a bicycle
bar, and the speed is also controlled by this bar.

The method employed in this is as follows: To start the carriage press
the lever down; to reverse it throw the lever up and to guide the wagon
turn the lever either to the right or left. The front axle instead of
turning horizontally plays up and down, in order that the machinery may
be on a level with the rear wheels, while the front wheels are set on
the axle by a pivotal joint and are connected with the guiding lever by
bars with ball bearings. The carriage complete weighs about 220 pounds,
and the essential features are already covered by patents while others
are pending.

It is estimated that the carriages can be sold for about $400, and a
stock company will probably be formed to manufacture them.

FIGURE 22.--FROM THE _Springfield Evening Union_, September 16, 1893.]

Toward the latter part of the following week, Frank was ready to give
the product of his labors its first road trial. On September 21 the
completed carriage was rolled onto the elevator at Russell's shop.
Seeing that the running gear was too long for the elevator, they raised
the front of the machine, resting the entire weight of 750 pounds on the
rear wheels. Once outside the building, they pushed it into an area
between the Russell and Stacy buildings. After dark, "so no one will
see," Will Bemis, Mr. Markham's son-in-law, brought a horse and they
pulled the phaeton out to his barn on Spruce Street.[28] There, on
Spruce and Florence Streets the first tests were made. The next day
Frank wrote his brother saying, "Have tried it (the carriage) finally
and thoroughly and quit trying until some changes are made. Belt
transmission very bad.[29] Engine all right." He did admit the engine
seemed to be well loaded most of the time. He also had an idea in mind
to replace the poor transmission, explaining the plan to Charles: "The
three gears[30] on secondary shaft have friction clutches, the two bevel
gears on same shaft are controlled by a clutch which frees one and
clutches the other at will. This provides a reverse."



 Cat. No. 48304.  8 inch                      Price, each, $3 20
    "     50304. 10   "                            "        3 70
    "     52304. 12   "                            "        4 30
    "     54304. Detached Gas Lighting Relays      "        2 75

 For Spark Coils with Relay Attachment, add $2.50 to price for Spark Coil.

FIGURE 23.--TYPE OF SPARK COIL the Duryeas are believed to have used in
their electrical circuit, as shown in a catalog illustration.
(Smithsonian photo 46858-A.)]

The _Springfield Evening Union_ of September 22 carried a notice of the
trial. This report, too, commented on the faulty transmission and the
plan already in Frank's mind for the new transmission.

     ... The friction belt allowed of the speed being steadily increased
     or diminished at the will of the driver and caused no sudden
     forward motion of the carriage, but while this arrangement has many
     advantages it uses up the power so that the two-horse power
     furnished by the motor [somewhat less than the rating Frank gave
     the engine] was reduced to less than three-fourths horse power on
     reaching the main shaft. This would not be sufficient to propel the
     carriage up steep grades but would be sufficient to run the
     carriage on level road.

     The inventors will do away with this belt in favor of a clamp gear
     and will make the drum wheel smaller. By this means there will be
     very little power lost in transmission to the shaft and by a
     patented arrangement the carriage may be started gradually but the
     speed must be increased by shifting the clamp gear to a succession
     of gears on the driving wheel of the motor. The speed of the
     carriage will be fixed permanently according to the size of the
     gear that the smaller one is shifted to. The test of the machine
     with the gear arrangement will be made soon.

In October Frank decided on another vacation and went to Chicago to see
the Columbian Exposition. Charles had come up from Peoria to see the
fair and the two talked over the progress on their motor wagon, and
discussed the transmission problem. They gave particular attention to
everything relating to engines and motor carriages, and Frank recalls
seeing a Daimler quadricycle that impressed him with its performance.[31]
Just what decisions the two might have made there are unknown, yet it is
likely that they agreed to give the old transmission one more chance to
prove itself.

Returning to Springfield, probably in the first week of November, Frank
gave the friction drive its final test, this time substituting a leather
belt for the rubber one first used.[32] Mr. Markham, though intensely
interested in the experiments, apparently was dubious concerning the
safety of the carriage. It had no brakes, and fearing failure of the
transmission on a downgrade, he was reluctant to ride in the machine. On
November 9 he asked Will Bemis to try it for him. The following day the
_Springfield Morning Union_ gave a description of the run:

     Residents in the vicinity of Florence street flocked to the windows
     yesterday afternoon astonished to see gliding by in the roadway a
     common top carriage with no shafts and no horse attached. The
     vehicle is operated by gasoline and is the invention of Erwin
     Markham and J. F. Duryea. It has been previously described in The
     Union and the trial yesterday was simply to ascertain the practical
     value of a leather friction surface which has been substituted for
     the rubber one previously used. The vehicle, which was operated by
     Mr. Bemis, started from the corner of Hancock avenue and Spruce
     street and went up the avenue, up Hancock street and started down
     Florence street, working finely, but when about half-way down the
     latter street it stopped short, refusing to move. Investigation
     showed that the bearing had been worn smooth by the friction and a
     little water sprinkled upon it put it in running condition again.
     The rest of the trip was made down Florence and down Spruce street,
     to the residence of the inventors. They hope to have the vehicle in
     good working condition soon.

[Illustration: FIGURE 24.--RUNNING GEAR OF DURYEA VEHICLE, showing the
second engine and other parts as used in January 1894.]

The same evening, the late edition ran a brief paragraph stating that
"the test was made to determine the value of a leather friction surface
for propelling the wagon, that had been substituted in place of the
rubber surface, used in the former test." Bemis, according to Frank
Duryea's recollection, was not impressed with the performance of the
machine, saying "the thing is absolutely useless," and for a time it
appeared that further support from Markham would not be forthcoming.
Frank, believing eventual success to be near, drew up plans showing his
geared transmission, and with these managed to gain Markham's partial
support. Money for material and use of the shop was to continue, but
Frank was to complete the work on his own time.

Now receiving no salary, Frank worked hurriedly on the transmission
throughout late November, December, and the first two weeks of January.
First discarding the old friction drum and shaft, and the shipper-fork
carriage, he bolted a rawhide bevel gear to the lower surface of the
flywheel. This turns two bevel gears, in opposite directions, on a
countershaft directly underneath, approximately in the position of the
old jackshaft. The right bevel gear is secured to the main countershaft
on which two clutches are mounted, one on each side of the crankshaft.
On a sleeve turning freely around the countershaft is mounted the
reverse bevel gear and clutch. Three free-running clutch drums, the
right one carrying the high-speed gear, the two on the left carrying the
combination low speed and reverse gear between them, complete the
countershaft assembly. The clutch assemblies are of Frank Duryea's
design, having internal arms, expanding outward to press leather-faced
shoes against the inner surface of the drum, thus securing the drum and
its gear to the shaft. Behind this machinery is the jackshaft with its
small differential on the right, two laminated rawhide gears[33] meshing
with the iron gears of the countershaft, and the internal-gear sprockets
hanging on the small pinions at either end. A sliding cam bar, mounted
nearly in the position of the former shipper-fork carriage, is operated
by the vertical movement of the tiller handle to engage any one of the
three clutches. With the tiller depressed, the vehicle is in reverse.
Elevating it slightly puts it into low gear, and raising it still higher
runs the machine at its highest speed.

[Illustration: FIGURE 25.--HALF OF JACKSHAFT, showing rawhide gears,
double shrouded pinion and half of the Columbia differential.]

[Illustration: FIGURE 26.--HALF OF JACKSHAFT showing double-shrouded
pinion and half of the Columbia differential.

[Illustration: FIGURE 27.--CAM BAR IN FOREGROUND, operated by tiller,
actuates the various clutches of the transmission. The overflow gasoline
tank with the hand pump can be seen in the rear.]




  SPECIFICATION forming part of Letters Patent No. 540,648, dated
    June 11, 1895.

  Application filed April 30, 1894. Serial No. 509,466. (No model.)

  _To all whom it may concern_:

  Be it known that I, CHARLES E. DURYEA, a
  citizen of the United States, residing at Peoria,
  in the county of Peoria and State of Illinois,
  have invented new and useful Improvements                     5
  in Road-Vehicles, of which the following is a

  The object of this invention is to produce a
  road vehicle which shall be self-propelled, not
  unduly heavy, simple and easy of control and                 10
  comparatively inexpensive, together with
  such minor objects as will become hereinafter

  The invention more particularly relates to
  the construction and arrangement of parts for                15
  constituting the driving gearing and to the
  means for controlling the action thereof; to
  an improved manner of mounting the front,
  or steering, wheels upon the front axle, and
  of mounting the said axle relative to the running            20
  gear frame, and to the means for effecting
  the steering; to the appliances for the support
  of the motor and driving mechanism in
  an advantageous and efficient manner, and,
  generally, to improved and simplified details                25
  of construction throughout the vehicle, all as
  will hereinafter be rendered more apparent,
  and the invention consists in constructions
  and combinations of parts, all substantially
  as will hereinafter fully appear and be set                  30
  forth in the claims.

  Reference is to be had to the accompanying
  drawings, in which--

  Figure 1 is a sectional elevation from front
  to rear of the improved road-vehicle. Fig. 2 is              35
  a plan view of the running and driving gear,
  the vehicle-body being understood as removed.
  Fig. 3 is a front elevation of the vehicle. Fig.
  4 is a perspective view of the support and suspension
  devices for the driving mechanism.                           40
  Fig. 5 is a vertical sectional view, longitudinally,
  through the shiftable driving-gear, the
  controlling devices employed in conjunction
  with this mechanism being seen in side elevation.
  Figs. 6 and 7 show the above-mentioned                       45
  controlling devices as in operative relations
  differing the one from the other and
  also from that of Fig. 5.

  Similar letters of reference indicate corresponding
  parts in all of the views.                                   50

  The parts will now be described in detail
  with reference to said drawings, and A represents
  the body which is spring supported
  on the frame, B, of the running gear. This
  frame, as shown, is rectangular, and has the                 55
  body-supporting springs, B{2}, similar to those
  found in common carriages. This frame has,
  affixed thereto, at its rear ends, sleeves, _a_, _a_,
  which loosely embrace the rear wheel axle, D,
  which is the driven axle of the vehicle. The                 60
  axle, E, for the front wheels is centrally secured
  to the running gear frame, B, by the
  horizontal king-bolt, _b_, whereby such axle
  may have a swinging movement relative to
  the frame in a vertical plane, but it has no                 65
  swinging movement horizontally, the wheels
  being swivel-mounted on the ends of this axle
  peculiarly, as will shortly hereinafter be set

  The body, as shown, is in the form of an                     70
  inverted box, the motor, H, and driving gear
  being accommodated within the downwardly
  opening inclosure constituted thereby, and
  the body also has the upwardly open box-like
  forward extension, or pit, A{2}, for the accommodation       75
  of the feet of the rider, the rider's
  seat being constituted by the top forward portion
  of the box body. Some other suitable
  design of body may, of course, be used in lieu
  of this one shown.                                           80

  The front wheels, _d_, _d_, are hung to the front
  axle, E, so that the center of each wheel base
  is in a line coincident with the axis of the pivotal
  connection which is provided between the
  journals for the wheels and the axle, which                  85
  arrangement practically destroys any tendency
  to deflection from the course that might
  otherwise arise from striking an obstacle,
  and so renders the steering easier. In order
  to effect this the axle is formed with yoked                 90
  ends, the yoke members, _f_, _f_, being above and
  below the longitudinal line of the axle. The
  short journal, _g_, shown for each wheel, has at
  its inner end an upwardly and downwardly
  extended arm, _h_, which is return-bent to be                95
  loosely embraced by the axle yoke, _f_, _f_. The
  cone pointed screws, _c_, passed through the
  yoke members, _f_, and into sockets therefor in
  the arms, _h_, of the journals, _g_, constitute the
  means for the swivel connection between said                100
  parts. The lock-nuts, _c_{2}, manifestly, are employed
  with utility in this connection.

  It will be perceived that inasmuch as in the
  arrangement shown, the pivotal connections

 (No Model.)      4 Sheets--Sheet 2.


  No. 540,648.    Patented June 11, 1895.

  _Fig. 2._

  J. D. Garfield
  K. I. Clemons

  Chas. E. Duryea
  by Chaprictlo Attys.

specifications of the first patent issued to C. E. Duryea. It can be
readily seen that this drawing was not made after the plan of the first

As the work moved nearer completion Frank realized that the final tests
would have to be conducted on roads made icy by falling snows. He had
considerable doubt whether the narrow iron tires would have enough
traction to move the phaeton. Soon he devised an expedient for this
situation, communicating to Charles on December 22 that he was "having
Jack Swaine [a local blacksmith] make a couple of clutch rims so we can
get over this snow and ice.... Our detachable rims referred to will be
of 1/8 iron 1-3/4 wide and drawn together at one point by two screws,
one on either side of felloe. It will be studded with calks in two

[Illustration: FIGURE 29.--MR. AND MRS. FRANK DURYEA examining vehicle
in the Smithsonian Institution before restoration.]

January 18, 1894, was a day of triumph for Frank Duryea. Writing Charles
about his success the next day he said, "Took out carriage again last
night and gave it another test about 9 o'clock." The only difficulty he
mentioned was a slight irregularity in the engine, caused by the tiny
leather pad in the exhaust-valve mechanism falling out.[35] Speaking of
this trip, Frank recalled in 1956:

     When I got this car ready to run one night, I took it out and I had
     a young fellow with me; I thought I might need him to help push in
     case the car didn't work.... We ran from the area of the shop where
     it was built down on Taylor Street. We started out and ran up
     Worthington Street hill,[36] on top of what you might call "the
     Bluff" in Springfield. Then we drove along over level roads from
     there to the home of Mr. Markham who lived with his son-in-law,
     Will Bemis, and there we refilled this tank with water. [At this
     point he was asked if it was pretty well emptied by then.] Yes, I
     said in my account of it that when we got up there the water was
     boiling furiously. Well, no doubt it was. We refilled it and then
     we turned it back and drove down along the Central Street hill and
     along Maple, crossed into State Street, dropped down to Dwight,
     went west along Dwight to the vicinity where we had a shed that we
     could put the car in for the night. During that trip we had run, I
     think, just about six miles, maybe a little bit more. That was the
     first trip with this vehicle. It was the first trip of anything
     more than a few hundred yards that the car had ever made.

  SEPT. 1960       A. A. BALUNEK]

Now Frank could give demonstration rides with the motor carriage, hoping
to encourage more investors to back future work. Cautious Mr. Markham
finally got his ride, though Frank had to assure him that the engine of
the brakeless vehicle would hold them back on any hill they would
descend. The carriage on which he had spent so many hours was to see
little use after that. Its total mileage is probably less than a hundred
miles. Little additional work is known to have been performed on the
carriage after January 1894; there is, however, a letter[37] Frank sent
his brother on January 19 which tells of contemplated muffler
improvements. Another message was dispatched to Charles on March 22,
mentioning the good performance of the phaeton on Harrison Avenue
hill.[38] This was possibly the last run of the machine, for no further
references have been discovered.

Frank spent the months of February and March in preparing drawings, some
of which accompanied their first patent application,[39] while others
were to be used in the construction of an improved, 2-cylinder carriage.
Work on the new machine started in April. The old phaeton, in the
absence of used-car lots, was put into storage in the Bemis barn.[40]
Later, on the formation of the Duryea Motor Wagon Company in 1895, it
was removed to the barn of D. A. Reed, treasurer of the company.[41]
There it remained until 1920, when it was obtained by Inglis M. Uppercu
and presented to the U.S. National Museum.

       *       *       *       *       *


   [1]  S. H. OLIVER, _Automobiles and Motorcycles in the U.S. National
        Museum_ (U.S. National Museum Bulletin 213, Washington:
        Smithsonian Institution, 1957), p. 24.

   [2]  G. R. DOYLE, _The World's Automobiles_ (London: Temple Press
        Limited, 1959), p. 67.

   [3]  Recorded interview with Frank Duryea in the U.S. National Museum,
        November 9, 1956.

   [4]  Charles Duryea's statement to _Springfield Daily Republican_,
        April 14, 1937.

   [5]  FRANK DURYEA, _America's First Automobile_ (Springfield, Mass.:
        Donald Macaulay, 1942), p. 4.

   [6]  Letter from Charles Duryea to Alfred Reeves, March 25, 1920; copy
        in Museum files.

   [7]  History notes dictated by Charles E. Duryea in the office of David
        Beecroft, editor of _Automobile Trade Journal_, on January 10,
        1925. Copy in Museum files. Hereinafter, these notes are
        referred to as "history."

   [8]  Frank Duryea in statement made to the Senate Committee on Public
        Administration of Massachusetts, February 9, 1952.

   [9]  DURYEA, op. cit. (footnote 5), p. 6.

  [10]  Copy of contract in Museum files.

  [11]  Affidavit of William Rattman, March 19, 1943, states that the
        Russell ledgers give that date.

  [12]  Recorded interview with Frank Duryea in U.S. National Museum,
        November 6, 1957.

  [13]  Letter from Frank Duryea to David Beecroft, November 15, 1924;
        copy in Museum files.

  [14]  Letter from Charles Duryea to C. W. Mitman, March 21, 1922; copy
        in Museum files.

  [15]  See "history" (footnote 7), p. 6.

  [16]  DURYEA, op. cit. (footnote 5), p. 8.

  [17]  Copy of letter in Museum files.

  [18]  DURYEA, op. cit. (footnote 5), p. 12.

  [19]  Letter from Frank Duryea to Charles Duryea, November 3, 1893,
        states that the engine could be run at 700 as well as 500 rpm.
        Copy in Museum files.

  [20]  DURYEA, op. cit. (footnote 5), p. 14. Also in letter from Charles
        Duryea to C. W. Mitman, January 11, 1922; copy in Museum files.

  [21]  Letter from Charles Duryea to C. W. Mitman, January 11, 1922;
        also letter from Frank Duryea to David Beecroft, November 15,
        1924. Copies in Museum files.

  [22]  Letter from Charles Duryea to F. A. Taylor, December 5, 1936,
        says he "thought" they had five teeth. Copy in Museum files.

  [23]  Frank later wrote his brother, January 1894, that he fixed the
        tank so it would not draw sediment from the bottom. Copy of
        letter in Museum files.

  [24]  The number of mufflers Frank Duryea constructed is not known. He
        wrote Charles, December 22, 1893, that he "will try a new
        muffler also."

  [25]  Selden Patent Evidence, vol. 9, p. 110.

  [26]  See "history" (footnote 7), p. 2. Charles wrote, "Some parts of
        these [referring to the batteries], like the jars, I had on hand
        for six or eight years, and did not need to buy."

  [27]  Ibid., p. 15.

  [28]  Ibid., p. 15

  [29]  Frank stated in this letter that the friction drum originally had
        two belts, forward and reverse, but since they tended to foul
        each other, he removed the reverse belt and left the other to
        serve for both directions. How the shipper fork might have
        handled two belts is not understood.

  [30]  As actually constructed there are only two gears on the secondary
        shaft. He obviously discovered that one gear secured to two
        clutches would serve for both forward and reverse. Space was
        also limited.

  [31]  Recorded interview with Frank Duryea in U.S. National Museum,
        November 9, 1956.

  [32]  Letter from Frank Duryea to Charles Duryea, November 8, 1893.
        Copy in Museum files.

  [33]  Frank Duryea, in a recorded interview in the U.S. National Museum
        on November 6, 1957, said that he believed these had been
        purchased from Rochester Rawhide Company.

  [34]  Letter from Frank Duryea to Charles Duryea, December 22, 1893.
        Also letter from Frank Duryea to David Beecroft, November 15,
        1924. Copies in Museum files.

  [35]  Telling of the first use of the car in later days, Frank Duryea
        mentions the many noises and vibrations that accompanied the
        trip: the vibrating tiller, the tinny sounding muffler, the
        clattering chains. He later reported speeds of 3 mph in low gear
        and 8 mph in high gear.

  [36]  Letter from Frank Duryea to Charles Duryea, Jan. 19, 1894, says
        they went up hill via Summer and Armor Streets, then out Walnut
        to Bemis' at Central Street School.

  [37]  The letter read: "I have designed a new muffler and we will
        proceed to make it before long, in a day or two. Instead of one
        shell 1/8-inch thick I shall put a shell 1/16-inch thick inside
        another of equal thickness, but about 1 inch greater diameter
        i.e., one chamber within another so as to cause sound to turn
        corners to get out. Still another shell will be added if it
        prove insufficient, making it turn about again--taking care in
        each case to give ample room for expansion--outer one need not
        be more than 1/32 inch possibly. Will let two threaded rods with
        nuts hold heads on both or on three cases, if the 3d be

  [38]  This letter gives further proof that the car never had a brake.
        Frank said the car came back down the hill with no brake, but
        that the engine held the vehicle back.

  [39]  DURYEA, op. cit. (footnote 5), p. 37.

  [40]  It is possible that a few parts were removed at this time to be
        used on the two-cylinder car. The muffler may have been one of
        these, and even more likely, the governor parts. Charles Duryea
        wrote to C. W. Mitman December 27, 1921, stating that his
        younger brother Otho and a Henry Wells had put in a battery and
        gasoline in 1897 and started the engine. Because the chains were
        not on the car they could not attempt to operate it; but the
        engine ran too fast, and finally something broke, probably the
        engine frame, found to be broken during the recent restoration.
        Charles thought the engine ran too fast because some of the
        governor parts were already missing.

  [41]  Recorded interview with Frank Duryea in the U.S. National Museum,
        November 9, 1956. On the formation of the Duryea Motor Wagon
        Company, Mr. Markham was rewarded for his part of the venture.
        He had invested nearly $3000 in the work, and sold out his
        rights in the company for approximately a $2000 profit.

       *       *       *       *       *

Paper 34 - Transcriber's Note

The transcriptions retain all typographical and gramatical errors.

       *       *       *       *       *


  PAPER 35



  _Silvio A. Bedini_

                             DEVELOPMENT OF ASTRONOMICAL CLOCKS     32

                                              DESIGNER BORGHESI     33

                                            CLOCKMAKER BERTOLLA     34

                                           FIRST BORGHESI CLOCK     38

                                          SECOND BORGHESI CLOCK     41

                              BORGHESIAN THEORY OF THE UNIVERSE     54

                                                     LAST YEARS     57


                                                       APPENDIX     71

                                                   BIBLIOGRAPHY     76

[Illustration: Figure 1.--THE DIAL PLATE of the Borghesi clock, showing
the horary and astronomical indications which are automatically

  _Silvio A. Bedini_

  _The Borghesi Astronomical Clock_
  _In the Museum of History and Technology_

     _The history of the 18th-century Borghesi astronomical clock is
     described here from contemporary source material. The evolution
     of its design by Father Francesco Borghesi and the building of
     the complex mechanism devised by the clockmaker, Bartolomeo
     Antonio Bertolla, is a story of the vision of one man turned
     into reality by another. The result of their collaboration is
     the unique, astronomical timepiece now in the Museum of History
     and Technology._

     THE AUTHOR: _Silvio A. Bedini is curator of mechanical and
     civil engineering in the Smithsonian Institution's Museum of
     History and Technology._

     "... All this work I had performed eagerly, so that, while in
     my room, I might contemplate leisurely, both during the day and
     in the night, the true face of the heavens and of the seas
     unobscured by clouds, even though I had no astronomical

With these words, Father Francesco Borghesi (1723-1802) of Mechel
described the reasons which inspired him to invent a unique astronomical
clock which is now in the horological collection of the Museum of
History and Technology.

This complicated mechanism, which performs a multitude of functions, was
designed by Father Francesco Borghesi, a secular priest in Venezia
Tridentina. It was constructed in 1764 under his direction by a
provincial clockmaker named Bartolomeo Antonio Bertolla (1702-1789) of
Mocenigo di Rumo. It was the second of two complicated astronomical
clocks which Father Borghesi designed and which Bertolla constructed.
According to contemporary sources, this clock was presented to the
Empress Maria Theresa of Austria soon after its completion.

Its history is rather hazy, except for the fact that in 1780 this second
Borghesi timepiece was still in the Imperial Palace in Vienna. The clock
was again noted in 1927 when it was sold at a public auction in New
York.[2] Subsequently, it was acquired for the Smithsonian Institution.

Development of Astronomical Clocks

The history of the great theoretical and mechanical achievement which
the Borghesi clock represents has been most adequately covered
elsewhere.[3] Consideration of the development of equation and
astronomical clocks is required here only for the purpose of relating
the Borghesi timepiece with the other significant developments in this
branch of horology.

The invention of the anchor escapement in about 1670, and the consequent
greater accuracy in time-telling, led to increased preoccupation with
precision. Daily differences in time as recorded by sundials and clocks
became more noticeable. Finally, in the second half of the 17th century,
some attempt was made to construct mechanical clocks combined with
sundials as well as astronomical clocks.

With the improvement of precision time-telling, it became necessary to
reconcile the actual difference between true and mean time. Although a
great variety of time-equation tables were produced, there was a
considerable margin for error in their use. This led to the construction
of mechanical clocks in which the equation of time was automatically
accomplished. A few were produced late in the 17th and early 18th
century at considerable cost and, consequently, with little popularity.
Equation sundials were also developed which were elaborately ingenious,
but they were not completely practical. Inevitably, they were supplanted
by the mechanical equation clock.

Probably the first documented mention of an equation clock is in the
diary of John Evelyn who recorded that in 1666 he visited the Royal
Society where he witnessed a curious clock, which showed the equation of
time, being presented by a certain Mercator. More data on the subject
appeared in the first two decades of the 18th century, when Henry Sully,
Joseph Williamson, Daniel Quare, and Thomas Tompion--who were among the
foremost English clockmakers of all time--produced elaborate examples of
these timepieces. Another significant maker was Dowe Williamson, who
became Court Clockmaker to Emperor Charles VI of Austria. In London,
Joseph Williamson produced some of the finest astronomical timepieces of
this type that have been known. The interest in the subject next shifted
to France where many fine examples were produced during the first half
of the 18th century.

Just after the middle of the 18th century, the subject of astronomical
clocks suddenly became a major horological preoccupation in another
region, namely, Austria, where the work in this field was apparently
done exclusively by members of the clergy. The earliest was Father
Philipp Matthäus Hahn (1739-1790) of Württemberg.[4] Father Hahn
considered the equation of time as only one part of a plan to represent
astronomical occurrences by means of clockwork. In addition to
planetaria and similar mechanisms, Father Hahn produced two
extraordinary astronomical, tall-case clocks, both of which survive in
public museums.

       *       *       *       *       *


The author wishes to acknowledge the valuable assistance received from
the following: DR. AMOS AVERY, Amherst, Massachusetts; MR. EDWIN A.
BATTISON, curator of light machinery and horology, U.S. National Museum;
DOTT. RICHARD BLAAS, Oesterreiches Staatsarchiv, Vienna; DOTT. ADOLFO
CETTO, librarian, Biblioteca Comunale di Trento, who made copies of
Borghesi's two volumes available; SIGNOR MARIO DI MARIO, editor of _La
Clessidra_, Rome, who permitted several of the illustrations in Sig.
Luigi Pippa's article to be used herein; MR. WALTER A. GILBERT, Norwich,
Connecticut; DR. HEINRICH LINARDI, Uhrenmuseum der Stadt Wien, Vienna;
Museo Nazionale della Scienza e della Tecnica, Milan, for their
cooperation on the descriptions and illustrations of the restored
clockshop of Bartolomeo Antonio Bertolla; and DR. EDWARD WATERS,
Division of Music, Library of Congress, Washington, D.C.

The translation from Francesco Borghesi's Latin texts, which made this
study possible, were made by: REV. NEIL HERLIHY, S.J., REV. FRANCIS J.
HEYDEN, S.J., and REV. STEPHEN X. WINTERS, S.J., Georgetown University,
Washington, D.C.; and REV. DANIEL HUNTER, O.P., and REV. ROBERT STENGER,
O.P., Dominican House of Studies, Washington, D.C.

       *       *       *       *       *

inventor and designer of the astronomical clock in the Museum of History
and Technology.]

Another of the clerical clockmakers was Father Aurelianus à San Daniele
(1728-1782), an Augustine monk in the monastery of the Imperial Court at
Vienna.[5] His four complicated astronomical clocks, which exist in
museums at present, are comparable to those produced by Father Hahn. The
third cleric was Brother David à San Cajetano (1736-1796) in the same
Augustine order to which Father Aurelianus belonged. He achieved note as
the author of various publications, including _Neue Rädergebäude_[6]
[New Construction of Wheels] relating to planet-wheels, or gear-trains
containing epicyclic elements. He constructed a clock based on an
elaborate astronomical design which was substantially different from the
others. The fourth of the ecclesiasts who designed astronomical clocks
in this period was Father Klein of Prague, who produced a complicated
astronomical timepiece in about 1738.

The fact that such important and outstanding examples of astronomical
clocks were produced exclusively by ecclesiasts in Austria during the
second half of the 18th century is especially significant. It is
particularly so when a fifth cleric is added to the group, also an
Austrian subject although Italian by heritage, in the person of Father
Francesco Borghesi.

Although only Father Borghesi's second astronomical clock is now known,
it is apparent that this example in the Museum of History and Technology
represents an experiment in astronomical time-telling comparable to any
of the timepieces produced by Father Hahn, Father Aurelianus, Brother
David à San Cajetano or Father Klein.

This combination of five clerical clockmakers who lived in the same
region during the same period of time is sufficiently unusual. However,
the fact that each of them apparently worked without association with
any of the others leads to the conjecture that a common factor must have
led them to their individual preoccupation with astronomical horology.
What the link may have been is not apparent from the surviving records
of the lives and works of these clerics. Certainly it was not an
interest in astronomy or clockmaking per se, because other than the
astronomical clocks, none of these horological inventors--with the
possible exception of Father Hahn--worked in any other aspect of the
fields of astronomy or horology. However, after a comprehensive study of
Father Borghesi's writings, there is little doubt of the religious basis
of his own inspiration.

Designer Borghesi

Father Borghesi's story takes place in the picturesque mountainous
region of what was then known as Venezia Tridentina (since 1947,
Trentino-Alto Adige) in northern Italy, along the Tyrolean border of
Austria. Because of its strategic position as the passage between
Innsbruck and Verona, the possession of the Tridentina was contested
again and again in the European wars, but during Father Borghesi's
lifetime, the Tridentina was under Austrian domination.

[Illustration: Figure 3.--PANORAMA of the village of Mechel in the
valley of the Non, birthplace of Father Borghesi.]

Deep within this mountainous district is the romantic valley of the Non,
or Anáuni, with its great forests and ancient castles. Most maps do not
mark it, and the tourist guides ignore it.[7] One of the chief
communities is Cles, with its historic Renaissance buildings. The major
city of the region is Trent on the Adige River, with its surviving Roman
relics and Romanesque and Renaissance architecture.

The little villages scattered throughout the valley of the Non played no
part in history, but such names as Mechel and Mocenigo di Rumo reflect
the interchange of sovereignty. It was in the little village of Mechel
that Francesco Borghesi was born in 1723.[8] Local records are meager
and inadequate, and many of the details of Borghesi's life must be
assumed. Inasmuch as the village was in a rural, agricultural district,
Borghesi may have come from a family of farmers, vintners, or village
tradesmen. Borghesi sought an education by entering the priesthood and
was ordained a secular priest in Salzburg. He was first assigned as
curate to the village parish of Rumo in the valley of the Non, a short
distance from his birthplace.[9] Later, he was transferred to his native
Mechel. He was inherently a man of simple tastes and of great piety. He
tended to the needs of his mountain villagers and attended the births,
weddings and deaths of his parishioners. It was during his assignment in
this tiny community that Father Borghesi met and became friendly with
the clockmaker, Bartolomeo Antonio Bertolla of nearby Mocenigo di Rumo.

Clockmaker Bertolla

Bartolomeo Antonio Bertolla was born in Mocenigo di Rumo, a short
distance from Mechel, in 1702.[10] Nothing is known of his boyhood,
other than the fact that he was mechanically inclined. At the age of 17
he was apprenticed to become a clockmaker with the master, Johann Georg
Butzjäger of Neulengbach, a small village on the edge of the great
Vienna woods.[11] This region was then part of the domain of the
Archduke of Austria, of which Sankt Pölten was the capital.

clockmaker, of Mocenigo di Rumo. The canvas in oils is owned by
descendants. In the upper left-hand corner is an inscription, now hardly
legible, indicating that the portrait may have been painted after
Bertolla's death on January 15, 1789. Translated, it states: "Bartolomeo
Antonio Bertola [sic] Celebrated Mechanician and Inventor of various
Instruments. Repairer of the clocks of Venice, Verona, Trent, and other
localities. Maker of the Work which combines the Copernican and
Ptolemaic Systems devised by Father Francesco Borghesi of Mechel,
Laureate Mathematician, and humbly offered to Her Imperial Majesty Maria
Theresa. Died in piety in his home at Rumo on 15 January 1789 at the age
of 86." (_Courtesy of Sig. Luigi Pippa of Milan._)]

[Illustration: Figure 5.--THE VILLAGE OF MOCENIGO DI RUMO in the valley
of the Non. Arrow points to Bertolla's home and workshop at far left.]

[Illustration: Figure 6.--CERTIFICATE OF APPRENTICESHIP awarded to
Bartolomeo Antonio Bertolla upon completion of his 3-year apprenticeship
at Neulengbach, dated December 27, 1722.]

Bertolla began his apprenticeship with Butzjäger under the auspices of
the Corporation of Blacksmiths of Sankt Pölten in 1719. His training was
supervised by two master locksmiths, Johann Christian Winz and Peter
Wisshofer, who were members of the Corporation, and were assigned to
serve as patrons for the apprentice. It was their obligation to make
certain that he received good care and adequate instruction from his
master. While he worked in Butzjäger's shop, Bertolla lived with the
master's family in their home.

Bertolla's 3 years at Neulengbach passed quickly as he sought to absorb
all that his master could teach him. Butzjäger was considered to be a
good craftsman in the region, yet today there is not even a mention of
his name in the lists of clockmakers. He specialized in the production
and repair of "great clocks" which included tall-case, domestic
timepieces, and tower clocks. Butzjäger treated his apprentice well, and
in return Bertolla rewarded him by being diligent and honest. His
subsequent work is sufficient indication that he developed into an
extremely skilled craftsman, and he became the equal of any clockmaker
of his time.

The 3 years of apprenticeship were completed and on December 27, 1722,
Bertolla received a certificate from the Corporation of Blacksmiths
which assured whomever it might concern of Bertolla's skill, diligence
and honesty, and permitted him to open his own shop as a clockmaker
under the auspices of the Corporation. This document, which has been
preserved by Bertolla's descendants, is an interesting record of the
organization of the trade guilds in the 18th century, and, for that
reason, has been translated from the original German:

     We, the Superiors and other masters of the honorable
     corporation of municipal blacksmiths, armorers, and of smiths,
     in the Imperial City of St. Pölten in Austria by the river
     Enns, DECLARE BY THESE PRESENTS put in force by this document
     to anyone who waits to hear.... That the honorable and able
     BARTOLOMEO ANTONIO BERTOLLA of Rumo in Lentzberg, the Tyrol, on
     the 27th day of the month of December of the year 1719 was
     consigned as apprentice for three years, in the presence of two
     sponsoring masters for the purpose, the honorable Johann
     Christian Winz and Peter Wisshofer, both of them master
     locksmiths representing the entire honorable Corporation and
     others of open shop--to the honorable JOHANN GEORG BUTZJÄGER,
     incorporated with us, citizen and master clockmaker for large
     clocks in the merchant-village of Neulengbach in Wienerwald, as
     his master of the art, would have therefore perfectly and
     rightfully worked and learned, and

     that afterwards, on the day and year noted at the bottom, he
     will be newly declared free and independent before us,
     representative of an entire and honorable Corporation and with
     open shop, of his above-mentioned master and of the two
     sponsoring masters mentioned,

     and since he eagerly requested a truthful certificate of
     apprenticeship for his honest service as an apprentice and for
     his good behavior, and we having great pleasure as well as the
     duty of favoring the truth and well knowing that the aforesaid
     BARTOLOMEO ANTONIO BERTOLLA has learned honestly the art of
     clockmaking for great clocks from his aforesaid master, and
     that he has always behaved with honesty, obedience,
     faithfulness and diligence both towards his master and towards
     us to our complete satisfaction and, therefore, we cannot in
     any manner refuse his request, rather we wish to grant it with
     a clear conscience.

     WE THEREFORE ADDRESS TO EVERYONE and to anyone in whatever
     state and rank, but particularly to those interested in our
     branch of this art, our respectful and courteous entreaty and
     request to consider BARTOLOMEO ANTONIO BERTOLLA well
     recommended for his honest apprenticeship and his good
     behavior, and to desire to favor him in every way, in such a
     manner that will assure our gratitude whenever an occasion
     presents itself.

     For this purpose, we issue, as we have declared we wish to
     issue to you, BARTOLOMEO ANTONIO BERTOLLA, this certificate of
     apprenticeship, attaching to it the seal of our Corporation.

     Executed in the city of St. Pölten on 27 December 1722.[12]

His apprenticeship over, Bertolla returned to his native region where he
soon established a reputation for himself as one of the most skillful
clockmakers in the Tridentina and produced timepieces of fine quality in
some quantity. No records have survived concerning his personal life,
but it is believed that he married probably soon after his return. He
had no children of his own. To expand his business, he eventually took
into his shop two nephews, the sons of a brother and a sister, as

Bertolla's work brought him a sufficient number of clients, and he
produced elaborate clocks for his more wealthy patrons.

In 1752, it is recorded that he repaired the great clock in the
campanile of the Church of the Assumption of the Virgin Mary in Cles,
the regional capital of the valley of the Non. The clock dated probably
from the 16th century, and it seems likely that Bertolla replaced the
original two-wheel train with a three-wheel movement, and that he added
the present anchor escapement.[13]

It is not possible to determine when Father Borghesi first made
Bertolla's acquaintance, but it may be assumed that they had become
friends in the late 1750's.

After he had come to know Bertolla, Father Borghesi apparently spent
many hours in the clockmaker's shop. He was fascinated by mechanics in
any form, and the complications of clockwork particularly intrigued him.
Bertolla was patient with the young priest, explaining the tools he had
and their uses, the clocks he produced or repaired, and the principles
which were involved. Father Borghesi listened willingly and as his
understanding of timepieces grew, his curiosity increased.

In spite of himself, the priest could not be satisfied with the ordinary
aspects of his friend's work and wanted to learn more. From a casual
pastime, the study of time became an obsession with him. There was but
one recourse: he went back to studying once again. This time it was not
theology, however, but the sciences. Every moment he could spare went
into the perusal of books on mathematics, astronomy, and associated
subjects. He progressed rapidly, driven by his overpowering interest and
aided by his quick intellect.

Little by little, Borghesi managed to acquire the basic texts that
explained this new world to him, probably borrowing them from old
seminary friends. As each new book came into his hands, he devoured it
in his desire to master its contents. He discussed each new principle or
precept that he learned with Bertolla. Together, they attempted to apply
his new learning to the calculations necessary for a timepiece which
would demonstrate the astronomical theories in visual form. Borghesi
taught himself slowly, step by step, and the result was a profound
understanding of astronomical science. He conceived the project of
constructing a great astronomical clock which he felt could be
accomplished by combining Bertolla's mechanical skills with his own
recent mastery of astronomy and mathematics.

First Borghesi Clock

It is not difficult to visualize the two men, the priest and the
clockmaker, as they sat together night after night working out their
plans. Father Borghesi would painstakingly outline the astronomical
principles he wished to have the clock exhibit and the mathematical
principles which would be involved to operate them. Bertolla
concentrated on them and tried to transcribe the principles into
functional mechanical terms, visualizing each operation in terms of
wheels and gears. Little by little the two men coordinated the numerous
elements and welded them into an operating entity. They adjourned either
to the stark simplicity of the rectory or, probably more often, to
Bertolla's little home workshop, the priest standing over his friend
while the latter worked at his bench in the dark paneled interior
illuminated only by the several lamps on the work benches.

This first clock which the two men combined to create is a monument to
the great scientific knowledge of the self-taught priest and the
technical ability of the clockmaker--a unity combining astronomical
science, mechanics, and artistry. The story of the project is told in a
little book, _Novissima Ac Perpetua Astronomica..._, which Borghesi
later published. Explaining the incentive which inspired him, and the
premises from which he began his work, he wrote:

     From the foundation of astronomical science long ago,
     innumerable [and] repeated observations of both ancient and
     modern astronomers, emerged at last from their hiding places.
     Made light of by the jests of so many outstanding intellects,
     they have so successfully brought to light the paths of the
     stars and their motions, which are more complicated to us than
     the Gordian knots. Now it is possible for even an amateur in
     astronomy, sufficiently instructed, to predict for any given
     time not only the mean position of the planets, but also their
     true longitude and latitude, and even the true time of their
     conjunctions, and their ecliptic oppositions, with all the
     attendant circumstances. Yet, until now, no hypothesis has been
     devised which would force an automaton to show to us, before
     our very eyes, the eclipses of the planets in their true and
     certain times.

     For though there have been men seeking with all their might to
     bind by laws their artificial heavens, by I know not how many
     and how great calculations, and to systematize the complexities
     of the rotations of celestial bodies; nevertheless, all of
     them, as if by common agreement, considered themselves to have
     made great contributions to mechanico-theoretical astronomy.
     However, they have only attained, even though closely, the mean
     locations of the secondary mobiles, and those by a certain
     rather crude calculation. Some attained by more, some by less,
     but all by some degree of wandering from the truth, either worn
     out by the intricacies of the motions, or deceived and
     deceiving by the errors of their calculations. This fact those
     well know, who, setting about to collect information of this
     kind, even those publicized not long ago, with true
     astronomical calculation, have been bored to death while
     digging out by the most elementary and superficial arithmetical
     torture, the worst of fallacies spontaneously erupting from

     It would seem that true calculations alone can be desired in
     mechanico-astronomics. Long study had not only convinced me
     that an automaton was within the realm of possibility, but that
     there were many mechanical systems by which it could be
     achieved. I girded myself for a new project and developed it
     theoretically from the ground up, but under such unhappy
     auspices that not only did all hope fail that anyone would ever
     appear who might have seemed willing to set his hand to the
     work, but that the new discovery itself was scoffed at by many
     as altogether a nightmarish delirium of an unbridled

The first months of the project must have seemed like an inspired dream
to the two men, and then must have followed a period of hopeless
depression. Bertolla undoubtedly felt many times that the clock was an
aspiration far beyond their combined abilities and means, but the priest
would not be thwarted in his ambition and refused to abandon the
project. He felt that it was a work that they were destined to produce.
Many times, he wrote, he chided and begged and shamed his erstwhile
partner into resuming the project where it had been last abandoned.
Little by little, the first clock began to take form. As each new
difficulty was encountered, the two men would go back over the notes and
sketches to trace the problem to its source. Often a new part of the
mechanism would nullify another which had thus far operated
successfully, and a complete rearrangement would be required.

[Illustration: Figure 7.--TITLE PAGE of Father Borghesi's first book.
The translation in its entirety is: "The Most Recent, Perpetual,
Astronomical Calendar Clock: Theoretical--Practical: by means of which
besides the hours, the minutes and seconds; the current year, the month;
the day of the month and the day of the week; the dominical letter,
epact, and thence, the day of all the feastdays, both fixed and movable;
the solar cycle; the golden number; the Roman indiction; the dominant
planet of any year and its sign; the phases of the moon and its mean
age: and all the motions of the sun and the moon as to longitude,
latitude, eccentricity, etc., are immediately seen, so accurately that
[not only] the true new full moons and the true quadrature, etc., of the
sun and moon appear, but also, all solar and lunar eclipses--both
visible and invisible; as in heaven, so on the clock, they are
conspicuously celebrated in their true times, and those of the past and
those of the future, with their circumstances of time and duration,
magnitude, etc., can be quickly determined. All this was devised and
brought to light by the author, Francesco Borghesi of Anáuni, a secular
priest of Trent, A.A.L.L. & Doctor of Philosophy. (Trent: From the
printshop of Giovanni Battista Monauni, With Permission of Superiors.)"
(_Title page reproduced by permission of the Biblioteca della Citta di

Again and again, Bertolla threw up his hands in despair and begged
Father Borghesi to abandon the enterprise. He protested that he was not
capable of producing such a complicated mechanism; he had neither the
tools nor the skill. The priest wished to produce a clock such as the
world had never seen before, such as the greatest scientists and
clockmakers of all time had never been able to make. But Bertolla felt
that he was only a provincial craftsman who could not hope to surpass
them all with only his simple tools and training.

In his book on the first clock, _Novissima Ac Perpetua Astronomica..._,
Father Borghesi wrote that when he had finally come within a few weeks
of the embryo stage in the development of his clock, he was faced with
the problem of bolstering the sagging enthusiasm of Bertolla. The
clockmaker's original enthusiasm had shown promise of great results, but
as the days passed and the problems of the multiplex and generally
unfamiliar apparatus to be forged for the workings of the automaton
became more complex, his ardor decreased. Finally, Bertolla became so
discouraged by the scoffers and frustrated by the fact that the work was
insufficiently organized that Father Borghesi wrote that "it almost
became a harder task for me to bolster up by daily opportunity and
importunity the failing patience of the artisan, frightened away from
the work already begun, than it was for me to extract from the inner
recesses of mathematics and astronomy, without light and without a
guide, the whole fabric of the machine itself!"

In spite of Bertolla's protests, Father Borghesi prevailed, reviving his
friend's interest once more until the two were deep in the project
again. Months passed as they worked together on the mechanism and it
seemed as if they lived for no other purpose. Inevitably, Bertolla's
health began to suffer, undermined as it was by the constant nervous
tension, and he eventually became ill from mental strain. He was forced
to spend some time in bed, and for many weeks the subject of the clock
was not discussed. Bertolla's other work, by which he made his living,
suffered and it was several months before he was able to return to his
little shop.

One year passed into another and the work progressed slowly. The first
clock, which easily should have been finished in less than a year, was
not completed until after three full years had passed. However, when the
priest and the clockmaker put the finishing touches to their great
clock, the result surpassed the greatest possible expectations, for it
was truly a masterpiece. Not only did it illustrate the ecliptic
phenomena of the moon, the sun and earth occurring in their proper time,
as well as many other things, but it showed these operations as they
succeeded in proper order, taking place through the centuries.

With mutual feelings of great pride, the two friends surveyed the result
of their three years of endeavor. Bertolla realized that he had reached
a point of maximum achievement in his work. He probably felt that now he
could relax again, that his sleep would no longer be troubled by
confused nightmares of wheels and gears that did not mesh together. Time
was to prove otherwise.


Father Borghesi soon came to the conclusion that it would be desirable
to have a written description to explain the mechanism of the clock and
its many indicators. He thereupon wrote out the story of how the clock
was made, the reasons for embarking on the enterprise, the difficulties
he had encountered, and the success which had crowned his and Bertolla's
mutual labors. Finally, he described the operation of the clock's
mechanism and the functions of its array of indicators.

The little book was written in Latin and only a few copies were printed,
presumably at the priest's own expense, on a handpress by Giovanni
Battista Monauni, printer to the Bishop in Trent. The little volume was
stated by contemporary writers to have been published in 1763, although
no date appears on the title page. The title translated is, in part,
_The Most Recent, Perpetual Astronomical Calendar Clock,
Theoretical--Practical...._ The work begins with an introduction for the
reader in which Father Borghesi stated that:

     ... the little work, which, as far as I was concerned could
     easily have been finished in a year, was only completed after
     about three years. Fortunately, however, it was so far beyond
     the expectations of most, that not only am I able to foretell
     with certainty all the lunar ecliptic phenomena and the solar,
     or rather terrestrial, phenomena, carefully worked out in their
     true periods, among many other matters exhibited by the
     machine; but also, within a few hours, I can exhibit by
     altogether tangible evidence to the skeptics and the doubting
     those very same phenomena, occurring within the space of many
     years, or even centuries, and succeeding one another in proper
     order, with their many attendant circumstances. I was not much
     concerned about the other eclipses, such as those of Mercury,
     Venus, and the other stars wandering through the zodiac, or
     about the other solar eclipses from the transit of Mercury or
     Venus, since they are altogether undiscernible to the naked
     eye, and very few compilers of ephemerides wish them to be
     noted, probably for the same reason.

     Do not, however, expect, star-loving reader, that here anything
     at all that you may wish can be drawn forth as from its source,
     for to demand this would be almost the same as to seek to drain
     as from a cup all the vast knowledge of the many arithmetical
     sciences from the narrow confines of one book. You will
     understand how impossible that is when, through prolonged
     labor, you have grown somewhat more mature in this kind of

     Wherefore, rather fully, and out of consideration for you, I
     have decided, setting aside these prolixities, with completely
     synoptic brevity and with all possible clarity to expound for
     you simply the proportion of the movements, the description of
     the machine, and its usage. As a result, when you have
     progressed a little in theoretical mechanics, you will not only
     be able to reduce all these things to their astronomical
     principles, but you may find the way more smoothly laid out for
     you even for perfecting the machine itself. And, thus, you may
     be more effectively encouraged to a successful conclusion. Let
     it be so now for you through the following 10 chapters!

After these rather hopeful assurances, Father Borghesi proceeded to
provide a detailed description of the clock dial and functions in the 10
short chapters which he had promised, under a separate section entitled
"Synopsis Totius Operis Mechanici," which is translated in its entirety
in the appendix.

As Father Borghesi prepared his little volume about his first clock, and
described its unusual features and outlined its functions, which were
primarily to place in evidence the celestial constellations, it occurred
to him that it would now be easier after the experience he had acquired
with his first timepiece, to construct another clock, which would
present the motions of the two astronomical systems, the Ptolemaic and
the Copernican. In this first book, he promised the reader that he would
undertake the second project. It is fortunate that Father Borghesi
undertook this project for the second clock is the only example of his
work that is known to exist today. Extensive research has not shown what
happened to the first clock, although several sources state that both
timepieces were presented to Empress Maria Theresa sometime between 1764
and 1780.

Second Borghesi Clock

Father Borghesi lost no time in initiating the project of the second
clock. The first and most important step was to inform Bertolla and
enlist his assistance. Bertolla was adamant: he had had enough of
complicated astronomical movements. He was delighted by the prospect of
returning to his former simple life, producing simple, domestic,
elementary movements for his country clients. Father Borghesi begged and
cajoled. The second clock would be a much simpler one to construct, he
persisted. After all, they had gained invaluable experience from the
production of the first clock. Furthermore, he had already completed its

Bertolla apparently wavered in his resolve and, unwillingly and against
his better judgment, he allowed the priest's inducements to prevail.
Once again, the two friends yielded their leisure hours to a study of
the priest's books and drawings as Father Borghesi enthusiastically
elaborated his design for the timepiece, and Bertolla attempted to
transcribe astronomical indications into terms of wheel counts. The
second clock was, as Borghesi had promised, much easier of execution.
Within a year, it was completed and functioned with complete success.

[Illustration: Figure 8.--THE BORGHESI CLOCK in the Museum of History
and Technology, constructed in 1764 by Bartolomeo Antonio Bertolla of
Mocenigo di Rumo from the designs of Father Francesco Borghesi of Rumo
and Mechel.]

[Illustration: Figure 9.--ANOTHER VIEW of the Borghesi clock.]

This is the clock now in the Museum of History and Technology. It is
housed in a tall case of dark-red mahogany veneered on oak, with
restrained carving featuring ribands and foliate motifs. Gilt-brass
decorations flank the face of the hood, which is surmounted by three
gilt-brass finials in the form of orbs. A wide door in the waist may be
opened to attend the weights. The case is 7 feet 8 inches high, 20-1/2
inches wide at the waist, and 14 inches in depth.

The dial is of gilt brass, measuring 21 inches high and 15 inches in
width, with a number of supplementary silvered dials visible through its
openings. Instead of hands, the dial utilizes three concentric rings
moving around a central disc, the indications of which are read at two
bisecting gilt lines inscribed in the glass face. Twelve separate
functions are performed by the chapter ring assembly alone, and there
are 14 openings on the dial. It is estimated that the clock performs 30
separate functions, including striking and chiming. Of the multiple
chapter rings, the outermost is 1-1/8 inches wide, the center ring is
3/8 inch wide, and the innermost ring measures 1-1/4 inches in width.


The gilt dial is incised throughout with figures and inscriptions in
engraving of the very finest quality, as is evidenced in the
illustrations. The frontispiece is surmounted at its center by the
crowned double eagle of the House of Hapsburg, indicating the identity
of the sovereign in whose reign it was made, Emperor Francis I or the
Empress Maria Theresa of Austria. Below the eagle at either side are
flying cherubs supporting ribands with inscriptions. Centered at the
bottom of the frontispiece immediately above the chapter rings is the
moving silvered orb representing the sun. Surrounding it is a tableau of
the Holy Trinity, with the Virgin Mary being crowned by Christ holding a
cross at the left and God with a sword in hand at the right, and a dove
representing the Holy Spirit hovering over the Virgin's head. Father S.
X. Winters, S.J., considers it reminiscent of the triptych "The
Coronation of the Virgin" by Fra Lippo Lippi.

[Illustration: Figure 10.--DIAGRAM OF the dial plate.]

[Illustration: Figure 11.--DIAL PLATE of the Borghesi clock.]


A Dominating planet, represented by its symbol and its house;

B Dominical letter (Lit. Dom.);

C Epacts (Cyc. EpEC);

D Roman indiction (Ind. Rom.), part of the reckoning of the Julian

E Solar cycle, (Cyc. Sol.), part of the reckoning for the Julian period;

F Golden number (Num. Aur.), part of the reckoning for the Julian

G, H, I, J The era, or the current year; part of the six windows of the
Iris, or rainbow;

K Shuttered winding hole, for winding up the weights; part of the six
windows of the Iris;

L The era, or the month of the current year; part of the Iris, or six
windows of the rainbow;

M The sun in its epicycle;

N The 12 signs of the sun's anomaly;

O, P The first chapter ring representing the equatorial globe of the
week, revolving from left to right;

Q The coming day indicated through the window;

R The second chapter ring; including the synodic-periodic measure of
the tides, the days of the median lunar-synodic age, the signs and
degrees of the signs for mean distance of the moon from the sun;

S Epicycle of the moon with signs of its anomaly;

T Head of the dragon (Cap. Draconis);

U Tail of the dragon (Cauda Draconis), for measuring eclipses of the
earth and of the moon;

V Third chapter ring, with degrees of lunar latitude and some fixed

W Fourth chapter ring, showing firmament of fixed stars, signs of the
zodiac and degrees of the signs, the months of the year, and days of the
months, revolving left to right for the course of a mean astronomical

X Adjustment marked _Claudit_ (it closes) and _Aperit_ (it opens) for
disengaging dial work for the purpose of making astronomical experiments
and computations;

Y Adjustment marked _Concitat_ (it accelerates) and _Retardit_ (it
retards) for fast and slow adjustments of the movement.

In the upper spandrels of the dial are two more cherubs bearing ribands
with inscriptions. In the lower left corner is a magnificent engraving
of Atlas upholding the globe of the world, inscribed with the zodiac,
over his head. The lower right corner features the figures of two
noblemen apparently examining and discussing an orb upon a table, the
significance of which is not clear.

[Illustration: Figure 12.--EMPRESS MARIA THERESA, to whom Father
Borghesi is stated to have presented his two astronomical clocks. The
coin bearing her portrait is in the Museum of History and Technology.]


Beginning with the uppermost part of the frontispiece, there are nine
inscriptions in Latin on the dial plate. The topmost is _Franciscvs I
sit plan. Dominator aeternvs._ The phrase has reference to Francis I,
who was Emperor of the Holy Roman Empire, from 1745-1765, and husband of
Empress Maria Theresa of Austria. The phrase may be translated as "May
Francis I be the eternal ruler by favor of the planets" or more simply
"Long Live Francis I, Emperor."[14] Although the dial plate of the
Borghesi clock is inscribed with his name, the records indicate that
the clock was presented to Maria Theresa. Francis I may have already
died before the presentation was made.

[Illustration: Figure 13.--PORTRAIT OF FRANCIS I, Emperor of the Holy
Roman Empire, to whom Father Borghesi's astronomical clock in the Museum
of History and Technology appears to have been inscribed.]

From the left to right over the tableau of the Holy Trinity is the
phrase "Lavs sacrosanctae Triadi Vni Deo, et Deiparae" (Praise [be] to
the most Holy Trinity, to the one God, and to the Mother of God).

Within the upper left and right spandrels is inscribed:

     Isthaec, Signum grande apparvit in Coelo * sancta Dei genitrix
     amicta sole * Illibato pede Lvnae et serpentis nigra premens
     Cornva * bis senis pvlcherrime Coronata syderibvs * Tempe
     indesinenter clavsa, scatvrigo signata * Cedrvs in Libano,
     Cypresvs in Monte Sion * Mater pvrae Dilectionis sanctaeqve
     spei * Chara patris aeterni proles, Verbi Mater, sponsaqve
     procedentis *, gratiae et gloriae circvmdata varietate.

This inscription is a eulogy to the Virgin Mary assembled from the texts
of Holy Scripture. In addition, each _lemma_, contained within
asterisks, carries out the chronogram 1764, the year the clock was
completed. Each _lemma_ is translated and identified from the
Douay-Rheims version of the Bible:

     This woman: a great sign appeared in Heaven (Apocalypse 12:1) *
     The Holy Mother of God clothed with the sun (Apocalypse 12:1) *
     And with unharmed foot crushing the black horns of the moon
     (Apocalypse 12:1) and the serpent (Genesis 3:15) * Most
     beautifully crowned with twice-six (Apocalypse 12:1) * A garden
     [_Tempe_[15]] enclosed, sealed with a fountain [spring of
     water] (Song of Songs 4:12) * Like a cedar in Lebanon, and a
     cypress tree on Mount Zion; (Ecclesiasticus 24:17) * Mother of
     pure love and of holy hope: Beloved daughter of the Eternal
     Father, Mother of the Word, Spouse of the Holy Spirit:
     (Ecclesiasticus 24:24) * Surrounded with a diversity of grace
     and glory (Psalms 44:10).

[Illustration: Figure 14.--THE BOTTOM RIGHT CORNER of the dial plate,
showing two noblemen contemplating an orb, with the inscription "Diligit
Avdaces Trepidos Fortvna Repellet." (Fortune favors the daring and
rejects the timid.)]

At the lower left corner below the figure of Atlas upholding the world
is the phrase, _Assidvo proni donant di cvncta labori_. (The favorable
gods willingly grant all things to the assiduous laborer.) The same
phrase is quoted by Father Borghesi in the text of his second volume.
The last inscription appears at the lower right corner under the figures
of the two noblemen, _Diligit avdaces trepidos fortvna repellet_.
(Fortune favors the daring and rejects the timid.) The last two
inscriptions are in dactylic hexameter. They appear to be original
compositions inasmuch as no classical prototypes have been identified.

[Illustration: Figure 15.--THE BOTTOM LEFT CORNER of the dial plate,
showing the engraving of Atlas, with the inscription "Assidvo proni
donant di cvncta labori." (The favorable gods willingly grant all things
to the assiduous laborer.)]


[Illustration: Figure 16.--DETAIL OF FRONTISPIECE of the Borghesi clock,
showing the apertures for calendar indicators and the details of the

In addition to the inscriptions previously noted on the outer dial
plate, there are three major inscriptions in the central dial. The
outermost states _Circulus horarius Soli_, _Lunae_, _Fixis_, _Nodis_,
_Aestuique marino communis_ (the hour circle, common to the sun, the
moon, the fixed stars, the nodes and to the sea tide). This inscription
is divided into four parts by the insertion of four divisions for the
day into canonical hours: [_Horae_] _Nocturnae_ (night hours);
_Matutinae_ (morning hours); _Diurnae_ (daytime hours) and _Vespertinae_
(evening hours).

The next section of the central dial is inscribed
_Intumescite--Detumescite_ (rise and fall of the tides) repeated at
intervals of approximately every six hours. Within the next section is
the following inscription, inscribed continuously around the ring:

     Lege fluunt, refluunt, dormitant hac maris undae: Ad Phoebi et
     Phoebes concordia iussa moventur Aequora; discordi iussu
     suspensa quiescunt.

Translated, this is:

     By this law the sea waves ebb and flow and lie dormant: When
     Phoebus and Diana agree in their commands, the waters are
     moved; when they disagree, the waters lie silent.[16]

Within the central boss of the dial plate, the name of the maker is

     Bvrghesio Doctore, et Bertolla Limatore Annaniensibvs*

Translated, this is:

     [By] Doctor Borghesi and Bertolla, mechanician citizens of


There are 12 windows in the frontispiece, through each of which appears
an indication relating to time. Beginning at the top of the frontispiece
of the dial, the first opening occurs on the breast of the imperial
eagle. This indicates the dominating planet, represented by its symbol,
and its house.

The opening in the eagle's left claw, labeled "Lit. Dom." is the
dominical letter. The first seven days in the month of January are each
assigned one of the letters _a_ through _g_ in order of appearance. The
letter which coincides with the first Sunday within this period is
called the dominical letter, and it serves for the following year. In
leap year, two letters are required, one to February 29th and the letter
next proceeding for the remainder of the year. This letter is used in
connection with establishing the date of Easter Sunday. The date of
Easter regulates the dates of the other movable feasts.

The eagle's right claw is labeled "Cyc. EpEC" and represents the epact,
or the age of the moon on January 1st. It serves to find the moon's age
by indicating the number of days to be added to each lunar year in order
to complete a solar year. Twelve lunar months are nearly 11 days short
of the solar year, so that the new moons in one year fall 11 days
earlier than they did the preceding year. However, 30 days are deducted
as an intercalary month since the moon has made a revolution in that
time, and the remainder, 3, would be the epact.

Below the imperial eagle two winged cherubs support a riband with three
indictions of the Julian period. This period of 7980 years is the
product derived from multiplying together the sums of 28, which
represents the cycle of the sun; 19, representing the cycle of the moon;
and 15, which represents the Roman indiction. The Julian period is
reckoned to have begun from 4713 B.C. so that the period will be
completed in A.D. 3267. The first of the three openings is marked "Ind.
Rom." or "Roman indiction," which was an edict by the Emperor
Constantine in A.D. 312, providing for the assessment of a property tax
at the beginning of each 15-year cycle. It continues to be used in
ecclesiastical contracts. The second opening, which occurs immediately
below the eagle, is marked "Cyc. Sol." (cycle of the sun). This cycle
takes a period of 28 years, after which the days of the week once again
fall upon the same days of the month as they did during the first year
of the former cycle. There is no relationship with the course of the sun
itself, but was invented for the purpose of determining the dominical
letter which designates the days of the month on which the Sundays occur
during each year of the cycle. Since cycles of the sun date from 9 years
before the Christian era, it is necessary to add the digit 9 to the
digits of the current year and then divide the result by 28. The
quotient is the number of cycles which has passed, and the remainder
will be the year of the cycle answering to the current year. The third
opening on the riband is labeled "Num. Aur." (golden number). Meton, an
astronomer of Athens, discovered in 432 B.C. that after a period of 19
years the new and the full moons returned on the same days of the month
as they had before, and this is called the cycle of the moon. The Greeks
were so impressed with this calculation that they had it inscribed in
letters of gold upon stone, hence the golden number. The First Council
of Nicaea in A.D. 325 determined that Meton's cycle was to be used to
regulate the movable feasts of the Church.

Immediately above the chapter rings is an opening through which the orb
of the sun is visible.


In a separate chapter in his second volume, entitled "Descriptio
Authomatis Summa totius Operis Mechanici" (Description of the
Automaton--Summary of the Complete Mechanism), Father Borghesi provided
a description of the functions of the various indicators, prefixing it
with the short poem shown in figure 18. He then continues:

     In the middle of the frontispiece, as at the center of the
     universe, the terraqueous globe of the week revolves, with a
     daily motion turning from right to left, bringing with it from
     the round window the coming day and at the circumference the
     circle of hours common to the sun, to the moon, to the fixed
     stars, to the head and tail of the dragon, and to the raging

     The second circle revolves the synodic-periodic measure of the
     raging sea, the days of the median lunar-synodic age, the signs
     and individual degrees of the signs of the distance of the moon
     from the middle of the sun within the time of 29 terrestrial
     revolutions, hours This circle revolves likewise
     from right to left around the center of the earth. In this
     second circle, another little orb revolves, bringing with it
     the epicycle of the moon, in which the little circle of the
     moon (whose illuminated middle always faces towards the sun),
     running from left to right through the signs of the anomaly;
     within 13 revolutions of the earth, hours 18.39.16. It descends
     from apogee to perigee and in just as many others it returns
     from perigee to apogee, to be carried down thus to true, back
     and front from the longitude and distance from the sun and from
     the middle of the earth.

     The third circle (on which I have tried to indicate
     astronomically-geometrically in their places, the degrees of
     lunar latitude both in the south and in the north, and some
     fixed stars, those, namely, which can be separated by us from
     the moon which goes between) from left to right turns around
     the center of the earth, stretching out the head and tail of
     the dragon, on the inside above the second circle for noting
     and measuring the sun (but I should rather say the earth), and
     the eclipses of the moon, within 346 revolutions of the earth,
     hours 14.52.23.

     The fourth circle, in which the heaven of the fixed stars,
     reduced to the correct ascent of our times, the signs of the
     zodiac and the individual degrees of the signs, the months of
     the year and the single days of the month can be seen, likewise
     makes its journey around the earth from left to right in 365
     terrestrial revolutions, hours 5.48.56.; that is, within a
     median astronomical year. Above this annual orb, the sun, in
     its small epicycle, gliding through the 12 signs of the
     anomaly, within the space of 182 terrestrial revolutions, hours
     15.6.58., from left to right, falls from apogee to perigee;
     and, within the same time, rises from perigee to apogee, and
     brings with it, the index, namely its central radius, inhering
     to the axis of the equatorial orb and cutting the four greatest
     circles from the center.

     When the sun has been moved around, Iris shows from six windows
     the era, that is, the current year. Two winged youths take
     their place next to Iris, carrying the Julian period: namely,
     the Roman indiction, the cycle of the sun and the golden
     number, on a leaf of paper held between them. The imperial
     eagle stands out on top (as if added to the frontispiece)
     carrying on its breast the dominating planet and in its talons
     the ecclesiastical calends (that is, the dominical letter and
     the epact).


Two attachments, in the form of small superimposed dials are situated at
the base of the dial plate, at either side and immediately below the
fourth chapter ring. In his second volume, Father Borghesi stated that
they "are not moved from inside the clock, but the one at the right
[inscribed _concitat_ and _retardat_] serves for loosening
[accelerating] and tightening [retarding] time; that is, the reins of
the perpendicular."

In other words, the purpose of this attachment is for adjusting the
pendulum to make the clock operate fast or slow. The second attachment,
which appears at the left, and which is inscribed "Claudit" (close) and
"Aperit" (open) serves the purpose of "... preparing the mechanism in a
moment, as swiftly as you wish, for sustaining the astronomical
experiments of which you will hear later; when these things have been
done, it restores the mechanism to its natural motion at the same

This adjustment relates to the final section of Father Borghesi's second
book, entitled "Chronologo-Astronomicus Usus Authomatis"
(Chronological-Astronomical Use of the Automaton), which is translated
from the Latin in its entirety:

     With one glance at this automaton, you can quickly answer these
     questions: What hour the sun shows, the moon, any fixed star,
     the head and tail of the dragon. Is the sea swelling with
     periodic heat [at high tide?] or is it deflated [low tide], or
     quiescent? How many days is it from mean new moon or full moon?
     By how many signs and degrees is the moon distant from the sun,
     and from its nodes? What sign of the zodiac does the sun
     occupy, the moon, the head and tail of the dragon? Is the sun
     or the moon, in apogee or perigee, ascending or descending?
     What is the apparent speed of the sun and of the moon? What is
     the apparent magnitude of the solar and lunar diameter, and of
     the horizontal parallax of the umbra and penumbra of the earth?
     What is the latitude of the moon? Is it north or south? Does
     the moon hide [occult eclipse] any of the fixed stars from the
     earth dwellers, and which of these does it obscure? Is there a
     true new or full moon? Is the sun in eclipse anywhere on earth?
     What is the magnitude, and the duration of this eclipse, with
     respect to the whole earth? Can it be seen in the north or in
     the south? Is the moon in eclipse? Total or partial? Of what
     magnitude, etc.? What limb of the moon is obscured? How many
     years have passed from a given epoch? Is this year a leap year,
     or a common year--first, second, or third after leap year? What
     is the current month of the year, and what day of the month and
     of the week? Which of the planets is dominant? What days of the
     year do the various feasts fall on, and the movable feasts
     during the ecclesiastical year? And many other similar
     questions, which I pass over here for the sake of brevity.

     Besides, this device can be so arranged for any time
     whatsoever, past or future, and for the longitude of any
     region, and can be so manipulated by hand, that within the
     space of a very short time there can be provided in their
     proper order, the various orbits of the luminous bodies, their
     alternating eclipses, as many as have taken place through the
     course of many years, or even from the beginning of the world;
     or those that will be seen as long as the world itself shall
     last, with all their attendant circumstances (year, month, day,
     duration, magnitude, etc.). All these can be seen with great
     satisfaction of curiosity and of learning, and hence with great
     pleasure to the soul. In the meanwhile, the little bells
     continually play, at their proper, respective times. So that,
     all exaggeration aside, a thousand years pass, in the sight of
     this clock, as one day!

     I am aware of your complaints, O star-loving reader--that my
     description is too meager and too succinct. Lay the blame for
     this on those cares, hateful both to me and to you, more
     pressing, which forbid me and deprive you of a methodical
     explanation of the work.


Father Borghesi specified that the entire mechanism was equal in weight
to a seventh part of a _Centenarii Germanici_, a Germanic hundredweight.
This is probably the Austrian centner which is equivalent to 123.4615
pounds. Therefore, the clock mechanism weighs approximately 17.6 pounds.

The clock operated for a hundred days and more at a single winding,
according to Father Borghesi, and by means of a pendulum with a leaden
bob weighing 60 Viennese pounds, attached at a height of 5 feet. Father
Borghesi stated the weight of the pendulum to be 60 _librarum
Viennensium_, but the Viennese libra does not appear among the weights
of the Austrian Empire. However, using the average libra, an ancient
Roman unit of weight equal to 0.7221 pound, it may be assumed that the
driving weight should be approximately 45 pounds.

Father Borghesi, however, does not venture to provide any description
whatsoever of the movement of his second clock in his book. He gave the
following reasons:

     But beyond this, I entirely omit [a description of] the further
     apparatus of the very many wheels, etc., inside the clock which
     carry on its functions, lest I become too verbose for some
     persons. To explain more thoroughly the internal labyrinth of
     the entire mechanism, from which the movement of the circles or
     heavens, etc., are derived, would seem to entangle in too many
     complicated perplexities.... Therefore, that I might not delay
     longer, and perhaps to no purpose, I have thought it better to
     leave the whole work to the proportionate calculus of the
     arithmeticians and the technical skill of mechanics. If they
     have any desire to construct a similar mechanism, they will
     follow the aforesaid motions of the heavens, etc., not only by
     one means alone but by many, more swiftly through thoughtful
     study than by any amount of instruction.

     For whoever is well versed in the theory of calculus and sets
     to work at any given project, will discover any desired motion
     by a thousand and more ways, by one or another gearing of
     wheels; which an industrious mechanic will carry out in
     actuality and without too much difficulty. Nor is there any
     reason for anyone to be discouraged, so long as he is not
     disgusted by the amount of labor for there is nothing truer
     than the old saying "The favorable gods grant everything to the
     assiduous laborer."

     Nay, further, even this little work itself can be improved on
     and surpassed by new inventions. Otherwise that other old
     adage, almost as old as the world, would prove false, "What you
     have found already done, you can easily repeat, nor is it
     difficult to add to what has already been invented." Relying on
     this principle, I have already conceived some new things to be
     added to the present little work.

[Illustration: Figure 17.--MOVEMENT OF BORGHESI CLOCK viewed from the
right side, with details of chiming mechanism.]


There is a discrepancy between Father Borghesi's written description in
his second book of the number of bells and those which currently exist
in the clock. At the present time, there are two sets of bells attached
to the upper part of the movement. While Father Borghesi indicated that
there were two sets of bells in the clock, he described the first set by
stating that:

     ... there are three bells inside the clock: The largest, when
     struck by a little hammer at each mean new moon, signifies the
     new moon. The smallest indicates in the same way the full moon
     at the time of the mean full moon, by automatic sound. When on
     the equatorial earth, the sun appears anywhere in eclipse, two
     bells (the largest and the medium) sounding together
     automatically, announce that eclipse at the time of the mean
     new moon. (I think it is evident that eclipses of the sun occur
     at new moons and eclipses of the moon at full moon.)

     When the moon is eclipsed, the smallest and the medium bells,
     simultaneously and automatically, announce the event to the ear
     at the time of the mean full moon. Besides, at the proper time
     and automatically, the largest of these bells announces the
     current solar hour and the smallest bell strikes the quarter

In the clock today, the first set consists of a smaller bell fixed
within a larger one. It is presumably these bells that indicate the
eclipses and also strike the hours and quarter hours. A pull cord
attached to the striking mechanism repeats the current hour and quarter
hours at will. The second set consists of nine meshed bells struck with
individual hammers operated by means of a pinned cylinder as in a music
box. On the hour, the chimes play one of two melodies, which may be
changed at will. While not identified, these appear to be Tyrolean folk
melodies. The largest of this set of bells is dissimilar to the other
chimes, and may be the third bell described by Father Borghesi to
signify the new moon.


One of the most curious aspects of the second clock produced by Father
Borghesi and Bertolla, as well as of the second published volume, is the
presence of chronograms which occur repeatedly on the clock dial and
throughout the _Novissimum Theorico-Practicum Astronomicum Authoma_ from
the title page to the end of the book. Interestingly enough, Father
Borghesi did not utilize this device even once in his first little book.

[Illustration: Figure 18.--A CHRONOGRAM in the text of Father Borghesi's
second volume, indicating the year 1764. The poem is translated as: "In
the Mount of 'Anáuni,' the inscrutable heavens are led, You learn from
these all the labors of the sun and the moon. Here you are shown and
hear the conjunction of the moon: And a bell brings to the ears by its
sound, all eclipses."]

Webster defines a chronogram as an inscription, sentence, or phrase in
which certain letters express a date or epoch. The method used by Father
Borghesi for forming chronograms was a simple one. He used combinations
of uppercase and lowercase letters in two sizes in the inscriptions on
the clock dial and in his writings. At first this curious combination in
the inscriptions on the dial plate was a source of considerable
speculation. The extremely fine quality of the engraving and artistry
was such that these combinations could only be deliberate in nature and
not the accidental whims or accidents of the engraver. Accordingly, they
must be chronographic in intention. Such proved to be the case.

Borghesi used the larger size of uppercase letters to form the
chronogram, and each chronogram was complete within a phrase or line. He
accomplished this by using for this purpose those letters of the
alphabet which form the Roman numerals. The uppercase letters found
within words are copied off in the order in which they appear in the
inscription or phrase. These are then converted into their numerical
equivalents, and totaled. Taking the uppermost inscription on the clock
dial as the first example:

    FranCIsCVs I sIt pLan. DoMInator aeternVs

The letters which are intended to form the chronogram are:

     C  I  C  V I I  L  D    M  I V

    100 1 100 5 1 1 50 500 1000 1 5

These figures added together total 1764.

The second inscription on the clock dial which forms a chronogram is

    LaVs saCrosanCtae TrIaDI VnI Deo, et DeIparae

     L V  C   C  I  D  I V I  D   D  I

    50 5 100 100 1 500 1 5 1 500 500 1 = 1764.

The third inscription required a little more planning, because of its
greater length. Accordingly, Father Borghesi divided it into nine parts,
each of which is separated from the other by means of asterisks. Each of
the nine parts of the inscription formed a chronogram which, in every
instance, totals to the date 1764, the year in which the second clock
was completed. The same procedure was followed with the inscriptions in
the lower left and the lower right corners of the dial as well as with
the maker's inscription within the central disk. This inscription is

    BVrghesIo DoCtore, et BertoLLa LIMatore AnnanIensIbVs

    V I  D   C   L  L  L I  M   I I V

    5 1 500 100 50 50 50 1 1000 1 1 5 = 1764.

The inscriptions within the chapter ring are not utilized for
chronograms, however. It is apparent that Father Borghesi was required
to make a most careful selection of the texts for his inscriptions in
order that none of the phrases included any additional letters which
formed Roman numerals than would total to the date he desired to
indicate, namely, 1764. Where it was necessary, he employed an asterisk
to separate parts of texts so that each would produce the same total.
Any letter that did not form a Roman numeral, even if capitalized or
used in a larger size, did not interfere with the formation of the

In spite of his ingenuity in designing a text which would include only
such of the letters representing the Roman numerals which would provide
the chronograms for 1764, Father Borghesi experienced some difficulties,
particularly in place names. He accordingly changed them in order to
avoid the inclusion of letters that would have disturbed his totals.
Examples are MEGGL instead of MECHL, which had an extra C, and RVNNO
instead of RVMO, which had an extra M.


When the clock had been completed and proved to work successfully,
Borghesi once more reduced a description of the clock and its function
to published form in a second little volume published by Monauni. This
second work was also in Latin, the title of which is translated as _The
Most Recent Theoretical-Practical Astronomical Clock According to the
Equally Most Recent System of the World_. As with his first book, Father
Borghesi devoted a number of pages to a preface addressed to the reader,
which is translated from the Latin:

     This mechanical instrument was far from being ready for public
     notice. A great deal of time and work remained to produce a
     machine of this new system from the very foundations; then, by
     a most accurate calculation to bring the motions of many wheels
     up-to-date with the most recent astronomical observations; and,
     finally, to fashion it with the craftsman's file, often enough
     with a weary hand. All this work I had performed eagerly, so
     that, while in my room, I might contemplate leisurely, both day
     and night, the true face of the heavens and the seas unobscured
     by clouds, even though I had no astronomical equipment. But,
     then I remembered that, in my book on the first clock, I had
     promised a description of a new (at least, as far as is known
     to me) clock. Moreover, friends with astronomical interest, who
     took part in the oft-repeated astronomical experiments
     concerning this clock, persuaded me that the intellectual world
     would enjoy having a greater knowledge and a description of
     this work. However, it was not only the promises nor the
     desires of many which moved me to write this work, but I also
     thought it was necessary to set forth, before the description
     of the clock, an exposition of the astronomical system
     according to which this clock was constructed, so that the
     complete work would be evident to all. I was concerned about
     making this timepiece more acceptable and more understandable
     to those people who are far distant and unable to see it, so
     that this present exposition would obtain credulity among all.
     I could find no better method than to set forth for the reader
     the theory of the universe which I figured out after many
     sleepless nights.

     In testing this theory day after day, it not only appeared to
     be complete, and true, but each day it appeared more
     conformable to reality; it captured my mind in such a way that
     I finally adhered to it. I desired, while I lived, to erect
     this work as a monument to the theory. To do this, I digressed
     a bit from the true-to-life pattern to the mechanical order so
     that I could transfer all the movements of the heavens, etc.
     (which I enjoyed thinking about more), to the plane surface of
     the clock's face. In this way, the ecliptical spectacles of the
     stars, etc., would appear at their proper times clearly before
     the eyes of the viewer. I could also avoid many difficulties
     which otherwise, perhaps, even the hands of the most skillful
     craftsmen could never solve.

[Illustration: Figure 19.--MOVEMENT OF THE BORGHESI CLOCK, viewed from
the rear, showing rear of dial plate.]

[Illustration: Figure 20.--TITLE PAGE of Father Borghesi's second
book. The translation in its entirety is: "The Most Recent
Theoretical-Practical Astronomical Clock According to the Equally Most
Recent System of the World. Author: Francesco Borghesi of Mechel of
Anáuni * Priest of Trent, Doctor of Philosophy * (The System of the
Clock) Ingeniously connected to new theoretical laws published 1764: and
the constructor, Bartholomeo Antonio Bertolla of Rumo, similarly from
Anáuni * who skillfully produced this work * in this same current year
of Our Lord * which is the year 5713 [sic] since God created this earth.
(Trent: From the Printshop of Giovanni Battista Monauni, With Permission
of the Superiors.)" (_Title page reproduced by courtesy of the
Biblioteca della Citta di Trento._)]

     You ought to know, therefore, that as a result of my nightly
     meditations, I have rejected, after much consideration, all the
     explanations of the universe thus far published. All other
     theories of the make-up of the universe, however admirable, and
     however many there are, turn the sun and earth around in an
     ecliptic in an annual movement. Thus, Philolaus was the first
     to move the earth from the center of the universe and move it
     through the void; afterwards, Aristarchus of Samos and then
     Copernicus moved the earth with the moon. The Egyptians, as
     well as Pythagoras, Ptolemy, Tycho, Riciolus, Longomontanus,
     etc., thought that the sun moved through the degrees of the
     ecliptic each year. But I attributed this movement to neither
     earth nor sun for the movement of both is only apparent. I did
     not vainly surmise the annual equilibrium in all astronomical
     observations to be from the daily movement of the same axis
     moved at the poles of the heavens. Nor, in like manner, is
     there a better way to satisfy physical experiments. To you,
     then, most cultured reader: If you, perhaps, can make any use
     or draw pleasure from this most faithful description of my new
     theory and the mechanical instrument, refer it first to God on
     High from whom is everything that is best, and then to those
     avidly awaiting this little work. Lastly, if you find any
     statement less fitting; in your humanity, do not disdain to
     excuse it.

Borghesian Theory of the Universe

In Father Borghesi's second volume, there is a separate chapter entitled
"An Exposition of the Latest Theory of the Universe." This follows the
introduction to the reader, and in it Father Borghesi proposed:

     That you might rightly conceive my new system of the world and
     mechanically, as it were, construct it, imagine for yourself,
     beneath that most happy seat of the Blessed and above all other
     heavens, a kind of spherical convexity, everywhere equidistant
     from the center of the earth, and endowed with absolutely no

     On the inside, at two points diametrically opposite each other,
     this convexity has two most sturdy poles (to speak
     mechanically), projecting towards the center (which you call
     the poles of the heavens), and the largest immobile semicircle,
     in some manner is drawn from the center of one pole to the
     center of the other. This semicircle in the middle, namely at a
     point equidistant from each pole, is thought to be secured by
     some sign, for example, by that "o," for arranging more
     perceptibly the seat of the sun (as will be shown later). This
     much must be conceived first.

     You must understand that imposed on these poles is the first
     mobile [Primum Mobile], everywhere convex, and divided, into 12
     equal parts [Dodecatemoria], by the 6 greatest circles,
     intersecting each other at the centers of the poles. Then it is
     divided by another equally great circle, everywhere equidistant
     from the poles, into two hemispheres. One hemisphere of 12
     parts, proceeding in order from west [setting] to east [rising]
     should be assigned the respective signs of the zodiac; that is,
     one to Aries, the next to Taurus, and so on, etc. The circle
     which cuts those 12 parts transversely in the middle, you call
     the ecliptic. Then, these capital spaces of the Primum Mobile
     are subdivided by degrees, minutes, etc., both in longitude and
     in latitude, so that this heaven represents a kind of great
     spherical net, extended to capture the longitude and latitude
     of the stars, and Mobile on the aforementioned poles. Note,
     however (and this is almost the leading point of the system),
     in that circle of longitude which divides the sign of Gemini
     from Cancer and Arcitenens [Sagittarius] from Capricorn, you
     must conceive two points, directly opposite each other and
     removed about twenty-three and a half degrees from the poles:
     Boreal [the northern] between Gemini and Cancer; Austral [the
     southern] between Sagittarius and Capricorn. These two points
     by some power (imagine it is magnetic power), equal between
     them, hold the terraqueous orb suspended in the middle, by
     acting on the axis of the same orb (imagine it is iron) in such
     a way that the earth is continually drawn to those two points
     as to two opposite centers. It is never nearer to one, for as
     it is about to move towards one, the opposite power is
     constantly drawing it back. Thus, both those points and the
     axis of the earth are always held in one common line, wherever
     those points happen to be carried by the rotation of this

     Again, it is necessary for you to conceive in this heaven,
     first, two great circles, bisecting each other at right angles
     in the centers of these two magnets. One of these circles,
     passing through the first point of Aries and Libra in the
     ecliptic, is called equinoctial colure: the other circle,
     passing consequently between the first point of Cancer and
     Capricorn, is called solstitial colure. Beneath these are
     likewise imagined many other great circles, in the centers of
     the magnets dividing crosswise in the shape of an "X." But if,
     receding from these magnets, you describe circles (parallel to
     each other and ever greater and greater, up to the greatest
     circle which you will perceive is called the equator),
     equidistant from each magnet and obliquely splitting the
     ecliptic in the equinoctial colure, you can then behold a
     great, new, woven net in this heaven of the Primum Mobile. This
     net most beautifully expands to extract the straight ascent and
     descent of the stars, etc., from the vast ocean of the heavens,
     catching the straight ascent in the greatest circles and, in
     other unequal circles, parallel to each other and obliquely
     cutting across, most safely catching the descent.

     Immediately below the Primum Mobile place the heaven of the
     fixed stars (and, that the idea might be clearer), revolving
     separately on the same poles on which the Primum Mobile
     revolves. Through this heaven, the filaments of the little
     nets, etc., seem to the eyes of you on earth as if they shine.
     In this heaven, you should conceive in their fixed places, the
     fixed stars, a proportionate, inviolable distance from each
     other, and, indeed, if you will, the heavenly images, etc.,
     depicted, and all carried along at the same time with their
     heaven by one motion.

     Conceive a straight line running from the center of the earth
     to that sign "o" noted in the semicircle of the supreme
     immobile heaven. On this line, greatly below the heaven of the
     fixed stars, place the center of the solar epicycle, holding an
     area in common with the ecliptic and subject to absolutely no
     motions, but at such a distance from the center of the earth
     that the semidiameter of the earth has little, if any,
     proportion with the distance of the solar epicycle from the
     earth. Around the sun, moving continually in this epicycle (its
     immobile palace) through the degrees of the anomaly, you can
     revolve, with motions proportionate to the system, the five
     planets: Mercury and Venus (the nearest barons of the sun),
     then Mars, Jupiter and, most remote, Saturn, with its
     respective satellites, etc., eccentrically surrounding the
     earth itself and the moon in their immense ambit and wandering
     by their proper motions through the zodiac.

     Nevertheless, not far from the earth you should imagine
     fabricated, as from most refined crystal, the heaven of the
     moon everywhere equidistant from the center of the earth and
     revolving separately on the same poles (prolonged even to this
     place) on which the Primum Mobile and the heaven of the fixed
     stars revolve. In the middle of this, that is, in some point
     equally removed from the poles, you place the center of the
     lunar epicycle, movable also by the common rotation of the
     lunar heaven. I refrain from the other movements of the moon in
     latitude, etc., as also those of the five planets, etc., which
     the theory in no way excludes, lest by a variety of congested
     motions explained too abundantly, either you might be confused
     about the fundamental concept of the system or, while adorning
     the theory and trying to embellish the least things more
     widely, you might reject also the things which are capital.

     Here you already have the whole machine, but still inert and to
     be animated for the first time by motions accommodated to the
     system. Nevertheless, before I assign motion to the individual
     parts of the world, so that the thing might later appear more
     clearly to you, I arrange all things thus: first, as if by
     hand, I turn the Primum Mobile until the Boreal magnetic point
     comes to the level or the area of the semicircle described in
     the supreme immobile convexity; then I turn the heaven of the
     fixed stars until, for example, the heel of Castor (a star of
     the third magnitude), almost in the ecliptic and indeed in our
     time not far distant from the solstitial colure, likewise falls
     nearly at the level of the aforesaid semicircle. Later, I turn
     the lunar heaven until I bring the center of the lunar epicycle
     to the same level. Then, I turn the earth until some
     predetermined city, for example, Trent, situated in the
     northern zone with a latitude of about forty-six degrees, is
     brought to the oft-mentioned level.

     From things arranged in this way and from what has gone before,
     it is evident (with the motions of the luminaries in epicycles
     left out, however, lest you be distracted by the explanation)
     that at Trent, just as in the whole northern hemisphere, it is
     the summer solstice; and, conversely, in the southern
     hemisphere, it is the winter solstice. The reason is because
     the northern magnetic point together with the northern half of
     the earthly axis is at its highest point towards the sun,
     immovably residing in a line sent through the level of the
     highest semicircle; and, conversely, the southern magnetic
     point with the corresponding half of the axis is most removed
     from the same. It further follows, that noonday and the new
     moon coincide, and the heel of Castor almost reaches the
     summit, etc.

     Now, beginning from this hypothetical situation of the whole
     world as from the root of the motions, I move all things in
     their circles so that the earth turns on its axis with a
     revolving motion from west to east in each 24 hours of median
     time. The lunar heaven completes one circle around its poles
     likewise from west to east in the time of 29 terrestrial
     revolutions, hours The sphere of the fixed stars
     on the same poles revolves once from east to west within 365
     revolutions of the earth, hours The Primum Mobile on
     the poles (common to the heaven of the fixed stars and the
     heaven of the moon), is moved once in the same way from east to
     west, a little faster, however, than the heaven of the fixed
     stars, yet within 365 revolutions of the earth, hours 5.48.56;
     that is, within a median astronomical year.

     Now, behold for yourself a new world supported on new poles and
     provided with new motions and laws. Now you, reader and lover
     of the stars, turn it, and revolve it as long as it pleases
     you, and compare it astronomically and physically with the
     Copernican or the Tychonian systems or with whatever one
     pleases you more, and judge which one seems more consonant with
     nature when all things are examined. But if you aren't able to
     reconcile this theory with some astronomical observations or
     physical experiments and think it should be eliminated from
     the group of theories, see that I might know this while life is
     still my companion, so that I might think with you, if this is
     possible. Also, so that, in gratitude for the detected or
     perhaps hidden error, I might speak or write, and you won't
     have to shout in vain in bold ridicule and with no applause
     after the fleeing shades of the dead and the mute ashes. But,
     if you object that the daily motion of the revolving earth and
     the annual motion of its whirling axis do not sufficiently
     agree with certain texts of Sacred Scripture, and if those
     things which the Copernicans and the Longomontanists say do not
     convince you, then reject my whole system as an old wives'

       *       *       *       *       *


ANOMOLIA or anomaly, is the angular distance of a planet from its
perihelion (that point of the orbit of a planet which is nearest to the
sun) as seen from the sun.

AEQUINOCTIUM or the equinox, is the time in which days and nights are
equal in the space of hours. There are two equinoxes: the spring
equinox--c. 8 calends of April in the sign of Aries; and the fall
equinox--c. 10 calends of October in the sign of Libra.

AERAS is derived from _aera_, _aerae_, which originally meant a given
number, usually used in regard to money. The word was later extended to
mean a number used in any calculation, and finally it came to mean a
certain time from which subsequent times were counted, e.g., _Anno
Domini_, after the Birth of Christ.

COLURI or the Colures, which are two circles in the heavenly sphere,
passing through the poles of the world and cutting each other at right
angles: the one passes through the equinoctial points of Aries and Libra
and is called _Colurus Aequinoctiorum_ or equinoctial colure; the other
touches the _solstitialia_ of Cancer and Capricorn and is called
_Colurus Solstitiorum_ or solstitial colure. They are called _Colurus_,
which is translated as "mutilated tails," for the part which emerges in
the Antarctic is not visible and is quasitruncated.

ECLIPTICA or the ecliptic, is an imaginary line in the heavens in which
the sun was supposed to have performed its annual course.

EPICYCLUS or epicycle, is a small orb which, being fixed in the deferent
of a planet, is carried along with its motion and yet, with its own
peculiar motion, carries the body of the planet fastened to it round
about its proper center.

IRIS or the rainbow. In mythology, Iris was the daughter of Thaumatis
and Electra, messenger of Juno of the goddesses and Jove of the gods.

SOLSTITIUM or the solstice, is that time when the sun seems to stand
still for a short time: when the sign of Cancer enters the month of June
(equivalent to the summer solstice, when the sun begins to recede from
us); and when the sign of Capricorn enters the month of December
(equivalent to the winter solstice, when the sun begins to accede to

       *       *       *       *       *

Last Years

There is a break in the story of Borghesi and Bertolla for the next five
years. The second clock may have been the last project on which the
priest and the clockmaker worked together, for very good reasons. The
two clocks must have represented a considerable financial investment in
materials and in time, and neither of the men was in sufficiently
affluent circumstances to undertake the luxury of such a hobby without
some form of recompense. The publication of the two little volumes must
have also been done at Father Borghesi's expense. The income of the
parish priest in a small mountain village could not have been equal to
the relatively great costs of the projects that had been completed. It
seems probable that the priest attempted to sell his clocks to a wealthy
patron, perhaps the Baron of Cles, or he may have attempted to obtain
some form of recompense for the continuation of his research. However,
no records can be found of such patronage if it existed. If Borghesi had
received financial assistance while the projects were in progress, he
would certainly have made adequate mention of the patron's name and
assistance in one or the other of the two volumes which he

The next record relating to Borghesi which has been found is the
description of a letter written by an anonymous mathematician late in
1768 or early in 1769. It was 28 pages in length, written in Latin, in
the form of a reply to the writer's brother, on the subject of the clock
invented by Borghesi. It consisted primarily of a criticism launched
against Borghesi's first little volume published in 1763.

The anonymous letter is without date, place, or signature. This writer
claimed that Father Borghesi had made many errors in his book,
presumably in the description of the clock's functions, and in the basic
theories upon which the priest had predicated his research. No complete
copy of the letter's text has been found for study, although it is
described at length in Tovazzi's _Biblioteca Tirolese_. Tovazzi noted
that four copies of the letter existed at that time, and that he
personally had filed one in the Biblioteca di Cles in Trent. However,
every attempt to locate a copy at the present time has been

If the anonymous letter was brought to the attention of Father Borghesi,
it must have introduced a disturbing note into his life and cost the
priest many unhappy moments. He was not, however, dissuaded from his
preoccupation with horology. Several years later, in 1773, Father
Borghesi was working on yet another astronomical clock, this time
presumably without the assistance of Bertolla. This third clock was
reported by Tovazzi to have been "of minimum expense but of maximum

No subsequent information relating to it has come to light, and there is
no record that it was actually completed.

Again there is a period of silence in the life of Father Borghesi which
no amount of research has yet been able to pierce. Whatever the
circumstances may have been, it is reported by several of the sources
noted that both the first and the second clock did, in fact, become the
property of the Empress Maria Theresa in Vienna. The presentation was
made sometime during the period between the completion of the second
clock in 1764 and the year 1780. There is some discrepancy in the
contemporary accounts as to whether Father Borghesi presented one or two
clocks to the Empress, but all the sources with but one exception record
that both clocks were acquired by the Empress.

It is doubtful that Father Borghesi had originally intended to give his
clocks to the Empress at the time that they were made, for he would most
certainly have made some mention of such an intention in the two little
volumes which he published about them. If he saw the letter published by
the anonymous mathematician in late 1768 or 1769, it is possible that he
decided to make the presentation in expiation of his sense of guilt for
the amount of his time which the creation of the timepieces had
consumed. On the other hand, it is just as possible that Father Borghesi
may have forwarded copies of his two little volumes to the Imperial
Court at Vienna, and that the Empress expressed a desire to acquire the

Father Tovazzi states that in 1780 "the clock invented by him [Borghesi]
was preserved in Vienna, Austria, at the Imperial Court from which the
inventor was receiving an annual pension of 400 florins." No records in
the Palace archives relating to the clock have yet been found, nor
records of payment of an annuity to Father Borghesi. However, a more
exhaustive investigation of the Furniture Depository of the Imperial
Court may bring forth related records. It was the implication in Father
Tovazzi's account that the second clock had been presented to the
Empress prior to the publication of the anonymous, critical letter in
1768 or 1769. He believed that it was envy of Father Borghesi's
ingenuity, fame and financial benefit that had caused the anonymous
mathematician to publish his letter, for Tovazzi asked "Who would have
encountered opposition to such a marvel? Envy is not yet dead, and has
always reigned."

This last-mentioned theory about the presentation may be the most likely
one. Some evidence may be found in the second clock itself which bears
out this assumption. The multiple chapter ring, with its many
inscriptions, is engraved and silvered in a relatively crude manner,
presumably by Bertolla himself. The main dial plate, however, which is
of gilt brass, is engraved with the utmost skill by one of the great
masters of the art. The inscription below the Imperial Hapsburg eagle
relates to Francis I, Emperor of the Holy Roman Empire. It is entirely
possible that although Father Borghesi originally had no intention of
giving the clock to the Emperor or the Empress at the time that it was
made, he later changed his mind. Accordingly, he may have commissioned a
master engraver, possibly in Trent or in Vienna itself, to produce a
dial plate which would be of such a quality as to be worthy of the
Emperor himself. If so, this was done shortly after the clock was
completed, for the Emperor died in August of the following year. Perhaps
by the time that the clock was ready, the Emperor had already died, and
Father Borghesi gave the clock instead to Maria Theresa without revising
the inscription.

The acceptance of the clocks by the Empress, and the annuity which was
his reward, would have constituted considerable honor even for one of
the foremost clockmakers of the Empire, but for a humble parish priest
in a little village, such notable Imperial recognition was overwhelming.
Possibly as a result of it, a change was noted in Father Borghesi in the
next few years. His conscience began to bother him, and he began to
question whether he had done right in spending so much of his time and
thought on his horological research. He became more and more confused in
his own mind. Had he spent too much time in mechanical studies to the
neglect of his ecclesiastical duties? If this had been the case, he had
committed the most grievous sin.

Exaggerated though these thoughts may appear, they were undoubtedly of
the most critical importance to the middle-aged priest. His mental
turbulence and confusion increased daily, and it soon became apparent to
others around him. By June 1779, he was completely in the grip of his
obsession, and his parishioners began to whisper amongst themselves that
their pastor was being tortured by the devil. They were unable to help
him, and he became more and more preoccupied with his problem. The years
passed slowly as the pastor became more vague and more tortured by his

There probably was continued contact between Father Borghesi and
Bertolla for at least some time after the development of his illness.
Bertolla had retired from active work, but continued to pursue his
interests in his clockshop as much as his health and advanced years
permitted. A clock which he made at the age of 80 survives and is
described and illustrated in the following section on "The Clocks of
Bartolomeo Antonio Bertolla." Finally, on January 15, 1789, Bertolla
passed away and Father Borghesi was left alone, deprived of the
companionship he had enjoyed with the older man for the past two or
three decades. One of Bertolla's nephews continued to work in the master
clockmaker's workshop, but there did not appear to be any association
between the younger man and Father Borghesi.

At last, in 1794, Father Borghesi lost his sanity completely, and he was
forced to relinquish his pastoral duties to a curate. For the remaining
eight years of his life, he continued to live in the rectory of the
little parish church in Mechel where most of his life had been spent,
his needs undoubtedly attended by the parishioners he could no longer
serve. During this period, until his death at the age of 79 on June 12,
1802, Father Borghesi lived on, oblivious of those around him.
Seemingly, he retired to another world; perhaps to that universe which
he had tried to reproduce in his second clock.

The Clocks of Bartolomeo Antonio Bertolla

The ingenuity displayed in the Borghesi clock by its constructor,
Bartolomeo Antonio Bertolla, requires a consideration of the other
examples of his work that have survived. The most important of his
clocks are probably the one in the Episcopal Palace at Trent and another
made for the Baron of Cles.

The one which survives in the Episcopal Palace to the present time, is
extremely tall and is housed in an elaborately decorated narrow case of
black or ebonized wood approximately 9 to 10 feet in height. The upper
part of the case is decorated with elaborately carved and gilt rococo
motifs. The movement operates for one year at a winding, indicates and
strikes the hours, and shows the lunar phases. It has an alarm, and will
repeat the strike at will, indicating the number of the past hour and
the quarters. The gilt brass dial is decorated with silver-foliated
scrollwork in relief at the corners, inside the chapter ring, and within
the broken arch. Featured above the chapter ring is the coat of arms,
executed in silver, of the patron for whom the clock was made,
Cristoforo Sizzo di Noris. Di Noris was Bishop of Trent for 13 years,
from 1763 to 1776.

The clock which Bertolla made for the Baron of Cles is a tall, narrow,
case clock of ebony or ebonized pearwood which is approximately 9-1/2
feet in height. The decoration of the case is considerably more
conservative than the one made for Di Noris, but the black wood is
decorated with silver trim and carved designs in the wood itself. The
dial is decorated with silver scrollwork and spandrels within and around
a raised chapter ring. The clock operates for one month at each winding,
has an alarm, indicates and strikes the hours, and will repeat the
quarters. This handsome timepiece is still in the possession of the
descendants of the Baron of Cles.

[Illustration: Figure 21.--TALL-CASE CLOCK BY BERTOLLA in the Episcopal
Palace in Trent, made for Bishop Cristoforo Sizzo di Noris. A striking
and repeating clock with lunar phases. (_Courtesy of Museo Nazionale
della Scienza e della Tecnica, Milan._)]

[Illustration: Figure 22.--INTERIOR OF BERTOLLA'S WORKSHOP, showing
detail of ceiling. (_Courtesy Museo Nazionale della Scienza e della
Tecnica, Milan._)]

[Illustration: Figure 23.--INTERIOR OF BERTOLLA'S WORKSHOP, showing the
main workbench and the collection of clockmakers' tools. (_Courtesy of
Museo Nazionale della Scienza e della Tecnica, Milan._)]

[Illustration: Figure 24.--FUSEE CUTTER used by Bertolla. Now in the
collection of the Museo Nazionale della Scienza e della Tecnica,

[Illustration: Figure 25.--INTERIOR OF BERTOLLA'S WORKSHOP, showing
details of paneling and floor case with Bertolla manuscripts. (_Courtesy
of Museo Nazionale della Scienza e della Tecnica, Milan._)]

According to Pippa,[19] certain characteristics become apparent in a
study of the surviving clocks by Bertolla. The tall-case clocks are
narrow and range in height from 7-3/4 feet to 10-1/2 feet. The cases had
this excessive height in order to obtain the greatest fall for the month
and year movements which Bertolla constructed. For the weight assembly,
he substituted a drum wound with a key at the point of the driving wheel
in place of the customary pulley. The addition of an intermediate wheel
augmented the drop of the weight.

Bertolla's movements were solidly constructed from well-hammered brass
and iron. He favored the recoil anchor escapement in his clocks and the
Graham dead-beat anchor escapement with a seconds' pendulum. The
escapement was not always placed in the traditional location in the
upper center between the plates. Bertolla occasionally displaced the
pendulum to one side, to the lower part of the movement or placed it
entirely between two other small plates.[20]

He utilized every type of striking work, including the music-box
cylinder common in the clocks of the Black Forest and the rack and
snail. Bertolla most frequently employed the hour strike and _grand
sonnerie_. He often used a single hammer on two bells of different sound
with the rack and snail. An example of this type is the clock he
produced at the age of 80. To achieve the necessary axis of rotation for
the hammer, which is perpendicular to the plate when it strikes the
hours, it moves to an oblique position and displaces one of the two long
pins in an elongated opening.

Bertolla's dial plates were generally well executed, with a raised or
separate chapter ring applied to a brass or copper plate, such as a
copper-plate _repoussé_ and gilt with baroque motifs, or upon a smooth
brass plate with spandrels of _repoussé_ work usually of silver, in
relief and attached. The engraving of the chapter rings was excellent.
The hands were well executed in steel or perforated bronze, and
occasionally of _repoussé_ copper; gilt was applied to the hands made of
forged steel.

[Illustration: Figure 26.--DIAL PLATE of a brass lantern clock made by
Bertolla, found in his workshop after his death. (_Courtesy of Museo
Nazionale della Scienza e della Tecnica, Milan._)]

In the course of time, Bertolla's home workshop passed from one
generation to another within the family. Inevitably, it underwent many
modifications until the only original part of the building that remained
intact from Bertolla's time was his clockshop.

[Illustration: Figure 27.--MOVEMENT of a brass lantern clock made by
Bertolla. (_Courtesy of Museo Nazionale della Scienza e della Tecnica,

Within the last few years, the workshop room was acquired complete with
contents from Bertolla's descendants, and installed in the Museo
Nazionale della Scienza e della Tecnica in Milan as an exhibit of a
typical 18th-century clockmaker's shop. The original workshop was
dismantled in Mocenigo di Rumo and completely rebuilt in the museum,
including the walls, ceiling and floor. The paneling and woodwork of the
walls and ceiling, which have been preserved intact, are hand-cut fir,
with columns, trim and moldings carved by hand. A small painting is
featured in the center of the coffered ceiling. The original shop
benches and chests of drawers are set around the reconstructed shop and
Bertolla's tools and equipment laid out as they had been originally.
Other clockmaker's tools and equipment in the museum's collection are
also displayed. Approximately 40 percent of the tools are the original
items from Bertolla's shop. Parts of clocks and works in progress are
on view on the benches as they were in Bertolla's time.[21] Also
preserved in the museum are sketches found in Bertolla's manuscripts,
some of which are reproduced on the following pages.

[Illustration: Figure 28.--DETAIL OF WALL of Bertolla's workshop, with
regulatory clock made by his nephew, Alessandro Bertolla of Venice. Note
wheel layouts, etc., scribed in the paneling. (_Courtesy of Museo
Nazionale della Scienza e della Tecnica, Milan._)]

[Illustration: Figure 29.--TABLE CLOCK BY BERTOLLA in the collection of
Doctor Vittorio dal Lago of Bergamo. The dial indicates the days of the
week and of the month, the names of the months and lunar phases. The
clock strikes the hours and quarters and repeats. (_Courtesy of Sig.
Luigi Pippa of Milan._)]

The shop contains two completed clocks made by Bertolla. One is a
weight-driven lantern clock typical of the 18th century, Italian style
with brass dial, plates and posts, anchor escapement, and striking
work. The dial is engraved in the usual style of Bertolla's baroque
design, and the hands are of pierced bronze. Another clock associated
with Bertolla and found in the shop, was made by his nephew, Alessandro
Bertolla, who worked in Venice after his apprenticeship with his uncle
had been completed. This clock is a regulator with a seconds' pendulum
and sweep hand on an enameled dial. The original case has not survived.

[Illustration: Figure 30.--LAYOUT OF THE WHEELWORK of a clock made by
Bertolla for His Excellency Paulo Dona, inscribed "Design No. 1."
(_Courtesy of Museo Nazionale della Scienza e della Tecnica, Milan._)]

[Illustration: Figure 31.--PENDULUM ARRANGEMENT SKETCH for an
unidentified clock found in Bertolla's workshop. (_Courtesy of Museo
Nazionale della Scienza e della Tecnica, Milan._)]

[Illustration: Figure 32.--STRIKING CLOCK SKETCH found in Bertolla's
manuscripts. (_Courtesy of Museo Nazionale della Scienza e della
Tecnica, Milan._)]

[Illustration: Figure 33.--FIFTEEN-DAY STRIKING CLOCK SKETCH, inscribed
"Design No. 3," found in Bertolla's workshop. (_Courtesy of Museo
Nazionale della Scienza e della Tecnica, Milan._)]

[Illustration: Figure 34.--DIAL PLATE of a brass lantern clock made by
Bertolla at the age of 80. (_Courtesy of Museo Nazionale della Scienza e
della Tecnica, Milan._)]

[Illustration: Figure 35.--MOVEMENT of brass lantern clock produced by
Bertolla at the age of 80, showing details of movement and double bell.
(_Courtesy of Museo Nazionale della Scienza e della Tecnica, Milan._)]

One of the most interesting of Bertolla's clocks, and probably the last
one which he produced, was found in his workshop. This timepiece
indicates the hours, minutes and quarters by means of a single hand or
index. The weight-driven clock strikes the hours and quarters on two
bells with a single hammer. The chapter ring, which is soldered to the
dial plate, is marked for the minutes on the outer rim and for the four
quarters inside it. Over the center of it, is a semicircular opening in
the dial plate through which is visible a revolving disk attached behind
the dial plate. This disk is marked with the hours and revolves from
right to left, the current hour being indicated by a projection from the
minute ring. The brass dial plate is engraved with simple floral
designs in the corners and around the broken arch. There is no
comparison between this crude and simple decoration and the extremely
fine quality of the engraving on the dial plate of the Borghesi clock,
for instance. In the center of the dial plate is engraved the following:

     "Questo orologio l'ideai e lo feci nella mia avanzata età
     d'anni 80. Bart^{o} Ant^{o} Bertolla"

     (I designed and made this clock at my advanced age of 80 years.
     Bartolomeo Antonio Bertolla.)

       *       *       *       *       *


   [1]  BORGHESI, _Novissimum Theorico-Practicum Astronomicum Authoma
        Juxta Pariter Novissimum Mundi Systema..._, pp. 8-9.

   [2]  WENHAM, "Tall Case Clocks," p. 33.

   [3]  VON BERTELE, "The Development of Equation Clocks," parts 1
        through 5.

   [4]  ENGELMANN, _Philipp Matthäus Hahn_; VISCHER, _Beschreibung
        mechanischer Kunstwerke..._.

   [5]  LLOYD, _Some Outstanding Clocks Over Seven Hundred Years,
        1250-1950_, pp. 116, 118, 120.

   [6]  SAN CAJETANO, _Praktische Anleitung für Künstler..._.

   [7]  FRANCH, _La Valle di Non_.

   [8]  BONOMI, _Naturalisti, Medici e Tecnici Trentini_, p. 16

   [9]  AMBROSI, _Scrittori ed Artisti Trentini_, pp. 132, 525.

  [10]  Ibid.

  [11]  PIPPA, "Antonio Bartolomeo Bertolla," pp. 22-23.

  [12]  Ibid., p. 22.

  [13]  Ibid., p. 23.

  [14]  The abbreviation in the inscription "pLan" is difficult to
        interpret. According to Father F. X. Winters, S.J., it may
        represent "sit planetis" or "sit planetarum." The use of an
        abbreviation was necessary to prevent the addition of another
        letter I or M, which would have disturbed the formation of the
        chronogram desired. Literally, "sit planetis" means "May he be
        eternal ruler _by_ [or _through_] favor of the planets," while
        "sit planetarum" is to be translated "May he be eternal ruler
        _of_ the planets." Father Winters considered both versions
        somewhat overexaggerated and proposed that the best translation
        might be "Long Live Francis I, Emperor."

  [15]  The word "Tempe" refers to the Vale of Tempe, in Thessaly,
        through which the Peneus River flows. It is between Mounts
        Olympus and Ossa, and is situated between the town of Larissa
        and the sea. In mythology, it is told that these mounts were
        originally joined and Hercules separated them to allow the river
        to pass between them. The word "Tempe" is also used to mean any
        pleasant place. Thus, the inscription "Tempe indesinenter
        clausa, Scaturigo signata" is literally translated "Tempe always
        closed, A fount of water sealed up" or, freely translated, as "A
        garden enclosed, a fountain sealed up."

  [16]  "Phoebi" or Phoebus, called Apollo, the sun god; Phoebes or
        Diana, the moon goddess, sister of Apollo.

  [17]  PIPPA, op. cit. (footnote 11), pp. 23-25.

  [18]  PERINI, _Statistica del Trentino, Biblioteca Communale del
        Trentino_, vol. 2, p. 57 (cons. 6, carta 9); TOVAZZI,
        _Biblioteca Tirolese_, pp. 406-407.

  [19]  PIPPA, op. cit. (footnote 11), pp. 24-25.

  [20]  PIAMONTE, _La Nauna Descritta al Viaggiattore_.

  [21]  ESPOSTI, "La Sala 'Innocente Binda' al Museo della Scienza e
        della Tecnica di Milano," pp. 18-21.



     [Translated from the section entitled "Synopsis Totius Operis
     Mechanici" in Francesco Borghesi's first book _Novissima Ac
     Perpetua Astronomica Ephemeris Authomatica


Of three movable indices, the farthest from the center of the dial is
fitted with an index on either side and marked with four segments of a
circle. Immediately below are five numbers, divided into the days of
setting the measure of the mean-synodic age of the moon, and into signs,
degrees of the signs, and of the distance of the moon from the sun.
These, in each revolution, revolve once around the solar disk
superimposed on the mean synodic-lunar disk, and also around the lunar
disk. The upper indices, meanwhile, in the two external greatest orbits,
measure the time continuously, in the accustomed manner of the
Germans--the middle index measuring by hours and the uppermost by the
first minutes [of hours].


Inside these three circles, perpendicular above their center, is a small
index of the seconds of minutes. At each first minute of time, being the
fastest of all, it describes the smallest orbit. Next to this are two
other slightly larger circles divided into 30 degrees, one [rotating?]
from the right, the other from the left. These two indices are arranged
in such a fashion that the one rotating from the observer's left
completes its period 12 times during one, mean, solar-astronomical year.
The one [rotating] from the right likewise completes its cycle 12 times
during the period of one mean-synodic moon. In between these, there is
placed another small sphere, divided into 40 arbitrary parts, whose dial
does not move automatically, but is moved by hand for speeding up or
slowing down the course of the time, or of the perpendicular.


Diagonally from the sides of the center of the three larger indices, six
other indices revolve: three on the left from one center, and three on
the right from another. The uppermost of the three which are on the
right of the observer [and which are] decorated with a small disk of the
sun, runs its cycle once during a mean solar-astronomical year. The
second measures the distance of the sun from its apogee. The third
revolves 12 times, with each lunar revolution from one node to the same
[repeated] node. Under the point of the uppermost index, first lie the
months of the year which are inscribed, and the days of each month, but
having only 28 days assigned to February; then the signs of the zodiac,
and their several degrees. The circle corresponding to the middle index,
extending through the first semicircle from apogee to the lower perigee
and returning through the second semicircle to the upper locations of
apogee, shows the true equation or eccentricity of the sun, joined with
the little equation of the moon in syzygy. [These equations are]
measured by geometric-astronomic proportion for each distance of the
sun from its apogee or perigee in degrees, and in sufficiently small
parts of degrees, with the title added above in their proper places,
whether an addition is to be made to the mean location of the sun or a
subtraction from the same, so that the true longitude of the sun may be
calculated. Three circles are assigned to the lowest index, of which 30
degrees of distance of the moon from its nodes comprise the larger. The
middle circle is based on the hypothesis of the mean invariable
diameters (that is, of the sun, the moon, and the terrestrial shadow),
and is divided into hours and quarters of duration. The last circle is
divided by the trigonometric laws into the inches of magnitude of lunar
eclipses. Lying between these circles, there is another eccentric circle
(black with a spot) exhibiting the shadow of the earth, in which the
little moon sinks itself, carried by the lowest index. In any ecliptic
full moons, the patent number of inches of immersion somehow affects the
minds of the cultured, but also the scheme of maximum obscuration
affects the eyes of the illiterate themselves.


Of the three indices which revolve from the left, the uppermost
completes its cycle within 12 hours, just as the hour index. The middle
one with two pointers on diametrically opposite sides, carries the marks
of conjunction and opposition of the luminous bodies, with a movement
equal to the course of the sun from lunar apogee or perigee. The lowest
index, fitted with a single pointer, indicates the motion of the moon
from its apogee or perigee. Under these three indices, there is situated
a common circle, divided into 12 parts, each of which are further
divided into 30 parts through its outer circumference. I have said a
common circle, for, with respect to the first index, the division
represents 12 hours, and the double subdivision representing the double
set of minutes of the hours serves for an excitator for anytime at all,
at will. For as often as the little index reaches the twelfth hour,
first being moved by hand wherever you prefer, a little hammer strikes
the little bell many times. But if you observe the second or the third
index, the first division provides the signs, and the subdivision of the
signs gives the individual degrees of the distance of the sun from the
lunar apogee, or of the moon from its apogee, respectively. To this is
added two other interior circles from the same center: to the larger is
inserted the equation of the center of the moon in its conjunctions and
oppositions; and on the smaller the equation of the same moon in its
quarters, astronomically-geometrically proportioned to the distance of
the moon from its apogee or perigee. In the first case, the equation is
to be subtracted from the mean longitude of the moon, descending from
apogee to perigee; in the second case, to be added to the mean longitude
of the moon ascending from perigee to apogee; and, in the third
semicircle of the index, as the rubric directs, common to both
equations, added around the center.


Perpendicularly under the center of the machine, two other indices are
carried about one and the same center. The one nearer to the
observer--bearing in one of two points diametrically opposite the small
disk of the sun, in the other the disk of the moon--runs a course equal
to the motion of the sun from the head or the tail of the dragon
(_Draco_). The other, of simple construction, marked with a small moon,
signifies in like manner the motion of the moon from the head or the
tail of the dragon.

Immediately below, there is a larger circle, common [referring] to both
these indices, which is divided into 12 parts. Each of these parts in
turn, in the outer periphery, is subdivided further into 30 parts, which
are the 12 signs of the zodiac and the individual degrees of the signs
of distance of the sun and the moon from the head of the dragon.

In the second circle is read the latitude of the moon, measured by
degrees, etc., on a trigonometric scale, by signs and degrees of
distance of the moon from its nodes, that is, from the head or tail of
the dragon. When the second index is descending from the head of the
dragon to the tail, the latitude will be to the north of the solar path;
that is, the ecliptic. On the other hand, it will be south of the
ecliptic when the same index is returning upward from the tail to the
head of the dragon as advised by the title inscribed on the third

Finally, on the fourth and last circle are seen more prime minutes of
the circle for reducing the orbit of the moon to the ecliptic. That the
true longitude of the moon may be obtained more accurately, these must
be subtracted from the longitude of the moon already calculated in the
first and third quadrant of the circle of the second index. On the other
hand, they are to be added to the same in the second and fourth
quadrant, as is noted in their respective places, according to the
theory of right ascensions.

Here, then, [you have] as finally completed, delineation of the great
index which was partially described before in this book.

From two points of that index which perpendicularly correspond to the
center of these circles, a pair of compasses, by an unvaried aperture up
to the circumference of the first larger circle, has marked off four
segments of a circle. The two larger segments, equal among themselves,
in one aperture refer to the sun, and the two smaller in the other,
likewise equal, refer to the moon. The one pointer is for determining
the solar eclipses; the other, for lunar. Both segments of each
division, like little wings of the index, stretch to the extent of the
degree of distance of the moon from its nodes, and to which that
determined latitude corresponds. On one side, that latitude precisely
equals the radii of the earth, the sun, and the moon, as the termini of
solar eclipses; and, on the other side, precisely equals the radii of
the earth's shadow and of the moon, as the confines of lunar eclipses.
The apexes of the last index, diametrically limited [opposite], indicate
the age of the moon, and its mean distance from the sun; one pointer,
upon which the sun sits, measuring the mean days and degrees from the
full moon; the other, on which the moon sits, measuring the mean days
and degrees from the new moon.


Besides the larger and smaller indices already mentioned, all [of which]
revolve within the periphery of the three largest circles, six dials in
this clock also revolve within the same circles which are to be seen
through six openings of the frontispiece. The first of these, intended
to indicate the phases of the moon by an unusual method (completely
black, and decorated with the characters of the principal aspects of the
moon) continually revolves interiorly around the center of the machine
and at the new moon, it completely removes from sight the face of the
moon through the round window. It continually recedes through the first
half of the circle until, at the time of the full moon, it restores the
moon, looking out with a full star. Soon again, too slow to be
observed, it returns through the other half of the circle, so that in
the next conjunction, the whole face of the moon may have a covering of
darkness, once again to be removed.

The other dials are moved by spontaneous advances at stated times. The
first of these shows, through a square opening, the day of the month;
the second, through another opening, shows the current day of the week
with the characters of the seven planets which, according to ancient
superstition, preside over each day of the week (now, by a truer form of
religion divided by the Church into ferias, etc.); that is, the sun, the
moon, Mars, Mercury, Jupiter, Venus and Saturn, to which I have added
the numbers of the ferias. These two little dials are advanced daily, by
a sudden movement at midnight. The remaining three are changed
automatically only once a year on the first of January.

The first of these dials contains five little cells, opening from a
common window: in the first cell, at the edge of the dial, is found the
dominical letter; in the second, the cycle of the sun; in the third, the
character; in the fourth, the sign; and, in the fifth, the house of the
planet dominating the year. The second dial shows the epacts, with the
golden number. The third, and last of all, shows the Roman cycle.

Finally, as indicated by the epact and the dominical letter in an
immovable table added outside, are the feastdays and other movable
events of the year; that is, Easter, the four seasons, the Rogation
Days, etc.


But lest the various movements of the indices and the various beginnings
of the divisions tend to cause some fatigue, the precaution has been
taken, that all the indices by common law are moved from the top towards
the right of the observer, and from thence all the arithmetic divisions
of the circles take their beginning. And lest the multitude of different
figures should deceive the eye, the larger divisions of the circles have
been marked by Roman numbers, that is, by capital letters of the
alphabet; others, in other places, by differently colored numbers. Thus,
the movements of the indices, the distribution of the circles and the
multitude of numbers not only do not disturb the eyes and the mind, but
rather marvelously delight them.


After having completed briefly the description of the dial and the
indices and their motions, I have not without reason delayed in
satisfying the desires of many who wish to learn at least the method by
which, from this mechanism, may be calculated the true times of new and
full moons, and their ecliptics. In order to make these matters clearer,
it is necessary that they be explained here at greater length.

With the indices, then, adjusted astronomically-geographically to the
longitude of any given region, and to the mean time whether past,
present or future, and assuming the clock to be in normal operation (as
at present it has been for a whole year and more), then the moon will be
in conjunction with the sun in the heavens. When the equations on the
mechanism are examined, the sun and moon shall be found to be in the
same degree of longitude, and in the same part of a degree. There will
also be an ecliptic new moon that is in conjunction with a solar
eclipse, or rather with a terrestrial eclipse. This will occur if, at
that time, both apexes of the first index, located below the center of
the clock, are hidden by the two segments of the circle extending from
the center of the mechanism through the lowest index.

And the eclipse will be greater and greater and, consequently, visible
in more regions of the earth, the more deeply the two pointers,
indicating the distance of the sun from its apogee, are hidden in the
center of the segments.

But whether the eclipse takes place in the head or in the tail of the
dragon, or whether it is north or south, is indicated by the small disk
of the sun attached to one of the two pointers hidden by the segments of
the circle. If, at that time, the little disk shall be found in the head
of the dragon inscribed on the plane of the dial, then the sun has been
snatched from the earth and ingloriously entombed, as it were, in the
huge jaw of the dragon. Then, ... the heavens themselves will lend aid
to the woeful pomp of the senseless funeral in full darkness by suddenly
lighting the unhappy lamps of the fixed stars. However, if the little
disk occupies the tail of the dragon on the mechanism, then the sun in
the heavens also, as if freed from the toils of the immense dragon's
tail, will emerge without difficulty.

The center of the eclipse will traverse the hemisphere of the earth
north of the solar path, always nearer to the pole of the ecliptic, in
proportion to the inclination of the disk to the north. On the other
hand, if the little disk inclines to the left semicircle, then the
people south of the solar path will enjoy the spectacle of the total
central eclipse.

But if the little disk remains neutral (inclining neither way) and
remains halfway between the two sections of the circle, then the
greatest solar eclipse will take place at the equator and those who live
near the poles of the ecliptic will not enjoy a trace of that eclipse.
This is because the half of the equatorial diameter enormously
outmeasures even the greatest apparent semidiameters of the sun and of
the moon, even taking as a norm the smallest horizontal parallax of the

What has been said about the true new moon is to be understood also,
proportionately, about the true full moon. For when, with respect to the
equations of the centers, the moon shall be distant on the mechanism by
a full semicircle from the sun (also in the heavens it will be truly in
opposition to the sun) there will be a true full moon. Likewise, the
moon in the heavens will be in eclipse if, at the time of opposition,
the pointers of the little index (which we mentioned before) situated
below the center of the clock are so far away from the belly of the
dragon that they are forced to lie under the two smaller segments of the
circle which, in all full moons, are always to be moved from the index
of the synodic moon to the region of that little index. As a matter of
fact, the closer the little pointers approach to the middle of the
segments, the more obscured it will be.

You will know, furthermore, that the eclipse of the moon occurs in the
head of the dragon if the disk of the little moon, attached to the other
point of the little index, is raised to the head of the dragon;
conversely, when the little disk of the moon inclines to the tail, the
eclipse is taking place in the tail of the dragon.

And, accordingly, when you observe the little moon of the index inclined
to one or other section of the circle, so also in the heavens, the
eclipse of the moon is only partial and the northern or the southern
part of the moon is illuminated.

The current time will indicate whether the lunar eclipse is visible or
not. As the new moon ecliptic falls during the day, the eclipse will not
be visible, since the earth denies a sight of the moon which is below
the horizon. But, conversely, if there are no clouds, the eclipse will
be visible anywhere, if the luminous bodies are ecliptically in
opposition at night.

Since lunar eclipses appear to all people as being of the same magnitude
and duration, and begin and dissipate at the same absolute moment of
time, I decided to reveal another facet of this spectacle on the right
side of the center of the clock (see chapter III above). There, at the
time of the true ecliptic full moon, as the pointer of the third little
index shows, you can ascertain the hours, etc., of duration, and the
inches of greatest obscuration. The little moon attached to the index is
a model of the actual eclipsed moon.


Thus, with the aid of this machine, solar and lunar eclipses of the past
can be recalled and future ones can be foreseen. Indeed, if the index of
prime minutes is speeded up by hand, whose wheel imparts motion to the
other indices and shields, then, the dials and openings will foretell
the year, month, day, hour, etc., of any future eclipse. I foresaw that
the times would thus be evolved too slowly, and that the clock wheels
would be considerably worn by repeated experiments (if, for instance, by
the rotation of the index of prime minutes, to whose period only a
single hour corresponds, the future new and full moon ecliptics were
being investigated). Therefore, I took care that the wheel which
immediately communicates motion to the index of the synodic moon should
be so fitted internally to the mechanism that by the reversal of any
external index, the wheel would be removed from its proper position;
whenever desired, it could be quickly and most accurately restored to
its proper place.

In this way, since the close meshing of the wheels is released, you can
extend the experiment for many years, even for many centuries. You have
only to guide with your hand the index of the synodic moon on the
circles, always intently observing whether, in the passage which this
index makes over the little index, both pointers of the little index are
hidden by the segments of the circle. Having observed this, look at the
index moved by hand, for if this has carried the solar disk halfway
between the two larger segments of the circle to the region of the
hidden little index, then you will know that eclipse will be a solar
eclipse. On the other hand, you will know that it will be a lunar
eclipse, if the index (moved by hand) has carried the moon, situated
between the two smaller segments of the circle, to the same region
(i.e., the hidden part of the circle). The solar disk and the lunar disk
alternately will reveal to you the circumstances of both eclipses. The
current year will be given by the Julian period, reducible to any
desired epoch, and, contained in the solar cycle, the golden number and
the Roman cycle. The month of the year and also the day of the month
will be indicated by the pointer of the little index, first on the right
side of the clock. And what I have said of future eclipses should be
equally understood of past eclipses, so long as the index, which can be
moved either way at will, is moved in reverse.

Finally, though 55 wheels were employed to carry so many dials, all are
driven by one source of power not exceeding the third part of a Germanic
hundred-weight which, suspended at the geometric height of five feet
(about the ordinary stature of a man), keeps the whole machine in
operation for a hundred days and more.

Although the machine repeats hours and quarter hours at will and,
consequently, the number of wheels and the rest of the apparatus
necessary for these functions is thereby increased, it has not grown to
an unwieldy size, however much one might erroneously imagine it to be.
It does not exceed the bulk of ordinary clocks hanging from a wall;
indeed, it scarcely equals these.

The entire machine, ready for operation, does not weigh more than 156
ounces, although it is made of steel or brass throughout and further
weighted with two bells and a rather large brass dial-plate.

Of course, there are many more things to be said, especially about the
mechanical structure of the wheels, but fearing to tire my kind reader
unduly by exceeding the bounds of a summary, I am forced to put an end,
though unwillingly, to this sufficiently shortened explanation of the
work. I have hope of giving satisfaction to many more when I shall have
communicated to the learned world another and completely new automatic
work, grander than this present one. It is already theoretically
completed in all its calculations, but still to be worked out
mechanically from the very beginning, if but God, thrice Best and
Greatest, bless the undertaking and mercifully grant life and health--to
whom be in, and from, and through all things, all honor and glory in
eternity and beyond.


The following works have been used in compiling the material for this
paper. They are frequently referred to in the text in shortened form.

     AMBROSI, FRANCESCO. _Scrittori ed artisti Trentini._ Trent:
     Giovanni Zippel, 1883.

     BONOMI, L. _Naturalisti, medici e tecnici Trentini._ Trent:
     privately printed, 1930.

     BORGHESI, FRANCESCO. _Novissima ac Perpetua Astronomica
     Ephemeris Authomatica Theorico-Practica._ Trent: Giovanni
     Battista Monauni, 1763(?).

     ---- _Novissimum Theorico-Practicum Astronomicum Authoma Juxta
     Pariter Novissimum Mundi Systema._ Trent: Giovanni Battista
     Monauni, 1764.

     ENGELMANN, MAX. Philipp Matthäus Hahn. Berlin: Verlag Fischer,

     ESPOSTI, ALFREDO DEGLI. La sala 'Innocente Binda' al Museo
     della Scienza e della Tecnica di Milano. _La Clessidra_ (July
     1960), anno 16, no. 7, pp. 18-21.

     FRANCH, LEONE. _La Valle di Non._ Trent, 1953.

     LLOYD, H. ALAN. _Some outstanding clocks over seven hundred
     years, 1250-1950._ London: Leonard Hill, 1958.

     MOSNA, EZIO. _Trento._ Trent, 1914.

     PERINI, AGOSTINO (compilatore). _Statistica del Trentino,
     Biblioteca Communale del Trentino._ Vol. 2, p. 57 (cons. 6,
     carta 9).

     PIAMONTE, GUISEPPE. _La nauna descritta al viaggiattore._
     Milan, 1829.

     PIPPA, LUIGI. Antonio Bartolomeo Bertolla. _La Clessidra_
     (January 1961), anno 17, no. 1, pp. 22-25.

     SAN CAJETANO, DAVID À. _Praktische Anleitung für Künstler, alle
     astronomische Perioden durch brauchbare bisher noch nie
     gesehene ganz neue Räderwerke mit Leichtigkeit vom Himmel
     unabweichlich genau auszuführen, sammt Erweiterung der Theorie
     des neuen Rädergebäudes._ Vienna: privately printed, 1793.

     TOVAZZI, GIANGRISOSTOMO. _Biblioteca Tirolese._ Vol. 2, art.
     329, MS. 168, pp. 406-407. Trent, 1780.

     VISCHER, GEORGE F. _Beschreibung mechanischer Kunstwerke,
     welche unter der Direktion und Anweisung M. Philipp Matth.
     Hahn, Pfarrers in Kornwestheim..._. Stuttgart: Mezler, 1774.

     VON BERTELE, HANS. The development of equation clocks. _La
     Suisse Horologere_ (1959-1961), parts 1 through 5.

     WENHAM, EDWARD. Tall case clocks. _The Antiquarian Magazine_
     (May 1927), vol. 8, no. 4, p. 33. [The Borghesi clock is
     illustrated only from a photograph of the Anderson Art
     Galleries in New York, and mislabeled "Astronomical Clock made
     in Jena, 1656, in elaborate mahogany case."]

       *       *       *       *       *


  PAPER 36


  _Robert M. Vogel_

                                                   EARLY CAREER     80

                                              THE BOLLMAN TRUSS     85

                                         W. BOLLMAN AND COMPANY     91

                                 FINAL USE OF THE BOLLMAN TRUSS     95

                                            KNOWN BOLLMAN WORKS     99

                                                   BIBLIOGRAPHY    104

_Robert M. Vogel_


[Illustration: Figure 1.--WENDEL BOLLMAN, C.E. (1814-1884). (_Photo
courtesy of Dr. Stuart Christhilf._)]

     _The development of structural engineering has always been as
     dependent upon the availability of materials as upon the
     expansion of theoretical concepts. Perhaps the greatest single
     step in the history of civil engineering was the introduction
     of iron as a primary structural material in the 19th century;
     it quickly released the bridge and the building from the
     confines of a technology based upon the limited strength of
     masonry and wood._

     _Wendel Bollman, self-taught Baltimore civil engineer, was the
     first to evolve a system of bridging in iron to be consistently
     used on an American railroad, becoming one of the pioneers who
     ushered in the modern period of structural engineering._

     THE AUTHOR: _Robert M. Vogel is curator of civil engineering in
     the Smithsonian Institution's Museum of History and

Wendel Bollman's name survives today solely in association with the
Bollman truss, and even in this respect is known only to a few older
civil and railroad engineers. The Bollman system of trussing, along with
those of Whipple and Fink, may be said to have introduced the great age
of the metal bridge, and thus, directly, the modern period of civil

Bollman's bridge truss, of which the first example was built in 1850,
has the very significant distinction of being the first bridging system
in the world employing iron in all of its principal structural members
that was used consistently on a railroad.

The importance of the transition from wood to iron as a structural and
bridge building material is generally recognized, but it may be well to
mention certain aspects of this change.

The tradition of masonry bridge construction never attained the great
strength in this country which it held in Europe, despite a number of
notable exceptions. There were several reasons for this. From the very
beginning of colonization, capital was scarce, a condition that
prevailed until well into the 19th century and which prohibited the use
of masonry because of the extremely high costs of labor and transport.
An even more important economic consideration was the rapidity with
which it was necessary to extend the construction of railways during
their pioneer years. Unlike the early English and European railways,
which invariably traversed areas of dense population and industrial
activity, and were thus assured of a significant financial return almost
from the moment that the first rail was down, the Baltimore and Ohio
and its contemporaries were launched upon an entirely different
commercial prospect. Their principal business consisted not so much in
along-the-line transactions as in haulage between principal terminals
separated by great and largely desolate expanses. This meant that income
was severely limited until the line was virtually complete from end to
end, and it meant that commencement of return upon the initial
investment was entirely dependent upon the speed of survey, graduation,
tunneling, and bridging.

[Illustration: Figure 2.--MODEL OF B. H. LATROBE'S TRUSS, built in 1838,
over the Patapsco River at Elysville (now Daniels), Maryland. (_Photo
courtesy of Baltimore and Ohio Railroad._)]

The need for speed, the general attenuation of capital, and the simple
fact that all the early railroads traversed thickly forested areas
rendered wood the most logical material for bridge and other
construction, both temporary and permanent.

The use of wood as a bridge material did not, of course, originate with
the railroads, or, for that matter, in this country. The heavily wooded
European countries--Switzerland in particular--had a strong tradition of
bridge construction in timber from the Renaissance on, and naturally a
certain amount of this technique found its way to the New World with the
colonials and immigrants.

America's highway system was meager until about the time the railroad
age itself was beginning. However, by 1812 there were, along the eastern
seaboard, a number of fine timber bridges of truly remarkable structural
sophistication and workmanship.

It was just previous to the advent of the railroads that the erection of
highway bridges in this country began to pass from an art to a science.
And an art it had been in the hands of the group of skilled but
unschooled master carpenters and masons who built largely from an
intuitive sense of proportion, stress, and the general "fitness of
things." It passed into an exact science under the guidance of a small
number of men trained at first in the scientific and technical schools
of Europe, and, after about 1820, in the few institutions then
established in America that offered technical instruction.

The increasing number of trained engineers at first affected highway
bridge construction not so much in the materials used but in the way
they were assembled. In a bridge designed by a self-taught constructor,
the cheapness of wood made it entirely feasible to proportion the
members by enlarging them to the point where there could be no question
as to their structural adequacy. The trained engineer, on the other
hand, could design from the standpoint of determining the entire load
and then proportioning each element according to the increment of stress
upon it and to the unit capacity of the material.

By the time railroads had started expanding to the West there had been
sufficient experience with the half dozen practical timber truss systems
by then evolved, that there was little difficulty in translating them
into bridges capable of supporting the initial light rail traffic.

In spite of its inherent shortcomings, wood was so adaptable that it met
almost perfectly the needs of the railroads during the early decades of
their intense expansion, and, in fact, still finds limited use in the

Early Career

Wendel Bollman was born in Baltimore of German parents in 1814. His
father was a baker, who in the same year had aided in the city's defense
against the British. Wendel's education, until about the age of 11, was
more or less conventionally gained in public and private schools in
Baltimore. He then entered into informal apprenticeship, first to an
apothecary in Sheperdstown, Virginia (now West Virginia), and then to
one in Harpers Ferry. In 1826 or 1827 he became ill and returned to
Baltimore for cure. From that time on his education was entirely

[Illustration: Figure 3.--TRUSSED BEAM.]

It is of interest, in light of his later career, to note that on the
Fourth of July 1828, he marched with other boys in a procession that was
part of the Baltimore and Ohio Railroad's cornerstone-laying ceremony.
Shortly afterward, he apprenticed himself to a carpenter for a brief
time, but when the work slacked off he obtained work with the B. & O.
The right-of-way had been graded for about five miles by that time, but
no rail was down. The boy was at first given manual work, but soon
advanced to rodman and rapidly rose as he gained facility with the
surveying apparatus. In the fall of 1829 he participated in laying the
first track. As his mother was anxious that he continue his education in
carpentry, he left the railroad in the spring of 1830 to again enter
apprenticeship. He finished, became a journeyman, helped build a
planter's mansion in Natchez, and returned to Baltimore in 1837 to
commence his own carpentry business. The next year, while building a
house in Harpers Ferry, he was asked to rejoin the B. & O. to rebuild
parts of its large timber bridge over the Potomac there, which had
fallen victim to various defects after about a year's use.

[Illustration: Figure 4.--SIMPLE BEAM of 50-foot span with three
independent trussing systems. Bollman's use of this method of support
led to the development of his bridge truss. This drawing is of a
temporary span used after the timber bridge at Harpers Ferry was
destroyed during the Civil War. (In Baltimore and Ohio Collection,
Museum of History and Technology.)]

Shortly after the Harpers Ferry bridge reconstruction, Bollman was made
foreman of bridges. It is apparent that, on the basis of his practical
ability, enhanced by the theoretical knowledge gained by intense
self-study, he eventually came to assist Chief Engineer Benjamin H.
Latrobe in bridge design. He later took this work over entirely as
Latrobe's attentions and talents were demanded in the location and
extension of the line between Cumberland and Wheeling.

[Illustration: Figure 5.--BOLLMAN'S ORIGINAL PATENT DRAWING, 1851. (In
National Archives, Washington, D.C.)]

The B. & O. did not reach its logical destination, Ohio (actually
Wheeling, West Virginia, on the east bank of the Ohio River) until 1853.
In the years following Bollman's return to the railroad, the design of
bridges was an occupation of the engineering staff second in importance
only to the location of the line itself. During this time Bollman
continued to rise and assume greater responsibilities, being appointed
master of road by Latrobe in 1848. In this position he was responsible
for all railroad property that did not move, principally the
right-of-way and its structures, including, of course, bridges.

The recognition of Bollman's abilities was in the well-established
tradition of the B. & O., long known as America's first "school of
engineering," having sponsored many early experiments in motive power,
trackwork, and other fundamental elements of railroad engineering. It
furnished the means of expression for such men as Knight, Wright,
Whistler, Latrobe, and Winans.

[Illustration: Figure 6.--PLAN OF HARPERS FERRY BRIDGE as built by
Latrobe. The second Winchester track was later removed.]

Of these pioneer civil and mechanical engineers, some were formally
trained but most were self-taught. Bollman's career on the B. & O. is of
particular interest not only because he was perhaps the most successful
of the latter class but because he was probably also the last. He may be
said to be a true representative of the transitional period between
intuitive and exact engineering. Actually, his designing was a composite
of the two methods. While making consistent use of mathematical
analysis, he was at the same time more or less dependent upon empirical
methods. For years, B. & O. employees told stories of his sessions in
the tin shop of the railroad's main repair facility at Mount Clair in
Baltimore, where he built models of bridges from scraps of metal and
then tested them to destruction to locate weaknesses. It seems most
likely, however, that the empirical studies were used solely as checks
against the mathematical.

[Illustration: Figure 7.--RECENT MODEL of Bollman's Winchester span.
Only two of the three lines of trussing are shown. The model is based on
Bollman's published description and drawings of the structure. (USNM
318171; Smithsonian photo 46941.)]

In the period when Bollman began designing--about 1840--there were fewer
than ten men in the country designing bridges by scientifically correct
analytical methods, Whipple and Roebling the most notable of this group.
By 1884, the year of Bollman's death, the age of intuitive design had
been dead for a decade or longer.

[Illustration: Figure 8.--THE BALTIMORE AND OHIO RAILROAD'S Potomac
River crossing at Harpers Ferry, about 1860. Bollman's iron "Winchester
span" of 1851 is seen at the right end of Latrobe's timber structure of
1836, which forms the body of the bridge. (_Photo courtesy of Harpers
Ferry National Historical Park._)]

The B. & O. was in every way a truly pioneer enterprise. It was the
first practical railroad in America; the first to use an American
locomotive; the first to cross the Alleghenies. The spirit of innovation
had been encouraged by the railroad's directors from the outset. It
could hardly have been otherwise in light of the project's elemental

The first few major bridges beyond the line's starting point on Pratt
Street, in Baltimore, were of rather elaborate masonry, but this may be
explained by the projectors' consciousness of the railroad's
significance and their desire for permanence. However, the
aforementioned economic factors shortly made obvious the necessity of
departure from this system, and wood was thereafter employed for most
long spans on the line as far as Harpers Ferry and beyond. Only the most
minor culverts and short spans, and those only in locations near
suitable quarries, were built of stone.

In addition to the economic considerations which prompted the company to
revert to timber for the major bridges, there were several situations in
which masonry construction was unsuitable for practical reasons. If
stone arches were used in locations where the grade of the line was a
relatively short distance above the surface of the stream to be crossed,
a number of short arches would have been necessary to avoid a very flat
single arch. In arch construction, the smaller the segment of a circle
represented by the arch (that is, the flatter the arch), the greater the
stress in the arch ring and the resulting horizontal thrust on the

[Illustration: Figure 9.--BOLLMAN SKEW BRIDGE at Elysville (now
Daniels), Maryland, built in 1853-1854. (_Photo courtesy of Maryland
Historical Society._)]

The piers for the numerous arches necessary to permit an optimum amount
of rise relative to the span would have presented a dangerous
restriction to stream flow in time of flood. By the use of timber
trusses such crossings could be made in one or two spans with, at the
most, one pier in the stream, thus avoiding the problem.

The principal timber bridges as far west as Cumberland were of Latrobe's
design. These were good, solid structures of composite construction, in
which a certain amount of cast iron was used in joints and wrought iron
for certain tension members. They were, however, more empirical than
efficient and, for the most part, not only grossly overdesigned but of
decidedly difficult fabrication and construction.

What is interesting about the Latrobian timber trusses, however, is the
effect they appear to have had upon Bollman's subsequent work in the
design of his own truss. This effect is evidenced by the marked analogy
between the primary structural elements of the two types. The Latrobe
truss at Elysville (fig. 2) was only partially a truss, inasmuch as the
greater part of the load was not carried from panel to panel, finally to
appear at the abutments as a pure vertical reaction, but was carried
from each panel (except the four at the center) directly to the bearing
points at the piers by heavy diagonal struts, after the fashion of the
famous 18th-century Swiss trusses of the Grubenmanns. It was a
legitimate structural device, and the simplest means of extending the
capacity of a spanning system. However, it was defective in that the
struts applied considerable horizontal thrust to the abutments,
requiring heavier masonry than would otherwise have been necessary.

It is quite likely that Latrobe did not have absolute confidence in the
various pure truss systems already patented by Town, Long, and others,
and preferred for such strategic service a structure in which the panel
members acted more or less independently of one another. It will be seen
that, similarly, the individual panel loads in Bollman's truss were
carried to the ends of the frame by members acting independently of one

The Bollman Truss

There had never been any question about the many serious inadequacies of
wood as a bridge material. Decay and fire risk, always present, were the
principal ones, involving continuous expenditure for replacement of
defective members and for fire watches. It was, in fact, understood by
the management and engineering staff of the B. & O. that their timber
bridge superstructures, though considered the finest in the country,
were more or less expedient and were eventually to be replaced. In this
regard it is not surprising that Latrobe, a man of considerable
foresight, had, at an early date, given serious thought to the possible
application of iron here.

[Illustration: Figure 10.--POTOMAC RIVER CROSSING of the Baltimore and
Ohio at North Branch, Maryland, built in 1856. There are three Bollman
deck trusses. (_Photo courtesy of Baltimore and Ohio Railroad._)]

[Illustration: Figure 11.--THE FINK TRUSS. (_Smithsonian photo

[Illustration: WENDEL BOLLMAN'S

Patent Iron Suspension Railroad Bridge.

The undersigned would inform the officers of Railroads and others, that
he is prepared to furnish Drawings and Estimates for Bridges, Roofs,
etc., on the plan of Bollman's Patent.

The performance of these bridges, some of which have been in use for six
years, has given entire satisfaction. Their simplicity of construction
renders repairs easy and cheap, and by a peculiar connection of the Main
and Panel Rods at the bottom of the Posts, all danger from the effects
of expansion, which has heretofore been the chief objection to Iron
Bridges, is entirely removed.

    Baltimore, Md.

Figure 12.--ADVERTISEMENT in the _Railroad Advocate_, August 1855.]

The world's first major iron bridge, the famed cast-iron arch at
Coalbrookdale, England, had been constructed in 1779. Its erection was
followed by rather sporadic interest in this use of the material. The
first significant use of iron in this country was in a series of small
trussed highway arches erected by Squire Whipple over the Erie Canal in
the early 1840's, over 60 years later. In these, as in most of the
earlier iron structures, an arch of cast iron was the primary support.
The thrust of the arches was counteracted by open wrought-iron links
with other wrought- and cast-iron members contributing to the truss

The Whipple bridges promoted a certain amount of interest in the
material. In the B. & O.'s annual report for the fiscal year 1849
appears the first record of Latrobe's interest in this important matter.
In the president's message is found the following, rather offhand,

     $6,183.19 have been expended toward the renewal of the Stone
     Bridges on the Washington Branch, carried off by the flood of
     Oct. 7th, 1847. Preparations are made and contracts entered
     into, for the reconstruction of the large Bridges at Little
     Patuxent and at Bladensburg which will be executed in a few
     months.... It is proposed to erect a superstructure of Iron
     upon stone abutments, at each place--with increased span, for
     greater security against future floods.

It is interesting to note that it was indeed Bollman trusses to which
the president of the railroad had referred. How much earlier than this
date Bollman had evolved his peculiar trussing system is not clear. The
certain influence of Latrobe's radiating strut system of trussing has
been mentioned. As likely an influence was another basic technique
commonly used to increase the capacity of a simple timber beam--that of
trussing--i.e., placing beneath the beam a rod of iron that was anchored
at the ends of the beam and held a certain distance below it at the
center by a vertical strut or post. This combination thus became a truss
in that the timber portion was no longer subject to a bending stress but
to a simple one of compression, the rod absorbing the tensile stress of
the combination. The effect was to deepen the beam, increasing the
distance between its extreme fibers and--by thus reducing the bending
moment--reducing the stress in them (see fig. 3).

[Illustration: Figure 13.--THE FOUR BOLLMAN SPANS at Harpers Ferry that
survived the Civil War. The spans were completed in 1862-1863. (_Photo
courtesy of Baltimore and Ohio Railroad._)]

It apparently occurred to Bollman that by extending the number of rods
in a longitudinal direction, this effect could be practically amplified
to such an extent as to be capable of spanning considerable distances.
He almost certainly did not at first contemplate an all-iron system, but
rather a composite one such as described. It is entirely likely that
such trussed beams, with multiple systems of tension rods, were used by
Bollman as bridging in temporary trestlework along the line as early as
1845 (see fig. 4).

It is impossible to say whether Bollman himself, or Latrobe, was struck
with the logic of further elaborating upon the system and,
simultaneously, translating the timber compression member into one of
cast iron. Cast iron would naturally have been selected for a member
that resisted a compressive stress, as it was considerably cheaper than
wrought iron. But more important, at that time wrought iron was not
available in shapes of sufficient sectional area to resist the
appreciable buckling stresses induced in long compression members. The
cost of building up members to sufficient size from the very limited
selection of small shapes then rolled would have been prohibitive.

The trussing rods, subjected to tension, were of wrought iron inasmuch
as the sectional area had only to be sufficient to resist the primary
axial stress.

The first all-iron Bollman truss was constructed over the Little
Patuxent River at Savage Factory, near Laurel, Maryland, in 1850. In the
chief engineer's report for the year 1850, Latrobe was able to state
that the truss had been completed and was giving "much satisfaction."
He went on at some length to praise the "valuable mechanical features"
embodied therein, and expressed great confidence that iron would become
as important a material in the field of civil engineering as it was in
mechanical engineering.

[Illustration: Figure 14.--THE HARPERS FERRY BRIDGE as completed after
the Civil War. It was used by the Baltimore and Ohio until 1894, and as
a highway bridge until 1936. (Photo 690, Baltimore and Ohio Collection,
Museum of History and Technology.)]

The cost of this first major Bollman bridge was $23,825.00. Its span was
76 feet. Latrobe's confidence was well placed. The Savage span and
another at Bladensburg may be considered successful pilot models, for,
in spite of a certain undercurrent of mistrust of iron bridges within
the engineering profession--due mainly to a number of failures of
improperly designed spans--Latrobe felt there was sufficient
justification for the unqualified adoption of iron in all subsequent
major bridge structures on the B. & O.

Almost immediately following completion of the Savage Bridge, Bollman
undertook the design of replacements for the large Patapsco River span
at Elysville (now Daniels), Maryland, and the so-called Winchester span
of the B. & O.'s largest and most important bridge, that over the
Potomac at Harpers Ferry. Harpers Ferry bridge, a timber structure, had
been designed by Latrobe and built in 1836-1837 by the noted bridge
constructor Lewis Wernwag. It was peculiar in having a turnout, near the
Virginia shore, whereby a subsidiary road branched off to Winchester
(see fig. 6). Only the single span on this line, situated between the
midriver switch and the shore, was slated for replacement, as the other
seven spans of the bridge had been virtually reconstructed in the decade
or so of their history and were in sound condition at the time.

The Winchester span (fig. 8), which was the first Bollman truss to
embody sufficient refinement of detail to be considered a prototype, was
completed in 1851. Bollman was extremely proud of the work, with perfect
justification it may be said. The 124-foot span was fabricated in the
railroad's extensive Mount Clair shops. It was subdivided into eight
panels by seven struts and seven pairs of truss rods. An interesting
difference between this span and Bollman's succeeding bridges was his
use of granite rather than cast iron for the towers. The span consisted
of three parallel lines of trussing to accommodate a common road in
addition to the single-track Winchester line.

The distinctive feature of the Bollman system was the previously
mentioned series of diagonal truss links in combination with a cast-iron
compression chord, which Bollman called the "stretcher." The spacing
between the chord and the junction of each pair of links was maintained
by a vertical post or strut, also cast.

[Illustration: Figure 15.--NORTH STREET (now Guilford Avenue) bridge,
Baltimore. In this transitional composite structure cast iron was used
only in the relatively short sections of the upper chord. For the long
unsupported compression members of the web system, standard wrought-iron
angles and channels were built up into a large section. The decorative
cast-iron end posts were non-structural. (Photo in the L. N. Edwards
Collection, Museum of History and Technology.)]

Much of the appeal of this design lay unquestionably in the sense of
security derived from the fact that each of the systems acted
independently to carry its load to the abutments. The lower chords,
actually nonfunctional in the primary structure, were included merely to
preserve the proper longitudinal spacing between the lower ends of the
struts. A certain lack of rigidity was inherent in the system due to
that very discontinuity which characterized its action; however, this
was compensated for by a pair of light diagonal stay rods crossing each
panel. These rods served the additional function of distributing
concentrated loads to adjacent struts much in the manner of the bridging
between floor joists in a building.

In the Winchester span the floor system was of timber for reasons of
economy. This was a very minor weakness inasmuch as any stick could be
quickly replaced, and without disturbing the function of the structure.
Bollman received a patent for his truss in January 1852, and in the same
year published a booklet describing his system in general and the
Harpers Ferry span in particular. Here, he first calls it a "suspension
and trussed bridge," which is indeed an accurate designation for a
system which is not strictly a truss because it has no active lower
chord. (The analogy to a suspension bridge is quite clear, each pair of
primary rods being comparable to a suspension cable.) Thereafter,
Bollman's invention was generally termed a suspension truss.


Bollman's 1852 publication was widely disseminated here and abroad and
studied with respectful interest by the engineering profession. Its
drawings of the structure were copied in a number of leading technical
journals in England and Germany. Although there is no record that the
type was ever reproduced in Europe, there can be little doubt that this
successful structural use of iron by the most eminent railroad in the
United States and its endorsement by an engineer of Latrobe's status
gave great impetus to the general adoption of the material. This
influence was certainly equal to that of Stephenson's tubular iron
bridge of 1850 over the Menai Strait, or Roebling's iron-wire suspension
bridge of 1855 over Niagara gorge. The Bollman design had perhaps even
greater influence, as the B. & O. immediately launched the system with
great energy and in great numbers to replace its timber spans; on the
other hand, Roebling's structure was never duplicated in railroad
service, and Stephenson's only once.

[Illustration: Figure 16.--_Left:_ CONJECTURAL SECTION of Bollman's
segmental wrought-iron column, about 1860, and section of the standard
Phoenix column; _right:_ Phoenix column as used in truss-bridge
compression members.]


By the late 1850's iron was well established as a bridge material
throughout the world. Once the previous fears of iron had been stilled
and the attention of engineers was directed to the interpretation of
existing and new spanning methods into metal, the Bollman truss began to
suffer somewhat from the comparison. Although its components were simple
to fabricate and its analysis and design were straightforward, it was
less economical of material than the more conventional panel trusses
such as the Pratt and Whipple types. Additionally, there was the
requisite amount of secondary metal in lower chords and braces necessary
for stability and rigidity.

A factor difficult to assess is Bollman's handling of his patent, which
was renewed in 1866. There is sufficient evidence to conclude that he
considered the patent valuable because it was based upon a sound design.
Therefore, he probably established a high license fee which, with the
truss's other shortcomings, was sufficient to discourage its use by
other railroads. As patron, the B. & O. had naturally had full rights to
its use.

An additional defect, acknowledged even by Bollman, arose because of the
unequal length of the links in each group except the center one. This
caused an unevenness in the thermal expansion and contraction of the
framework, with the result that the bridges were difficult to keep in
adjustment. This had the practical effect of virtually limiting the
system to intermediate span lengths, up to about 150 feet. For longer
spans the B. & O. employed the truss of another of Latrobe's assistants,
German-born and technically trained Albert Fink.

The Fink truss was evolved contemporaneously with Bollman's and was
structurally quite similar, being a suspension truss with no lower
chord. The principal difference was the symmetry of Fink's plan, which
was achieved by carrying the individual panel loads from the panel
points to increasingly longer panel units before having them appear at
the end bearings. This eliminated the weakness of unequal strains. The
design was basically a more rational one, and it came to be widely used
in spans of up to 250 feet, generally as a deck-type truss (see fig.

W. Bollman and Company

Bollman resigned from the Baltimore and Ohio in 1858 to form, with John
H. Tegmeyer and John Clark, two of his former B. & O. assistants, a
bridge-building firm in Baltimore known as W. Bollman and Company. This
was apparently the first organization in the United States to design,
fabricate, and erect iron bridges and structures, pioneering in what 25
years later had become an immense industry. The firm had its foundation
at least as early as 1855 when advertisements to supply designs and
estimates for Bollman bridges appeared over Tegmeyer's name in several
railroad journals (see fig. 12).

Bollman's separation from the B. & O. was not a complete one. The
railroad continued its program of replacing timber bridges with Bollman
trusses, and contracted with W. Bollman and Company for design and a
certain amount of fabrication. There is some likelihood that eventually
fabrication was entirely discontinued at Mount Clair, and all parts
subsequently purchased from Bollman.

The firm prospered, erecting a number of major railroad bridges in
Mexico, Cuba, and Chile. Operations ceased from 1861 to 1863 because of
difficult wartime conditions in the border city of Baltimore. Following
this, Bollman reentered business as sole proprietor of the Patapsco
Bridge and Iron Works.

[Illustration: QUINCY BAY BRIDGE

Bay (branch of the Mississippi River) at Quincy, Illinois. The pivot
draw-span was formed of two Bollman deck trusses supported at their
outer ends by hog chains. The bridge was built in 1867-1868 by the
Detroit Bridge and Iron Co., Bollman licensee. (Clarke, _Account of the
Iron Railway Bridge ... at Quincy, Illinois_.)]

The most noteworthy of Bollman's works in this period was a series of
spans at Harpers Ferry. The B. & O.'s timber bridge had been destroyed
by Confederate forces in June 1861, and the crossing was thereafter made
upon temporary trestlework. This was a constant source of trouble, with
continuing interruptions of the connection from high water, washouts,
and military actions. The annoyance and expense of this became so great
that the company decided to risk an iron bridge at the crossing. In July
and August 1862, two sections of Bollman truss, spans no. 4 and no. 5
were completed. As this occurred during the time when W. Bollman and
Company was inoperative, the work was produced at Mount Clair to
Bollman's design and, undoubtedly, erected under his supervision. Five
weeks later, on September 24, these and Bollman's famous Winchester span
of 1851 were blown up by the Confederates, and the line's business was
again placed at the mercy of trestling.

The spirit of the B. & O. administration indeed seems to have been
unshakable when, in the face of such heartbreaking setbacks, it
determined to again bridge the river with iron, even at the height of
the hostilities. In November, span no. 5 was erected, and by April 1863
nos. 3, 4, and 6 also. These were the four straight spans in midriver
between the "wide" (or "branch," or "wye") span and the span on the
Maryland shore over the Chesapeake and Ohio Canal (see fig. 13).
Although the wood floor system of these spans was burned for strategic
reasons by U.S. troops later in 1863, they survived the war.

In 1868 the remaining trestlework was replaced with Bollman trusses.
This magnificent structure served the railroad until 1894 when the
right-of-way was realigned at Harpers Ferry. However, the half used by
the common road remained in use until carried away by the disastrous
flood in 1936. The piers may still be seen.

During the prewar years, Bollman evolved a structural development of
most profound importance, which is usually associated with the Phoenix
Iron Works and its founder, Samuel J. Reeves. In the erection of a high
trestlework viaduct for the Havana Railroad, Bollman apparently became
concerned with the tensile weakness of cast iron when applied in long,
unsupported columns. Although a column is normally subjected to
compressive stresses, when the slenderness ratio--that is, the length
divided by the radius of gyration of the cross section--becomes great, a
secondary bending stress may be produced. If this stress becomes great
enough, the value of the tensile stress in one side of the column may
actually exceed the principal compressive stress, and a net effect of
tension result.

[Illustration: Figure 18.--OHIO RIVER CROSSING of the Baltimore and Ohio
at Benwood, West Virginia, completed in 1870. Bollman deck trusses were
used in the approaches on both sides. (Photo 693, Baltimore and Ohio
Collection, Museum of History and Technology.)]

[Illustration: Figure 19.--PATAPSCO RIVER crossing of the Baltimore and
Ohio between Thistle and Ilchester, Maryland. (Photo 695, Baltimore and
Ohio Collection, Museum of History and Technology.)]

As already mentioned, the few available rolled-iron shapes were of
relatively small area and quite unsuitable for use as columns unless
combined and built up in complex fabrications. The normal practice at
the time was to use cast compression members in iron bridges and
structures, with their sectional area so proportioned to the length that
a state of tension could not exist. In the case of long members, this
naturally meant that an excessive amount of material was used.

[Illustration: Figure 20.--TWO VIEWS OF BOLLMAN-BUILT "water-pipe truss"
that carries Lombard Street over Jones Falls in Baltimore. Built in

Bollman was conscious of the problem from his experience with the
stretchers and struts of his truss, and he must have been aware of the
great advantage which would be obtained by a practical method of forming
such members in wrought iron, the tensile resistance of which is
equivalent to the compressive. He eventually developed the forerunner of
what came to be known as the Phoenix form by having special segmental
wrought-iron shapes rolled by Morris, Tasker and Company of
Philadelphia, these shapes being combined into a circular section with
outstanding flanges for riveting together. The circular section is
theoretically the most efficient to bear compressive loading. A column
of any required diameter could be produced by simply increasing the
number of segments, the individual size of which never exceeded
contemporary rolling mill capacity (see fig. 16).

The design exhibits the inspired combination of functional perfection
and simplicity that seems to characterize most great inventions.

[Illustration: Figure 21.--THE HARPERS FERRY BRIDGE toward the end of
its career, carrying a common road over the Potomac. The westernmost
line of trussing and span no. 1 had been removed long before. View
through the Winchester span looking toward Maryland in 1933. (_Photo
courtesy of Harpers Ferry National Historical Park._)]

It may have been because he had no facilities for rolling that Bollman
communicated his idea to Reeves, although this seems illogical. At any
rate, Reeves and his associates patented the system extensively, and the
Phoenix column was eventually employed to the virtual exclusion of
cast-iron and other types of wrought-iron columns. By the end of the
19th century it began to pass from use, as mills became capable of
producing larger sections with properties relatively favorable to column
use and more adaptable to connection with other members.

Final Use of the Bollman Truss

The Bollman truss found occasional use elsewhere than on the B. & O.
lines, but generally only when erected on contract by Patapsco Bridge
and Iron Works. However, the fact that Bollman could profitably erect
this bridge in the severely competitive 1870's indicates that the harsh
criticism of the system by authorities of such stature as Whipple was
not necessarily justified. Bollman's advertisements, in fact, refer to
the favorable recommendations of other such renowned engineers as
Herman Haupt and M. C. Meigs.

[Illustration: Figure 22.--BOLLMAN DECK TRUSSES in the North River
Bridge built in 1873 at Mount Crawford, Virginia, on the Valley Railroad
of Virginia (B. & O.). Each end span is 98 ft. 6 in.; the river span is
148 ft. 9 in. (Photo 756, Baltimore and Ohio Collection, Museum of
History and Technology.)]

An interesting application of the system was in a drawbridge, formed of
two Bollman deck spans, over an arm of the Mississippi at Quincy,
Illinois (see fig. 17). The first iron bridge in Mexico was erected by
Bollman over the Medellín River about 1864. Another work of this period,
which attracted considerable attention, was a pair of bridges that
Bollman erected over North Carolina's Cape Fear River in 1867-1868.
These bridges were notable for their foundation on cast-iron cylinders,
sunk pneumatically. This was one of the first instances of the use of
the process in America, and the depth of 80 feet below the water surface
reached by one cylinder was considered remarkable for years afterward.

In the last active decade or so of his career, Bollman produced hundreds
of minor bridges and other structures. In 1873 he supplied the castings
for the splendid iron dome of Baltimore's City Hall and erected the
ingenious water-main truss which carries Lombard Street over Jones Falls
in that city. In this structure the top and bottom chords of the central
line of trussing are cast-iron water mains, bifurcated at the abutments,
and joined by cast- and wrought-iron web members (see fig. 20).

In the mid 1870's Bollman saw his truss pass into obsolescence. This was
due primarily to the generally increasing distrust of cast iron for
major structural members due to its brittleness, but advances in
structural theory, availability of a greater variety of rolled
structural shapes, and the increasing loading patterns of the period all

Savage, Maryland. The bridge was built elsewhere in 1852 and was moved
to this now-abandoned Baltimore and Ohio industrial siding in about

Although no Bollman trusses were built by Bollman or the B. & O. after
1875, those in use were only removed as required by heavier motive
power. The Harpers Ferry span, as noted, remained in full main-line
service until 1894. Bollman trusses on feeder lines were continued in
use until much later; a number of them on the Valley Railroad of
Virginia (see fig. 22) were not removed until 1923. However, only on the
most isolated spurs was the Bollman truss permitted to reach really ripe
age. The sole known remaining example (fig. 23) stands on such a
branch--ironically, at Savage, over the Little Patuxent, the site of the
first Bollman span. This is not the 1850 bridge, but one built in 1852
and moved to the present site 30 years later. The fate of the first span
is not known.

[Illustration: Figure 24.--HOT-WATER AND CHOCOLATE PITCHERS of the
10-piece, silver tea service presented to Bollman by his fellow
employees when he resigned from the Baltimore and Ohio in 1858. A
railroad motif was used throughout, each piece being circled at top and
bottom by a track, complete with rail of accurate section and ties.
Spouts are in simulation of hexagonal sheet-iron chimneys, with seams
riveted, and the handles are in the form of a surveyor's telescope. On
the various pieces are engraved the designs of the more important B. &
O. bridges. Throughout is a wonderful profusion of bits and objects of
railroadiana in low relief, high relief, and fully modeled. In Board of
Directors Room, Baltimore and Ohio Railroad Company, Baltimore, Md.
(_Photo courtesy of Baltimore and Ohio Railroad._)]

Known Bollman Works

(All B. & O. works listed were designed by Bollman and built by the
railroad, unless otherwise indicated.)

  Dates of   Location             Type     No. spans  Remarks
  service                                  / length
                                           of each

  1850-?     Savage, Md., Little  Bollman    1/76'    First Bollman truss
             Patuxent River       through             erected; granite towers;
                                  truss               cost, $23,825. B. & O. RR.

  1851-?     Bladensburg, Md.,    Bollman    1/?      Second Bollman truss
             Anacostia River      through             erected; granite towers;
                                  truss               cost, $19,430. B. & O. RR.

  1851-1862  Harpers Ferry, Va.,  Bollman    1/124'   Winchester span; first
             Potomac River        through             major Bollman truss; three
                                  truss               lines of truss; granite
                                                      towers; blown up by
                                                      Confederate Army on
                                                      September 24, 1862.
                                                      B. & O. RR.

  1851-?     Baltimore, Md.,      Trestle    --       Wood trestle bents with
             Carey Street                             wrought-iron diagonals.
                                                      First use of iron
                                                      structural members in
                                                      trestlework. Total length
                                                      76 feet. B. & O. RR.

  1852-      Savage, Md., Little  Bollman    2/±80'   Still standing. Moved to
             Patuxent River       through             Savage in 1888; original
                                  truss               location unknown. This and
                                                      succeeding Bollman trusses
                                                      use iron towers. B. & O.

  1852 (or   Marriottsville,      Bollman    1/50'    One of first Bollman
  1853)-?    Md., Patapsco River  truss               trusses with iron towers.
                                                      B. & O. RR.

  1853-?     Zanesville, Ohio,    Bollman    4/124'   Double track, Central Ohio
             Muskingum River      truss      (or      RR. Designed by Bollman;
                                             5/160')  built by Douglas, Smith &
                                                      Co., Zanesville.

  1854-      Elysville (now       Bollman    3/97'9"  Upper bridge, skew. Cost,
  1870(?)    Daniels),  Md.,      through             $24,477.59. B. & O. RR.
             Patapsco River       truss

  1854-1862  Monocacy, Md.,       Bollman    3/119'   Blown up September 8,
             Monocacy River       truss               1862; rebuilt in 1864.
                                                      Cost, $22,722.59.
                                                      B. & O. RR.

  1854-?     Eastern Ohio         Bollman    1/40'    C. O. RR. Section 76
                                  truss(?)            adjacent to 300-ft.

  1855-?     Bridgeville, Ohio,   Bollman    1/71'    C. O. RR.
             Salt Creek           deck truss

  Pre-1855-? Buffalo, N.Y.        --         --       Unidentified. Mentioned by
                                                      George Vose in Railroad
                                                      Advocate (June 9, 1855).

  1856-?     Elysville, Md.,      Bollman   3/111'    Lower Bridge. B. & O. RR.
             about 1-1/4 miles    through
             east of 1854         truss
             bridge, Patapsco

  Pre-1856-? Marriottsville,      Bollman   1/48'9"   Referred to as "Tunnel
             Md.                  truss(?)            Bridge" in B. & O. RR.
                                                      annual report, 1856.

  1856-?     Near Ijamsville,     "Iron     3/23'9"   Possibly trussed beams;
             Md., Bush Creek      girders"            mentioned in B. & O. RR.
                                                      annual report, 1856.

  1856-?     Near Ijamsville,     "Iron     2/23'9"   As above.
             Md., Bush Creek      girders"

  1856-      North Branch, Md.,   Bollman   3/142'    Partially destroyed in
  c.1862     Potomac River        deck truss          Civil War. B. & O. RR.

  1860-1906  Chile, Angostura     Bollman   4/115'    Chilean Railways.
             River                truss(?)            Designed and built by
                                                      Bollman. Replaced by
                                                      bridge built by French
                                                      firm of Schneider,
                                                      Cruesot & Co.

  1860-1910  Chile, Paine River   Bollman   1/?       As above.

  Post-      Ilchester, Md.,      Bollman   1/?       B. & O. RR.
  1860-?     Patapsco River       through

  Pre-1861-? Cuba                 Bridges   --        All bridges on Havana
                                  and                 RR., including iron
                                  station             station house and bridge
                                  house               at Guines. Designed and
                                                      built by Bollman.

  Pre-1861-? Cuba                 Bridges   --        All bridges on Cienfuegos
                                                      RR., Cárdenas RR., and
                                                      Havana & Matanzas RR.
                                                      Designed and built by

  Pre-1861-? Cuba                 Trestle   --        Trestle with wrought-iron
                                                      columns (the first such
                                                      ever constructed). Havana
                                                      RR. Designed and built by

  1862-1862  Harpers Ferry, Va.,  Bollman   2/160'    Span no. 3 (July 24) and
             Potomac River        through             span no. 4 (August 21).
                                  truss               Blown up September 24,
                                                      1862. B. & O. RR.

  1862-1936  Harpers Ferry, Va.,  Bollman   1/160'    Span no. 5 (November).
             Potomac River        through             B. & O. RR.

  1863-1936  Harpers Ferry, Va.,  Bollman   3/160'    Spans nos. 3, 4, and 5.
             Potomac River        through             Constructed previous to
                                  truss               April 1863. B. & O. RR.

  1863-?     Berwyn, Md., Paint   Bollman   ?         Iron bridge mentioned in
             Branch               truss(?)            B. & O. RR. annual report,

  1863(4?)-? Clinton, Iowa,       Pivot     1/360'    Built by Detroit Bridge
             Mississippi River    draw                & Iron Works. It was the
                                                      longest in the world at
                                                      time of completion.
                                                      Designed by Bollman.

  1864-?     Laurel, Md.,         Bollman   ?         Replaced stone arch that
             Patuxent River       truss               had been washed out. B. &
                                                      O. RR.

  c. 1864-?  Near Veracruz,       Bollman   1/115'    Veracruz & Jucaro RR.
             Mexico, Medellín     through             First iron bridge in
             River                truss               Mexico. Designed and
                                                      built by Bollman.

  1864-?     Near Point of        Bollman   1/80'(?)  Iron bridge mentioned in
             Rocks, Md., Back     truss(?)            B. & O. RR. annual
             Creek                                    report, 1864. The span
                                                      length given is that of
                                                      previous stone arch.

  1864-?     Bladensburg, Md.,    Bollman   1/?       Span for second track, to
             Anacostia River      truss               match 1851 span. B. & O.

  1868-?     Cape Fear, N.C.,     Bollman   2/146'6"  Wilmington Railway Bridge
             Northeast Branch,    truss(?)  1/164'    Co. This bridge was
             Cape Fear River                pivot     connected to that over
                                            draw/150' the Northwest Branch by
                                                      2-1/2 miles of timber
                                                      trestling. Designed and
                                                      built by Bollman.

  1868-?     Cape Fear, N.C.,     Bollman   1/217'(?) See above.
             Northwest Branch,    truss(?)  pivot
             Cape Fear River                draw/150'

  1868-?     Quincy, Ill.,        Bollman   4/85'     Chicago, Burlington &
             Quincy  Bay (in      deck      pivot     Quincy RR. The pivot draw
             Mississippi River)   truss     draw/190' was formed of two 85-ft.
                                                      simple Bollman deck spans
                                                      whose outer ends hung from
                                                      hog chains. Designed by
                                                      Bollman; built by Detroit
                                                      Bridge & Iron Works.

  1869-      Baltimore, Md.,      Warren     2/100'   North Avenue Bridge.
  c.1892     over Jones Falls,    truss      2/55'6"  Composite double
             B. & O. RR., and                         intersection truss;
             Northern Central                         timber top chord and
             RR.                                      posts, wrought-iron lower
                                                      chord and ties. In 55-ft.
                                                      spans, both chords
                                                      timber. Cost, $73,588.
                                                      Built by Bollman.

  c.1869-    Harpers Ferry, Va.,  Bollman    4/?      Canal span (no. 8), Wide
  1936       Potomac River        through             span  (no. 2), Winchester
                                  truss               span, and West End span.
                                                      Destroyed by flood in
                                                      1936. B. & O. RR.

  1870-      Baltimore, Md.,    Iron         1/108'   Charles Street Bridge.
  c.1895     Jones Falls        "Isometrical          Three lines of trussing.
                                truss"                Cost, $20,297. Built by
                                (probably             Bollman.
                                Pratt type)

  1870-      Bellaire, Ohio-      Bollman    9/107'-  In approaches; 2 spans on
  1893 &     Benwood W. Va.,      deck       125'     Ohio side; 7 on West
  1900       Ohio River           truss               Virginia side. B. & O. RR.

  1870-      Belpre, Ohio-        Bollman    16/?     In approaches; 7 spans on
  c.1895     Parkersburg, W.      deck                Ohio side; 9 on West
             Va., Ohio River      truss               Virginia side. B. & O. RR.

  1870-?     Elysville, Md.,      Bollman    4/?      Skew; replacement of
             Patapsco River       through             Upper Bridge(?). B. & O.
                                  truss               RR.

  1871-      Baltimore, Md.,      Timber     ?        Decker Street (now
  c.1895     Jones Falls          and iron            Maryland Avenue) Bridge.
                                  truss               Cost, $24,975. Built by

  1871-      Baltimore, Md.,      Warren     1/100'   North Avenue Bridge.
  c.1892     over Northern        truss               Composite double
             Central RR. at                           intersection truss;
             Jones Falls                              cast-iron top chord and
                                                      posts; wrought-iron
                                                      bottom chord and ties.
                                                      West span. Built by

  1873-1923  Cave Station, Va.,   Bollman    1/98'7"  Valley Railroad of
             Middle River         deck       1/63'5"  Virginia (B. & O.) Bridge
                                  truss               no. 120. The main span
                                                      was a Whipple deck truss.
                                                      Replaced with plate
                                                      girders. Designed by

  1873-1923  Mount Crawford,      Bollman    2/98'6"  Valley Railroad of
             Va., North River     deck       1/148'9" Virginia (B. & O.) Bridge
                                  truss               no. 117. Designed by

  1873-1923  Verona, Va., North   Bollman    3/98'7"  Valley Railroad of
             River                deck                Virginia (B. & O.) Bridge
                                  truss               no. 129. The main span
                                                      was a 147-ft. Whipple
                                                      deck truss. Designed by

  1873-?     Wadesville, Va.,     Bollman    1/147'8" Span length given is that
             Opequon Creek        through             of previous wood span
                                  truss               that burned in 1862. B.
                                                      & O. RR.

  c. 1873-   Baltimore, Md.       Iron roof  ?        First Presbyterian
                                  trusses             Church. Built by Bollman;
                                                      possibly designed by him.

  1873-      Baltimore, Md.       Cast-iron           City Hall. Cost, $12,840.
                                  stairs              Designed by George A.
                                                      Frederick, architect;
                                                      built by Bollman.

  1873-      Baltimore, Md.       Cast-iron           Dome of the City Hall.
                                  framework           Cost, $70,525. Designed
                                                      by George A. Frederick;
                                                      built by Bollman.

  1875-      Baltimore, Md.,      Iron truss 1/?      Fayette Street Bridge.
  c.1913     Jones Falls                              Cost, $9,396. Built by

  1876-      Baltimore, Md.,      "Single-   1/?      Canton Avenue (now Fleet
  c.1913     Jones Falls          beam iron           Street) Bridge. Cost,
                                  bridge"             $8,904. Built by Bollman.

  1876-      Baltimore, Md.,      "Single-   1/?      Eastern Avenue Bridge.
  c.1913     Jones Falls          beam iron           Cost, $12,382. Built by
                                  bridge"             Bollman.

  1877-      Baltimore, Md.,      Pratt and  1/88'6"  Lombard Street Bridge.
             Jones Falls          bowstring           Three lines of truss;
                                  truss               two outer trusses,
                                                      composite cast- and
                                                      wrought-iron polygonal
                                                      Pratt type; center
                                                      composite bowstring with
                                                      Pratt-system web. Both
                                                      chords are cast-iron
                                                      water mains, bifurcated
                                                      at the end bearings;
                                                      cast-iron posts and
                                                      wrought-iron ties. In
                                                      service. Cost, $7,632.
                                                      Designed by Jas. Curran,
                                                      Baltimore water
                                                      department; built by

  1877-      Baltimore, Md.,      Iron truss  1/?     Bath Street Bridge. Cost,
  c.1913     Jones Falls                              $4,172. Built by Bollman.

  1879-?     Baltimore, Md.       Drawbridge  1/?     Over entrance to City
                                                      Dock. Cost, $13,182.
                                                      Built by Bollman.

  1879-      Baltimore, Md.,      Warren     2/173'9" North Street (now
  c.1930     over Jones Falls     truss               Guilford Avenue) Bridge.
             and railroad                             Composite trusses;
             tracks                                   cast-iron top chord and
                                                      end posts; wrought-iron
                                                      bottom chord and web
                                                      members. Cost, $38,772.45.
                                                      Built by Bollman;
                                                      designed by Latrobe.

  1881-1960  Baltimore, Md.,      Wrought-   1/?      Union Avenue Bridge.
             (Woodberry),         iron Pratt          Built by Bollman;
             Jones Falls          truss               possibly designed by him.

  ?-?        Harpers Ferry, Va.,  Bollman    1/148'   Arsenal Branch, B. & O.
             Arsenal Canal        through             RR. Skew type. Span
                                  truss               length is that of
                                                      previous timber span.

  ?-?        Baltimore, Md.,      Bollman    2/?      B. & O. RR.
             Gwynns Falls         through


_A history and description of the Baltimore and Ohio Railroad by a
citizen of Baltimore._ Baltimore, 1853.

Baltimore and Ohio Railroad Company. _A list of the officers and
employees of the Baltimore and Ohio Railroad for November, 1857._
Baltimore, 1857.

----. _Third annual report of the president and directors to the
stockholders of the Baltimore and Ohio Rail Road Company._ Baltimore:
1829. (Also the fourth through 38th annual reports. Baltimore,

----. _Baltimore and Ohio exhibits at the Century of Progress._ Chicago,

_Biographical cyclopedia of representative men of Maryland and the
District of Columbia._ Baltimore, 1879.

BOLLMAN, WENDEL. _Iron suspension and trussed bridge as constructed for
the Baltimore and Ohio Rail Road Co. at Harper's Ferry, and on the
Washington branch of this road._ Baltimore, 1852.

----. Letter to John W. Garrett dated June 17, 1862. In files of
Division of Mechanical and Civil Engineering, United States National
Museum, Washington, D.C.

----. _Report of Mr. Bollman in relation to Central Ohio Rail Road._
Baltimore, 1854.

BRYANT, WILLIAM C. _Picturesque America._ New York, 1874.

CLARKE, THOMAS CURTIS. _An account of the iron railway bridge across the
Mississippi River at Quincy, Illinois._ New York, 1869.

COLBURN, ZERAH. American iron bridges. _Minutes of the proceedings of
the Institution of Mechanical Engineers_ (1863), vol. 22, pp. 540-573.

CONDIT, CARL. _American building art:--The nineteenth century._ New
York: Oxford Press, 1960.

GRAY, GEORGE E. Notes on early practice in bridge building.
_Transactions of the American Society of Civil Engineers_ (1897), vol.
37, pp. 2-16.

GREINER, JOHN E. The American railroad viaduct--Its origin and
evolution. _Transactions of the American Society of Civil Engineers_
(1891), vol. 25, pp. 349-372.

LANG, PHILIP GEORGE. Bollman trusses on Valley of Virginia Branch will
soon be memories. _Baltimore and Ohio Magazine_ (October 1923), pp.

----. The old Baltimore and Ohio bridge crossing the Potomac River at
Harpers Ferry, West [sic] Virginia. _Engineering News-Record_ (September
17, 1931), p. 446.

MALEZIEUX, EMILE. _Travaux publics des Etats-Unis d'Amerique en 1870._
Paris, 1873.

MCDOWELL, W. H. Unpublished engineer's report to the president and
directors of Wilmington Railway Bridge Company, Wilmington, North
Carolina, dated March 12, 1868. Typewritten copy in files of Division of
Mechanical and Civil Engineering, U.S. National Museum, Washington, D.C.

SMITH, CHARLES SHALER. _Comparative analysis of the Fink, Murphy,
Bollman and triangular trusses._ Baltimore, 1865.

SMITH, WILLIAM P. _The book of the great railway celebrations of 1857._
Baltimore, 1858.

TYRRELL, HENRY G. _History of bridge engineering._ Chicago, 1911.

WHIPPLE, SQUIRE. _Bridge building._ Albany, New York, 1869.

       *       *       *       *       *


  PAPER 37


  _Edwin A. Battison_

_Edwin A. Battison_


    _Among the earliest known examples of screw-thread cutting machines
    are the screw-cutting lathe of 1483, known only in pictures and
    drawings, and an instrument of the traverse-spindle variety for
    threading metal, now in the Smithsonian Institution, dating from the
    late 17th or early 18th century. The author shows clearly their
    evolution from something quite specialized to the present-day tool.
    He has traced the patents for these instruments through the early
    1930's and from this research we see the part played by such devices
    in the development of the machine-tool industry._

    THE AUTHOR: _Edwin A. Battison is associate curator of mechanical
    and civil engineering in the Smithsonian Institution's Museum of
    History and Technology._

Directness and simplicity characterize pioneer machine tools because
they were intended to accomplish some quite specialized task and the
need for versatility was not apparent. History does not reveal the
earliest forms of any primitive machines nor does it reveal much about
the various early stages in evolution toward more complex types. At best
we have discovered and dated certain developments as existing in
particular areas. Whether these forms were new at the time they were
first found or how widely dispersed such forms may have been is unknown.
Surviving evidence is in the form of pictures or drawings, such as the
little-known screw-cutting lathe of 1483 (fig. 1) shown in _Das
mittelalterliche Hausbuch_.

This lathe shows that its builder had a keen perception of the necessary
elements, reduced to bare essentials, required to accomplish the object.
Present are the coordinate slides often credited to Henry Maudslay. His
slides are not, of course, associated with the spindle; neither is there
any natural law which compels them to guide the tool exactly parallel
with the axis of revolution. In this sense the screw-cutting lathe in
the _Hausbuch_ is superior because it is in harmony with natural law and
can generate a true cylinder, whereas Maudslay's lathe can only transfer
to the work whatever accuracy is built into it.

In principle this machine shown in the _Hausbuch_ is very advanced as we
see when we follow the design through to the present time. The artist,
whose drawings give us our only knowledge of the machine, himself was
obviously not very familiar with the details of its function. Reference
to figure 1 shows that the threads on the lead screw and on the work,
wind in opposite directions. This must be an error in delineation since
the two are closely coupled together without any intervening mechanism
so that the only possible result on the work must be a thread winding in
the same direction as on the original screw. The work also is shown
threaded for its entire length; this cannot be accomplished with any one
location of the cross-slide. We are left with the question of whether
this slide was used in two locations or whether the artist, possibly
working from notes or an earlier rough sketch, failed to show an
unthreaded portion on one end or the other of the work.

MASTER-SCREW TYPE of thread-cutting machine. From the inconsistencies,
such as right- and left-hand threads on master and work, it appears that
the artist had scant insight into actual function. From plate 62 of _Das
mittelalterliche Hausbuch, nach dem Originale im Besitze des Fürsten von
Waldburg-Wolfegg-Waldsee, im Auftrage des Deutschen Vereins für
Kunstwissenschaft, herausgegeben von Helmuth Th. Bossert und Willy F.
Storck_ (Leipzig: E. A. Seemann, 1912).]

Of at least equal importance with the lead screw and work and their
relationship to each other is the tool-support with its screw-adjusted
cross-slide (fig. 2). Just how this was attached to the frame of the
machine so that it placed the tool at a suitable radius is again a
questionable point. The very well-developed cutting tool is sharpened to
a thin, keen edge totally unsuited for cutting metal but ideal for use
on a softer, fibrous substance: undoubtedly wood, in this instance.
Unfortunately, the angle at which the artist chose to show us this
cutter is not a view from which it is possible to judge whether or not
the tool has been made to conform to the helix angle of the thread to be
cut. This cross-slide, in conjunction with the traversing work spindle,
gives us a machine having two coordinate slides yielding the same effect
as the slide rest usually attributed to Henry Maudslay at the end of the
18th century. Actually, an illustration of coordinate slides independent
of the spindle had been published as early as 1569 by Besson[1] and
knowledge of them widely disseminated by his popular work on mechanics.
These slides are shown as part of a screw-cutting machine with a
questionably adequate connection, by means of cords, between the master
screw and the work.

It was the author's pleasure recently to obtain for the Smithsonian
Institution and identify a small, nicely made, brass instrument which
had been in two collections in this country and one collection in
Germany as an unidentified locksmith's tool (fig. 3). This proved to be
an instrument of the traverse-spindle variety for threading metal.
Fortunately, all essential details were present including a cutter (A in
figure 4); this instrument was identified by the signature "Manuel
Wetschgi, Augspurg." The Wetschgis were a well-known family of gunsmiths
and mechanics in Augsburg through several generations. Two bore the
given name Emanuel: the earlier was born in 1678 and died in 1728. He
was quite celebrated in his field of rifle making and became chief of
artillery to the Landgrave of Hesse-Kassel shortly before his death in
his 51st year. Little is known of the later Emanuel Wetschgi except that
he was at Augsburg in 1740. Tentative attribution of the instrument has
been made to the earlier Emanuel, chiefly on the basis of his recognized
position as an outstanding craftsman.

[Illustration: Figure 2.--CROSS-SLIDE for the thread-cutting lathe of
_Das mittelalterliche Hausbuch_, shown in figure 1. It is remarkable not
only for its early date, but also for its high state of development with
a crossfeed screw which had not become universally accepted 300 years
later. The cutter, shown out of its socket, is obviously sharpened for
use on wood.]

In several respects this little machine differs from its predecessor of
the _Hausbuch_, as might be expected when allowance is made for the
generations of craftsmen who undoubtedly worked with such tools over the
roughly 200 years of time separating them. Another factor to consider
when comparing these two machines is that one was used on metal, the
other probably only on wood. Therefore, it is not surprising to find on
the later machine an outboard or "tailstock" support for the work. The
spindle of this support has to travel in unison with the work-driving
spindle so that it is not an unexpected discovery to find that it is
spring-loaded. Figure 5 shows how this spring may be adjusted to
accommodate various lengths of work by moving the attachment screw to
various holes in both the spring and in the frame. Also visible in the
same illustration is a rectangular projection at the other end of the
spring which engages a mating hole in the "tailstock" spindle to prevent
its rotation.

[Illustration: Figure 3.--SMALL THREAD-CUTTING LATHE which was made to
be held in a vise during use. It was found as shown here, with only the
operating crank missing. The overall length is approximately 12 inches,
depending on the adjustment of parts. (Smithsonian photo 46525B.)]

Figure 6 shows the traversing spindle and nut removed from the machine.
Provision has been made for doing this so easily that there is every
reason to believe that, originally, there were various different spindle
and nut units which could be interchangeably used in the machine.
Additional evidence tending to support this concept exists in the
cutting tool (fig. 4), which must have been intended for serious work as
it has been carefully fitted in its unsymmetrical socket. The cutting
blade of this tool, which works with a scraping rather than a true
cutting action, is too wide to form a properly proportioned thread when
used with the existing lead screw. This may well indicate that the tool
was made for use with a lead of coarser pitch, now lost.

[Illustration: Figure 4.--THE WORKING AREA of figure 3, showing the tool
and signature. (Smithsonian photo 46525A.)]

Perhaps the most startling feature of this machine when compared with
the machine of the _Hausbuch_, is the absence of a cross-slide for
adjusting the tool. Possibly this can be explained by the blunt scraping
edge on the tool. In actual use, recently, to cut a sample screw, using
a tool similar to the one found in the machine (fig. 7), it was found
advantageous to be free of a cross-slide and thus be able to feed the
tool into the work by feel rather than by rule, as would be done with a
slide rest. In this way, it was possible to thread steel without
tearing, as the cutting pressure could readily be felt and the tool
could release itself from too heavy a cut. Size on several screws could
be repeated by setting the tool to produce the desired diameter when its
supporting arm came to rest against the frame of the machine. The screws
used in the machine itself were apparently made in just such a way. They
were not cut with a die as the thread blends very gradually into the
body of the screw without the characteristic marks left by the cutting
edges of a die. Threads cut with a single-point tool controlled by a
cross-slide usually end even more abruptly than those cut by a die,
while it would be quite simple with a machine of the nature we are
considering to bring the thread to a gentle tapering end as seen in
figure 8 (another view of the screw A in fig. 3) by gradually releasing
the pressure necessary to keep the tool cutting as the end of the
thread was approached.

against the work, showing the method and range of adjustment. Note the
rectangular projection to engage a mating socket in the spindle, to
prevent spindle rotation. (Smithsonian photo 46525.)]

[Illustration: Figure 6.--WORK SPINDLE AND ITS NUT removed from the
machine to illustrate how easily another spindle and nut of different
pitch could be substituted. (Smithsonian photo 46525C.)]

That machines of this general type having the lead screw on the axis of
the work were competitive with other methods and other types of machines
over a long period of time may be seen from figures 9 and 10. The
machine, left front in figure 9 and in more intimate detail in figure
10, can be seen to differ little from that shown in _Das
mittelalterliche Hausbuch_ of 1483. The double work-support is, of
course, a great improvement, while the tool-support is regressive since
it lacks a feed screw.

The development of engineering theory, coupled with the rising needs of
industry, particularly with the advent of the Industrial Revolution,
brought about accelerated development of screw-cutting lathes through
the combination of screw-cutting machines with simple lathes as seen in
figure 9 and in detail in figure 11. One important advance shown here
is driving the machine by means of a cord or band so that any means of
rotary power could be applied, not just hand or foot power. Of greater
interest and technical importance to this study is the provision, seen
to better advantage in figure 11, for readily changing from one master
lead screw to another. This had already been achieved in the Manuel
Wetschgi machine, as far as versatility is concerned, although not in
quite such a convenient way.

[Illustration: Figure 7.--THREAD OF MODERN FORM recently cut, using the
old screw and nut but with a new tool. The material threaded is
carbon-steel drill rod. (Smithsonian photo 49276A.)]

Figure 12, the headstock of another and more advanced lathe than shown
in figures 9 and 11 but of the same type, shows "keys" (D), each of
which is a partial nut of different pitch to engage with a thread of
mating pitch. The dotted lines in figure 13 show the engaged and
disengaged positions of one of these keys, and figure 14 shows the
spindle with the various leads, C. At D is a grooved collar to be
engaged by the narrow key shown in operating position at the left in
figure 12 for the purpose of controlling the endwise movement of the
spindle when used for ordinary turning instead of thread-cutting. In
return for greater convenience and freedom from the expense of the many
separate spindles, as typified by the Wetschgi machine, a sacrifice has
been made in the length of the thread which can be cut without

[Illustration: Figure 8.--BINDING SCREW seen at A in figure 3, showing
the long smooth fadeout of the thread below the shoulder. (Smithsonian
photo 49276.)]

[Illustration: Figure 9.--MAKING SCREWS IN FRANCE in the third quarter
of the 18th century. From _L'Encyclopédie, ou dictionnaire raisonné des
sciences, des arts et des métiers ... receuil de planches sur les
sciences, les arts libéraux, et les arts méchaniques, avec leur
explication_ (Paris: 1762-1772), vol. 9, plate 1.]

[Illustration: Figure 10.--DETAILS OF THE MACHINE in the left foreground
of figure 9, showing the crude tool-support without screw adjustment.
From _L'Encyclopédie_, vol. 9, plate 2.]

This reduction in the length that could conveniently be threaded was no
great drawback on many classes of work. This can be realized from figure
16 which shows a traverse-spindle lathe headstock typical of the
mid-19th century. During the years intervening between the machines of
figures 12 and 16, the general design was greatly improved by removing
the lead screws from the center of the spindle. This made possible a
shorter, much stiffer spindle and supported both ends of the spindle in
one frame or headstock rather than in separate pieces attached to the
bed. The screws were now mounted outside of the spindle-bearings, one at
a time, while the mating nuts were cut partially into the circumference
of a disk which could be turned to bring any particular nut into working
position as required. With this arrangement, a wide variety of leads
either right or left hand could be provided and additional leads could
be fitted at any future time. Screw-cutting lathes of this design were
popular for a very long time with instrument makers and opticians who
had little need to cut screws of great length.

[Illustration: Figure 11.--DETAILS OF THE THREADING LATHE seen in the
right foreground of figure 9 showing the method of drive and support for
the work. From _L'Encyclopédie_, vol. 9, plate 1.]

The demands of expanding industry for greater versatility in the
production of engineering elements late in the 18th century set the
stage for the evolution of more complex machines tending to place the
threaded spindle lathes in eclipse. Maudslay's lathe of 1797-1800 (fig.
15) appeared at this time when industry was receptive to rapid
innovation. Unfortunately, the gearing which once existed to connect the
headstock spindle with the lead screw has long been lost. At this time
it is quite difficult to say with certainty whether the original gear
set offered a variety of ratios, as was true of slightly later Maudslay
lathes, or a fixed ratio. The plausibility of the fixed ratio theory is
supported by the very convenient means, seen in figure 15, for removing
the lead screw in preparation for substitution of one of another pitch.
All that is required is to back off its supporting center at the
tailstock end and withdraw the screw from its split nut[2] and from the
driving clutch near the headstock. This split nut also would have to be
changed to one of a pitch corresponding to that of the screw. While more
expensive than a solid nut, it neatly circumvents the need (and saves
the time involved) to reverse the screw in order to get the tool back to
the point of beginning preliminary to taking another cut. David
Wilkinson's lathe of 1798 (fig. 17) which was developed in Rhode Island
at the same time shows the same method of mounting and driving the
master screw. At least in the United States, this method of changing the
lead screw instead of using change gears remained popular for many
years. Examples of this changeable screw feature are to be found in the
lathes constructed for the pump factory of W. & B. Douglas Company,
Middletown, Connecticut,[3] in the 1830's. Middletown, at that time one
of the leading metal-working centers in one of the chief industrial
States, had been for many years the site of the Simeon North arms
factory which rivaled Whitney's. In this atmosphere, it is reasonable to
expect that machinery constructed by local mechanics, as was the custom
in those days, would reflect the most accepted refinements in machine

[Illustration: Figure 12.--WELL-DEVELOPED EXAMPLE of lathe headstock
having several leads on the spindle and provision for mounting the work
or a work-holding chuck on the spindle. Adapted from _L'Encyclopédie_,
vol. 10, plate 13.]

[Illustration: Figure 13.--END VIEW OF THE HEADSTOCK seen in figure 12,
showing the keys or half nuts which engage the threaded spindle, in
engaged and disengaged positions. From _L'Encyclopédie_, vol. 10, plate

[Illustration: Figure 14.--SPINDLE OF FIGURES 12 AND 13, showing the
several leads and the many-sided seat for the driving pulley. Note the
scale of feet. From _L'Encyclopédie_, vol. 10, plate 16.]

Roughly twenty years later, Joseph Nason of New York patented[4] the
commercially very important "Fox" brassworker's lathe (fig. 18). While
this does have a ratio in the pair of gears connecting the work spindle
and master screw, it is clear from the patent that various pitches are
to be obtained by changing screws, not by changing gears. The patent
sums it up as follows:

     A nut upon the end of the stud ... is unscrewed when the guide
     screw is to be removed or changed. The two wheels ... should have
     in their number of teeth a common multiple. They are seldom or
     never removed and their diameters are made dissimilar only for the
     purpose of giving to the guide screw a slower rate of motion than
     that of the mandrel whereby it may be made of coarser pitch than
     that of the screw to be cut and its wear materially lessened.

The introduction of gearing between the spindle and the lead screw, for
whatever purpose, could not help but introduce variable factors caused
by inaccuracies in the gears themselves and in their mounting. These
were of little consequence for common work, particularly when coupled to
a screw which, itself, was of questionable accuracy. The increasing
refinements demanded in scientific instruments and in machine tools
themselves after they had reached a relatively stable form dictated that
attention be dedicated to improved accuracy of the threaded components.

[Illustration: Figure 15.--MAUDSLAY'S WELL-KNOWN screw-cutting lathe of
1797-1800, showing the method of mounting and driving changeable master
screws. (_Photo courtesy of The Science Museum, London._)]

LATHE, typical of the mid-19th century, showing the traverse spindle,
interchangeable lead screws, and semicircumferential nut containing
several leads. The nut may be brought into engagement by the lever at
top rear of the headstock. This releases the end thrust control on the
spindle simultaneously with engagement of the nut. (Smithsonian photo

patented in the United States in 1798. Note the ready facility with
which the lead screw may be exchanged for another and the same means of
supporting and driving as in figure 15. (U.S. National Archives photo.)]

An attack on this problem, which interestingly reverts to the
fundamental principle of motion derived from a master screw without the
intervention of other mechanism (fig. 19), is covered by a patent[5]
issued to Charles Vander Woerd, one-time superintendent of the Waltham
Watch Company. The problem is well stated in the patent:

     This invention relates to the manufacture of leading screws to be
     used for purposes requiring the highest attainable degree of
     correctness in the cutting of the screw-threads of said screw ...
     as, for example, in machines for ruling lines in glass plates to
     produce refraction [sic] gratings for the resolution of the lines
     of the solar spectrum, such machines being required to rule many
     thousands of lines on an inch of space by a marking device which is
     reciprocated over the glass plate and is fed by the action of a
     leading screw after the formation of each line. Great difficulty
     has been experienced in constructing a leading screw for this and
     other purposes, in which the thread is so nearly correct as to
     produce no perceptible variation in the microscopic spaces between
     the ruled lines or gratings.... Various causes prevent the
     formation of a thread on the rod or blank, which is absolutely
     uniform and accurate from end to end of the rod. Among other causes
     are the variations of temperature from time to time, the
     imperfections of the operating leading screw, the springing of the
     leading screw and of the rod that is being threaded, and other
     unavoidable causes, all of which, although apparently trivial and
     producing only slight variations in the thread at different parts
     of the rod or blank, are of sufficient moment to be seriously
     considered when a screw of absolute accuracy is desired.

[Illustration: Figure 18.--NASON'S LATHE, patented in 1854, showing a
master lead screw driven at less than work speed so that the master
could be of a coarser and more durable pitch than the work. U.S. patent

It is interesting to note in figure 19 that Vander Woerd's machine, to
avoid the problems outlined in his patent, has returned to a starkly
simple design. We are not told, however, how he originated this master
screw which is used to produce the accurately threaded work pieces.
Later generations, in the search for ever-greater accuracy, also
returned to the fundamental simplicity of a master screw as we shall see
when we consider the refinements in mechanism necessary to the extended
development of the automobile and the airplane.

[Illustration: Figure 19.--VANDER WOERD'S PATENT, seen here, covered the
combination of a master screw, toolslide and work in a rigid frame to be
supported and driven by outside means of no required precision. U.S.
patent 293930 dated February 1884.]

As the power and speed of automobiles and aircraft increased, critical
parts became more highly stressed. Gears and threaded parts were
particularly troublesome details of the mechanism because of the
stresses concentrated in them, and, in the case of gears, because of the
internal and external stresses originating in minute deviations from the
ideal of tooth form and spacing. The problems were not entirely new but
had hitherto been solved by increasing the size of the parts, an avenue
of limited utility to designers in these fields where total weight as
well as the effects of mass and inertia are so important. By making
these parts of heat-treated steel, the strength could be made suitable
while the size and mass of the parts were kept within bounds. The
necessary processes of heat-treating were not always applicable to
finished parts as they sometimes destroyed both finish and accuracy.
Grinding, which was well developed for the simple plane, cylindrical,
and conical surfaces so widely used in mechanisms, had to be extended to
threads and gears so that they could be finished after heat-treating.
Sometimes the gear teeth themselves were ground; for other applications
it was sufficient to improve the accuracy of the gear cutters.

[Illustration: Figure 20.--A HOB-GRINDING MACHINE patented in 1932 and
incorporating the master-screw principle. Carl G. Olson's U.S. patent

Attempts to produce gear hobs free of the imperfections and distortions
introduced by heat treatment led to another return to the use of the
master lead screw. Figure 20 illustrates a machine having this feature
which was patented in 1932 by Carl G. Olson.[6] In speaking of the
spindle-driving mechanism disclosed in earlier patents, the patent goes
on to say:

     This driving mechanism includes an integral spindle 20, one
     extremity thereof being designed for supporting a hob 22 and the
     other extremity thereof being formed so as to present a lead screw
     24. The spindle 20 is mounted between a bearing 26 and a bearing
     28, the latter bearing providing a nut in which the lead screw 24
     rotates.... From the description thus far given it will be apparent
     that the rotation of the lead screw 24 within the bearing or nut 28
     will cause the hob to be moved axially, the lead of the screw 24
     being equal to the lead of the thread in the hob.

Claim 8 which concludes the descriptive portion of the patent states in

     In a hob grinding machine of the class described, a rotary work
     supporting spindle, means for effecting longitudinal movement of
     the spindle, a tool holder for supporting a grinding wheel in
     operative position with respect to the work supported by the
     spindle during the rotary and longitudinal movement thereof, ...

Even before this patent was applied for, another patent was pending for
the purpose of modifying the pitch of the lead screw without the use of
change gears in spite of the wide acceptance of such gear mechanisms for
over a hundred years.

[Illustration: Figure 21.--A HOB-GRINDING MACHINE OF 1933, showing use
of the master screw with a modifier but without change gears. Carl G.
Olson's U.S. patent 1901926.]

[Illustration: Figure 22.--A SINE-BAR DEVICE to modify the effective
lead of a master lead screw without introducing a complex mechanism
which would be both difficult to make and to operate within the required
close limits. Carl G. Olson's (1933) U.S. patent 1901926.]

Figure 21 shows a plan view[7] of the machine, and figure 22 a detailed
view of the sine-bar mechanism actuated by the master screw, 6, to
modify the effective pitch of the lead screw in accordance with the
realities of practice as stated in the preamble of the patent:

     This invention relates to material working machines, and
     particularly to machines such as hob grinders and the like, wherein
     the work is reciprocated through the agency of a lead screw.

     In the manufacture of hobs it is common practice to employ the same
     machine for grinding hobs of varied diameters, and in order to
     employ such a machine in this manner the pitch of the lead screw,
     thereof, which actuates the work carrier, must conform to the axial
     pitch of the hob to be ground. This will be readily apparent when
     it is understood that the helix angles of hobs vary in accordance
     with their diameters and, consequently, the difference between the
     normal pitch and the axial pitch correspondingly varies. While the
     requirement for the normal pitch may be the same for hobs of
     different diameters, it is necessary to change the axial pitch in
     accordance with a change in the hob diameter, and this axial pitch
     of the hob is equal to the pitch of the lead screw which actuates
     the work carrier in grinding machines heretofore used. Hence, in
     order to adapt such machines to cover a wide range of leads, it is
     necessary to provide a large number of interchangeable lead screws
     and obviously this represents a large investment, and the
     interchanging of these screws requires the expenditure of
     considerable time in setting up the machine for each job.

Thread-grinding machines were being designed concurrent with the
development of hob-grinding machines. Many were entirely concerned with
features peculiar to the problems of wheel-dressing and to automatic
characteristics. An invention to embody the use of a master screw and
concerned with the precision grinding of worm threads, for use in
gearing, was patented by Frederick A. Ward in this era.[8] That part of
the invention pertaining to the use of a master screw, "a rotary work
holder mounted on said carriage and provided with a driving spindle, an
exchangeable master screw and stationary nut detachably secured to said
spindle and head,..." is shown in figure 23.

[Illustration: Figure 23.--DETAILS OF A WORK SPINDLE WITH WORK, showing
the use of a master lead screw to control the pitch of a precision worm
thread being ground. From the 1933 U.S. patent 1899654, of F. A. Ward's
worm-grinding machine.]

Machines embodying the principle of the master lead screw are found in
constant use by industry at the present time for specialized
application. Whenever technological changes again reopen the topic of
thread-cutting to a new degree of accuracy or call for a reevaluation of
popular methods for any other reason, we may expect to see another
resurgence of the master-screw method, for no other design eliminates so
many variables or rests on such firm and fundamental natural principles
as the machine of _Das mittelalterliche Hausbuch_ of 1483, the earliest
such machine now known.

       *       *       *       *       *


   [1]  JACQUES BESSON, _Des instruments mathématiques, et méchaniques,
        servants à l'intelligence de plusiers choses difficiles, &
        necessaires à toutes républiques_, 1st ed. (Orleans, 1569).
        [Also available in later editions in French, German, and

   [2]  J. FOSTER PETREE, introduction, _Henry Maudslay, 1771-1831, and
        Maudslay Sons and Field, Ltd._ (London: The Maudslay Society,

   [3]  _American Machinist_ (September 28, 1916), vol. 45, no. 13,
        pp. 529-531.

   [4]  U.S. patent 10383 issued to Joseph Nason of New York, January 3,

   [5]  U.S. patent 293930 issued to Charles Vander Woerd of Waltham,
        Massachusetts, February 19, 1884.

   [6]  U.S. patent 1874592, filed June 8, 1929, issued to C. G. Olson of
        Chicago, Illinois, August 30, 1932, and assigned to the Illinois
        Tool Works, also of Chicago.

   [7]  U.S. patent 1901926, filed February 16, 1928, issued to C. G.
        Olson of Chicago, Illinois, March 21, 1933, and assigned to the
        Illinois Tool Works, also of Chicago.

   [8]  U.S. patent 1899654, filed August 31, 1931, issued to F. A. Ward
        of Detroit, Michigan, February 28, 1933, and assigned to the
        Gear Grinding Company of Detroit, Michigan.

       *       *       *       *       *

Typographical Corrections

  Page 107: "... servants à l'intelligence de plusieurs choses difficiles,
            & nécessaires ..." (had "a," "plusiers," "necessaires")

       *       *       *       *       *


  PAPER 38


  _Robert A. Chipman_

                          ELECTROSTATIC INSTRUMENTS BEFORE 1800    123


                          ELECTRICAL INSTRUMENTATION, 1800-1820    125

                                            OERSTED'S DISCOVERY    126


                                        CHRONOLOGY AND PRIORITY    127

                           ORIGINAL ELECTROMAGNETIC MULTIPLIERS    129

                                                    CONCLUSIONS    135

                                                ACKNOWLEDGMENTS    136

_Robert A. Chipman_


created by Schweigger, Poggendorf and Cumming in 1821, made for an
exhibit in the Museum of History and Technology, Smithsonian
Institution. (Smithsonian photo 49493.)]

    _The history of the early stages of electromagnetic instrumentation
    is traced here through the men who devised the theories and
    constructed the instruments._

    _Despite the many uses made of voltaic cells after Volta's
    announcement of his "pile" invention in 1800, two decades passed
    before Oersted discovered the magnetic effects of a voltaic circuit.
    As a result of this and within a five-month period, three men,
    apparently independently, announced the invention of the "first"
    electromagnetic instrument. This article details the merits of their
    claims to priority._

    THE AUTHOR: _Robert A. Chipman is chairman of the Department of
    Electrical Engineering at the University of Toledo in Toledo, Ohio,
    and consultant to the Smithsonian Institution._

Electrostatic Instruments before 1800

It is the fundamental premise of instrument-science that a device for
detecting or measuring a physical quantity can be based on any
phenomenon associated with that physical quantity. Although the
instrumentation of electrostatics in the 18th century, for example,
relied mainly on the phenomena of attraction and repulsion and the
ubiquitous sparks and other luminosities of frictional electricity, even
the physiological sensation of electric shock was exploited
semiquantitatively by Henry Cavendish in his well-known anticipation of
Ohm's researches. Likewise, Volta in 1800[1] described at length how the
application of his pile to suitably placed electrodes on the eyelids, on
the tongue, or in the ear, caused stimulation of the senses of sight,
taste and hearing; on the other hand, he reported that electrodes in the
nose merely produced a "more or less painful" pricking feeling, with no
impression of smell. The discharges from the Leyden jars of some of the
bigger frictional machines, such as van Marum's at Leyden, were found by
1785 to magnetize pieces of iron and to melt long pieces of metal

The useful instruments that emerged from all of this experience were
various deflecting "electrometers" and "electroscopes" (the words were
not carefully distinguished in use), including the important goldleaf
electroscope ascribed to Abraham Bennet in 1787.[3]

In 1786, Galvani first observed the twitching of the legs of a dissected
frog produced by discharges of a nearby electrostatic machine, thereby
revealing still another "effect" of electricity. He then discovered that
certain arrangements of metals in contact with the frog nerves produced
the same twitching, implying something electrical in the frog-metal
situation as a whole. Although Galvani and his nephew Aldini drew from
these experiments erroneous conclusions involving "animal electricity,"
which were disputed by Volta in his metal-contact theory, it is
significant from the instrumentation point of view that the frog's legs
were unquestionably by far the most sensitive detector of metal-contact
electrical effects available at the time. Without their intervention the
development of this entire subject-area, including the creation of
chemical cells, might have been delayed many years. Volta himself
realized that the crucial test between his theory and that of Galvani
required confirming the existence of metal-contact electricity by some
electrical but nonphysiological detector. He performed this test
successfully with an electroscope, using the "condensing" technique he
had invented more than a decade earlier.

Instrumenting Voltaic or Galvanic Electricity, 1800-1820

In his famous letter of March 20, 1800, written in French from Como,
Italy, to the president of the Royal Society in London, Volta made the
first public announcement of both his "pile" (the first English
translator used the word "column"), and his "crown of cups" (the same
translator used "chain of cups" for Volta's "couronne de tasses"). The
former consisted of a vertical pile of circular disks, in which the
sequence copper-zinc-pasteboard, was repeated 10 or 20 or even as many
as 60 times, the pasteboard being moistened with salt water. The "crown
of cups" could be most conveniently made with drinking glasses, said
Volta, with separated inch-square plates of copper and zinc in salt
water in each glass, the copper sheet in one glass being joined by some
intermediate conductor and soldered joints to the zinc in the next

Volta considered the "crown of cups" and the "pile" to be essentially
identical, and as evidences of the electrical nature of the latter,

    ... if it contains about 20 of these stories or couples of metal, it
    will be capable not only of emitting signs of electricity by
    Cavallo's electrometer, assisted by a condenser, beyond 10° or 15°,
    and of charging this condenser by mere contact so as to make it emit
    a spark, etc., but of giving to the fingers with which its
    extremities (the bottom and top of the column) have been touched
    several small shocks, more or less frequent, according as the
    touching has been repeated. Each of these shocks has a perfect
    resemblance to that slight shock experienced from a Leyden flask
    weakly charged, or a battery still more weakly charged, or a torpedo
    in an exceedingly languishing state, which imitates still better the
    effects of my apparatus by the series of repeated shocks which it
    can continually communicate.[4]

The "effects" provided by Volta's pile and crown-of-cups are therefore
electroscope deflection, sparks, and shocks. Later in the letter, he
describes the stimulation of sight, taste, and hearing as noted earlier,
but nowhere does he mention chemical phenomena of any kind, or the
heating of a wire joining the terminals of either device. Hence, except
for the additional physiological responses, he adds nothing to the
catalog of observations on which instruments might be based. His
familiarity with the moods of the torpedo (electric eel) seems to be

The reading of Volta's letter to the Royal Society on June 26, 1800, its
publication in the Society's _Philosophical Transactions_ (in French)
immediately thereafter, and its publication in English in the
_Philosophical Magazine_ for September 1800,[5] gave scientists
throughout Europe an easily constructed and continuously operating
electric generator with which innumerable new physical, chemical, and
physiological experiments could be made. Editor-engineer William
Nicholson read Volta's letter before its publication and, by the end of
April, he and surgeon Anthony Carlisle had built a voltaic pile.
Applying a drop of water to improve the "connection" of a wire lying on
a metal plate, they happened to notice gas bubbles forming on the wire,
and pursued the observation to the point of identifying the electrical
decomposition of water into hydrogen and oxygen.

Within two or three years innumerable electrochemical reactions had been
described, some of which, one might think, could have served as
operating principles for electrical instruments. Although the phenomena
of gas formation and metal deposition were in fact widely used as crude
indicators of the polarity and relative strength of voltaic piles and
chemical cells during the period 1800-1820 (and the gas bubbles were
made the basis of a telegraph receiver by S. T. Soemmering), the
quantitative laws of electrolysis were not worked out by Faraday until
after 1830, and not until 1834 was he satisfied that the electrolytic
decomposition of water was sufficiently well understood to be made the
basis for a useful measuring instrument. Describing his
water-electrolysis device in that year, he wrote:

    The instrument offers the only _actual measurer_ [italics his] of
    voltaic electricity which we at present possess. For without being
    at all affected by variations in time or intensity, or alterations
    in the current itself, of any kind, or from any cause, or even of
    intermissions of actions, it takes note with accuracy of the
    quantity of electricity which has passed through it, and reveals
    that quantity by inspection; I have therefore named it a

In passing, Faraday commented that the efforts by Gay-Lussac and Thenard
to use chemical decomposition as a "measure of the electricity of the
voltaic pile" in 1811 had been premature because the "principles and
precautions" involved were not then known. He also noted that the
details of _metal deposition_ in electrolysis were still not
sufficiently understood to permit its use in an instrument.[7]

The heating of the wires in electric circuits must have been observed so
early and so often with both electrostatic and voltaic apparatus, that
no one has bothered to claim or trace priorities for this "effect." The
production of incandescence, however, and the even more dramatic
combustion or "explosion" of metal-foil strips and fine wires has a good
deal of recorded history. Among the first to burn leaf metal with a
voltaic pile was J. B. Tromsdorff of Erfurt who noted in 1801 the
distinctly different colors of the flames produced by the various common
metals. In the succeeding few years, Humphry Davy at the Royal
Institution frequently, in his public lectures, showed wires glowing
from electric current.

Early electrical instrumentation based on the heating effect took an
unusual form. Shortly after 1800, W. H. Wollaston, an English M.D.,
learned a method for producing malleable platinum. He kept the process
secret, and for several years enjoyed an extremely profitable monopoly
in the sale of platinum crucibles, wire, and other objects. About 1810,
he invented a technique for producing platinum wire as fine as a few
millionths of an inch in diameter, that has since been known as
"Wollaston wire." For several years preceding 1820, no other instrument
could compare the "strengths" of two voltaic cells better than the test
of the respective maximum lengths of this wire that they could heat to
fusion. One can sympathize with Cumming's comment in 1821 about "the
difficulty in soldering wires that are barely visible."[8]

Electrical Instrumentation, 1800-1820

The 20 years following the announcement of the voltaic-pile invention
were years of intense experimental activity with this device. Many new
chemical elements were discovered, beginnings were made on the
electrochemical series of the elements, the electric arc and
incandescent platinum wires suggested the possibilities of electric
lighting, and various electrochemical observations gave promise of other
practical applications such as metal-refining, electroplating, and
quantity production of certain gases. Investigators were keenly aware
that all of the available means for measuring and comparing the
_electrical_ aspects of their experiments (however vaguely these
"electrical aspects" may have been conceived), were slow, awkward,
imprecise, and unreliable.

The atmosphere was such that prominent scientists everywhere were ready
to pounce immediately on any reported discovery of a new electrical
"effect," to explore its potentialities for instrumental purposes. Into
this receptive environment came H. C. Oersted's announcement of the
magnetic effects of a voltaic circuit, on July 21, 1820.[9]

[Illustration: Figure 2.--"GALVANOMETER" WAS THE NAME given by Bischof
to this goldleaf electrostatic instrument in 1802, 18 years before
Ampère coupled the word with the use of Oersted's electromagnetic
experiment as an indicating device.]

Oersted's Discovery

Many writers have expressed surprise that with all the use made of
voltaic cells after 1800, including the enormous cells that produced
the electric arc and vaporized wires, no one for 20 years happened to
see a deflection of any of the inevitable nearby compass needles, which
were a basic component of the scientific apparatus kept by any
experimenter at this time. Yet so it happened. The surprise is still
greater when one realizes that many of the contemporary natural
philosophers were firmly persuaded, even in the absence of positive
evidence, that there _must_ be a connection between electricity and
magnetism. Oersted himself held this latter opinion, and had been
seeking electromagnetic relationships more or less deliberately for
several years before he made his decisive observations.

His familiarity with the subject was such that he fully appreciated the
immense importance of his discovery. This accounts for his employing a
rather uncommon method of publication. Instead of submitting a letter to
a scientific society or a report to the editor of a journal, he had
privately printed a four-page pamphlet describing his results. This, he
forwarded simultaneously to the learned societies and outstanding
scientists all over Europe. Written in Latin, the paper was published in
various journals in English, French, German, Italian and Danish during
the next few weeks.[10]

In summary, he reported that a compass needle experienced deviations
when placed near a wire connecting the terminals of a voltaic battery.
He described fully how the direction and magnitude of the needle
deflections varied with the relative position of the wire, and the
polarity of the battery, and stated "From the preceding facts, we may
likewise collect that this conflict performs circles...." Oersted's
comment that the voltaic apparatus used should "be strong enough to heat
a metallic wire red hot" does not excuse the 20-year delay of the

Beginnings of Electromagnetic Instrumentation

The mere locating of a compass needle above or below a suitably oriented
portion of a voltaic circuit created an electrical instrument, the
moment Oersted's "effect" became known, and it was to this basic
juxtaposition that Ampère quickly gave the name of galvanometer.[11] It
cannot be said that the scientists of the day agreed that this
instrument detected or measured "electric current," however. Volta
himself had referred to the "current" in his original circuits, and
Ampère used the word freely and confidently in his electrodynamic
researches of 1820-1822, but Oersted did not use it first and many of
the German physicists who followed up his work avoided it for several
years. As late as 1832, Faraday could make only the rather noncommittal
statement: "By current I mean anything progressive, whether it be a
fluid of electricity or vibrations or generally progressive forces."[12]

Nevertheless, whatever the words or concepts they used, experimenters
agreed that Oersted's apparatus provided a method of monitoring the
"strength" of a voltaic circuit and a means of comparing, for example,
one voltaic battery or circuit with another.

It was perfectly clear, from Oersted's pamphlet, that if a compass
needle was deflected clockwise when the wire of a particular voltaic
circuit lay above it in the magnetic meridian, the same needle would
_also_ be deflected clockwise if the wire was turned end-for-end and
placed _below_ the compass needle, without changing the rest of the
circuit. Anyone perceiving this fact might deduce, as a matter of logic,
that if the wire of the circuit was first passed above the needle, in
the magnetic meridian, then folded and returned in a parallel path below
the needle, the deflecting effect on the needle would be repeated, and a
more sensitive indicator would result, assuming that any additional wire
introduced has not affected the "circuit" excessively.

Since 1821, historical accounts of the origins of electromagnetism seem
to have limited their credit assignments for the conception and
observation of this electromagnetic "doubling" effect (or "multiplying"
effect, if the folding is repeated) to three persons. Almost without
exception, however, these accounts have given no specific information as
to precisely what each of these three accomplished, what physical form
their respective creations took, what experiments they performed, and
what functional understanding they apparently had of the situation. The
usual statement is simply that a compass needle was placed in a coil of
wire.[13] The main purpose of the present review is to recount some of
these details.

The following are the three candidates whose names are variously
associated with the "invention" of the first constructed electromagnetic
instrument, or "multiplier," or primitive galvanometer.

JOHANN SALOMO CHRISTOPH SCHWEIGGER (1779-1857) in 1820 had already been
editor for several years of the _Journal für Chemie und Physik_, and was
professor of chemistry at the University of Halle.

JOHANN CHRISTIAN POGGENDORF (1796-1877) in 1820 had only recently
entered the University of Berlin as a student following several years as
an apothecary's apprentice and a brief period as an apothecary. Four
years later, he succeeded Gilbert as editor of the influential _Annalen
der Physik_, a position he held for more than 50 years.

JAMES CUMMING (1771-1861) in 1820 was professor of chemistry at
Cambridge University.

Chronology and Priority

The earliest established date in the "multiplier" record is September
16, 1820, when Schweigger read his first paper to the Natural Philosophy
Society of Halle. There seems to be no reason to doubt that this report
justifies the frequently used label "Schweigger's multiplier."

In an exuberant support of Schweigger's position, Speter[14] with no
mention of Cumming and no hint of "invention" details, shows that
Poggendorf in 1821 admitted Schweigger's priority, but suffered some
lapse of memory 40 years later when writing sections of his biographical
dictionary, leaving a distinct suggestion that the invention was his.
Further confusion for later generations resulted from some ambiguous
entries in the _Allgemeine Deutsche Biographie_ of 1888. The name
"multiplier" seems not to have originated with Schweigger himself.
Speter credits it to Meineke as "working" editor of Schweigger's
_Journal_, but Seebeck seems to have used it much earlier.[15]

Conceding priority of conception to Schweigger (Cumming has not been a
real competitor on this point) does not alter the fact that all three
seem to have reached their results independently of one another, that
the first work of each on this subject was published within a period of
five months, that there were significant differences in their
conceptions of the uses and the optimum design of their devices and that
between them they provided an adequate foundation for the subsequent
development of the galvanometer to become the primary
electrical-measuring instrument.

In the matter of publication, Schweigger, as editor of what was
popularly called Schweigger's _Journal_, had an obvious advantage, and
presented his experiments beginnings on page 1 of the first volume of
his _Journal_ for 1821, published January 1 of that year.[16] Oersted's
paper had appeared two volumes previously. He began by referring to
Oersted's discovery as "the most interesting to be presented in a
thousand years of the history of magnetism." He was, in fact, so
impressed with the epochal nature of Oersted's achievement that he
commemorated it by giving his _Journal_ a second title so that "volume
one" of the new title could begin in the year after Oersted's

Poggendorf, as a relatively junior student, had no such easy access to
publicity, but he had a staunch admirer in one of his professors, Paul
Erman at the University of Berlin. Erman added a seven-page postscript
on Poggendorf's invention to his book _Outline of the Physical Aspects
of the Electro-chemical Magnetism Discovered by Professor Oersted_,
published before April 1821,[17] with an introductory paragraph:

    Herr Poggendorf, who is one of the most excellent ornaments of the
    lecture room and laboratory of the University here, carried out a
    very coherent and well-conceived investigation of electro-chemical
    magnetism, leading step-by-step to a method of amplifying this
    activity-phenomenon by means of itself.

The postscript begins by referring to the "condenser [_Kondensator_]
just brought to my attention by Herr Poggendorf" and explains that he
cannot release his treatise "without preliminary announcement of this
subject of the highest importance." (It can be inferred from the text
that the name "condenser" was chosen because of the device's enhancing
of magnetic measurements analogously to the enhancing of electric
measurements by Volta's electrostatic "condenser.")

Immediately on reading the book, Schweigger published extracts, mainly
of the postscript, with indignant comments on Erman's remissness (or
worse) in having failed to mention Schweigger's prior work.[18]

However, Erman was not alone in his unawareness, if it was that, of
Schweigger's discovery.

Rival editor Gilbert of the _Annalen der Physik_ reviewed Erman at much
greater length than Schweigger, reprinting most of the postscript with
evident enthusiasm, and stating in his preamble that the invention is
attributed to "a young physicist studying here in Berlin, Herr
Poggendorf."[19] Only in a footnote is the reader directed to another
footnote in the next article in the volume, where Gilbert finally states
that he "cannot leave unmentioned the fact that this amplifying
apparatus seems to be due to Herr Professor Schweigger." He then quotes
rather fully from Schweigger's first two papers.[16] Oersted in 1823
explained the situation thus: "The work of M. Poggendorf, having been
mentioned in a book on electromagnetism by the celebrated M. Erman
published very shortly after its discovery, became known to many
scientists before that of M. Schweigger. This is the reason for the same
apparatus carrying different names."[20]

The same confusion is well illustrated by the paper to which Gilbert
attached his confessional footnote mentioned above. Written by Professor
Raschig of Dresden, on April 3, 1821, the paper is entitled "Experiments
with the Electro-magnetic Multiplier," but the device, throughout the
paper, is repeatedly referred to in the phrase "Poggendorf's condenser,
or rather multiplier," an awkward combination that suggests editorial

The work of James Cumming at Cambridge is described in two papers which
he read to the Cambridge Philosophical Society in 1821, which were then
duly published in the _Transactions_ of that Society. The first, "On the
Connexion of Galvanism and Magnetism," was read April 2, 1821,[22] and
the second, "On the Application of Magnetism as a Measure of
Electricity," was read a few weeks later on May 21st.[23]

Though he quotes some unrelated 18th-century experiments by Ritter in
Germany, an 1807 publication of Oersted's, and electromagnetic
experiments with solenoids performed by Arago and Ampère in late 1820,
Cumming makes no mention of Schweigger or Poggendorf, and never uses the
word "multiplier." It, therefore, seems probable that his work was done
without knowledge of the German publications or inventions.

Original Electromagnetic Multipliers

Of the three sets of instruments made, respectively, by Schweigger,
Poggendorf and Cumming, those of Schweigger are the most elementary, and
the least realistic from a practical point of view. He makes little
effort to investigate the effect of any design parameters, but presents
some odd conductor configurations that involve unimportant variations of
the basic principle. The following extracts from his first three
papers[13] contain the major references to his conception, construction,
and use of his multiplier.


    That a powerful voltaic pile is required for these experiments (of
    Oersted) I have confirmed in my physics lectures, using an electric
    pile that was so strong it would easily produce potassium metal the
    second and third day after it was built. However, I soon saw that
    the electromagnetic effect was related, not to the pile, but to the
    simple circuit, and I was thereby led to perform the experiment with
    much greater sensitivity. To amplify these electromagnetic phenomena
    of the simple circuit it seemed to me necessary to adopt a different
    arrangement from that initiated by Volta, in order that the
    electrical phenomena of his simple circuit might be raised to a
    higher degree.

    Since a reversal of the effect occurs according to whether the
    connecting-wire lies over or under the needle, and likewise
    according to whether the wire leads from the positive or negative
    pole, thence I say it is an easy inference that a doubling of the
    effect is attainable, which is verified in practice.

    I present to the Society the simple "doubling apparatus"
    [_Verdoppelungs-Apparat_], where the compass is placed between two
    wires passing around it. A multiplication of the effect is easily
    obtained when the wire is not just once but many times wound around.
    A single turn suffices, however, to demonstrate Oersted's
    experiments, using small strips of zinc and copper dipped in
    ammonium-chloride solution.

Amid innumerable, rambling theorizations (such as, that "hydrogenation
affects magnetism as oxidation affects galvanism," or "sulphur,
phosphorous and carbon are especially significant in magnetism, since
iron in combination with any of these inflammable materials becomes a
magnet-material"), Schweigger announces that he looked for the reactive
force of the needle on the connecting wire in the simple Oersted
experiment, and that he used his "amplifying apparatus" to look for
magnetic effects from an electrostatic machine, but without success in
both cases. He suggests that he will continue with many more
electromagnetic experiments because "with the use of the
doubling-apparatus, the needle, instead of needing for excitation a cell
capable of generating sparks, approaches more closely the sensitivity of
a twitching nerve." However, "additional special experiments are
required to find to what limits the amplification can be increased by
the method I have created in the construction of this
doubling-apparatus, using multiple turns of wire."

[Illustration: Figure 3.--THIS WIRE "BOW-PATTERN" was the first
illustration Schweigger gave of his "doubling apparatus," though he had
presented a verbal description of a single-coil arrangement somewhat
earlier. The purpose of the bow pattern was to show that compass needles
at the centers of the two loops deflected in opposite directions. (From
_Journal für Chemie und Physik_.)]


[The first half of this paper describes successful observations of the
reaction-force of a magnetic needle on the connecting wire of a voltaic
circuit, achieved by pivoting the connecting wire in the form of brass
needles above and below the compass needle. Though the multiplier
configuration of needle and wire is in fact present here, Schweigger
does not mention it, evidently regarding this as a separate project. He

    In my lecture of September 16th, I showed that Oersted's results
    depend, not on the voltaic cell, but only on the connecting circuit.
    The principle I have used for amplification of the effects, for the
    construction of an electromagnetic battery as it were, was the
    winding of wire around the compass, and I now present to the Society
    a bow-pattern of multiple-wound, wax-insulated wire, Figure 3.
    [There were no illustrations with Schweigger's first paper.] While
    a single wire, using the weak electric circuit here, deflects the
    magnetic needle only 30° or 40°, if the compass is placed in one of
    the openings of this pattern, the needle is deflected 90° to the
    east, or in the other opening 90° to the west, using the same weak
    electric circuit....

The "bow-pattern" device has novelty interest only, adding nothing to
the elucidation of the multiplier phenomenon. The same is true of
Schweigger's next proposal, shown in figure 4. "... I will now add
another apparatus, which is just an extension of the previous one,
whereby the needle can take up any angle from 0° to 180°." A short
length of circular glass tubing, of inside diameter large enough to
contain a compass needle, stands with its axis vertical and has single
or multiple loops of wire wound on it in vertical diametral planes. In
the illustration, successive plane coils are inclined at 30° to one
another. "... the electric current flows through the whole wire, and the
needle moves under all of these currents, and coming always into another
loop can take any desired angle."

With much further theorizing about "the correlation of magnetism with
the cohesion of bodies," Schweigger states again his evaluation of his
discovery: "Oersted succeeded in electromagnetic research by using a
spark-producing cell, which could make a wire glow. My amplifying
electromagnetic device needs only a weak circuit of copper, zinc, and
ammonium chloride solution."[24]

[Illustration: Figure 4.--SCHWEIGGER MADE THIS peculiar construction of
wire coils, wound endwise on a short vertical section of glass tubing
with a compass needle inside, merely to startle his Halle audience with
the fact that the compass needle could rest in any of several stable
positions. (From _Journal für Chemie und Physik_.)]

[Illustration: Figure 5.--SCHWEIGGER'S SUGGESTION of one possible design
for an amplifying electromagnetic indicator. The components are wooden
rods and insulated wire. Position b referred to in the text is at the
bottom of the diagram between the letters a and c. (From _Journal für
Chemie und Physik_.)]


[This was presumably written between November 4, 1820, and the January
1, 1821, publication date of his _Journal_.]

    These wonderful new electrical effects[25] are most easily rendered
    perceptible with the help of the previously described wire loops. To
    focus attention on just one of the windings of Figure 3, we sketch a
    new drawing, Figure 5.... Since it is of major importance that these
    loops be made of silk-covered wire lying evenly on one another, it
    is convenient to wind the loops on two small slotted sticks of wood,
    although it is also possible to hold the wires together with wax or
    shellac, or to tie them together in an orderly manner with silk

    In Figure 5, Aa and Cc represent little slotted rods of wood on
    which the silk-covered wire is wound. Only three windings are shown
    in the figure, but I generally adopt three times that many. Now t is
    connected with the copper and d with the zinc, and the compass B set
    between the rods Aa and Cc with the coil perpendicular to the
    magnetic meridian and the terminals d, t at the east.

    The instant Z and K are dipped in the ammonium chloride solution,
    the needle turns around and stays with the north pole point

    If now the compass is taken out of the coil and put in position b,
    all effects are reversed, and are considerably weaker, for obvious

    It is of the same significance whether we bring the compass from B
    to b in Figure 5, or from mesh 1 to mesh 2 in Figure 3, only that in
    the latter case, because the compass is enclosed by the two sides, a
    stronger effect results....

    If now the coil is rotated ... so that the face previously north now
    faces south, then on connecting the electric circuit there is
    absolutely no trace of effect on the needle, assuming that the
    terminal wires are not reversed....

    It seems unnecessary to note that our magnetic coil can be placed in
    the direction of the magnetic meridian or at any arbitrary angle
    with it....

Following several pages of further talk about the relation of "cohesion
to magnetism" and about "unipolar and bipolar conductors," the only
additional item of interest is the observation that discharges of a
Leyden jar (_Kleistichen Flasche_) strong enough to burn strips of leaf
gold and to magnetize an iron rod in a coil, produced no compass-needle
deflections, even with the help of the "amplifying apparatus."

Schweigger, therefore, described the basic multiplier idea clearly
enough in his first paper, but offered no sketch of the simplest
construction until the third paper. In the second paper, meanwhile, he
had illustrated two peculiar designs involving the principle in less
elementary ways.

His indifference to whether the wire loops lie _in_ the magnetic
meridian (fig. 3) or perpendicular to it (fig. 5) or "at any other
arbitrary angle to it," reveals a poor appreciation of the
measuring-instrument potentialities. His conception seems to be
primarily that of a detector.

Poggendorf's invention, as first reported by Erman and presented to a
wider audience by Gilbert[26] was described as consisting of typically
40 to 50 turns of 1/10-line diameter, silk-covered copper wire tied
tightly together, with the whole pressed laterally to form an elliptical
opening in which a pivoted compass needle could move freely while
maintaining clearance of about 2 lines from the wire at all points.[27]

"This magnetic condenser can be a great boon to electro-chemistry," said
Erman, for "it avoids all the difficulties of electric condensers." He
noted that, using the condenser, Poggendorf had already established the
electric series for a great number of bodies, discovered various
anomalies about conductivities, and found a way of detecting dissymmetry
of the poles of a compass needle. On the other hand, even with the
condenser, no magnetic effects have so far been obtainable from a strong
tourmaline, or from a 12,000-pair, Zamboni dry cell.

Poggendorf's own account of his work finally appeared as a very long
article in the journal known as "Oken's Isis."[28] The editorial
controversies mentioned earlier may have occasioned this use of a
periodical of such minor status in the fields of physics and chemistry.

The source of Poggendorf's vision of the multiplier principle was a
little different from Schweigger's inspiration. Aiming at some detailed
analysis of Oersted's observation, Poggendorf ran the connecting wire of
his cell-circuit along a vertical line to just above or below the
pivot-point of the compass needle, then, after a right-angle bend,
horizontally above or below one of the poles of the needle. As he
studied the deflections produced for all four possible positions of such
a wire, with both cell polarities, he came to realize that if a
rectangular wire loop in a vertical plane enclosed a compass needle, all
parts of the horizontal sides of the loop would produce additive
deflections. By a separate experiment, he showed that the vertical sides
of the loop would also increase the deflections. He saw at the same time
that the effect of additional turns would be cumulative.

    The multiple surrounding of the needle by a silk-covered wire, in a
    plane perpendicular to the long axis of the needle, affords the
    physicist a very simple and sensitive means of detecting the
    slightest trace of galvanism, or of magnetism produced by it, so
    that I have given the name of magnetic condenser to this
    construction, though I attach no special value to this name ...

    In analyzing the astonishingly increased power which the condenser
    gives to the magnetic effect of a circuit, the first question that
    arises is how the effect varies with the number of turns, whether it
    increases indefinitely or reaches a maximum beyond which additional
    turns have no effect. The answer to this first question is linked to
    the solution of another, viz, whether the degrees deflection are a
    direct expression of the measure of the magnetic force or not.

    To instruct myself on this point I made use of three separate
    circuits, each containing an 8-turn condenser, and put these as
    close together as possible in the magnetic meridian ... with the
    needle between the windings. Each single circuit ... gave a
    deflection of 45° ... When two were connected the deflection was
    60°, and when finally all three were put in magnetic operation, the
    deflection grew to only 70°. It appears clearly from this that the
    angle of deflection is not in a simple ratio with the magnetic force
    acting on the needle....

Neither Poggendorf nor Schweigger seems to have ruled out, on logical
grounds alone, the possibility of deflections greater than 90°, with the
loop-plane in the magnetic meridian, though Poggendorf does add a vague
note that if the needle deflected too far it would encounter forces of
the opposing sign.

Poggendorf experimented with the size of the circuit wires, finding that
larger wires led to greater deflections. He noted that the size of the
cell plates and the nature of the cell's moist conductors would
certainly have a great effect, but that to investigate these in detail
would take undue time, and he therefore proposed to keep this part of
the apparatus constant, using one pair of zinc and copper plates 3.6
inches in diameter, separated by cloth soaked in ammonium-chloride

Poggendorf's principal quantitative study of his magnetic condenser used
13 identical coils, each with 100 turns. In order that the turns should
all be at approximately the same distance from the needle, the coils
were wound of the finest brass wire that could be silk-insulated, the
wire diameter being 0.02 lines. On adding coils one at a time across the
cell (i.e., connecting them in parallel), the deflections were as

  Turns              100     200     300      400     500     600    700
  Deflection in
    degrees           45      50      55    59-60      62      63     64

  Turns              800     900    1000     1100    1200    1300
  Deflection in
    degrees           65    65-1/2    66       66      66      66

Adding some coils with fewer turns, and connecting various combinations
"as a _continuum_" (i.e., in series), the deflections using the same
cell were:

  Turns             1      5     10     25      50     75    100    200
  Deflection in
    degrees        10     22     27     30   35-40     40     40     40

  Turns           300    400    500    600     700    800    900   1000
  Deflection in
    degrees        40     40     41     40      40     40     40     40

Making a few coils from wire with 1/8-line diameter, the deflections,
again using the same cell were:

  Turns                      5       25      50    100    Over 100
  Deflection in degrees    20-22    40-45    45     65          65

Since the needle used in these experiments was almost as long as the
inside clearance of the coils, no simple tangent law can be applied, and
it is not possible to discover an equivalent circuit in modern terms.
However, the constancy of the deflections for large numbers of turns in
each case indicates that the cell voltage and resistance were fairly
constant, and a rough estimate suggests that the cell resistance was
comparable to the resistance of one of the 100-turn coils of fine wire.
Such a value means that cell resistance limited the maximum deflections
for the parallel-connected multipliers, while coil resistance fixed the
limit in the series case.

For all of these reasons, it was impossible that any useful functional
law could be obtained from the data.

Poggendorf concluded only that "the amplifying power of the condenser
does not increase without limit, but has a maximum value dependent on
the conditions of plate area and wire size." He added two other
significant comments derived from various observations, that the basic
Oersted phenomenon is independent of the earth's magnetism, and that the
phenomenon is localized, i.e., is not affected by distant parts of the

Only a small fraction of Poggendorf's paper is devoted to elucidating
the properties of the condenser. A similar amount is concerned with
refuting various proposals, such as those of Berzelius and Erman, about
distributions of magnetic polarity in a conducting wire to account for
Oersted's results. More than half of the paper describes results
obtained by using the condenser to compare conductivities and cell
polarities under conditions where no effect had previously been
detectable. Notable is the observation of needle deflections in circuits
whose connecting wires are interrupted by pieces of graphite, manganese
dioxide, various sulphur compounds, etc., materials which had previously
been considered as insulators in galvanic circuits. Poggendorf gives
these the name of "semi-conductor" (_halb-Leiter_).

used at Cambridge in 1821. One is a single-wire "galvanometer,"
following Ampère's definition. Cumming called the multiple-turn
construction "galvanoscopes." He showed how to increase their
sensitivity by partial cancellation of the earth's magnetism at the
location of the compass needle. (From _Transactions of the Cambridge
Philosophical Society_, vol. 1, 1821.)]

Cumming's first mention of the multiplier phenomenon, in his paper of
April 2, 1821,[22] is quite casual, and describes only a one-turn
construction. He speaks first of single-turn ring of thick, brass wire,
and after noting that the sides of a circuit produce additive effects on
a needle, he comments that a flattened rectangular loop produces nearly
quadruple the effect of a single wire. The paper is primarily a review
of Oersted's work, with references to electromagnetic observations
before Oersted, and accounts of various related but nonmultiplier
experiments that Cumming has made. His second paper, of May 21st,
contains a fine plate (fig. 6) illustrating arrangements used in
investigating the subject of the paper's title "The Application of
Magnetism as a Measure of Electricity." (Neither Poggendorf nor any of
his commentators ever illustrated his "condenser.")

Although this plate is never referred to in the paper itself, a nearby
"Description" gives a few comments. The two wire patterns shown are
noted as simply "forms of spiral for increasing the electromagnetic
intensity." The mounted wire loop, with enclosed compass needle and
terminal mercury cups, is clearly identical in principle with the
devices of Schweigger and Poggendorf, and is called a "galvanoscope."
The largest structure illustrated does not involve the multiplying
effect. It is called a "galvanometer," consistent with Ampère's
definition of that word. To use it, two leads of a voltaic circuit are
inserted into the mercury cups AC and BD, and the board EFGH carrying
the cups is moved vertically until some "standard" deflection is
obtained on the compass needle below. The relative "strength" of the
circuit is then given by the calibrated position of the sliding section.
Uncertainties are undoubtedly introduced by the arbitrary positions of
the connecting wires from the test circuit to the mercury cups, but
Cumming drew some interesting conclusions from various measurements he

Observing needle deflections for various positions of the wire A-B, with
a "constant" voltaic circuit, he found that "the tangent of the
deviation varies inversely as the distance of the connecting wire from
the magnetic needle." Here is a combination of the deflection law for a
needle in a transverse horizontal field and the magnetic-force law for a
long, straight wire. The latter had been determined experimentally by
Biot and Savart, in November 1820, by timing the oscillations of a
suspended magnet.[29]

Cumming considers his straight-wire calibrated "galvanometer" to be a
device for "measuring" galvanic electricity; on the other hand, his
multiple-loop "galvanoscopes" are for "discovering" galvanic
electricity. With the multiplier instrument, he found galvanic effects
(i.e., needle deflections) using copper and zinc electrodes with several
acids not previously known to create galvanic action. A
potassium-mercury amalgam electrode created a powerful cell with zinc as
the positive electrode, establishing both the metallic nature of
potassium and the fact that it is the most negative of all metals.

In a third paper, presented April 28, 1823,[30] Cumming reports use of
the galvanoscope in experiments on the thermoelectric phenomena recently
discovered by Seebeck. His note that "for the more minute effects a
compass was employed in the galvanoscope, having its terrestrial
magnetism neutralized ..." seems to be the earliest mention of this
version of the astatic principle, a technique whose dramatic effects
were especially valuable in low-resistance thermoelectric circuits,
where the extra resistance of additional multiplier turns largely
offsets their magnetic contribution. In detail, "the needle is
neutralized by placing a powerful magnet North and South on a line with
its center; and another, which is much weaker, East and West at some
distance above it: by means of the first the needle is placed nearly at
right angles to the meridian, and the adjustment is completed by the

On varying the length of the connecting wire of the circuit, Cumming
found the deflections of the multiplier needle to be in a nearly
reciprocal relation. He speaks of the "conducting power of the wire,"
and seems not far from visualizing Ohm's law, of which no published form
appeared until 1826. Ohm's own experiments were made with very similar

[Illustration: Figure 7.--"SCHWEIGGER MULTIPLIER" used by Oersted in
1823. A thin magnetic needle is held in a light, paper sling at F,
suspended by a fine, vertical fiber. (From _Annales de Chimie et de


An effort has been made to show that electrical experimenters prior to
Oersted's discovery in 1820 were in desperate need of some electrical
instrument for galvanic or voltaic circuits that would combine
sensitivity, simplicity, reliability, and quick response. The nearly
simultaneous creation by Schweigger, Poggendorf and Cumming of an
arrangement consisting of a coil of wire and a compass needle provided
the first primitive version of a device to fill that need.

[Illustration: Figure 8.--COMPLETELY USELESS ARRANGEMENT of vertical
coil and horizontal, unmagnetized needle, presented in the _Edinburgh
Philosophical Journal_ of 1821 as "Poggendorf's Galvano-Magnetic
Condenser." Almost every aspect of Poggendorf's instrument has been
incorrectly represented.]

It appears that Schweigger is clearly entitled to credit for absolute
priority in the discovery, but the original sources suggest that both
his understanding of the device and the subsequent researches he
performed with it were markedly inferior to those of the other
independent discoverers. In using the generic label, "Schweigger's
Multiplier," there have been historical examples of attributing to
Schweigger considerably more sophistication than is justified. Figure 7
shows an instrument designed by Oersted in 1823,[20] which he says
"differs in only minor particulars from that of M. Schweigger." On
comparing figure 7 with figures 3, 4, or 5, the remark seems overly

The history of the multiplier instruments has had its fair share of
erroneous reports and misleading clues. A fine example is the
illustration of figure 8, taken from what is often quoted as the first
report in English on Poggendorf's "Galvano-Magnetic Condenser."[31] The
sketch is the editor's interpretation of a verbal description given him
by a visiting Danish chemist who, in turn, had received the information
in a letter from Oersted. It incorporates, faithful to the description,
a "spiral wire ... established vertically," with a needle "in the axis
of the spiral," yet by misunderstanding of the axial relations and of
the ratio of length to diameter for the coil, a completely meaningless
arrangement has resulted. The confusion is compounded by the specifying
of an _unmagnetized_ needle.

Schweigger and Poggendorf, through their editorial positions, were among
the best known of all European scientists for several decades. On one
basis or another their reputations are firmly established. Comparison of
the accounts of the early "multipliers," however, suggests that the
Reverend James Cumming, professor of chemistry at the University of
Cambridge, was a very perceptive philosopher. This was well understood
by G. T. Bettany who wrote in the _Dictionary of National Biography_
that Cumming's early papers "though extremely unpretentious," were
"landmarks in electromagnetism and thermoelectricity," and concluded
that: "Had he been more ambitious and of less uncertain health, his
clearness and grasp and his great aptitude for research might have
carried him into the front rank of discoverers."


I wish to thank Dr. Robert P. Multhauf, chairman of the Department of
Science and Technology in the Smithsonian Institution's Museum of
History and Technology, for encouragement in the writing of this paper
and for the provision of opportunity to consult the appropriate sources.
To Dr. W. James King of the American Institute of Physics, I am grateful
for many provocative discussions on this and related topics.

       *       *       *       *       *


   [1]  A. VOLTA, "On the Electricity Excited by the Mere Contact of
        Conducting Substances of Different Kinds," _Philosophical
        Transactions of the Royal Society of London_ (1800), vol. 90,
        pp. 403-431.

   [2]  Some little-known but delightful observations in the prehistory
        of electromagnetism are described in a letter written by G. W.
        SCHILLING from London to the Berlin Academy on July 8, 1769,
        published as "Sur les phénomènes de l'Anguleil Tremblante"
        [_Nouveaux Mémoires de l'Académie Royale des Sciences et
        Belles-Lettres_, 1770 (Berlin, 1772), pp. 68-74], translated to
        French from the original German. The letter recounts a multitude
        of experiments with various electric eels. The two observations
        of electromagnetic interest are that a piece of iron held by the
        hand in the eel's tank could be felt quivering even when the
        fish was stationary several inches away, and a compass needle
        showed a deflection, both in the water near the fish, and
        outside the tank, also with the fish stationary.

   [3]  ABRAHAM BENNET, _Philosophical Transactions of the Royal Society
        of London_ (1787), p. 26.

   [4]  Op. cit. (footnote 1), p. 403.

   [5]  _Philosophical Magazine_ (1800), vol. 7, pp. 289-311. [For a
        facsimile reprint, see _Galvani-Volta_ (Bern Dibner's Burndy
        Library Publication No. 7), Norwalk, Connecticut, 1952.]

   [6]  MICHAEL FARADAY, _Experimental Researches in Electricity_, vol. 1
        (London, 1839), paragraph 739, dated January 1834.

   [7]  Ibid., sec. 741.

   [8]  JAMES CUMMING, "On the Application of Magnetism as a Measure of
        Electricity," _Transactions of the Cambridge Philosophical
        Society_ (1821), vol. 1, pp. 282-286. [Also published in
        _Philosophical Magazine_ (1822), vol. 60, pp. 253-257.]

   [9]  H. C. OERSTED, _Experimenta Circa Effectum Conflictus Electrici in
        Acum Magneticam_ (Copenhagen, July 21, 1820).

  [10]  Full details of Oersted's work and publications are in _Oersted
        and the Discovery of Electromagnetism_ (Bern Dibner's Burndy
        Library Publication No. 18), Norwalk, Connecticut, 1961. The
        original Latin version and first English translation are
        reproduced in _Isis_ (1928), vol. 34, pp. 435-444.

  [11]  A. M. AMPÈRE, _Annales de Chimie et de Physique_ (1820), vol. 15,
        p. 67. The word "galvanometer" had been used much earlier by
        BISCHOF, "On Galvanism and its Medical Applications," _The
        Medical and Physical Journal_ (1802), vol 7, p. 529, for a form
        of goldleaf electroscope shown here in figure 2, but this use of
        the word does not seem to have been adopted by others.

  [12]  Op. cit. (footnote 6), paragraph 283, dated January 1833. A
        similar attitude was expressed in the same year by CHRISTIE,
        _Philosophical Transactions of the Royal Society of London_
        (1833), vol. 123, p. 96: "I adopt the word current as a
        convenient mode of expression, ... but I would not be considered
        as adopting any theoretical views on the subject...."

  [13]  Some prominent examples of this brevity of treatment are in E.
        HOPPE, _Geschichte der Elektrizität_ (Leipzig, 1884); O. MAHR,
        _Geschichtliche Einzeldarstellungen aus der Elektrotechnik_
        (Berlin, 1941); R. S. WHIPPLE, "The Evolution of the
        Galvonometer," _Journal of Scientific Instruments_ (1934), vol.
        7, pp. 37-43; WILLIAM STURGEON, _Scientific Researches_ (Bury,
        1850); A. W. HUMPHREYS, "The Development of the Conception and
        Measurement of Electric Current," _Annals of Science_ (1937),
        vol. 2, pp. 164-178.

  [14]  M. SPETER, "Klärung der Multiplikator-Prioritätsfrage
        Schweigger-Poggendorf," _Zeitschrift für Instrumentenkunde_
        (1937) vol. 57, pp. 29-32.

  [15]  T. SEEBECK, "Über den Magnetismus der Galvanischen Kette,"
        _Abhandlungen der Koenigliche Akademie der Wissenschaften zu
        Berlin_ (1820-1821), pp. 289-346. The phrase "Schweigger's
        multiplier" is used on page 319. The many experiments described
        in this paper added little or nothing to contemporary
        appreciation of the multiplier as an instrument.

  [16]  J. S. C. SCHWEIGGER, _Journal für Chemie und Physik_ (1821), vol.
        31, pp. 1-18, 35-42. Pages 1-6 are the paper presented in Halle
        on September 16, 1820; pages 7-18 are the paper presented in
        Halle on November 4, 1820, and pages 35-42 are "a few additional
        words." The preface to the whole volume is dated January 1,
        1821. A somewhat earlier public announcement referring to
        Schweigger's discovery appeared in the _Allgemeine
        Literatur-Zeitung_ (November 1820), no. 296, cols. 622-624, but
        this was lacking in detail and seems not to have been noticed by
        any scientists.

  [17]  P. ERMAN, _Umrisse zu den physischen Verhältnissen des von Herrn
        Prof. Oersted entdeckten elektro-chemischen Magnetismus_
        (Berlin, 1821). Hoppe (footnote 13) states that Erman's book was
        published in May; however, it is referred to in a letter dated
        April 3, 1821, by RASCHIG, _Annalen der Physik_ (1821), vol. 67,
        pp. 427-436.

  [18]  Op. cit. (footnote 16), vol. 32, pp. 38-50.

  [19]  _Annalen der Physik_ (1821), vol. 67, pp. 382-426, and footnote
        on pages 429-430 of same volume. The footnote accompanies the
        article by Raschig mentioned in footnote 17.

  [20]  H. C. OERSTED, "Sur le Multiplier electro-magnetique de M.
        Schweigger, et sur quelques applications qu'on en a faites,"
        _Annales de Chimie et de Physique_ (1823), vol. 22, pp. 358-365.

  [21]  "Versuche mit dem electrisch-magnetischen Multiplicator,"
        _Annalen der Physik_ (1821), vol. 67, pp. 427-436.

  [22]  _Transactions of the Cambridge Philosophical Society_ (1821),
        vol. 1, pp. 269-278.

  [23]  Op. cit. (footnote 8).

  [24]  The German word _Kette_ has been translated as "circuit"
        throughout. Although the equivalence of these words is clear,
        for example, in Ohm's work of 1826, the context in which _Kette_
        is sometimes used in 1820 and 1821 indicates that the concept of
        a "circuit," in the sense of the wiring external to the source
        of electricity, has not been established. The wiring is regarded
        more as something incidental, used to "close" the cell, the cell
        being considered essentially the whole of the apparatus. This
        view underlies the many attempts to correlate the Oersted
        phenomena with cell materials and design, and with the use of
        such terms as "chemical magnetism" by Erman and others.

  [25]  The reference here is to the Oersted-type experiments described
        in two papers by authors other than Schweigger on pages 19 to 34
        of the volume.

  [26]  Op. cit. (footnote 19), pp. 422-426.

  [27]  One "line" seems to have been about 1/12 inch.

  [28]  J. G. POGGENDORF, "Physisch-chemische Untersuchungen zur näheren
        Kenntniss des Magnetismus der voltaischen Säule," _Isis von
        Oken_ (1821), vol. 8, pp. 687-710. Most of Poggendorf's
        numerical data is also in C. H. PFAFF, _Der Elektromagnetismus_
        (Hamburg, 1824), along with some of Pfaff's own work.

  [29]  Reported in _Annales de Chimie et de Physique_ (1820), vol. 15,
        pp. 222-223.

  [30]  "On the Development of Electro-Magnetism by Heat," _Transactions
        of the Cambridge Philosophical Society_ (1823), vol. 2, pp.

  [31]  "Account of the New Galvano-Magnetic Condenser invented by M.
        Poggendorf of Berlin," _Edinburgh Philosophical Journal_ (July
        1821), vol. 5, pp. 112-113.

       *       *       *       *       *

Transcriber's Notes.

The following assumed typographical errors have been corrected:

  Page 125: J. B. [Johann Bartholomacus] Tromsdorff--should
              be Johann Bartholomäus Trommsdorff?

  Page 134: "paper of April 2, 1821,[22] is quite"--had "1921."

  Footnote 13: "_Geschichte der Elektrizität_"--had "Elektrizitat."

  Footnote 16: "_Journal für Chemie und Physik_"--had "and."

One questionable spelling has been retained as follows:

  Footnote 20: "Sur le Multiplier electro-magnetique..."--should be

       *       *       *       *       *


  PAPER 39


  _Howard I. Chapelle_


                                     CONTROVERSIAL DESCRIPTIONS    147

                                               COPENHAGEN PLANS    150

                                   HISTORY OF DOUBLE-HULL CRAFT    152

                                         SAIL AND INBOARD PLANS    157

                                       RECONSTRUCTING THE PLANS    161

                                                       APPENDIX    167


_Howard I. Chapelle_


[Illustration: Figure 1.--SCALE MODEL of Fulton's _Steam Battery_ in
the Museum of History and Technology. (Smithsonian photo P-63390-F.)]

     _Robert Fulton's "Steam Battery," a catamaran-type blockship, was
     built during the War of 1812. Until recently, not enough material
     has been available to permit a reasonably accurate reconstruction
     of what is generally acknowledged to be the first steam

     _With the discovery, in the Danish Royal Archives at Copenhagen, of
     plans of this vessel, it is now possible to prepare a
     reconstruction and to build a model._

     _This article summarizes the history of the vessel, describes the
     plans and the reconstruction, and also evaluates its design with
     particular attention to the double-hull construction._

     THE AUTHOR: _Howard I. Chapelle is curator of transportation in the
     Smithsonian Institution's Museum of History and Technology._

The identity of the first steam man-of-war has been known for many
years, and a great deal has been written and published on the history of
this American vessel. Until recently, the only available drawing of the
ship has been a patent drawing made for Robert Fulton. This does not
comply with contemporary descriptions of the steamer and the drawing or
plan is out of proportion with the known dimensions. The lack of plans
has heretofore made it impossible to illustrate the vessel with any
degree of precision, or to build a scale model.

The discovery in 1960 of some of the plans of this historic ship in the
Danish Royal Archives at Copenhagen now makes possible a reasonably
accurate reconstruction of the vessel and also clarifies some of the
incomplete and often confusing descriptions by contemporary writers.

Of the numerous published accounts of the ship that are available, the
most complete is David B. Tyler's "Fulton's Steam Frigate."[1] A
contemporary description of the vessel by the British Minister to
Washington, 1820-23, Stratford Canning, was published by Arthur J.
May.[2] In _Naval and Mail Steamers of the United States_, by Charles B.
Stuart,[3] and _The Steam Navy of the United States_, by Frank M.
Bennett,[4] the history of the ship and some descriptive facts are
given. Stuart, in an appendix, gives in full the report of the
Supervisory Committee (set up to administer the building contract).
Tyler and Stuart, and the Committee Report are the principal sources
from which the following summary of the ship's history is drawn.

[Text of Illustration: Plate N^o. 1.


Figure 1^st. _Transverse section A her Boiler. B the steam Engine. C the
water wheel. E E her wooden walls 5 feet thick, diminishing to below the
waterline as at F.F draught of water 9 feet D D her gun deck_

_Scale 1/12 inch=1 foot_


_Scale 1/24 inch=1 foot_

Figure II^d. _This shews her gun deck, 140 feet long 24 feet wide,
mounting 20 guns. A the Water wheel_

Figure III^d

_Side View_

_Scale 1/24 inch=1 foot_


_November 1813._

_S M^c Elroy del._

_"Stuart's Naval & Mail Steamers U.S."_

_Sarony & Major. Eng. N.Y._]

[Illustration: Figure 2.--"DEMOLOGOS," A WOOD ENGRAVING based on the
sketch which Robert Fulton showed to President Madison in 1813. This
wood engraving appears as plate 1 in Charles B. Stuart's _Naval and Mail
Steamers of the United States_, and illustrates the section on Naval
Steamers, from which the account "The Demologos; or, Fulton the First,"
is here reproduced (pp. 167-171). Stuart obtained the sketch, assumed to
have been made for Fulton's patent on the design of the _Steam Battery_,
from the files of the U.S. Navy Department.]

On December 24, 1813, Robert Fulton invited a group of
friends--prominent merchants, professional men and naval officers--to
his home in New York City and there presented a proposal for a project
of great local interest. At that time the War of 1812 was in its second
year and the economic effect of the British naval blockade was being
felt severely. The blockade cut off seaborne trade and posed a constant
threat of attack upon New York and other important ports, particularly
Baltimore. To defend the ports, it had been proposed to build mobile
floating batteries or heavily built and armed hulks with small sailing
rigs, but the high cost of these and their doubtful value in helping to
break the blockade, compared to the value and action of a very heavy,
large frigate, or a 74-gun ship, caused authorities to hesitate to
proceed with the construction of any blockships or floating batteries.

Fulton's proposal concerned a floating battery propelled by steam
power. He believed that steam propulsion not only would give it
effective maneuverability with no loss of gunpower, but also would allow
a successful attack upon the Royal Navy blockading ships during periods
of protracted calm, when sailing men-of-war were nearly helpless. The
blockaders then could be attacked and picked off, one by one, by the
heavily armed steamboat.

Among those present at the meeting was Major General Henry Dearborn, a
leading citizen and soldier who was later to become noted in American
political history. The first step taken during this meeting was the
founding of the Coast and Harbor Defense Company with Dearborn as
president, Fulton as engineer, and Thomas Morris as secretary. Next, a
committee was established to raise funds from Federal, State, and New
York City governments as well as from individual contributors to build
the battery. The members of this committee consisted of General
Dearborn, Commodore Stephen Decatur, U.S.N.; General Morgan Lewis;
Commodore Jacob Jones; U.S.N.; Noah Brown, shipbuilder; Samuel L.
Mitchill; Henry Rutgers; and Thomas Morris.

The committee proved cumbersome and was reduced to General Lewis, Issac
Bronson, Henry Rutgers, Nathan Sanford, Thomas Morris, Oliver Wolcott,
and John Jacob Astor. Known as the Coast Defense Society and with the
name of _Pyremon_ given the ship in prospectus, they attempted,
unsuccessfully, to raise funds privately.

The estimated sums to build a battery 130 feet long, with a 50-foot
beam, capable of a speed of 5 mph, and carrying 24 long guns (18-pdr.),
was $110,000. Fulton, still the chief engineer, in an effort to interest
the Federal Government, built a model of the proposed vessel and
submitted it to some prominent naval officers--Commodore Stephen
Decatur, Jacob Jones, James Biddle, Samuel Evans, Oliver Perry, Samuel
Warrington, and Jacob Lewis. All gave their support to the Society in a
written statement and this recommendation proved helpful to the project
in Congress and in the Navy Department. In the process of passing a bill
which went to the Senate Naval Affairs Committee calling for $250,000
for the construction of the floating battery, the sum was raised to
$1,500,000 for the construction of "one or more" floating batteries and
passed on March 9, 1814.

To supervise the start of construction, the Coast Defense Society
appointed a committee consisting of Dearborn, Wolcott, Morris, Mitchill,
and Rutgers, with Fulton as engineer, and a model and drawing of the
proposed vessel was submitted to the Patent Office. The Secretary of the
Navy, although supporting the project, delayed action until he had
weighed the importance of the batteries in relation to other war needs,
for at this time the naval shipbuilding program on the Great Lakes was
considered of prime importance. He also raised some technical questions
concerning the design of the batteries, which Fulton answered with a
description of the vessel as 138 feet on deck, 120 feet on the keel, 55
feet beam (each hull to have a 20-foot beam and the "race" between to be
15 feet wide), draft 8 or 9 feet loaded, and the intended speed was to
be 4-1/2 to 5 mph. The ship was to carry 24 long guns (32-pdr.), the
engine was to be 130 hp, and the total cost, $200,000. In his letters to
the Secretary of the Navy, Fulton stated that Adam and Noah Brown would
build the hull for $69,800 and that he would build the engine, machinery
and boilers for $78,000, a total of $147,800. He intended to have the
boilers, valves, fastenings, and air pumps of brass or copper, which
would raise the machinery costs 59 percent above that of stationary
engines and boilers then in use.

On May 23, 1814, the Secretary of the Navy authorized the Coast Defense
Society and its committee to act as Navy agents and to enter into the
contracts required to build a vessel, and to draw on the Navy
storekeepers or Navy Yard commandants for such stores or articles on
hand needed for construction. The contracts were prepared and the
committee now was officially empowered to act for the Society, with
Rutgers, Wolcott, Morris, Dearborn, Mitchill, and Fulton. On June 4,
Dearborn asked the Navy Department for $25,000 advance, for work had
started. On the 6th, he informed the Secretary that he had been ordered
to assume command of the defenses of Boston and that Rutgers had been
appointed chairman of the construction committee in his place.

It is apparent that the Navy Department was pressed for funds, due to
the very extensive shipbuilding programs on Lakes Erie, Ontario, and
Champlain in addition to the seagoing vessels being built in some of the
coastal ports. This was certainly one cause for the Secretary of the
Navy's reluctance to carry out the requirements of the bill passed by
Congress immediately after its signature and, also, this reluctance
caused the supervisory committee much embarrassment in its
administration of the contract.

Another factor which caused difficulty in the administration of the
contract was the position of Adam and Noah Brown. The brothers were
deeply involved in the shipbuilding program on the Lakes, in which they
were associated at times with Henry Eckford. The Browns constructed a
blockhouse, shops, and quarters at Erie; in addition to Perry's two
brigs and five of his schooners, they also built some of the Lake
Ontario vessels and, later, the _Saratoga_ on Lake Champlain. In their
New York yard, whose operation continued throughout the war, they built
some large letter-of-marques: the _General Armstrong_, _Prince de
Neufchatel_, _Zebra_, _Paul Jones_, and some smaller vessels. They also
cut down the 2-decked, merchant ship _China_ into a single flush-deck
letter-of-marque, renamed _Yorktown_; and they had a contract to build
the sloop-of-war _Peacock_. It is remarkable that the Browns could
undertake and complete so much work between 1813 and 1815 and still be
able to build the steam battery in a very short time.

With the contracts in order, the Browns began building. The keels of the
battery were laid June 20, 1814. It is apparent that the Browns prepared
the original hull plans, undoubtedly before the building authority was
obtained. The vessel required only about four months to build; she was
launched October 29, 1814, at 9 a.m. This was an excellent performance,
considering the size of the vessel, the amount of timber required and
handled in her massive construction, and the other work being done by
the builders. During the ship's construction, sightseers were a nuisance
and finally guards had to be obtained. During the building of the steam
battery, work had to be practically stopped on the sloop-of-war
_Peacock_ at one period after she had been partially planked.

There were difficulties in obtaining metalwork for the vessel during her
construction, due to the blockade and the demand for such material for
other shipbuilding at New York. On November 21, 1814, the ship was towed
from the Browns' yard on the East River by Fulton's _Car of Neptune_ and
_Fulton_, each lashed to the sides of the battery, and taken to Fulton's
works on the North River. There Fulton supervised in person the
completion of the vessel and construction of her machinery. Undoubtedly
only a little of his time was required in inspection of the Browns' work
on the battery, for the shipbuilders had been closely associated with
Fulton throughout the life of the project and were fully capable as ship
designers. The work on the machinery was another matter, however, for
men capable of working metal were scarce and few workmen could read
plans. Fulton had some of the work done outside of his own plant,
particularly the brass and copper work (mostly by John Youle's foundry).
As a result, Fulton was required to move from plant to plant, keeping
each job under almost constant observation and personally supervising
the workmen. The equipment then available for building a large engine
was inadequate in many ways. The large steam cylinder presented a
problem: it had to be recast several times and some of the other parts
gave trouble, either in casting or in machining and fitting.

[Illustration: Figure 3.--SCALE MODEL of _Steam Battery_, showing double
hull, in the Museum of History and Technology. (Smithsonian photo

Guns for the battery were another problem. Only 3 long guns (32-pdr.),
were available at the Navy Yard. The Secretary of the Navy promised some
captured guns then at Philadelphia. Because of the blockade, these had
to come overland to New York. The captured guns thus obtained were
probably English, part of the cargo of the British ship _John of
Lancaster_ captured by the frigate _President_ early in the war.
Apparently 24 guns were obtained this way; only 2 were obtained from the
Navy Yard. In July the Supervising Committee carried out some
experimental damage studies, in which a 32-pdr. was fired at a target
representing a section of the topsides of the battery. Drawings of the
result were sent to the Secretary of the Navy.

Further problems arose over the delays of the government in making
payments: the banks discounted the Treasury notes, so the Committee
members had to advance $5,000 out of their own pockets. There was fear
that British agents might damage the vessel, and although the project
was undoubtedly known to the British, no evidence of any act of sabotage
was ever found. Captain David Porter was assigned to the command of the
battery in November, and it was upon his request that the vessel was
later rigged with sails.

With the _Steam Battery_ approaching completion, the Secretary of the
Navy became more enthusiastic and the construction of other batteries of
this type was again proposed. Captain Stiles, a Baltimore merchant,
offered to build a steam battery, the hull to cost $50,000; the entire
cost of the vessel, $150,000, was raised in Baltimore and the frames of
a battery erected. Another battery was projected at Philadelphia and the
Secretary of the Navy wanted one or more built at Sackett's Harbor, but
naval officers and Fulton objected. A bill put before Congress to
authorize another half million to build steam batteries passed the first
reading January 9, 1815, went to the House February 22, 1815, but the
end of the war prevented any further action on it.

On February 24, 1815, Fulton died. He had been to Trenton, New Jersey,
to attend a hearing on the steamboat monopoly and, on the way back, the
ferry on North River was caught in the ice. Fulton and his lawyer,
Emmet, had to walk over the ice to get ashore. On the way, Emmet fell
through and Fulton got wet and chilled while helping him. After two or
three days in bed Fulton went to his foundry to inspect the battery's
machinery causing a relapse from which he died. This resulted in some
delay in completing the machinery and stopped work on the _Mute_, an
80-foot, manually propelled, torpedo boat that Fulton was having built
in the Browns' yard.

It was decided to suspend work on the Baltimore battery after an
expenditure of $61,500, but the New York battery was to be completed to
prove the project was practical. The final payment of $50,000 was made
four months after it was requested.

Charles Stoudinger, Fulton's foreman or superintendent, was able to
complete and install the ship's machinery. On June 10, 1815, the vessel
was given a short trial run in the harbor with Stoudinger and the Navy
inspector, Captain Smith, on board. This trial revealed the need of some
mechanical alterations; sails were not used, and it was found she could
stem the strong tide and a fresh headwind. The vessel also was visited
by the officers of French men-of-war at anchor in the harbor.

On July 4, 1815, she was given another trial. She left Fulton's works at
Corlear's Hook at 9 a.m., ran out to Sandy Hook Lighthouse, bore west
and returned, a total of 53 miles under steam, reaching her slip at 5:20
p.m. She was found to steer "like a pilot boat." This prolonged trial
revealed that the stokehold was not sufficiently ventilated and more
deck openings were required. The windsails used in existing hatches were
inadequate. The paddle wheel was too low and had to be raised 18 inches,
and there were still some desirable modifications to be made in the

On September 11, 1815, she was again given a trial run. All alterations
had been made, including the addition of hatches and raising the paddle
wheel, and her battery was on board with all stores, supplies, and
equipment. She had 26 long guns (32-pdr.), mounted on pivoted carriages,
and now drew 10 feet 4 inches. On this day she left her slip at 8:38
a.m. and went through the Narrows into the Lower Bay, where she
maneuvered around the new frigate _Java_ at anchor there. The battery
then was given a thorough trial under steam and sail and, with the ship
underway, her guns were fired to see if concussion would damage the
machinery. The vessel was found to be a practical one, capable of
meeting the government's requirements in all respects; her speed was
5-1/2 knots. However, the stokehold temperature had reached 116°
Fahrenheit! She returned to her slip at 7:00 p.m.

On December 28, 1815, the Committee in a written report to the
Secretary of the Navy,[5] gave a description of the vessel and praised
her performance. At this time a set of plans was made by "Mr. Morgan,"
of whom no other reference has appeared, and sent to the Navy
Department. These cannot now be found. The Committee recommended the
battery be commissioned and used for training purposes. This suggestion
was not followed.

The ship remained in her slip during the winter, and in June 1816 she
was turned over to the Navy and delivered to Captain Samuel Evans,
commandant of the New York Navy Yard. Captain Joseph Bainbridge was
assigned to her command. However, she was not commissioned and soon
after her delivery she was housed over and placed "in ordinary," that
is, laid up. The final settlement showed that the Committee, as Navy
agents, had paid out $286,162.12 with $872.00 unpaid, as well as a claim
for $3,364.00 by Adam and Noah Brown, making a total of $290,398.12.

The following year, on June 18, 1817, she was unroofed and put into
service with a small crew. With President James Monroe on board, she
left the Navy Yard about noon for a short trip to the Narrows and then
to Staten Island and returned in the evening. The next day she was again
placed "in ordinary."

Four years later, in 1821, when her guns and machinery were removed, it
was found that she was rapidly becoming rotten. She was then utilized as
a receiving ship. At 2:30 p.m. on June 4, 1829, she blew up, killing 24
men and 1 woman, with 19 persons listed as injured. Among those killed
was one officer, Lt. S. M. Brackenridge. Two lieutenants and a Sailing
Master were hurt, four midshipmen were severely injured, and five
persons were listed as missing. The explosion of 2-1/2 barrels of
condemned gunpowder was sufficient, due to her rotten condition, to
destroy the ship completely. A Court of Inquiry blamed a 60-year-old
gunner, who supposedly entered a magazine with a candle to get powder
for the evening gun. It was stated to the court that about 300 pounds of
powder in casks and in cartridges was on board the ship at the time.[3]

She was not replaced until the coast-defense steamer _Fulton_ was built
in 1837-38, though in 1822 the Navy purchased for $16,000 a "steam
galliot" of 100 tons, the _Sea Gull_, to be used as a dispatch boat for
the West Indian squadron engaged in suppressing piracy during 1823. In
1825 she was laid up at Philadelphia, and in 1840 she was sold for

It is a curious fact that the battery did not receive an official name,
as did the sailing blockship on the ways at New Orleans, which at the
end of the War of 1812 was officially listed as the _Tchifonta_. Nor was
the battery given a number, as were the gunboats. In official
correspondence and lists, the steam battery is referred to as the
"Fulton Steam Frigate," or as the "Steam Battery," but in later years
she was referred to as the "Fulton" or "Fulton the First." Perhaps the
explanation is that as she was the only one of her kind she was not
numbered, and as she was not considered fit for coastal or extended
ocean voyages, she was not given a name.

Surviving Designs for Floating Batteries

The designs of American blockships that have survived are those of the
_Tchifonta_,[6] 145 feet long, 43-foot moulded beam, 8-foot 6-inch depth
in hold, and about 152 feet 9 inches on deck. She was to carry a battery
of 22 long guns (32-pdr.), on the main deck 12 carronades (42-pdr.), on
forecastle and quarter decks. She was to have been rigged to rather
lofty and very square topgallant sails, and would have been capable of
sailing fairly well, though of rather shoal draft, drawing only about 8
feet 6 inches when ready for service. She was sold on the stocks at the
end of the war and her later history is not known.

Another and earlier design for a blockship, or floating battery, was
prepared by Christian Bergh for Captain Charles Stewart in 1806. This
was a sailing vessel for the defense of the port of New York, planned to
mount 40 guns (32-pdr.), on her two lower decks and 14 carronades
(42-pdr.), on her spar deck. She was to be 103 feet 6 inches between
perpendiculars, a 44-foot moulded beam, 10-foot depth of hold, and
drawing about 9 feet when ready for service. She was intended to be
ship-rigged, but was never built.[7] A few small sloop-rigged block
vessels also were built during Jefferson's administration. The
sloop-of-war _Saratoga_, built on Lake Champlain by the Browns, in 1813,
was practically a blockship. A plan for a proposed "Guard Ship," or
"Floating Battery," was made by James Marsh at Charleston, South
Carolina, in 1814. This was an unrigged battery, 200 feet extreme
length, 50-foot moulded beam, 9-foot depth of hold, to mount 32 guns
(42-pdr.), on a flush deck, with a covering deck above.[8]

proposed by James Marsh, Charleston, South Carolina, March 14, 1814.]

Through the courtesy of the trustees of the National Maritime Museum,
Greenwich, England, the Rigsarkivet, Copenhagen, Denmark, and the
Statens Sjöhistoriska Museum, Stockholm, Sweden, the author has been
able to illustrate in this article the designs of some of the early
floating batteries.

In the last quarter of the 18th century and later, the Danes had built
sail-propelled floating batteries or blockships, which were employed in
the defense of Copenhagen. The British built at least one sail-propelled
battery, the _Spanker_, in 1794. This was a scow of very angular form
with overhanging gun-deck, bomb-ketch-rigged, and about 120 feet overall
42-foot 4 inches moulded beam and 8-foot depth of hold. She is said to
have been a failure due to her unseaworthy proportions and form; the
overhanging gun deck and sides were objected to in particular. She is
called a "Stationary Battery" in her plans, which are in the Admiralty
Collection of Draughts, National Maritime Museum, Greenwich.

Controversial Descriptions

The contemporary descriptions of the Fulton _Steam Battery_ do not
agree. This was in part due to differences between the dimensions given
out by Fulton during the negotiations with the Federal Government, and
after the ship's construction was authorized. From the context of
various statements concerning the projected vessel, such as that of the
naval officers, the changes in the intended dimensions of the ship can
be seen. For example, the officers state the model and plan shown them
would produce a battery carrying 24 guns (24- and 32-pdrs.), and a letter
from Fulton to Jones,[9] shows she was to be 138 feet on deck and
55-foot beam. The final reported dimensions, given by the Supervisory
Committee,[10] are 156 feet length, 56 feet beam, and 20 feet depth.

In addition there are a few foreign accounts which give dimensions and
descriptions. The most complete was probably that of Jean Baptiste
Marestier, a French naval constructor who visited the United States soon
after the end of the War of 1812 and published a report on American
steamboats in 1824.[11] The _Steam Battery_ is barely mentioned though a
drawing of one of her boilers is given. Marestier made another report on
the American Navy, however. Extensive searches have been made for this
in Paris over the last 14 years, but this paper has not been found in
any of the French archives. References to the original text indicate
that the naval report dealt very extensively with the _Steam Battery_.
Some of his comments on the battery appeared in _Procès-verbaux des
Séances de l'Académie des Sciences_.[12] Marestier considered the powers
of the battery to have been overrated due to fanciful accounts of some
laymen writers. He was aware of the shortcomings of the double hull in a
steam vessel at the then-possible speeds, but he apparently thought two
engines, one in each hull and each with its boilers would be better than
Fulton's arrangement of boilers in one hull and engine in the other. He
noted that the paddle wheel turned 16-18 rpm and that steam pressure
sustained a column of mercury 25 to 35 centimeters. The safety valve was
set at 50 centimeters. Fuel consumption was 3-5/8 cords of pine wood per

In view of the access Marestier is known to have had to American naval
constructors, shipbuilders, and engineers, it is highly probable that he
not only obtained the building plan of the ship but also some of the
earlier project plans from the builders and from Fulton's
superintendent, Stoudinger. It is, therefore, a great misfortune that
his lengthy report on the _Battery_ cannot be produced.

A French naval officer who investigated the ship, M. Montgéry, also
wrote a description, published in "Notice sur la Vie et les Travaux de
Robert Fulton."[13]

[Illustration: Figure 5.--FLOATING BATTERY _Spanker_ built, in England
by William Barnard, at Deptford on the Thames, and launched June 14,
1794. Rigged as a bomb ketch, its length is 111 feet 7 inches in the
keel, extreme beam 42 feet 4 inches, depth of hold 8 feet. Upper deck
plan also shown.]

It should be noted in regard to what Montgéry wrote about the
_Battery_, that in 1821 it had been considered desirable to disarm the
ship. The engineer in charge, William Purcell, had reported that as
there were not proper scuppers, dirt and water had entered the hull and
had collected under the engine and boilers, causing damage to the hull,
and also that with guns removed, the _Battery_ would float too high for
the paddle wheel to propel the vessel; so it had been decided to remove
all machinery as well as the armament.

Montgéry's description, published in 1822, was taken from his report to
the Minister of Marine and Colonies. It noted the battery was made of
two hulls separated by a channel, or "race," 15-1/2 feet wide, running
the full length of the vessel. The two hulls were joined by a deck just
above the waterline, as well as by an upper deck, and also connected at
their keels by means of 12 oak beams each 1 foot square. The vessel was
152 feet long, 57 feet beam, and 20 feet deep. Sides were 4 feet 10
inches thick, and the ends of the hull were rounded and alike. There
were two rudders at each end, one on each hull, alongside the race. The
eight paddle blades, each 14-1/2 feet by 3 feet, turned in either
direction by stopping the engine piston at half-stroke and reversing the
flow of steam. Rigged with two lateen sails and two jibs, the ship
sailed either end first. The engine of 120 hp was in one hull and two
boilers were in the other. Other sources, Marestier, and Colden in
_Procès-verbaux des Séances de l'Académie des Sciences_,[14] gave
additional information (some of it incorrect): the engine was inclined,
with a 4-foot-diameter cylinder, 5-foot stroke, direct-connected to the
paddle wheel, which was turned at 18 rpm. The boilers were 8 × 22 feet
with the fireboxes in inside cylinders, each about 5 feet in diameter,
and extending about half the length of the boiler from the fire doors.
Two fire tubes, each about 3 feet in diameter, returned the gases from
the inside end of the fireboxes to the stacks at the firing end. Except
at the fire-door end, the firebox was completely surrounded by water.
The boiler pressure of about 6 psi was not maintained, varying somewhat
with each stroke of the engine.

Water level in the boilers was indicated by try cocks. The safety valve
was controlled by a counterbalanced lever. A jet of salt water was
injected into the exhaust trunk to form a vacuum by condensation. An air
pump transferred condensate and sea water into a tank from which it
passed overboard. Only about a tenth of this water was returned to the

Montgéry stated also that only the lower or gun deck was to be armed. No
bulwarks were on the spar deck, only iron stanchions to which were
fastened a breastwork of wet cotton bales when the _Steam Battery_ was
in action.

The _Battery_ was designed to carry 30 guns (32-pdr.), with 3 guns in
each end and 12 on each side, but no guns in the wake of paddle wheel
and machinery. Hatches to give air to the stokehold were located
amidships. The _Battery_ was to have been supplemented at the ends of
each hull by a Columbiad "submarine gun" (100-pdr.), Fulton's invention,
but these were not fitted. Provision was to be made in the fireboxes for
heating shot, and a force pump with a cylinder 33 inches in diameter was
employed to throw a stream of cold water, about 60-80 gallons per
minute, for a distance of about two hundred feet. This could be done
only when the paddle wheel was not in operation. The paddle wheel was
housed, the top fitted with stairs to the spar deck. The gun deck, over
the race, was used in part for staterooms, of which the bulkheads were
permanent. Hammocks for the complement of 500 men were to be slung on
the rest of the gun deck. The ship drew 10 feet 4 inches, with the port
sills about 5-1/2 feet above the loadline. Burning wood, the vessel
could carry about 4 days' supply of fuel; burning coal, she carried 12
days' supply.

Montgéry said that the vessel would be vulnerable to bombshells and hot
shot, and that furthermore she could be boarded. The displacement of the
ship, at service draft, was 1,450 tons, a figure Montgéry obtained from
a copy of the original plan given him by Noah Brown.

[Illustration: Figure 6.--FRENCH SKETCH, in Rigsarkivet, Copenhagen, of
inboard profile and arrangement of Fulton's _Steam Battery_, showing
details of the Fulton engine, probably taken from one of his preliminary

In 1935, Lieutenant Ralph R. Gurley, USN, attempted a reconstruction in
sketches of the vessel published in his article "The U.S.S. _Fulton_ the
First" in the _U.S. Naval Institute Proceedings_.[15] This
reconstruction was based on the Patent Office drawing prepared for
Fulton, and published by Stuart and Bennett, and the foregoing French
sources. The Patent Office drawing showed the engine was an inclined
cylinder and Lt. Gurley shows this in his sketch; in his text (p. 323)
he says, "The engine was an inclined, single-cylinder affair with a
4-foot base and a 5-foot stroke." Gurley's attempt to reconstruct the
_Steam Battery_ is the only one known to the author.

Copenhagen Plans

In 1960, Kjeld Rasmussen, naval architect of the Danish Greenland
Company, was requested by the author to inspect in the Danish Royal
Archives at Copenhagen a folio of American ship plans, the index of
which had listed some Civil War river monitors. Mr. Rasmussen found the
monitor plans had been withdrawn but discovered that three plans of
Fulton's _Steam Battery_ existed, as well as plans of the first
_Princeton_, a screw sloop-of-war.

Copies of the _Steam Battery's_ plans were obtained at Copenhagen in
September 1960 through the courtesy of the archivist, and were found to
consist of the lines, copied in 1817, an inboard profile and
arrangement, and a sail and rigging plan. From these the reconstruction
for a scale model was drawn and is presented here with reproductions of
the original drawings upon which the reconstruction is based.

It is apparent that Montgéry's description is generally accurate. The
vessel is a catamaran, made of two hulls, double-ended and exactly
alike. The outboard sides are "moulded," with round bilges, the inboard
sides are straight and flat, as though a hull had been split along the
middle line and then planked up flat where split. The hulls are
separated by the race, in which the paddle wheel is placed at
mid-length. The topsides are made elliptical at the ends, and the
midsection shows a marked tumble-home over the thick topside planking
but less on the moulded lines.

[Illustration: Figure 6.]

The lines plan agreed rather closely to Montgéry's description of the
hull. After careful fairing it was found the lines drawing would produce
a vessel 153 feet 2 inches overall outside the stems, or about 151 feet
over the planked rabbets, with a moulded beam of 56 feet and extreme
beam of 58 feet. The moulded depth was 22 feet 9 inches and the width of
the race was 14 feet 10 inches, plank to plank. The room and space of
framing shown was 2 feet. The designed draft appears to be 13 feet and
this would bring the port sills 5 feet 6 inches above the loadline and
the underside of the gun-deck beams about 2 feet 9 inches above the

The lines plan is a Danish copy, probably of the building plan by Noah
Brown, and may be based on the plan Montgéry obtained from Brown. The
spar deck has the iron stanchions (Gurley translated these as
"chandeliers") which are set inboard 4 feet from the plank-sheer. This
gives room for cotton bales, outboard the stanchions, to form a
barricade. As will be seen by comparing the original Danish drawing with
the model drawing, the construction indicates that the iron stanchions
should be carried around the ends of the hull in the same manner as
along the sides, since the lower ends of the iron stanchions pass
through the spar deck and are secured to the inside of the inner ceiling
of the gun deck. The rudders are as shown in the Danish drawing, and it
is supposed that they were operated ferryboat fashion, one at each end
of the vessel. Hence, each pair of rudders was toggled together by a
cross-yoke. This was probably operated by a tiller (possibly the
cross-yokes and tillers were of iron) pivoted under the beams of the gun
deck close to the ends of the ship. Tiller ropes led from a tackle under
the gun-deck through trunks to the spar deck, where the wheels were
placed. This allowed proper sweep to the tillers and operation of each
pair of rudders. The paddle wheel was apparently of iron, with wooden
blades, and agrees with Montgéry's description. In the plan for the
model it is shown raised 18 inches above the original design position,
to agree with trial requirements.

[Illustration: Figure 7.--ORIGINAL LINES OF ROBERT FULTON'S _Steam
Battery_, a Danish copy dated September 12, 1817; found in Rigsarkivet,

It should be observed that the close CL-to-CL frame spacing created a
hull having frames touching one another, at least to above the turn of
the bilge, so the vessel was almost solid timber, before being planked
and ceiled, from keel to about the loadline. The sides are not only
heavily planked but, after the frames were ceiled with extraordinarily
heavy, square timbering, a supplementary solid, vertical framing was
introduced inboard and another ceiling added. The sides scale about 5
feet from outside the plank to the inboard face of the inner ceiling at
the level of the gunports.

The hulls were tied together athwartship by the deck beams of the gun
deck and spar deck, except in the wake of the paddle wheel. Knees were
placed along the sides of the race at alternate gun-deck beams. In
addition, the 12 1-foot-square timbers, crossing the race at the rabbets
of the hulls, (mentioned by Montgéry) are shown. These must have created
extraordinary resistance, even at the low speed of this steamer. The
deck details shown are the results of reconstruction of the inboard

History of Double-Hull Craft

The use of catamaran hulls, or "double-hulls," has been periodically
popular with ship designers since the time of Charles II of England. The
earliest of such vessels known in the present day were four sloops or
shallops designed 1673-1687 by Sir William Petty, who was an inventor in
the field of naval architecture and received some attention from Charles
II and from the Royal Society.

The first Petty experiment, the _Simon & Jude_, later called _Invention
I_, was launched October 28, 1662. She was designed with two hulls
cylindrical in cross section, each 2 feet in diameter, and 20 feet long.
A platform connected the hulls, giving the boat a beam of a little over
9 feet. She had a 20-foot mast stepped on one of the crossbeams
connecting the hulls, with a single gaff sail. In sailing trials she
beat three fast boats: the King's barge, a large pleasure boat, and a
man-of-war's boat. This "double-bottom," also called a "sluiceboat" or
"cylinder," was later lengthened at the stern to make her 30 feet

[Illustration: Figure 7.]

The King did not support Petty, to the latter's great disappointment,
and Petty next built a larger double-bottom, _Invention II_. This
catamaran was lapstrake construction. Not much is known of this boat
except that she beat the regular Irish packet boat, running between
Holyhead and Dublin, in a race each way, winning a £20 wager. She was
launched in July 1663; what became of her was not recorded.

A third and still larger boat, the _Experiment_, launched December 22,
1664, appears to have been a large sloop. This vessel sailed by way of
the Thames in April 1665 and went to Oporto, Portugal. She left Portugal
October 20, 1665, for home, but apparently went down with all hands in a
severe storm.

[Illustration: Figure 8.--DANISH COPY OF ORIGINAL SAIL PLAN of Robert
Fulton's _Steam Battery_, dated September 12, 1817, in Rigsarkivet,

[Illustration: Figure 9.--LINES OF FULTON'S _Steam Battery_, as
reconstructed for a model in the Museum of History and Technology.]

[Illustration: Figure 10.--A RECONSTRUCTION OF INBOARD WORKS of the
_Steam Battery_, for construction of the model in the Museum of History
and Technology.]

For 18 years Petty did no more with the type, but finally, in July
1684, he laid down a still larger sloop with two decks and a mast
standing 55 feet above her upper deck. She was named _St. Michael the
Archangel_ and is probably the design in Pepys' _Book of Miscellaneous
Illustrations_ in Magdalene College, Cambridge, England. This vessel
proved unmanageable and was a complete failure.

[Illustration: Figure 11.--MODEL LINES REDRAWN to outside of plank to
show hydrodynamic form of the _Steam Battery_.]

Though the double canoes of the Pacific Islands were probably known to
some in Europe in 1662, there is no evidence that Petty based his
designs on such craft. He appears to have produced his designs
spontaneously from independent observations and resulting theories.
Before Petty concluded his experiments, a number of double-hull craft
had been produced by others; however, some "double" craft, such as
"double shallops" may have been "double-enders," as shown by a
"double-moses boat" of the 18th century and later.[16]

The use of two canoes, joined by a platform or by poles was common in
colonial times; in Maryland and Virginia, dugouts so joined were used to
transport tobacco down the tidal creeks to vessels' loading. Such craft
were also used as ferries. M. V. Brewington's _Chesapeake Bay Log
Canoes_[17] and Paul Wilstack's _Potomac Landings_[18] illustrate canoes
used in this manner. A catamaran galley, two round-bottom hulls, flat on
the inboard side (a hull split along the centerline and the inboard
faces planked up), 113 feet long and each hull a 7-foot moulded beam,
6-foot 6 inches moulded depth, and placed 13 feet apart, was proposed by
Sir Sidney Smith, R.N., in the 1790's, and built by the British
Admiralty. Named _Taurus_, she is shown by the Admiralty draught to have
been a double-ender, with cabins amidships on the platform, an iron
rudder at each end (between the hulls) steered with tillers (to unship),
and with a ramp at one end. The plans are undated, signed by Captain Sir
Sidney Smith, and a field-carriage gun is shown at the ramp end of the
boat. This, and the heavy rocker in the keels, suggests the _Taurus_ was
intended for a landing boat. No sailing rig is indicated, but tholes for
12 oars or sweeps on each side are shown. The oarsmen apparently sat on
deck, or on low seats, with stretchers in hatches between each pair of
tholes (Admiralty Collection of Draughts, The National Maritime Museum,
Greenwich, England).

[Illustration: Figure 12.--GENERAL PLAN of the _Taurus_, a catamaran
galley gunboat proposed by Sir Sidney Smith, R.N., to the British
Admiralty in the early years of the French Revolution. From the
Admiralty Collection of Draughts, National Maritime Museum, Greenwich.]

Another experimenter with the double-hull type of vessel was a wealthy
Scot named Patrick Miller who was particularly interested in manual
propulsion of vessels, employing geared capstans to operate paddle
wheels. In a letter dated June 9, 1790, Miller offered Gustav III of
Sweden a design for a double-hulled 144-gun ship-of-the-line (rating as
a 130-gun ship) propelled by manually operated capstans connected to a
paddle wheel between the hulls. She was rigged to sail, with five masts
and was to be 246 feet long, 63 feet beam, and 17 feet draft; the hulls
were 16 feet apart.

This project was submitted by the King to Fredrik Henrik af Chapman, the
great Swedish naval architect, who made an adverse report. Chapman
pointed out in great detail that the weight of the armament, the
necessary hull structure, the stores, crew, ammunition, spars, sails,
rigging and gear, would greatly exceed Miller's designed displacement.
He also pointed out the prime fault of catamarans under sail--slow
turning in stays. He suggested that the speed under sail would be
disappointing. He doubted that a double-hull ship of such size could be
built strong enough to stand a heavy sea. He remarked that English
records showed that a small vessel of the catamaran type had been built
between 1680 and 1700 which had sailed well (this may have been one of
Petty's boats), and that "36 years ago" he had seen 8 miles from London,
a similar boat that had been newly built by Lord Baltimore and was about
50 feet long; this was a failure and was discarded after one trial.
Therefore, said Chapman, the Miller project was not new but rather an
old idea. Chapman's final remark is perhaps the best illustration of his
opinion of the catamaran, "Despite all this, two-hull vessels are
completely sound when the theory can be properly applied; that is in
vessels of very light weight, and of small size, with crews of one or
two men."

A "model" of such a double-hull ship--the _Experiment_, built at Leith,
Scotland, in 1786 by J. Laurie--was sent to Sweden by Miller. She was
105 feet long, 31 feet beam, and cost £3000. This vessel arrived in the
summer of 1790 and King Gustav in a letter dated July 26 ordered Col.
Michael Anckerswärd to welcome the vessel at Stockholm. The King
presented Miller with a gold snuffbox and a painting was made of the
vessel. The _Experiment_ had five paddle wheels in tandem between her
hulls, operated by geared capstans on deck. These gave her a speed of 5
knots but caused the crew to suffer from exhaustion in a short time. The
vessel was badly strained in a storm and was finally abandoned at St.
Petersburg, Russia.[19]

[Illustration: Figure 12.]

Miller later turned to the idea of employing steam instead of manual
power and built a 25-foot double-hulled pleasure boat of iron fitted
with a steam engine built by William Symington. Also named _Experiment_,
she was an apparent success, so Miller had a 60-foot boat built of the
double-hull design and fitted with an engine built by Symington. She
reached a speed of 7 mph on the Forth and Clyde Canal. However, Miller
lost interest when he found that the Symington engine was unreliable and
that Great Britain showed very little public support for such projects.

Fulton was acquainted with Symington's work and probably had heard of
Miller's vessels. At any rate, he employed the double-hull principle in
his steam ferryboats, the first of which was the _Jersey_, a 188-ton
vessel built by Charles Browne, which began service July 2, 1812. The
next year he had a sister ship built, the _York_. These vessels were
based on his patent drawing of 1809. In 1814 he had another vessel of
this type built, the _Nassau_. It was, therefore, logical that he should
apply this design to the _Steam Battery_. The double-hull design had
worked well in these ferries, and the design would give protection from
shot to the paddle wheel. The _Battery_ would have the ability to run
forward or astern so as not to be exposed to a raking fire from the
enemy while maneuvering in action. The application of this "ferryboat"
principle to the _Battery_ reduced the need for extreme maneuverability,
the catamaran's weakest point, even at low speed.

The resistance factors in the design are of relatively small importance,
for the speed possible under steam in this period was very low. However,
the plans show an apparently efficient hull form for the power
available, aside from the drag of the beams across the race in the
vicinity of the keel. The displacement was adequate. The height of the
gun-deck above the water at the race made the _Battery_ unsuitable for
rough-water operation, but there is no evidence that Fulton or the
sponsors of the vessel considered the _Battery_ as a coastwise or
seagoing steamer. However, the clearance of the gun deck above the water
and the dip of the paddle wheel would have made the additional weight of
an upper- or spar-deck battery prohibitive even had experience in action
proven it desirable.

Sail and Inboard Plans

[Illustration: Figure 13.--LINES OF _Taurus_. From the Admiralty
Collection of Draughts, National Maritime Museum, Greenwich.]

The sail and rigging plan is likewise a Danish copy and shows the
two-masted lateen rig employed. The hull is shown with bulwarks and
gunports on the spar deck but no other evidence that the _Battery_ was
finished in this manner has been found. The rig resembles that of some
of Josiah Fox's designs for Jeffersonian gunboats--double-enders
designed to sail in either direction but without the jibs. The topmasts
do not appear to be more than signal poles and apparently were not
fitted with sails; however, some European lateeners did have triangular
topsails over a lateen and it is possible the _Battery_ may have carried
such sails. Considering the stability and displacement of the _Battery_,
the rig is very small and not sufficiently effective. Shrouds were not
required; the masts were supported by runners that were shifted when the
yards were reversed, and in tacking. Apparently the jibstays also could
be slacked off so that the lateen yards would not have to be dipped
under them.

[Illustration: Figure 14.--RUDDER DETAIL of _Taurus_. From the Admiralty
Collection of Draughts, National Maritime Museum, Greenwich.]

The inboard profile is on tracing paper and the notes are in French.
This drawing is of a simplified hull form having flat-bottom hulls with
chines. It is possible that this is a tracing of a preliminary drawing
obtained by Marestier or Montgéry, but no documentation can be found.
Its importance is that it shows in some detail the engine and boilers,
as well as the wheelbox, and another drawing of the paddle wheel, more
or less duplicating the wheel shown in the Danish plan. No details of
the deck arrangements are shown in any of the plans, except for the dome
skylight over the fireroom in the boiler hull.

Both the lines plan and the inboard drawing show construction
midsections and hull connections. These plans show that the engine was
not inclined, but rather was vertical, contrary to Fulton's patent
drawing. The piston rod and the crosshead obviously passed through its
gun deck in a large hatch. Also it is plain that there must have been
large hatches afore and abaft the wheelbox to make the stepped wheelbox
construction desirable. There also must have been a hatch in the gun
deck under the domed skylight. It is improbable that the engine and
skylight hatches were used for ladderways, passing scuttles, or

The boilers are shown in the inboard profile about as described and
drawn by Marestier but with two stacks on each boiler, one to each flue;
Marestier's sketch in his report on American steamships shows the flues
of each boiler trunked into a single stack. The battery had two boilers
and the stacks are at the boilers' fire-door end. The steam lines came
off the crown of the boilers and probably passed through the ends of the
wheelbox to the engine; a trunk for the steam lines would undoubtedly
have been necessary.

[Illustration: Figure 15.--SKETCH OF 130-GUN SHIP proposed by Patrick
Miller to King Gustav III of Sweden in 1790. In Statens Sjöhistoriska
Museum, Stockholm.]

[Illustration: Figure 16.--PATRICK MILLER'S manually propelled
(paddle-wheel) catamaran ship _Experiment_, built at Leith, Scotland,
1786. Scale drawing in Statens Sjöhistoriska Museum, Stockholm.]

The engine is shown to have had counterbalanced side levers, one on
each side, and a single flywheel on the outboard side. The cylinder is
over the condenser or "cistern," connected by the steam line and valve
box on the side. The cylinder crosshead is shown in the inboard profile
to have reached the underside of the beams of the upper deck. The
crosshead was connected by two connecting rods to the side levers. These
levers operated the paddle wheel by connecting rods to cranks on the
paddle-wheel shaft. There is another pair of connecting rods from the
side levers to the crosshead of the air pump. All connecting rods are on
one arm of the side levers, the other end having only a counterbalance
weight beyond the fulcrum bearing. The flywheel has a shaft fitted with
two gears, and is driven through idler gears from gears on the
paddle-wheel shaft; it turns at about twice the speed of the paddle
wheel. No other pumps or fittings are shown in the engine hull, although
manual pumps were probably fitted to fill and empty the boilers. Piping
is not shown.

[Illustration: Figure 17.--PAINTING OF THE _Experiment_ in the Statens
Sjöhistoriska Museum, Stockholm.]

The four rudders, toggled in pairs, are shown in both the lines and
inboard drawings, but the shape is different in the two plans. Operation
must have been by a tiller under the gun-deck beams. The outer end of
the tiller may have been pivoted on the toggle bar and the inboard end
fitted, as previously described, with steering cable or chain tackles.
This seems to be the only practical interpretation of the evidence.

Reconstructing the Plans

In the model it was necessary to reconstruct the deck arrangements
without enough contemporary description. The outboard appearance and
hull form, rig, and arrangement of armament require no reconstruction,
for all that is of importance is shown in the lines and rig drawings, or
in the inboard profile. The masts are shown to have been stepped over
the race on the gun deck. The iron stanchions are shown in the lines
drawing and in the construction section. However, their position at the
ends of the _Battery_ are apparently incorrectly shown in the original
lines plan. The construction section shows these stanchions to have been
stepped on the inside face of the inner ceiling and, as the ceiling
structure was carried completely around the ship, the stanchions in the
ends must have been placed inboard, as along the sides. The bowsprit was
above deck and would probably be secured in the knighthead timbers at
the ends of the hull, as well as by the heel bitts shown in the Danish
lines drawing. With the riding bitts shown inboard of the heel bitts at
each end of the vessel, it is obvious that she would work her ground
tackle at both ends and would therefore require two capstans; the
wheelbox would prevent effective use of a single one. The capstans might
be doubleheaded, as in some large frigates and ships-of-the-line.

[Illustration: Figure 18.--SAIL PLAN OF FULTON'S _Steam Battery_ as
reconstructed for model in the Museum of History and Technology.]

As to the remaining deck fixtures, hatches and fittings, these must be
entirely a matter of speculation. Ladderways, passing scuttles, hatches,
trunks, galley, heads and cabins were obviously required in a fighting
ship and can only be located on the theory that, when completed, the
_Battery_ was a practical vessel.

It has been stated that the officers' cabins were over the race; the
logical place for the heads, galley, wardroom and mess also would be
over the race, giving the remaining part of the gun deck for the
necessary hatches, ladderways, trunks, etc., in the two hulls, space
required for armament, and to sling the hammocks of a watch below. As
the vessel was never fully manned, apparently, the space for hammocks is
not a serious problem in a reconstruction. If the vessel had been manned
as proposed by 500 men, hammocks for over 200 would have been required,
which would give very crowded quarters in view of the limited space

Though no specific requirements were stated in the reports of the
trials, it seems reasonable to suppose that additional hatches were cut
in the decks to improve the fireroom ventilation. In the reconstruction
drawings, these hatchways as well as the other deck openings and deck
fittings--such as bilge pumps, companionways, skylights, binnacles,
wheels and wheel-rope trunks, cable trunks, steampipe casings, and stack
fiddleys--have been located in an effort to meet the imagined
requirements of the working of a ship of this unusual form.

[Illustration: Figure 19.--MODEL OF _Steam Battery_ in the Museum of
History and Technology. (Smithsonian photo 63990-E.)]

[Illustration: Figure 20.--LINES OF STEAMER _Congo_, built in 1815-1816
for the British Admiralty and converted to a sailing survey vessel. From
Admiralty Collection of Draughts, National Maritime Museum, Greenwich.]

There are some unanswered questions that arose in the preparation of
the reconstruction drawings. As has been shown, the original inboard
arrangement plan found in Copenhagen shows four smokestacks, while
Marestier's sketch of the vessel's boilers shows trunked flues
indicating that two stacks were used. It is possible that the boilers
were first fitted so that four stacks were required; alterations made as
a result of steaming trials may well have included the introduction of
trunked flues and the final use of two stacks in line fore-and-aft. This
would have required a rearrangement of the fiddley hatches amidships.

Another troublesome question was the doubtful arrangement of the four
companionways on the spar deck. Perhaps only two were fitted, one on
each side of the officers' staterooms while the ladderways at the crew's
end of the ship were simple ladder hatches.

The decision to use four bilge pumps is based upon the lack of drag in
the keel of the hulls, which would prevent accumulation of bilge water
at one end of the hull. The use of four single-barrel pumps instead of
four double-barrel pumps may be questioned, for chain pumps requiring
two barrels would have been practical.

Allowance for stores was made by use of platforms in the hold. It is
known from statements made to the Court of Inquiry, that the magazines
were amidships and that a part of these was close to the boilers. Fuel
and water would be in the lower hold under the platforms; hatches and
ladderways are arranged to permit fueling the ship.

A few prints or drawings of the ship, aside from the patent drawing,
have been found. There are two prints that show the launch of the
vessel. One, a print of 1815, is in possession of the Mariners' Museum,
Newport News, Va., and is reproduced in Alexander Crosby Brown's _Twin
Ships, Notes on the Chronological History of the Use of Multiple Hulled
Vessels_.[20] A poor copy of this print appears on page 13 of Bennett's
_Steam Navy of the United States_, and another and inaccurate sketch is
shown on page 8. These pictures were of no use in the reconstruction as
they show no details that are not in the Copenhagen plans. The patent
drawing does not show deck details and in fact does not represent the
vessel as built in any respect other than in being a catamaran with
paddle wheel amidships between the hulls.

The _Steam Battery_ did not have any particular influence on the design
of men-of-war that followed her. In the first place, steampower was not
viewed with favor by naval officers generally. This was without doubt
due to prejudice, but engines in 1820-30 were still unreliable when
required to run for long periods, as experienced by the early
ocean-going steamers. The great weight of the early steam engines and
their size in relation to power were important, and also important were
practical objections that prevented the design of efficient naval ocean
steamers until about 1840; even then, the paddle wheels made them very
vulnerable in action. Until the introduction of the screw propellor it
was not possible to design a really effective ocean-going naval steamer;
hence until about 1840-45, sail remained predominant in naval vessels
for ocean service, and steamers were accepted only in coast defense and
towing services, or as dispatch vessels.

No immediate use of the double hull in naval vessels of the maritime
powers resulted from the construction of the _Steam Battery_. The
flat-bottom chine-built design employed by Fulton in _North River_,
_Raritan_, and other early steamboats was utilized in the design for a
projected steamer by the British Admiralty in 1815-16. This vessel was
about 76 feet overall, 16-foot beam, and 8-foot 10 inches depth in hold.
Her design was for a flat-bottom, chine-built hull with no fore-and-aft
camber in the bottom, a sharp entrance, and a square-tuck stern with
slight overhang above the cross-seam. Her side frames were straight and
vertical amidships, but curved as the bow and stern were approached. She
was to be a side-paddle-wheel steamer, and her hull was diagonally
braced; the wheel and engine were to be about amidships where she was
dead flat for about 14 feet. However, the engine and boilers were not
installed; the engine was utilized ashore for pumping, and the vessel
was completed in the Deptford Yard as a sailing ship. Under the name
_Congo_ she was employed in the African coast survey. Her plan is in the
Admiralty Collection of Draughts, at the National Maritime Museum,
Greenwich, England.

The double hull continued to be employed in both steam and team
ferryboats in the United States and in England and France. A few river
and lake steamers were also built with this design of hull. Continued
efforts to obtain fast sailing by use of the double hull produced a
number of sailing catamarans; of these the Herreshoff catamarans of the
1870's showed high speed when reaching in a fresh breeze.

Designs for double-hulled steamers appeared during the last half of the
19th century; in 1874 the _Castalia_, a large, double-hull, iron,
cross-channel steamer, was built by the Thames Iron-works Company at
Blackwall, England. She was 290 feet long, and each hull had a beam of
17 feet. The paddle wheel was placed between the hulls and, ready for
sea, she drew 6-1/2 feet. She ran the 22 miles between Dover and Calais
in 1 hour and 50 minutes, a speed much slower than that of the
paddle-wheel, cross-channel steamers having one hull. Another
double-hull steamer was built for this service by Hawthorn, Leslie and
Company, Newcastle-on-Tyne, Scotland, in 1877. First named _Express_,
she was renamed _Calais-Douvres_ when she went into service in May 1878.
Her length was 302 feet, her extreme beam 62 feet, and each hull had a
beam of 18 feet, 3 inches. She drew 6-foot 7-1/2 inches ready for sea
and the paddle wheel was between the hulls. On her trials she made 14
knots and burned coal excessively. Sold to France in 1880, she was taken
out of service in 1889. Though popular, she was not faster than the
single-hull steamers in this service and had been a comparatively
expensive vessel to build and operate.

The many attempts to produce a very fast double-hull steamer and large
sailing vessels have led to disappointment for their designers and
sponsors. In the history of naval architecture, since Petty's time,
there have been a number of periods when the new-old idea of the double
hull has become popular. Craft of this type have been commonly well
publicized but, on the whole, their basic designs have followed the same
principles over and over again and have not produced the sought-for
increase in speed and handiness.

In very recent years there has been a revival in interest in sailing
double-hull boats that is enthusiastic as to very small craft and
somewhat restrained as to large boats. A few projects are under
development for double-hull craft, power and sail, of over 90-foot
length, including an oceanographic research vessel. In general, however,
the performance of double-hull boats has shown that Chapman's estimate
of the type was reasonably correct and that there are limitations,
particularly in maneuverability in the double-hull craft that could have
been found by reference to the history of past experiments with the



At the close of the year eighteen hundred and thirteen, Robert Fulton
exhibited to the President of the United States, the original drawing
from which the engraving on Plate One is sketched, being a
representation of the proposed war-steamer or floating-battery, named by
him, the Demologos. This sketch possesses more than ordinary interest,
from the circumstance that it is, doubtless, the only record of the
_first war-steamer in the world_, designed and drawn by the immortal
Fulton, and represented by him to the Executive, as capable of carrying
a strong battery, with furnaces for red hot shot, and being propelled by
the power of steam, at the rate of _four_ miles an hour.

It was contemplated that this vessel, besides carrying her proposed
armament on deck, should also be furnished with submarine guns, two
suspended from each bow, so as to discharge a hundred pound ball into an
enemy's ship at ten or twelve feet below her water-line. In addition to
this, her machinery was calculated for the addition of an engine which
would discharge an immense column of water upon the decks, and through
the port-holes of an enemy, making her the most formidable engine for
warfare that human ingenuity has contrived.

The estimated cost of the vessel was three hundred and twenty thousand
dollars, nearly the sum requisite for a frigate of the first class.

The project was zealously embraced by the Executive, and the national
legislature in March, eighteen hundred and fourteen, passed a law,
authorizing the President of the United States to cause to be built,
equipped, and employed, one or more floating batteries, for the defense
of the waters of the United States.

The building of the vessel was committed by the Coast and Harbor Defense
Association, to a sub-committee of five gentlemen, who were recognized
by the Government as their agents for that purpose, and whose
interesting history of the Steam Frigate is copied in Note A, of the
Appendix to this volume.

Robert Fulton, whose soul animated the enterprise, was appointed the
engineer; and on the twentieth day of June, eighteen hundred and
fourteen, the keel of this novel steamer was laid at the ship-yard of
Adam and Noah Brown, her able and active constructors, in the city of
New York, and on the twenty-ninth of the following October, or in little
more than four months, she was safely launched, in the presence of
multitudes of spectators who thronged the surrounding shores, and were
seen upon the hills which limited the beautiful prospect around the bay
of New York.

The river and bay were filled with steamers and vessels of war, in
compliment to the occasion. In the midst of these was the enormous
floating mass, whose bulk and unwieldy form seemed to render her as
unfit for motion, as the land batteries which were saluting her.

In a communication from Captain David Porter, U. S. Navy, to the Hon.
Secretary of the Navy, dated New York, October 29, 1814, he states,--"I
have the pleasure to inform you that the "FULTON THE FIRST," was this
morning safely launched. No one has yet ventured to suggest any
improvement that could be made in the vessel, and to use the words of
the projector, '_I would not alter her if it were in my power to do

"She promises fair to meet our most sanguine expectations, and I do not
despair in being able to navigate in her from one extreme of our coast
to the other. Her buoyancy astonishes every one, she now draws _only
eight feet three inches water_, and her draft will only be _ten_ feet
with all her guns, machinery, stores, and crew, on board. The ease with
which she can now be towed with a single steamboat, renders it certain
that her velocity will be sufficiently great to answer every purpose,
and the manner it is intended to secure her machinery from the gunner's
shot, leaves no apprehension for its safety. I shall use every exertion
to prepare her for immediate service; her guns will soon be mounted, and
I am assured by Mr. Fulton, that her machinery will be in operation in
about six weeks."

On the twenty-first of November, the Steam Frigate was moved from the
wharf of Messrs. Browns, in the East River, to the works of Robert
Fulton, on the North River, to receive her machinery, which operation
was performed by fastening the steamboat "Car of Neptune," to her
larboard, and the steamboat "Fulton," to her starboard side; they towed
her through the water from three and a-half to four miles per hour.

The dimensions of the "Fulton the First" were:--

     Length, one hundred and fifty-six feet.

     Breadth, fifty-six feet.

     Depth, twenty feet.

     Water-wheel, sixteen feet diameter.

     Length of bucket, fourteen feet.

     Dip, four feet.

     Engine, forty-eight inch cylinder, and five feet stroke.

     Boiler, length, twenty-two feet; breath, twelve feet; and depth,
     eight feet.

     Tonnage, two thousand four hundred and seventy-five.

By June, eighteen hundred and fifteen, her engine was put on board, and
she was so far completed as to afford an opportunity of trying her
machinery. On the first of June, at ten o'clock in the morning, the
"Fulton the First," propelled by her own steam and machinery, left the
wharf near the Brooklyn ferry, and proceeded majestically into the
river; though a stiff breeze from the south blew directly ahead, she
stemmed the current with perfect ease, as the tide was a strong ebb. She
sailed by the forts and saluted them with her thirty-two pound guns. Her
speed was equal to the most sanguine expectations; she exhibited a novel
and sublime spectacle to an admiring people. The intention of the
Commissioners being solely to try her enginery, no use was made of her
sails. After navigating the bay, and receiving a visit from the officers
of the French ship of war lying at her anchors, the Steam Frigate came
to at Powles' Hook ferry, about two o'clock in the afternoon, without
having experienced a single unpleasant occurrence.

On the fourth of July, of the same year, she made a passage to the ocean
and back, and went the distance, which, in going and returning, is
fifty-three miles, in eight hours and twenty minutes, without the aid of
sails; the wind and tide were partly in her favor and partly against
her, the balance rather in her favor.

In September, she made another trial trip to the ocean, and having at
this time the weight of her whole armament on board, she went at an
average of five and a half miles an hour, with and against the tide.
When stemming the tide, which ran at the rate of three miles an hour,
she advanced at the rate of two and a-half miles an hour. This
performance was not more than equal to Robert Fulton's expectations, but
it exceeded what he had premised to the Government, which was that she
should be propelled by steam at the rate of from three to four miles an

The English were not uninformed as to the preparations which were
making for them, nor inattentive to their progress. It is certain that
the Steam Frigate lost none of her terrors in the reports or
imaginations of the enemy. In a treatise on steam vessels, published in
Scotland at that time, the author states that he has taken great care to
procure _full_ and _accurate_ information of the Steam Frigate launched
in New York, and which he describes in the following words:--

"Length on deck, _three hundred feet_; breadth, _two hundred feet_;
thickness of her sides, _thirteen feet_ of alternate oak plank and cork
wood--carries forty-four guns, four of which are _hundred pounders_;
quarter-deck and forecastle guns, forty-four pounders; and further to
annoy an enemy attempting to board, can discharge _one hundred gallons
of boiling water in a minute_, and by mechanism, brandishes _three
hundred cutlasses_ with the utmost regularity over her gunwales; works
also an equal number of heavy iron pikes of great length, darting them
from her sides with prodigious force, and withdrawing them every quarter
of a minute"!!

The war having terminated before the "_Fulton the First_" was entirely
completed, she was taken to the Navy Yard, Brooklyn, and moored on the
flats abreast of that station, where she remained, and was used as a
receiving-ship until the fourth of June, eighteen hundred and
twenty-nine, when she was blown up. The following letters from Commodore
Isaac Chauncey (then Commandant of the New York Navy Yard) to the
Honorable Secretary of the Navy, informing him of the distressing event,
concludes this brief history of the _first steam vessel of war ever

       *       *       *       *       *

_June 5th, 1829_.


It becomes my painful duty to report to you a most unfortunate
occurrence which took place yesterday, at about half past two o'clock,
P. M., in the accidental blowing up of the Receiving Ship Fulton, which
killed twenty-four men and a woman, and wounded nineteen; there are also
five missing. Amongst the killed I am sorry to number Lieutenant S. M.
Brackenridge, a very fine, promising officer, and amongst the wounded
are, Lieutenants Charles F. Platt, and A. M. Mull, and Sailing-Master
Clough, the former dangerously, and the two last severely; there are
also four Midshipmen severely wounded. How this unfortunate accident
occurred I am not yet able to inform you, nor have I time to state more
particularly; I will, as soon as possible, give a detailed account of
the affair.

I have the honor to be, Sir,
  Very respectfully,

  _Secretary of the Navy, Washington._

_June 8th, 1829_.


I had been on board the "Fulton" all the morning, inspecting the ship
and men, particularly the sick and invalids, which had increased
considerably from other ships, and whom I had intended to ask the
Department permission to discharge, as being of little use to the
service. I had left the ship but a few moments before the explosion took
place, and was in my office at the time. The report did not appear to me
louder than a thirty-two pounder, although the destruction of the ship
was complete and entire, owing to her very decayed state, for there was
not on board, at the time, more than two and a-half barrels of damaged
powder, which was kept in the magazine for the purpose of firing the
morning and evening gun. It appears to me that the explosion could not
have taken place from accident, as the magazine was as well, or better
secured, than the magazines of most of our ships, yet it would be
difficult to assign a motive to those in the magazine for so horrible an
act, as voluntarily to destroy themselves and those on board. If the
explosion was not the effect of design, I am at a loss to account for
the catastrophe.

I have the honor to be, Sir,
  Very respectfully,

  _Secretary of the Navy, Washington_.




Commissioners superintending the construction of a steam vessel of war,
to the Secretary of the Navy._

NEW YORK, _December 28th, 1815_.


The war which was terminated by the treaty of Ghent, afforded, during
its short continuance, a glorious display of the valor of the United
States by land and by sea--it made them much better known to foreign
nations, and, what is of much greater importance, it contributed to make
them better acquainted with themselves--it excited new enterprises--it
educed latent talents--it stimulated to exertions unknown to our people

A long extent of coast was exposed to an enemy, powerful above every
other on the ocean. His commanders threatened to lay waste our country
with fire and sword, and, actually, in various instances, carried their
menaces into execution. It became necessary, for our defense, to resist,
by every practicable method, such a formidable foe.

It was conceived, by a most ingenious and enterprising citizen, that
the power of Steam could be employed to propel a floating battery,
carrying heavy guns, to the destruction of any hostile force that should
hover on the shores, or enter the ports of our Atlantic frontier. The
perfect and admirable success of his project for moving boats containing
travelers and baggage by the same elastic agent, opened the way to its
employment for carrying warriors and the apparatus for fighting.

The plan was submitted to the consideration of the executive of an
enlightened government. Congress, influenced by the most liberal and
patriotic spirit, appropriated money for the experiment, and the Navy
Department, then conducted by the honorable William Jones, appointed
commissioners to superintend the construction of a convenient vessel
under the direction of ROBERT FULTON, the inventor, as engineer, and
Messrs. Adam and Noah Brown, as naval constructors. The enterprise, from
its commencement, and during a considerable part of its preparatory
operations, was aided by the zealous co-operation of Major General
Dearborn, then holding his head-quarters at the city of New York, as the
officer commanding the third military district. The loss of his valuable
counsel in conducting a work which he had maturely considered, and which
he strongly recommended, was the consequence of his removal to another
section of the Union, where his professional talents were specially

The keels of this steam-frigate were laid on the twentieth day of June,
eighteen hundred and fourteen. The strictest blockade the enemy could
enforce interrupted the coasting trade, and greatly enhanced the price
of timber. The vigilance with which he guarded our coast against
intercourse with foreign nations, rendered difficult the importation of
copper and iron. The same impediment attended the supplies of coal
heretofore brought to New York from Richmond and Liverpool. Lead, in
like manner, was procured under additional disadvantages. These attempts
of the enemy to frustrate the design, were vain and impotent. All the
obstacles were surmounted. Scarcity of the necessary woods and metals
were overcome by strenuous exertions; and all the blockading squadron
could achieve, was not a disappointment in the undertaking, but merely
an increase of the expense.

So, in respect to tradesmen and laborers, there was an extraordinary
difficulty. Shipwrights had repaired to the lakes, for repelling the
enemy, in such numbers, that, comparatively speaking, few were left on
the seaboard. A large portion of the men who had been engaged in daily
work, had enlisted as soldiers, and had marched under the banners of the
nation to the defense of its rights--yet amidst the scarcity of hands, a
sufficient number were procured for the purpose which the Commissioners
had in charge. An increase of wages was the chief impediment, and this
they were enabled practically to overcome.

By the exemplary combination of diligence and skill, on the part of the
Engineer and Constructors, the business was so accelerated, that the
vessel was launched on the twenty-ninth day of October, amidst the
plaudits of an unusual number of citizens.

Measures were immediately taken to complete her equipment; the boiler,
the engine, and the machinery were put on board with all possible
expedition. Their weight and size far surpassed any thing that had been
witnessed before among us.

The stores of artillery in New York not furnishing the number and kind
of cannon which she was destined to carry, it became necessary to
transport guns from Philadelphia. A prize, taken from the enemy, put
some fit and excellent pieces at the disposal of the Navy Department. To
avoid the danger of capture by the enemy's cruisers, these were carted
over the miry roads of New Jersey. Twenty heavy cannon were thus
conveyed by the strength of horses. Carriages of the most approved model
were constructed, and every thing done to bring her into prompt action,
as an efficient instrument of war.

About this time, an officer, pre-eminent for bravery and discipline,
was commissioned by the government to her command. Prior to this event,
it had been intended by the Commissioners to finish her conformably to
the plan originally submitted to the Executive. She is a structure
resting upon two boats and keels, separated from end to end by a canal
fifteen feet wide, and sixty-six long. One boat contained the caldrons
of copper to prepare her steam. The vast cylinder of iron, with its
piston, levers, and wheels, occupied a part of its fellow; the great
water-wheel revolved in the space between them; the main or gun-deck
supported her armament, and was protected by a bulwark four feet ten
inches thick, of solid timber. This was pierced by thirty port-holes, to
enable as many thirty-two pounders to fire red hot balls; her upper or
spar deck was plain, and she was to be propelled by her enginery alone.

It was the opinion of Captain Porter and Mr. Fulton, that the upper deck
ought to be surrounded with a bulwark and stanchions--that two stout
masts should be erected to support latteen sails--that there should be
bowsprits for jibs, and that she should be rigged in a corresponding
style. Under authorities so great, and with the expectation of being
able to raise the blockade of New London, by destroying, taking, or
routing the enemy's ships, all these additions were adopted and
incorporated with the vessel.

It must here be observed, that during the exhaustion of the treasury,
and the temporary depression of public credit, the Commissioners were
exceedingly embarrassed--their payments were made in treasury notes,
which they were positively instructed to negotiate at par. On several
occasions even these were so long withheld, that the persons who had
advanced materials and labor were importunate for payment, and silently
discontented. To a certain extent, the Commissioners pledged their
private credit. Notwithstanding all this, the men, at one time, actually
broke off. The work was retarded, and her completion unavoidably
deferred, to the great disappointment of the Commissioners, until winter
rendered it impossible for her to act.

Under all this pressure, they, nevertheless, persevered in the important
object confided to them. But their exertions were further retarded by
the premature and unexpected death of the Engineer. The world was
deprived of his invaluable labors before he had completed this favorite
undertaking. They will not inquire, wherefore, in the dispensations of
Divine Providence, he was not permitted to realize his grand conception.
_His discoveries, however, survive for the benefit of mankind_, and will
extend to unborn generations.

At length all matters were ready for a trial of the machinery to urge
such a bulky vessel through the water. This essay was made on the first
day of June, eighteen hundred and fifteen. She proved herself capable of
opposing the wind, and of stemming the tide, of crossing currents, and
of being steered among vessels riding at anchor, though the weather was
boisterous and the water rough. Her performance demonstrated that the
project was successful--no doubt remained that a floating battery,
composed of heavy artillery, could be moved by steam. The Commissioners
returned from the exercise of the day, satisfied that the vessel would
answer the intended purpose, and consoled themselves that their care had
been bestowed upon a worthy object.

But it was discovered, that various alterations were necessary. Guided
by the light of experience, they caused some errors to be corrected, and
some defects to be supplied. She was prepared for a second voyage with
all practicable speed.

On the fourth of July she was again put in action. She performed a trip
to the ocean, eastward of Sandy Hook, and back again, a distance of
fifty-three miles, in eight hours and twenty minutes. A part of this
time she had the tide against her, and had no assistance whatever from
sails. Of the gentlemen who formed the company invited to witness the
experiment, not one entertained a doubt of her fitness for the intended

Additional expedients were, notwithstanding, necessary to be sought for
quickening and directing her motion. These were devised and executed
with all possible care.

Suitable arrangements having been made, a third trial of her powers was
attempted on the eleventh day of September, with the weight of
twenty-six of her long and ponderous guns, and a considerable quantity
of ammunition and stores on board; her draft of water was short of
eleven feet. She changed her course by inverting the motion of the
wheel, without the necessity of putting about. She fired salutes as she
passed the forts, and she overcame the resistance of the wind and tide
in her progress down the bay. She performed beautiful man[oe]uvres
around the United States' Frigate JAVA, then at anchor near the
light-house. She moved with remarkable celerity, and she was perfectly
obedient to her double helm. It was observed that the explosion of
powder produced very little concussion. The machinery was not affected
by it in the smallest degree. Her progress, during the firing, was
steady and uninterrupted. On the most accurate calculations, derived
from heaving the log, her average velocity was five and a-half miles per
hour. Notwithstanding the resistance of currents, she was found to make
headway at the rate of two miles an hour against the ebb of the East
River, running three and a-half knots. The day's exercise was
satisfactory to the respectable company who attended, beyond their
utmost expectations. It was universally agreed that we now possessed a
new auxiliary against every maratime invader. The City of New York,
exposed as it is, was considered as having the means of rendering itself
invulnerable. The Delaware, Chesapeake, Long Island Sound, and every
other bay and harbor in the nation, may be protected by the same
tremendous power.

Among the inconveniences observable during the experiment, was the heat
endured by the men who attended the fires. To enable a correct judgment
to be formed on this point, one of the Commissioners (Dr. Mitchel)
descended and examined, by a thermometer, the temperature of the hold,
between the two boilers. The quicksilver, exposed to the radiant heat of
the burning fuel, rose to one hundred and sixteen degrees of
Fahrenheit's scale. Though exposed thus to its intensity, he experienced
no indisposition afterwards. The analogy of potteries, forges,
glass-houses, kitchens, and other places, where laborers are habitually
exposed to high heats, is familiar to persons of business and of
reflection. In all such occupations, the men, by proper relays, perform
their services perfectly well.

The Government, however, will understand that the hold of the present
vessel could be rendered cooler by other apertures for the admission of
air, and that on building another steam frigate, the comfort of the
firemen might be provided for, as in the ordinary steamboats.

The Commissioners congratulate the Government and the nation on the
event of this noble project. Honorable alike, to its author and its
patrons, it constitutes an era in warfare and the arts. The arrival of
peace, indeed, has disappointed the expectations of conducting her to
battle. That last and conclusive act of showing her superiority in
combat, has not been in the power of the Commissioners to make.

If a continuance of tranquillity should be our lot, and this steam
vessel of war be not required for the public defense, the nation may
rejoice that the fact we have ascertained is of incalculably greater
value than the expenditure--and that if the present structure should
perish, we have the information never to perish, how, on a future
emergency, others may be built. The requisite variations will be
dictated by circumstances.

Owing to the cessation of hostilities, it has been deemed inexpedient to
finish and equip her as for immediate and active employ. In a few weeks
every thing that is incomplete could receive the proper adjustment.

After so much has been done, and with such encouraging results, it
becomes the Commissioners to recommend that the steam frigate be
officered and manned for discipline and practice. A discreet commander,
with a selected crew, could acquire experience in the mode of navigating
this peculiar vessel. The supplies of fuel, the tending of the fire, the
replenishing of the expended water, the management of the mechanism, the
heating of shot, the exercise of the guns, and various matters, can only
become familiar by use. It is highly important that a portion of seamen
and marines should be versed in the order and economy of the steam
frigate. They will augment, diffuse, and perpetuate knowledge. When, in
process of time, another war shall call for more structures of this
kind, men, regularly trained to her tactics, may be dispatched to the
several stations where they may be wanted. If, on any such disposition,
the Government should desire a good and faithful agent, the
Commissioners recommend Captain Obed Smith to notice, as a person who
has ably performed the duties of inspector from the beginning to the end
of the concern.

Annexed to the report, you will find, Sir, several statements
explanatory of the subject. A separate report of our colleague, the
honorable Oliver Wolcott, whose removal from New York precluded him from
attending to the latter part of the business, with his accustomed zeal
and fidelity, is herewith presented. A drawing of her form and
appearance, by Mr. Morgan, as being like to give satisfaction to the
department, is also subjoined, as are likewise an inventory of her
furniture and effects, and an account of the timber and metals
consolidated in her fabric.

It is hoped these communications will evince the pains taken by the
Commissioners, to execute the honorable and responsible trust reposed in
them by the Government.


       *       *       *       *       *


   [1]  _The American Neptune_ (1946), vol. 6, pp. 253-274.

   [2]  _The American Neptune_ (1944), vol. 4, pp. 327-329.

   [3]  New York, 1853, pp. 13-17.

   [4]  Pittsburgh, 1896, pp. 8-16.

   [5]  See pages 172 through 176 for this report, which is reproduced
        from CHARLES B. STUART, _Naval and Mail Steamers of the United
        States_ (New York, 1853), app., pp. 155-159.

   [6]  National Archives, Navy Records Plans, 80-7-14; and HOWARD I.
        CHAPELLE, _History of the American Sailing Navy_ (New York: W.
        W. Norton & Co., 1949), pp. 293-295.

   [7]  National Archives, Navy Records Plans, 80-7-9; and CHAPELLE,
        _History of the American Sailing Navy_, pp. 226, 228.

   [8]  National Archives, Navy Records Plans, 80-7-15.

   [9]  National Archives, Naval Records Collection, Miscellaneous
        Letters, 1819, II.

  [10]  See p. 169, reproduced from CHARLES B. STUART, _Naval and Mail
        Steamers of the United States_ (New York, 1853), p. 15.

  [11]  JEAN BAPTISTE MARESTIER, _Mémoire sur les bateaux à vapeur des
        États-Unis d'Amérique, avec un appendice sur diverses machines
        relatives à la Marine_ (Paris: L'imprimerie Royal, 1824).

  [12]  1820-1823, vol. 7, p. 437.

  [13]  _Annales de l'industrie nationale et étrangère, ou Mercure
        Technologique_ (Paris, 1822), pp. 760-762.

  [14]  January 27, 1823, vol. 7, pp. 436-438.

  [15]  January-March 1935, vol. 61, pp. 322-328.

  [16]  HOWARD I. CHAPELLE, _American Small Sailing Craft_ (New York:
        W. W. Norton & Co., Inc., 1951), pp. 29, 31.

  [17]  Newport News, Va.: The Mariners' Museum, 1937, p. 23.

  [18]  Indianapolis, Ind.: Bobbs Merrill, 1932, p. 291.

  [19]  HENRY WILLIAM EDWARD, _The Double Bottom or Twin Hulled Ship of
        Sir William Petty_ (Oxford: The Roxburghe Club, 1931).

  [20]  Publication No. 5 (Newport News: The Mariners' Museum, 1939),
        p. 22.

       *       *       *       *       *

Typographical Corrections

    Pg. 152: "the _Simon & Jude_, later called _Invention I_" (was "latter").

       *       *       *       *       *


  PAPER 40


  _Eduard Farber_

                            THE ELEMENT FROM ANIMALS AND PLANTS    178

                                                     EARLY USES    181


                                  PHOSPHATES AS PLANT NUTRIENTS    185

                           FROM INORGANIC TO ORGANIC PHOSPHATES    187

                                   PHOSPHATIDES AND PHOSPHAGENS    189

                                      NUCLEIN AND NUCLEIC ACIDS    192

                             PHOSPHATES IN BIOLOGICAL PROCESSES    197

                                          MEDICINES AND POISONS    198

_Eduard Farber_


     _The "cold light" produced by phosphorus caused it to be
     considered a miraculous chemical for a long time after its
     discovery, about 1669. During the intervening three centuries
     numerous other chemical miracles have been found, yet
     phosphorus retains a special aura of universal importance in
     chemistry. Many investigators have occupied themselves with
     this element and its diverse chemical compounds. Further
     enlightenment and insight into the ways of nature can be
     expected from these efforts._

     _Not only is the story of phosphorus a major drama in the
     history of chemistry; it also illustrates, in a spectacular
     example, the growth of this science through the discovery of
     connections between apparently unrelated phenomena, and the
     continuous interplay between basic science and the search for
     practical usage._

     THE AUTHOR: _Eduard Farber is a research professor at American
     University, Washington, D.C., and has been associated with the
     Smithsonian Institution as a consultant in chemistry._

When phosphorus was discovered, nearly three centuries ago, it was
considered a miraculous thing. The only event that provoked a similar
emotion was the discovery of radium more than two centuries later. The
excitement about the _Phosphorus igneus_, Boyle's _Icy Noctiluca_, was
slowly replaced by, or converted into, chemical research. Yet, if we
would allow room for emotion in research, we could still be excited
about the wondrous substance that chemical and biological work continues
to reveal as vitally important. It is a fundamental plant nutrient, an
essential part in nerve and brain substance, a decisive factor in muscle
action and cell growth, and also a component in fast-acting, powerful
poisons. The importance of phosphorus was gradually recognized and the
means by which this took place are characteristic and similar to other
developments in the history of science. This paper was written in order
to summarize these various means which led to the highly complex ways of
present research.

The Element from Animals and Plants

It was a little late to search for the philosophers' stone in 1669, yet
it was in such a search that phosphorus was discovered. Wilhelm Homberg
(1652-1715) described it in the following manner: Brand, "a man little
known, of low birth, with a bizarre and mysterious nature in all he
did, found this luminous matter while searching for something else. He
was a glassmaker by profession, but he had abandoned it in order to be
free for the pursuit of the philosophical stone with which he was
engrossed. Having put it into his mind that the secret of the
philosophical stone consisted in the preparation of urine, this man
worked in all kinds of manners and for a very long time without finding
anything. Finally, in the year 1669, after a strong distillation of
urine, he found in the recipient a luminant matter that has since been
called phosphorus. He showed it to some of his friends, among them
Mister Kunkel [sic]."[1]

Neither the name nor the phenomenon were really new. Organic
phosphorescent materials were known to Aristotle, and a lithophosphorus
was the subject of a book published in 1640, based on a discovery made
by a shoemaker, Vicenzo Casciarolo, on a mountain-side near Bologna in
1630.[2] Was the substance new which Brand showed to his friends? Johann
Gottfried Leonhardi quotes a book of 1689 in which the author, Kletwich,
claims that this phosphorus had already been known to Fernelius, the
court physician of King Henri II of France (1154-1189).[3] To the same
period belongs the "Ordinatio Alchid Bechil Saraceni philosophi," in
which Ferdinand Hoefer found a distillation of urine with clay and
carbonaceous material described, and the resulting product named
escarbuncle.[4] It would be worth looking for this source; although
Bechil would still remain an entirely unsuccessful predecessor, it does
seem strange that in all the distillations of arbitrary mixtures, the
conditions should never before 1669 have been right for the formation
and the observation of phosphorus.

[Illustration: Figure 1.--THE ALCHEMIST DISCOVERS PHOSPHORUS. A painting
by Joseph Wright (1734-1779) of Derby, England.]

For Brand's contemporaries at least, the discovery was new and exciting.
The philosopher Gottfried Wilhelm von Leibniz (1646-1716) considered it
important enough to devote some of his time (between his work as
librarian in Hanover and Wolfenbüttel, his efforts to reunite the
Protestant and the Catholic churches, and his duties as Privy Councellor
in what we would call a Department of Justice) to a history of
phosphorus. This friend of Huygens and Boyle tried to prove that Kunckel
was not justified in claiming the discovery for himself.[5] Since then,
it has been shown that Johann Kunckel (1630-1703) actually worked out
the method which neither Brand nor his friend Kraft wanted to disclose.
Boyle also developed a method independently, published it, and
instructed Gottfried Hankwitz in the technique. Later on, Jean Hellot
(1685-1765) gave a meticulous description of the details and a long
survey of the literature.[6]

[Illustration: Figure 2.--GALLEY-OVEN, 1869. The picture is a cross
section through the front of the oven showing one of the 36 retorts, the
receivers for the distillate, and the space in the upper story used for
evaporating the mixture of acid solution of calcium phosphate and coal.
(According to ANSELME PAYEN, _Précis de Chimie industrielle_, Paris,
1849; reproduced from HUGO FLECK, _Die Fabrikation chemischer Produkte
aus thierischen Abfällen_, Vieweg, Braunschweig, 1862, page 80 of volume
2, 2nd group, of P. BOLLEY'S _Handbuch der chemischen Technologie_.)]

To obtain phosphorus, a good proportion of coal (regarded as a type of
phlogiston) was added to urine, previously thickened by evaporation and
preferably after putrefaction, and the mixture was heated to the highest
attainable temperature. It was obvious that phlogiston entered into the
composition of the distillation product. The question remained whether
this product was generated _de novo_. In his research of 1743 to 1746,
Andreas Sigismund Marggraf (1709-1782) provided the answer. He found the
new substance in edible plant seeds, and he concluded that it enters the
human system through the plant food, to be excreted later in the urine.
He did not convince all the chemists with his reasoning. In 1789,
Macquer wrote: "There are some who, even at this time, hold that the
phosphorical ('phosphorische') acid generates itself in the animals and
who consider this to be the 'animalistic acid.'"[7]

Although Marggraf was more advanced in his arguments than these
chemists, yet he was a child of his time. The luminescent and
combustible, almost wax-like substance impressed him greatly. "My
thoughts about the unexpected generation of light and fire out of water,
fine earth, and phlogiston I reserve to describe at a later time." These
thoughts went so far as to connect the new marvel with alchemical wonder
tales. When Marggraf used the "essential salt of urine," also called
_sal microcosmicum_, and admixed silver chloride ("horny silver") to it
for the distillation of phosphorus, he expected "a partial conversion of
silver by phlogiston and the added fine vitrifiable earth, but no trace
of a more noble metal appeared."[8]

Robert Boyle had already found that the burning of phosphorus produced
an acid. He identified it by taste and by its influence on colored plant
extracts serving as "indicators." Hankwitz[9] described methods for
obtaining this acid, and Marggraf showed its chemical peculiarities.
They did not necessarily establish phosphorus as a new element. To do
that was not as important, at that time, as to conjecture on analogies
with known substances. Underlying all its unique characteristics was the
analogy of phosphorus with sulfur. Like sulfur, phosphorus can burn in
two different ways, either slowly or more violently, and form two
different acids. The analogy can, therefore, be extended to explain the
results in both groups in the same way. In the process of burning, the
combustible component is removed, and the acid originally combined with
the combustible is set free. Whether the analogy should be pursued even
further remained doubtful, although some suspicion lingered on for a
while that phosphoric acid might actually be a modified sulfuric acid.
Analogies and suspicions like these were needed to formulate new
questions and stimulate new experiments. They are cited here for their
important positive value in the historical development, and not for the
purpose of showing how wrong these chemists were from our point of
view, a point of view which they helped to create.

The widespread interest in the burning of sulfur and of phosphorus,
naturally, caught Lavoisier's attention. In his first volume of
_Opuscules Physiques et Chimiques_ (1774), he devoted 20 pages to his
experiments on phosphorus. He amplified them a few years later[10] when
he attributed the combustion to a combination of phosphorus with the
"eminently respirable" part of air. In the _Méthode de Nomenclature
Chimique_ of 1787, the column of "undecomposed substances" lists sulfur
as the "radical sulfurique," and phosphorus, correspondingly, as the
"radical phosphorique." The acids are now shown to be compounds of the
"undecomposed" radicals, the complete reversion of the previous concept
of this relationship. A part of the old analogy remained as far as the
acids are concerned: sulfuric acid corresponds to phosphoric; sulfurous
acid to phosphorous acid with less oxygen than in the former.[11]

Early Uses

In the 18th century, phosphorus was a costly material. It was produced
mostly for display and to satisfy curiosity. Guillaume François Rouelle
(1703-1770) demonstrated the process in his lectures, and, as Macquer
reports, he "very often" succeeded in making it.[12] Robert Boyle had
the idea of using phosphorus as a light for underwater divers.[13] A
century later, "instant lights" were sold, with molten phosphorus as the
"igniter," but they proved cumbersome and unreliable.[14] Because white
phosphorus is highly poisonous, an active development of the use in
matches occurred only after the conversion of the white modification
into the red had been studied by Émile Kopp (1844), by Wilhelm Hittorf
(1824-1914) and, in its practical application, by Anton Schrötter

[Illustration: Figure 3.--DISTILLATION APPARATUS (1849) for refining
crude phosphorus. The crude phosphorus is mixed with sand under hot
water, cooled, drained, and filled into the retort. The outlet of the
retort, at least 6 cm. in diameter, is partially immersed in the water
contained in the bucket. A small dish, made from lead, with an iron
handle, receives the distilled phosphorus. (From HUGO FLECK, _Die
Fabrikation chemischer Produkte ..._ page 90.)]

The most exciting early use, however, was in medicine. It is not
surprising that such a use was sought at that time. Any new material
immediately became the hope of ailing mankind--and of striving
inventors.[16] Phosphorus was prescribed, in liniments with fatty oils
or as solution in alcohol and ether, for external and internal
application. A certain Dr. Kramer found it efficient against epilepsy
and melancholia (1730). A Professor Hartmann recommended it against
cramps.[17] However, in the growing production of phosphorus for
matches, the workers experienced the poisonous effects. In the plant of
Black and Bell at Stratford, this was prevented by inhaling turpentine.
Experiments on dogs were carried out to show that poisoning by
phosphorus could be remedied through oil of turpentine.[18]

the red allotropic form, 1851. Redistilled phosphorus is heated in the
glass or porcelain vessel (g) which is surrounded by a sandbath (e) and
a metal bath (b). Vessel (j) is filled with mercury and water; together
with valve (k), it serves as a safety device. The alcohol lamp (l) keeps
the tube warm against clogging by solidified vapors. Because of hydrogen
phosphides, the operation, carried out at 260° C., had to be watched
very carefully. (According to Arthur Albright, 1851; reproduced from
HUGO FLECK, _Die Fabrikation chemischer Produkte ..._, page 112.)]

Chemical Constitution of Phosphoric Acids

In a long article on phosphorus, Edmond Willm wrote in 1876: "For a
century, urine was the only source from which phosphorus was obtained.
After Gahn, in 1769, recognized the presence of phosphoric acid in
bones, Scheele indicated the procedure for making phosphorus from
them."[19] Actually, Gahn used at first hartshorn (_Cornu cervi
ustum_), and Scheele doubted, until he checked it himself, that his
esteemed friend was right. A few years later, Scheele corrected Gahn's
assumption that the _sal microcosmicum_ was an ammonia salt; instead, it
is "a tertiary neutral salt, consisting of _alkali minerali fixo_ (i.e.,
sodium), _alkali volatili_, and _acido phosphori_."[20]

In the years after 1770, phosphorus was discovered in bones and many
other parts of various animals. Treatment with sulfuric acid decomposed
these materials into a solid residue and dissolved phosphoric acid. Many
salts of this acid were produced in crystalline form. Heat resistance
had been considered one of the outstanding characteristics of phosphoric
acid. Now, however, in the processes of drying and heating certain
phosphates, it became clear that three kinds of phosphoric acids could
be produced: _ortho_, _pyro_, and _meta_.

Berzelius cited these acids as examples of compounds which are ISOMERIC.
This word was intended to designate compounds which contain the same
number of atoms of the same elements but combined in different manners,
thereby explaining their different chemical properties and crystal
forms. It was in 1830 that Berzelius propounded this companion of the
concept, ISOMORPHISM, which was to collect all cases of equal crystal
form in compounds in which equal numbers of atoms of different elements
are put together in the same manner. Together, the two concepts of
isomerism and isomorphism seemed to cover all the known exceptions from
the simplest assumption as to specificity and chemical composition.

However, only a few years later Thomas Graham (1805-1869) proved that
the three phosphoric acids are not isomeric. He used the proportion of 2
P to 5 O in the oxide which Berzelius had thought justified at least
until "an example of the contrary could be sufficiently
established."[21] Refining the techniques of Gay-Lussac (1816) and
several other investigators, Graham characterized the three phosphoric
acids as "a terphosphate, a biphosphate, and phosphate of water."
Actually, this was the wrong terminology for what he meant and
formulated as trihydrate, bihydrate, and monohydrate of phosphorus
oxide. In his manner of writing the formulas, each dot over the symbol
for the element was to indicate an atom of oxygen; thus, he wrote:

    ...   :: ..   ...    . .
    H^{3} P  H^{2} P and H P.[22]

[Illustration: Figure 5.--OVEN FOR THE CALCINATION OF BONES, about 1870.
"The operation is carried out in a rather high oven, such as shown....
The fresh bones are thrown in at the top of the oven, B. First, fuel in
chamber F is lighted, and a certain quantity of bones is burnt on the
grid D. When these bones are burning well, the oven is gradually filled
with bones, and the combustion maintains itself without addition of
other fuel. A circular gallery, C, surrounds the bottom of the oven and
carries the products of combustion into the chimney, H. The calcined
bones are taken out at the lower opening, G, by removing the bars of
grid B." (Translation of the description from FIGUIER, _Merveilles de
l'industrie_, volume 3, 1874, page 537.)]

[Illustration: Figure 6.--AN ADVERTISEMENT with view of plant for
manufacturing superphosphate about 1867. (From E. T. FREEDLEY,
_Philadelphia and its Manufacturers in 1867_, page 288.)]

Graham had come to this understanding of the phosphoric acids through
his previous studies of "Alcoates, definite compounds of Salts and
Alcohol analogous to the Hydrates" (1831). Liebig started from analogies
he saw with certain organic acids when he formulated the phosphoric
acids with a constant proportion of water (aq.) and varying proportions
of "phosphoric acid" (P) as follows:

    2 P 3 aq.  phosphoric acid
    3 P 3 aq.  pyrophosphoric acid
    6 P 3 aq.  metaphosphoric acid.

[Illustration: Figure 7.--FLORIDA HARD-ROCK PHOSPHATE MINING. (From
Carroll D. Wright, _The Phosphate Industry of the United States_, sixth
special report of the Commissioner of Labor, Government Printing Office,
Washington, 1893, plate facing page 43.)]

Salts are formed when a "basis," i.e., a metal oxide, replaces water.
When potassium-acid sulfate is neutralized by sodium base, the acid-salt
divides into Glauber's salt and potassium sulfate, which proves the
acid-salt to be a mixture of the neutral salt with its acid. Sodium-acid
phosphate behaves quite differently. After neutralization by a potassium
"base" (hydroxide), the salt does not split up; a uniform
sodium-potassium phosphate is obtained. Therefore, phosphoric acid is
truly three-basic![23]

This result has later been confirmed, but the analogy by means of which
it had been obtained was very weak, in certain parts quite wrong.

The acids from the two lower oxides of phosphorus were also considered
as three-basic. Adolphe Wurtz (1817-1884) formulated them in 1846,
according to the theory of chemical types:

            O^{3}  phosphoric acid

            O^{2}  phosphorus acid

               O   hypophosphorous acid.[24]

Further proof for these constitutions was sought in the study of the
esters formed when the acids react with alcohols.

Among the analogies and generalizations by which the research on
phosphoric acid was supported, and to the results of which it
contributed a full share, was the new theory of acids. Not oxygen,
Lavoisier's general acidifier, but reactive hydrogen determines the
character of acids. In this brief survey, it seems sufficient just to
mention this connection without describing it in detail.

The study of phosphoric acids led to important new concepts in
theoretical chemistry. The finding of polybasicity was extended to other
acids and formed the model that helped to recognize the
polyfunctionality in other compounds, like alcohols and amines. The
hydrogen theory of acids was fundamental for further advance. In another
dimension, it is particularly interesting to see that large-scale
applications followed almost immediately and directly from the new
theoretical insight. The first and foremost of these applications was in

Phosphates as Plant Nutrients

One hundred years after the discovery of "cold light," the presence of
phosphorus in plants and animals was ascertained, and its form was
established as a compound of phosphoric acid. This knowledge had little
practical effect until the "nature" of the acid, in its various forms,
was explained through the work of Thomas Graham. From it, there started
a considerable technical development.

At about that time (1833), the Duke of Richmond proved that the
fertilizing value of bones resided not in the gelatin, nor in the
calcium, but in the phosphoric acid. Thus, he confirmed what Théodore de
Saussure had said in 1804, that "we have no reason to believe" that
plants can exist without phosphorus. Unknowingly at first, the farmer
had supplied this element by means of the organic fertilizers he used:
manure, excrements, bones, and horns. Now, with the value of phosphorus
known, a search began for mineral phosphates to be applied as
fertilizers. Jean Baptiste Boussingault (1802-1887), an agricultural
chemist in Lyons, traveled to Peru to see the guano deposits. Garcilaso
de la Vega (ca. 1540 to ca. 1616) noted in his history of Peru (1604)
that guano was used by the Incas as a fertilizer. Two hundred years
later, Alexander von Humboldt revived this knowledge, and Humphry Davy
wrote about the benefits of guano to the soil. Yet, the application of
this fertilizer developed only slowly, until Justus Liebig sang its
praise. Imports into England rose and far exceeded those into France
where, between 1857 and 1867, about 50,000 tons were annually received.

The other great advance in the use of phosphatic plant nutrients started
with Liebig's recommendation (1840) to treat bones with sulfuric acid
for solubilization. This idea was not entirely new; since 1832, a
production of a "superphosphate" from bones and sulfuric acid had been
in progress at Prague. At Rothamsted in 1842, John Bennet Lawes
obtained a patent on the manufacture of superphosphate. Other
manufactures in England followed and were successful, although James
Muspratt (1793-1886) at Newton lost much time and "some thousands of
pounds" on Liebig's idea of a "mineral manure."

Carroll D. Wright, _The Phosphate Industry of the United States ..._,
plate facing page 58.)]

It was difficult enough to establish the efficacy of bones and
artificially produced phosphates in promoting the growth of plants under
special conditions of soils and climate; therefore, the question as to
the action of phosphates in the growing plant was not even seriously
formulated at that time. The beneficial effects were obvious enough to
increase the use of phosphates as plant nutrients and to call for new
sources of supply. Active developments of phosphate mining and treating
started in South Carolina in 1867, and in Florida in 1888.[25]

In a reciprocal action, more phosphate application to soils stimulated
increasing research on the conditions and reactions obtaining in the
complex and varying compositions called soil. The findings of
bacteriologists made it clear that physics and chemistry had to be
amplified by biology for a real understanding of fertilizer effects.
After 1900, for example, Julius Stoklasa (1857-1936) pointed out that
bacterial action in soil solubilizes water-insoluble phosphates and
makes them available to the plants.[26]

Carroll D. Wright, _The Phosphate Industry of the United States ..._,
plate facing page 64.)]

The insight into the importance of phosphorus in organisms, especially
since Liebig's time, is reflected in the work of Friedrich Nietzsche
(1844-1900). This "re-valuator of all values" who modestly said of
himself: "I am dynamite!" once explained the human temperaments as
caused by the inorganic salts they contain: "The differences in
temperament are perhaps caused more by the different distribution and
quantities of the inorganic salts than by everything else. Bilious
people have too little sodium sulfate, the melancholics are lacking in
potassium sulfate and phosphate; too little calcium phosphate in the
phlegmatics. Courageous natures have an excess of iron phosphate." (See
volume 12 of _Nietzsche's Works_, edit. Naumann-Kröner, Leipzig, 1886.)
In this strange association of inorganic salts with human temperaments,
the role of iron phosphate as a producer of courage is particularly
interesting. What would a modern philosopher conclude if he followed the
development of insight into the composition and function of complex
phosphate compounds in organisms?

From Inorganic to Organic Phosphates

By the middle of the 19th century, the source of phosphorus in natural
phosphates and the chemistry of its oxidation products had been
established. The main difficulty that had to be overcome was that these
oxidation products existed in so many forms, not only several stages of
oxidation, but, in addition, aggregations and condensations of the
phosphoric acids. Once the fundamental chemistry of these acids was
elucidated, the attention of chemists and physiologists turned to the
task of finding the actual state in which phosphorus compounds were
present in the organisms. It had been a great advance when it had been
shown that plants need phosphates in their soil. This led to the next
question concerning the materials in the body of the plant for which
phosphates were being used and into which they were incorporated.
Similarly, the knowledge that animals attain their phosphates from the
digested plant food called, in the next step of scientific inquiry, for
information on the nature of phosphates produced from this source.

The method used in this inquiry was to subject anatomically separated
parts of the organisms to chemical separations. The means for such
separations had to be more gentle than the strong heat and destructive
chemicals that had been considered adequate up to then. The
interpretation of the new results naturally relied on the general
advance of chemistry, the development of new methods for isolating
substances of little stability, of new concepts concerning the
arrangements of atoms in the molecules, and of new apparatus to measure
their rates of change.

In the system of chemistry, as it developed in the first half of the
19th century, the new development can be characterized as the turn from
inorganic to organic phosphates, from the substance of minerals and
strong chemical interactions to the components in which phosphate groups
remained combined with carbon-containing substances.

PHOSPHORUS, invented by Thomas Parker of Newbridge, England, and
assigned to The Electric Construction Corporation of the same place. The
drawing is part of United States patent 482,586 (September 13, 1892).
The furnace was patented in England on October 29, 1889 (no. 17,060); in
France on June 23, 1890 (no. 206,566); in Germany on June 17, 1890 (no.
55,700); and in Italy on October 23, 1890 (no. 431). The following
explanation is cited from the U.S. patent:

Figure 1 [shown here] is a vertical section of the furnace, and Fig. 2
is a diagram to illustrate the means for regulating the electro-motive
force or quantity of current across the furnace.

F is the furnace containing the charge to be treated. It has an
inlet-hopper at _a_, with slides AA, by which the charge can be admitted
without opening communication between the interior of the furnace and
the outer air.

B is a screw conveyer by which the charge is pushed forward into the

_c´c´_ are the electrodes, consisting of blocks or cylinders or the like
of carbon fixed in metal socket-pieces _c c_, to which the
electric-circuit wires _d_ from the dynamo D are affixed. The current,
as aforesaid, may be either continuous or alternating. _c^{2}c^{2}_ are
rods of metal or carbon, which are used to establish the electric
circuit through the furnace, the said rods being inserted into holes in
conductors _c^{3}_ (in contact with the socket-pieces _c_) and in the
furnace, as shown.

_g_ is the outlet for the gas or vapor, _h_ the slag-tap hole, and _x_
the opening for manipulating the charge, the said openings being closed
by clay or otherwise when the furnace is at work.

I use coke or other form of carbon in the charge between the electrodes
_c´_, the said coke being in contact with the said electrodes, so that
complete incandescence is insured.

A means for varying the electro-motive force or quantity of current
across the furnace with the varying resistance of the charge is
illustrated by the diagram, Fig. 2. _c´ c^{2}_ indicate the electrodes
in the furnace, as in Fig. 1, and D is the dynamo and T its terminals. E
represents the exciting-circuit. R R are resistances, and R S is the
resistance-switch, which is operated to put in more or less resistance
at R as the resistance of the charge in the furnace lessens or
increases. This switch may be automatically operated, and a suitable
arrangement for the purpose is a current-regulator such as is described
in the specification of English Letters Patent No. 14,504, of September
14, 1889, granted to William Henry Douglas and Thomas Hugh Parker.]



  Patented Sept. 13, 1892.

  FIG. 1.]

[Illustration: FIG. 2.

  Thomas Parker_

  _By his attorneys
  Howson and Howson_

  George Baumann
  John Revell_]

[Illustration: Figure 11.--DIPPING OF MATCHSTICKS in France, about 1870.
The frame which holds the matches so that one end protrudes at the
bottom, is lowered over a pan containing molten sulfur. The
sulfur-covered matches are then dropped into a phosphorous paste. See
figure 12. (From FIGUIER, _Merveilles de l'industrie_, volume 3, 1874,
page 575.)]

Phosphatides and Phosphagens

The important phosphorus compounds in organisms are much more complex
than the simple salts, to which Nietzsche attributed such influence on
man's character. Long before he wrote, it was known that phosphoric acid
combines not only with inorganic bases to form salts, but with alcohols
to form esters. In the middle of the 19th century, Théophile Juste
Pelouze (1807-1867) extended this knowledge to an ester of glycerol.
This proved to be significant in several respects. Glycerol had been
shown by Michel Chevreul (1786-1889) as the substance in fats that is
released in the process of soap boiling, when the fatty acids are
converted into their salts. That it has the nature of an alcohol had
been demonstrated by Marcellin Berthelot. Instead of one "alcoholic"
hydroxyl group, OH, like ethanol (the alcohol of fermentation), or two
hydroxyl groups (like ethylene glycol), glycerol contains three such
groups. It was the only "natural" alcohol known at that time. That this
alcohol would combine with phosphoric acid could be predicted, but that
the ester, as obtained by Pelouze, still contained free acidic functions
and formed a water-soluble barium salt was a new experience.

[Illustration: Figure 12.--PAN FOR DIPPING MATCHSTICKS into phosphorus
paste, about 1870. The letters on the picture are: A, matches; B, water
bath; C, frame; D, plate; E, phosphorus paste; F, oven. The phosphorus
paste of Böttger, 1842, contained 10 phosphorus, 25 antimony sulfide,
12.5 manganese dioxide, 15 gelatin. According to Figuier (page 579), R.
Wagner substituted lead dioxide for the manganese dioxide. (From
FIGUIER, volume 3, 1874, page 576.)]


  (C_{6}H_{10}O_{5})_{_n_}   C_{6}H_{12}O_{6}      C_{6}H_{12}O_{6}
      glycogen                  glucose                 fructose
         ^|                        ^|                      ^|
         || H_{3}PO_{4}            || <-- ATP              || <--ATP
         |v                        |v                      |v
      ---------------+          ------+
   H--C--OPO_{3}H_{2}|       H--C--OH |              H _{2}C--OH
      |              |          |     |                    |
   H--C--OH          |       H--C--OH |                    C--(OH)--+
      |              |          |     |                    |        |
  HO--C--H           O <==> HO--C--H  O   <=======>    HO--C--H     |
      |              |          |     |                    |        O
   H--C--OH          |       H--C--OH |                 H--C--OH    |
      |              |          |     |                    |        |
   H--C--------------+       H--C-----+                 H--C--------+
      |                         |                          |
      CH_{2}OH             H_{2}C--OPO_{3}H_{2}+ADP   H_{2}C--OPO_{3}H_{2}+ADP

  glucose-1-phosphate        glucose-6-phosphate        fructose-6-phosphate
  (Cori-ester)               (Robison-ester)            (Neuberg-ester)
                                                          ^   |
                                                          |   | <-- ATP
                                                     +----|   |
                                                     | +------|
                                                     | |
                                                     | v
                                                  |      |
                                              HO--C--H   |
                 fructose-1,6-diphosphate         |      O
                  (Harden-Young-ester)         H--C--OH  |
                                                  |      |
                                             H_{2}C--OPO_{3}H_{2} + ADP
                                                  ||  O
                                                  || //
                             CH_{2}OPO_{3}H_{2}   || CH
                             |                    |v |  3-phosphoglycer-aldehyde
  dihydroxyacetone-phosphate C=O   <=============>   CHOH  (Fischer-ester)
                             |                       |
                             CH_{2}OH                CH_{2}OPO_{3}H_{2}
                                                    ||  + coenzyme + H_{3}PO_{4}
          1,3-diphosphoglyceric acid                CHOH + dihydro-coenzyme
           (Negelein-ester)                         |
                                           ADP --> ||
                                                   || O
                                                    |      +---+
             3-phosphoglyceric acid                 CHOH + |ATP|
               (Nilsson-ester)                      |      +---+
             2-phosphoglyceric acid                 |
                 phosphopyruvic acid                COPO_{3}H_{2}
                  (enol-)                          ||
                                           ADP --> ||
                  +------+                          |     +---+
                  |CO_{2}| + CH_3CHO    <--------   C=O + |ATP|
                  +------+   acetaldehyde           |     +---+
                  carbon    |                       CH_{3}
                  dioxide   | + dihydro-coenzyme  pyruvic acid
                     | CH_{3}CH_{2}OH | + coenzyme
                      ethyl alcohol

[Illustration: Figure 13.--SURVEY OF ALCOHOLIC FERMENTATION, 1951. The
"well-known scheme of alcoholic fermentation" according to Albert Jan
Kluyver (1888-1956), presented before the Society of Chemical Industry
in the Royal Institution, March 7, 1951. In _Chemistry & Industry_,
1952, page 136 ff., Kluyver restates that "... the fermentation of one
molecule of glucose is indissolubly connected with the formation of two
molecules of adenosine triphosphate (ATP) out of two molecules of
adenosine diphosphate (ADP)."]

Shortly after this experience had been gained, it became valuable for
understanding the chemical nature of a new substance extracted from a
natural organ. This substance was named lecithin by its discoverer,
Nicolas Théodore Gobley[27] (1811-1876), because he obtained it from egg
yolk (in Greek, _lékidos_). He used ether and alcohol for this
extraction. Had he used water and mineral acid instead, he would not
have found lecithin, but only its components. As Gobley and, slightly
later, Oscar Liebreich (1839-1908), subjected lecithin to treatment with
boiling water and acid, they separated it into three parts. One of them
was the glycerophosphoric acid of Pelouze, the second was the well-known
stearic acid of Chevreul, but the third was somewhat mysterious. This
third substance was the same as one previously noticed when nerves had
been subjected to an extraction by boiling water and acid and,
therefore, called nerve-substance or neurine. Adolf Friedrich Strecker
(1822-1871) established the identity of this neurine with a product he
had extracted from bile and which went under the name of choline.
Adolphe Wurtz (1817-1884) succeeded in synthesizing this substance from
ethylene oxide, CH_2.O.CH_2 and trimethylamine N(CH_3)_3.[28] Thus, all
three parts were identified, and Strecker put them together to construct
a chemical formula for lecithin, glycerophosphoric acid combined with a
fatty acid and with choline (a hydrate of neurine).

                        { OH       }
                      N { (CH_3)_3 } Choline
                        { C_2H_4O  }

    C_18H_33O_2 }               HO }
                }                  } PO
    C_16H_31O_2 }          C_3H_5O }

    Fatty Acids        Glycerophosphate
          according to Strecker

This formula was not quite correct. Richard Willstätter showed that an
internal neutralization takes place between the amino group and the free
acidic residue. This is expressed in his lecithin formula of 1918.

    |           O·CH_{2}·CH_{2}
    |          /          \
    CH_{2}·O--P=O         N(CH_{3})_{3}
               \          /

[Illustration: Lecithin (1918)]

When the aim was to distill elementary phosphorus out of an organic
material, it did not matter whether this was fresh or putrified. For
obtaining lecithin out of egg yolk and similar materials, it was
essential to use it in fresh condition. Otherwise, enzymes would have
decomposed it. Through more recent work, four enzymes have been
separated, which act specifically in decomposing lecithin. Enzyme A
removes one fatty acid and leaves a complex residue, called
lysolecithin, intact. Enzyme B attacks this residue and splits off the
remaining fatty acid group from it, enzyme C liberates only the choline
from lecithin, and enzyme D opens lecithin at the ester bond between
glycerol and phosphoric acid. This is shown in the following diagram.



    A      Lecithin      Lysolecithin and fatty

    B      Lysolecithin  Glycero-phospho-choline
                           and fatty acids.

    C      Lecithin      Phosphatidic acid and

    D      Lecithin      Phosphoryl choline and

Several fatty acids can be present in lecithin from various sources:
palmitic and oleic acid, besides the stearic acid which at first had
been thought the only one involved. In another group of extracts from
brain or nerve tissue, amino-ethanol H_{2}NCH_{2}CH_{2}OH is found
instead of the choline of lecithin. The variations include the alcohol,
to which the fatty acids and choline phosphate are attached, for
example, glycerol can be replaced by the so-called meat-sugar, inositol,
which has six hydroxyl groups in its hexagon-shaped molecule

[Illustration: Figure 14.--EDUARD BUCHNER (1860-1917) received the Nobel
Prize in Chemistry for his discovery of cell-free fermentation, the
first step in finding the role of phosphate in fermentations (1907).]

The generally similar behavior of these phosphate-and fat-containing
substances was emphasized by Ludwig Thudichum (1829-1901). He coined the
name phosphatides for this group of substances from seeds and
nerves.[29] His work on the phosphates in brain substance aroused
particular interest. When William Crookes drew his highly imaginative
picture of an "evolution" of the chemical elements, he put into it
"phosphorus for the brain, salt for the sea, clay for the solid
earth...."[30] But phosphatides occur in many places of organisms, in
bacteria, in leaves and roots of plants, in fat and tissues of animals.
And where phosphatides are found, there are also enzymes that
specifically act on them. They are called phosphatases to imply that
they split the phosphatides. In addition, enzymes are present, which
transfer phosphate groups from one compound to another. They are more
abundant in seeds of high fat content than in the more starch-containing
seeds, but even potatoes and orange juice have phosphatases.[31]

Thus, from phosphatides, phosphoric acid is generated, and they could
also be called phosphagens. Since 1926, however, the name phosphagens
has been reserved for a group of organic substances that release their
phosphoric acid very readily. The link between phosphorus and carbon is
provided by oxygen in the phosphatides, by nitrogen in the phosphagens.
In vertebrates, the basis for the phosphoric acid is creatine, whereas
invertebrates have arginine instead.

      H    OH                   OH
      |   /                    /
      N--P=O              NH--P=O
     /    \              /     \
    C=NH   OH           C=NH    OH
     \                   \
      N--CH_{2}COOH       NH
      |                   |
      CH_{3}              CH_{2}
    Creatine phosphate    CH_{2}

                       Arginine phosphate

Nuclein and Nucleic Acids

All parts of an organism are essential for life. Only with this in mind
does it make sense to say that the most important part of the cell is
its nucleus. From the nuclei of cells in pus and in salmon sperm, Johann
Friedrich Miescher (1811-1887) obtained a peculiar kind of substance,
which he named nuclein (1868). Its phosphate content was easily
discovered, but to find the exact proportions and the nature of the
other components required special methods of separation from
phosphatides and other proteins. It was difficult to develop such
methods at a time when little was known about the properties, and
particularly the stability, of a nuclein. For preparing nuclein from
yeast cells, Felix Hoppe-Seyler (1825-1895) described the following
details: Yeast is dispersed in water to extract soluble materials, like
salts or sugars. After a few hours, the insoluble material is separated,
washed once more with water, and then extracted with a very dilute
solution of sodium hydroxide. The slightly alkaline solution, freed from
insoluble residues, is slowly added to a weak hydrochloric acid. A
precipitate forms which is separated by filtration, washed with dilute
acid, then with cold alcohol, and finally extracted by boiling alcohol.
The dried residue is the nuclein.[32] It contains six percent
phosphorus. A little more washing with water, a slightly longer
treatment with acid or alcohol gives products of lower phosphorus
content. Many experimental variations were necessary to establish the
procedure that leads to purification without alteration of the natural

This was also true for the methods of chemical degradation, carried out
in order to find the components of nucleins in their highest state of
natural complexity. It was learned for example, that the special kind of
carbohydrate present in nucleins was very susceptible to change under
the conditions of hydrolysis by acids. Phoebus Aaron Theodor Levine
(1869-1940), therefore, used the digestion by a living organism. With E.
S. London, he introduced a solution of nucleic acid into, e.g., the
gastrointestinal segment of a dog through a gastric fistula and withdrew
the product of digestion through an intestinal fistula. Fortunately, the
products obtained in such degradations were not new in themselves. The
carbohydrate in this nucleic acid proved to be identical with D-ribose,
which Emil Fischer had artificially made from arabinose and named ribose
to indicate this relationship (1891). The nitrogenous products of the
degradation were identical with substances previously prepared in the
long study of uric acid. In the course of this study, Emil Fischer
established uric acid and a number of its derivatives as having the
elementary skeleton of what he called "pure uric acid," abbreviated to
purine. Out of Adolf Baeyer's work on barbituric acid came the knowledge
of pyrimidine and its derivatives.

[Illustration: Figure 15.--ALBRECHT KOSSEL (1853-1927) received the
Nobel Prize in Medicine and Physiology in 1910 for his work on nucleic
substances, which contain a high proportion of phosphorus. The chemical
bonds of this phosphorus in the molecules of nucleic substances were
determined in later work. (_Photo courtesy National Library of Medicine,
Washington, D.C._)]

From these findings, together with what Oswald Schmiedeberg (1838-1921)
had established concerning the presence of four phosphate groups in the
molecule (1899), Robert Feulgen (1884-1955) constructed the following
scheme of a nucleic acid. Feulgen's formula of 1918 is:

    Phosphoric acid--Carbohydrate--Guanine
    Phosphoric acid--Carbohydrate--Cytosine
    Phosphoric acid--Carbohydrate--Thymine
    Phosphoric acid--Carbohydrate--Adenine

Of the four basic components on the right, thymine occurs in the nucleic
acid from the thymus gland. Yeast contains uracil instead. The
difference between these two bases is one methyl group: thymine is a
5-methyluracil. In all of these basic substances, the structure of urea


is involved, and they form pairs of oxidized and reduced states:

         PURINE              PYRIMIDINE

     (reduced) Adenine + (oxidized) Thymine
    (oxidized) Guanine + (reduced)  Cytosine

       3N = CH4
        |   |
    2H--C   CH5
        ||  ||


        |  |    H
        |  |  7/          N==C--NH_{2}
    2H--C  C--N           |  |
        || ||5 \       H--C  C--NH
        || ||   \         || ||  \
        || ||    CH8      || ||   CH
        || ||   //        || ||  //
        3N--C--N          N--C--N
            4  9

            |  |
    NH_{2}--C  C--NH       N==C--NH_{2}  H--N--C=O
            || ||  \       |  |             |  |
            || ||   CH   O=C  C--H        O=C  CH
            || ||  //      |  ||            |  ||
            N--C--N     H--N--CH           HN--CH

         Guanine         Cytosine         Uracil

  The carbohydrate is ribose or deoxyribose.

        CHO            CHO
        |              |
     H--C--OH      HO--C--H
        |              |
    HO--C--H       HO--C--H
        |              |
    HO--C--H       HO--C--H
        |              |
        CH_{2}OH       CH_{2}OH

    Arabinose      L-Ribose

       Fischer and Piloty, 1891

      \(1)/-----O-----\(4) (5)
        C              CH--CH_{2}OH
      /   \(2)     (3)/
    HO     CH_{2}--HC(OH)


The exact position of phosphoric acid was established after long work
and verified by synthesis.[33]

A compound of adenine, ribose, and phosphoric acid was found in yeast,
blood, and in skeletal muscle of mammals. From 100 grams of such muscle,
0.35-0.40 grams of this compound were isolated. If the muscle is at
rest, the compound contains three molecules of phosphoric acid, linked
through oxygen atoms. It was named adenosine triphosphate or
adenyltriphosphoric acid,[34] usually abbreviated by the symbol ATP. It
releases one phosphoric acid group very easily and goes over in the
diphosphate, ADP, but it can also lose 2 P-groups as pyrophosphoric acid
and leave the monophosphate, AMP.

     |  |
    HC  C--N     +----O----+
     || ||  \\   |         |
     || ||   CH  |  OH  OH |  H       OH
     || ||  /    |  |   |  |  |      /
                 |  |   |  |  |      \
                 H  H   H  H  H       OH
      Adenine      D-Ribose      Phosphoric

This change of ATP was considered to be the main source of energy in
muscle contraction by Otto Meyerhof.[35] The corresponding derivatives
of guanine, cytosine, and uracil were also found, and they are active in
the temporary transfer of phosphoric acid groups in biological

Thus, the study of organic phosphates progressed from the comparatively
simple esters connected with fatty substances of organisms to the
proteins and the nuclear substances of the cell. The proportional amount
of phosphorus in the former was larger than in the latter; the actual
importance and function in the life of organisms, however, is not
measured by the quantity but determined by the special nature of the

[Illustration: Figure 16.--OTTO MEYERHOF (1884-1951) received one-half
of the Nobel Prize in Medicine and Physiology in 1922 for his discovery
of the metabolism of lactic acid in muscle, which involves the action of
phosphates, especially adenosine duophosphates. (_Photo courtesy
National Library of Medicine, Washington, D.C._)]

[Illustration: Figure 17.--ARTHUR HARDEN (1865-1940), left, AND HANS A.
S. VON EULER-CHELPIN (b. 1875), right, shared the Nobel Prize in
Chemistry in 1929. Harden received it for his research in fermentation,
which showed the influence of phosphate, particularly the formation of a
hexose diphosphate. Euler-Chelpin received his award for his research in
fermentation. He found coenzyme A which is a nucleotide containing
phosphoric acid.]

[Illustration: Figure 18.--GEORGE DE HEVESY (b. 1885) received the Nobel
Prize in Chemistry in 1943 for his research with isotopic tracer
elements, particularly radiophosphorus of weight 32 (ordinary phosphorus
is 31).]

[Illustration: Figure 19.--CARL F. CORI (b. 1896) AND HIS WIFE, GERTY T.
CORI (1896-1957) received part of the Nobel Prize in Medicine and
Physiology in 1947 for their study on glycogen conversion. In the course
of this study, they identified glucose 1-phosphate, now usually referred
to as "Cori ester," and its function in the glycogen cycle. (_Photo
courtesy National Library of Medicine, Washington, D.C._)]

The study of this function is the newest phase in the history of
phosphorus and represents the culmination of the previous efforts. This
newest phase developed out of an accidental discovery concerning one of
the oldest organic-chemical industries, the production of alcohol by the
fermentative action of yeast on sugar. A transition of carbohydrates
through phosphate compounds to the end products of the fermentation
process was found, and it gradually proved to be a kind of model for a
host of biological processes.

Specific phosphates were thus found to be indispensable for life. In
reverse, the wrong kind of phosphates can destroy life. As a result, an
important part of the new phase in phosphorus history consisted in the
study--and use--of antibiotic phosphorus compounds.

Phosphates in Biological Processes

The first indication that phosphorus is important for life came from the
experience that plants take it up from the substances in the soil. They
incorporate it in their body substance. What makes phosphorus so
important that they cannot grow without it? The next insight was that
animals acquire it from their plant food. It is then found in bones, in
fat and nerve tissue, in all cells and particularly in the cell nuclei.
What are its functions there?

The answers to such questions were developed from the study of a
long-known process, the conversion of carbohydrates into carbon dioxide
and alcohol by yeast. It started with Eduard Buchner's discovery of
1890, that fermentation is produced by a preparation from yeast in which
all living cells have been removed. When yeast is dead-ground and
pressed out, the juice still has the ability to produce fermentation.

It is strange, but in many ways characteristic for the process of
science, that the "riddle" of phosphorus in life was solved by first
eliminating life. In such "lifeless" fermentations, Arthur Harden found
that the conversion of sugar begins with the formation of a hexose
phosphate (1904). The "ferment" of yeast, called zymase, proved to be a
composite of several enzymes. Hans von Euler-Chelpin isolated one part
of zymase, which remains active even after heating its solution to the
boiling point. From 1 kilogram of yeast, he obtained 20 milligrams of
this heat-stable enzyme, which he called cozymase and identified as a
nucleotide composed of a purine, a sugar, and phosphoric acid.[36] In
the years between the two World Wars, zymase was further resolved into
more enzymes, one of them the coenzyme I, which was shown to be ADP
connected with another molecule of ribose attached to the amide of
nicotinic acid, or diphosphopyridine nucleotide:

       ^                           NH_{2}
      / \\                         |
     /   \\                    N   ^
     ||   |-CONH_{2}          //\ / \\
     ||   |                   |  ||  N
     \   //                   |  ||  |
       N_{+}                  N--+   |
       |                      |   \//
       |                      |    N
    H--C------+            H--C------+
       |      |               |      |
    H--C--OH  |            H--C--OH  |
       |      O               |      O
    H--C--OH  |            H--C--OH  |
       |      |               |      |
    H--C------+   O     O  H--C------+
       |          ||    ||    |
                  |     |
                  O-    OH

                 Coenzyme I

[Illustration: Figure 20.--FRITZ A. LIPMANN (b. 1899) shared with Hans
Adolf Krebs the Nobel Prize in Medicine and Physiology in 1953 for his
work on coenzyme A. He discovered acetyl phosphate as the substance in
bacteria, which transfers phosphate to adenylic acid.]

[Illustration: Figure 21.--ALEXANDER R. TODD (b. 1907) received the
Nobel Prize in Chemistry in 1957 for his research on nucleotides. He
determined the position of the phosphate groups in the molecule and
confirmed it by synthesis of dinucleotide phosphates.]

Its function is connected with the transfer of hydrogen between
intermediates formed through phosphate-transferring enzymes.
Fermentation proceeds by a cascade of processes, in which phosphate
groups swing back and forth, and equilibria between ATP with ADP play a
major role.

Many of the enzymes are closely related to vitamins. Thus, cocarboxylase
A, which takes part in the separation of carbon dioxide from an
intermediate fermentation product, is the phosphate of vitamin B_{1}.
Others of the B vitamins contain phosphate groups, for example those of
the B_{2} and B_{6} group, and in B_{12}, one lonely phosphate forms a
bridge in the large molecule that contains one atom of cobalt:
C_{63}H_{90}N_{14}O_{14}PCo. The formation of vitamin A from carotine
occurs under the influence of ATP.

The first stages in fermentation are like those in respiration, which
ends with carbon dioxide and water. These two are the materials for the
reverse process in photosynthesis. When light is absorbed by the
chlorophyll of green plants, one of the initial reactions is a transfer
of hydrogen from water to a triphosphopyridine nucleotide, which later
acts to reduce the carbon dioxide. Under the influence of ATP,
phosphoglyceric acid is synthesized and further built up by way of
carbohydrate phosphates to hexose sugars and finally to starch. In many
starchy fruits, a small proportion of phosphate remains attached to the
end product.

The synthesis of proteins is under the control of deoxyribonucleic acid
or ribonucleic acid, abbreviated by the symbols DNA and RNA. The genes
in the nucleus are parts of a giant DNA molecule. RNA is a universal
constituent of all living cells. Where protein synthesis is intense, the
content in RNA is high. Thus, the spinning glands of silkworms are
extraordinarily rich in RNA.[37]

In his research on the radioactive isotope P^32, George de Hevesy gained
some insight into the surprising mobility of phosphates in organisms: "A
phosphate radical taken up with the food may first participate in the
phosphorylation of glucose in the intestinal mucose, soon afterwards
pass into the circulation as free phosphate, enter a red corpuscle,
become incorporated with an adenosine triphosphoric-acid molecule,
participate in a glycolytic process going on in the corpuscle, return to
circulation, penetrate into the liver cells, participate in the
formation of a phosphatide molecule, after a short interval enter the
circulation in this form, penetrate into the spleen, and leave this
organ after some time as a constituent of a lymphocyte. We may meet the
phosphate radical again as a constituent of the plasma, from which it
may find its way into the skeleton."[38] Much has been added in the last
30 years to complete this picture in many details and to extend it to
other biochemical processes, including even the changes of the pigments
in the retina in the visual process, or in the conversion of chemical
energy to light by bacteria and insects.

Medicines and Poisons

In the delicate balance of these processes, disturbances may occur which
can be remedied by specific phosphate-containing medicines. Thus,
adenosine phosphate has been recommended in cases of angina pectoris
and marketed under trade names like sarkolyt, or in compounds named
angiolysine. A considerable number of physiologically active organic
phosphates can be found in the patent literature.[39] Yeast itself is
considered to be a valuable food additive.

On the other hand, there are phosphate compounds that act as poisons.
One group of such compounds was discovered in 1929 by W. Lange, who
wrote: "Of interest is the strong action of mono-fluorophosphate esters
on the human body--the effect is produced by very small quantities."[40]
Diisopropyl fluorophosphate has since become a potential agent for
chemical warfare. It inactivates an enzyme which controls the
transmission of nerve impulses to muscle, acetylcholine esterase.

Organic esters of phosphoric acids are used as insecticides. The
hexa-ethylester of tetraphosphoric acid, prepared by Gerhard Schrader by
heating triethylphosphate with phosphorus oxychloride,[41] actually
contains tetraethylpyrophosphate (TEPP) among others. Bayer's Dipterex,
the dimethyl ester of 2,2,2-trichloro-1-hydroxyethyl-phosphonate, has
been modified to dimethyl-2,2-dichlorovinyl-phosphate and is especially
active against the oriental fruit fly.[42]

[Illustration: Figure 22.--ARTHUR KORNBERG (b. 1918) AND SEVERO OCHOA
(b. 1905) shared the Nobel Prize in Medicine and Physiology in 1959.
Kornberg received it for research on the biological synthesis of
deoxyribonucleic acid. In particular, he found that four triphosphate
components and a small amount of the end product as a "template" had to
be present for the enzymatic synthesis. Ochoa received his share of the
prize for research in ribonucleic acid and deoxyribonucleic acid. In
particular, Ochoa synthesized polyribonucleotides and used the
radioactive isotope, P^{32}. The synthetic polyribonucleotides were
found to resemble the natural substances in all essentials.]

        Cl H  O
        |  | || OCH_{3}
        |  | ||/
    Cl--C--C--P             Bayer's L 13/59
        |  |   \              (Dipterex)
        |  |    OCH_{3}
        Cl OH

    (CH_{3})_{2}N O     O  N(CH_{3})_{2}
                 \||    ||/
                  P--O--P                  Schradan
                 /       \
    (CH_{3})_{2}N         N(CH_{3})_{2}


[Illustration: Figure 23.--MELVIN CALVIN (b. 1911) received the Nobel
Prize in Chemistry in 1961 for his research in photosynthesis, in which
he specified the function of phosphoglyceric acid as an intermediate in
the synthesis of carbohydrates from carbon dioxide and water by green

The story of phosphorus, which began 300 years ago, has acquired new
importance in this century. Many scientists have contributed to it: 13
of them have received Nobel Prizes for work directly bearing on the
chemical and biological importance of phosphorus compounds. In
chronological order, they are: Eduard Buchner, Albrecht Kossel, Otto
Meyerhof, Arthur Harden, Hans von Euler-Chelpin, George de Hevesy, Carl
F. Cori, Gerty T. Cori, Fritz Lipmann, Lord Alexander Todd, Arthur
Kornberg, Severo Ochoa, and Melvin Calvin. The developers of industrial
production and commercial utilization of phosphate compounds have had
other rewards.

Some impression of the continuing growth in this field[43] can be gained
from the following data.


annually "sold or used by producer" in the United States in million long
tons (2,240 lbs.)

    1880    0.2
    1890    0.5
    1900    1.5
    1910    2.655
    1920    4.104
    1930    3.926
    1940    4.003
    1945    5.807
    1950   11.114
    1955   12.265
    1955   (world: about 56)
    1960   17.202
    1962   19.060

Sources: U.S. Bureau of the Census. _Historical Statistics of the United
States 1789-1945_ (1949); _Statistical Abstract of the United States._


annually produced in the United States in short tons (2,000 lbs.)

    1939     43,000
    1944     85,679
    1950    153,233
    1956    312,200
    1958    335,750
    1959    366,350
    1960    409,096
    1961    430,617
    1962    451,970

Source: U.S. Department of Commerce.

       *       *       *       *       *


   [1]  WILHELM HOMBERG, _Mémoires Académie, 1666-1699_ (Paris, 1730),
        vol. 10, under date of April 30, 1692, pp. 57-61.

   [2]  FORTUNIO LICETUS, _Lithiophosphorus sive de lapide Bononiensi_
        (Venice, 1640).

   [3]  Cited in PETER JOSEPH MACQUER _Chymisches Wörterbuch_, 2nd ed.
        (Leipzig: Weidmann, 1789), vol. 4, p. 508, footnote "c" as
        "Kletwich (de phosph. liqu. et solid. 1689, Thes. II)."

   [4]  FERDINAND HOEFER, _Histoire de la Chimie_ (Paris, 1843), vol. 1,
        p. 339.

   [5]  G. W. VON LEIBNIZ, _Mémoires Académie_ (Paris, 1682); _Akademie
        der Wissenschaften, Miscellanea Berolinensia_ (Berlin, 1710),
        vol. 1, p. 91.

   [6]  JEAN HELLOT, _Mémoires Académie 1737_ (Paris, 1766), under date
        of November 13, 1737, pp. 342-378.

   [7]  MACQUER, op. cit. (footnote 3), p. 551.

   [8]  A. S. MARGGRAF, _Akademie der Wissenschaften, Miscellanea
        Berolinensia_ (Berlin, 1743), vol. 7, 342 ff.; see also WILHELM
        OSTWALD _Klassiker der Exakten Naturwissenschaften_ (Leipzig:
        Engelmann, 1913), no. 187.

   [9]  G. HANCKEWITZ, [Hankwitz], _Philosophical Transactions of the
        Royal Society of London_, 1724-1734, abridged (London, 1809),
        vol. 7, pp. 596-602.

  [10]  ANTOINE LAURENT LAVOISIER, "Sur la Combustion du Phosphore de
        Kunckel, Et sur la nature de l'acide qui resulte de cette
        Combustion," _Mémoires Académie 1777_, (Paris, 1780), pp. 65-78.

  [11]  GUYTON DE MORVEAU and others, _Méthode de Nomenclature Chimique_,
        Proposée par MM. de Morveau, Lavoisier, Bertholet, & de Fourcroy
        (Paris, 1787), plate 9.

  [12]  MACQUER, op. cit. (footnote 3), p. 513.

  [13]  MARIE BOAS, _Robert Boyle and Seventeenth Century Chemistry_ (New
        York: Cambridge University Press, 1958), p. 226; see also
        WYNDHAM MILES, "The History of Dr. Brand's Phosphorus
        Elementarus," _Armed Forces Chemical Journal_ (November-December
        1958), p. 25.

  [14]  ARCHIBALD CLOW and NAN L. CLOW, _The Chemical Revolution_
        (London: Batchworth Press, 1952), p. 451.

  [15]  ÉMILE KOPP, _Comptes-rendus hebdomadaires des Séances de
        l'Académie des Sciences, Paris_ (1844), vol. 18, p. 871; WILHELM
        HITTORF, _Annalen der Chemie und Pharmazie_, suppl. to vol. 4,
        p. 37; ANTON SCHRÖTTER, _Annales de Chimie et de Physique_,
        series 3, vol. 24 (1848), p. 406; see also Schrötter's report on
        "Phosphor und Zündwaaren" in A. W. VON HOFMANN, _Bericht über
        die Entwicklung der Chemischen Industrie_ (Braunschweig: Vieweg,
        1875), pp. 219-246.

  [16]  R. GLAUBER, _Furni Novi Philosphici_ (Amsterdam, 1649), vol. 2,
        pp. 12 ff.

  [17]  HERMANN SCHELENZ, _Geschichte der Pharmazie_ (Berlin: Springer,
        1904), p. 598.

  [18]  J. PERSONNE, _Comptes-rendus ..._, Paris (1869), vol. 68, pp.

  [19]  A. WURTZ, _Dictionnaire de Chimie_ (Paris, 1876), vol. 2, part 2,
        p. 951.

  [20]  KARL W. SCHEELE, _Nachgelassene Briefe und Aufzeichnungen_, edit.
        A. E. Nordenskiöld (Stockholm: Norstedt, 1892), pp. 38, 144.

  [21]  J. J. BERZELIUS, _Lehrbuch_, transl. F. Wöhler (Dresden, 1827),
        vol. 3, part 1, p. 96.

  [22]  THOMAS GRAHAM, _Philosophical Transactions of the Royal Society
        of London_ (1833), pp. 253-284.

  [23]  JUSTUS LIEBIG'S _Annalen der Pharmacie_ (1838), vol. 26,
        p. 113 ff.

  [24]  A. WURTZ, _Annales de Chimie et de Physique_, series 3, vol. 16
        (1846), p. 190.

  [25]  CARROLL D. WRIGHT, _The Phosphate Industry in the United States_,
        sixth special report of the Commissioner of Labor (Washington,

  [26]  J. STOKLASA, _Biochemischer Kreislauf des Phosphat-Ions im Boden,
        Centralblatt für Bakteriologie ..._ (Jena: Fischer, March 22,
        1911), vol. 29, nos. 15-19.

  [27]  N. T. GOBLEY, _Comptes-rendus_ ..., Paris (1845), vol. 21,
        p. 718.

  [28]  A. WURTZ, _Comptes-rendus_ ..., Paris (1868), vol. 66, p. 772.

  [29]  L. THUDICHUM, _Die chemische Constitution des Gehirns des
        Menschen und der Tiere_ (1901); see also H. WITTCOFF, THE
        PHOSPHATIDES (New York: Reinhold, 1951).

  [30]  WILLIAM CROOKES, _British Association for the Advancement of
        Science, Reports_ (1887), sec. B, p. 573.

  [31]  J. E. COURTOIS and A. LINO, _Progress in the Chemistry of Organic
        Natural Products_, edit. L. Zechmeister (Vienna: Springer
        Verlag, 1961), vol. 19, p. 316-373.

  [32]  A. WURT, _Dictionnaire de Chimie_, supp. part 2, [n.d.] p. 1087;
        A. KOSSEL, _Zeitschrift für physiologische Chemie_, series 3
        (1879), p. 284.

  [33]  ALEXANDER TODD, _Les Prix Nobel en 1957_ (Stockholm).

  [34]  HANS VON EULER-CHELPIN, _Les Prix Nobel en 1929_ (Stockholm).

  [35]  O. MEYERHOF and E. LUNDSGAARD, _Naturwissenschaften_ (Berlin,
        1930), vol. 18, pp. 330, 787.

  [36]  K. LOHMANN, _Naturwissenschaften_ (Berlin, 1929), vol. 17, p.
        624; C. H. FISKE and Y. SUBBAROW, _Science_ (Washington, 1929),
        vol. 70, p. 381 f.

  [37]  J. BRACHET, _Scientia, Revista di Scienza_ (1960), vol. 95, p.

  [38]  GEORGE DE HEVESY, _Les Prix Nobel en 1940_ (Stockholm). See also
        EDUARD FARBER, _Nobel Prize Winners in Chemistry_, 2nd ed. (New
        York: Schuman, 1963), p. 179.

  [39]  See, e.g., _Chemical Week_, vol. 77 (September 3, 1955), p. 79
        f.; J. BOLLE, _Chimie et Industrie_ (1960), vol. 83, p. 252.

  [40]  W. LANGE, _Berichte der Deutschen Chemischen Gesellschaft_
        (Berlin, 1929), vol. 62, p. 793; vol. 65 (1932), p. 1598.

  [41]  GERHARD SCHRADER, U.S. patent 2,336,302 of 1943 (priority in
        Germany, 1938); S. A. HALL and M. JACOBSON, _Industrial and
        Engineering Chemistry_ (1943), vol. 40, p. 694.

  [42]  A. M. MATTSEN and others, _Journal of Agriculture and Food
        Chemistry_ (1955), vol. 3, p. 319.

  [43]  JOHN B. VAN WAZER, _Phosphorus and its Compounds_, 2 vols. (vol.
        1, _Chemistry_; vol. 2 _Technology, Biological Functions and
        Applications_, New York: Interscience, 1958, 1961.

       *       *       *       *       *

Paper 40 - Transcriber's Note

The following typographical errors have been corrected:

  Page 180 "Abfällen, Vieweg, Braunschweig," - had "Viewig".

  Page 188 "wires d from the dynamo D" - had "dynano".

  Page 192 "But phosphatides occur" - had "phosphatide soccur".

  Page 193 "the nucleic acid from the thymus" - had "nucleidic".

  Page 199 "acetylcholine esterase." - had "acetylcholin".

  Page 200 "George de Hevesy, Carl F. Cori," - comma added after Hevesy.

  Footnote 39: "See, e.g., Chemical Week, vol. 77" - had "See. e.g."

The spelling of "Bertholet" [Claude Louis Berthollet] is as given on the
original title page of the work referenced in this paper.

Inconsistent hyphenation of chemical names has been retained.

       *       *       *       *       *


  PAPER 41


  _Robert M. Vogel_

                                                   INTRODUCTION    203

                                                 ROCK TUNNELING    206

                                          SOFT-GROUND TUNNELING    215

                                                   BIBLIOGRAPHY    239


_Robert M. Vogel_


using fire setting and hand chiseling to break out ore and rock.
MHT model--3/4" scale. (Smithsonian photo 49260-H.)]

     _During the years from 1830 to 1900, extensive developments took
     place in the field of tunneling, which today is an important,
     firmly established branch of civil engineering. This paper offers
     a picture of its growth from the historical standpoint, based on
     a series of models constructed for the Hall of Civil Engineering
     in the new Museum of History and Technology. The eight models
     described highlight the fundamental advances which have occurred
     between primitive man's first systematic use of fire for excavating
     rock in mining, and the use in combination of compressed air, an
     iron lining, and a movable shield in a subaqueous tunnel at the end
     of the 19th century._

     THE AUTHOR: _Robert M. Vogel is curator of heavy machinery and
     civil engineering, in the Smithsonian Institution's Museum of
     History and Technology._


With few exceptions, civil engineering is a field in which the ultimate
goal is the assemblage of materials into a useful structural form
according to a scientifically derived plan which is based on various
natural and man-imposed conditions. This is true whether the result be,
for example, a dam, a building, a bridge, or even the fixed plant of a
railroad. However, one principal branch of the field is based upon an
entirely different concept. In the engineering of tunnels the utility of
the "structure" is derived not from the bringing together of elements
but from the separation of one portion of naturally existing material
from another to permit passage through a former barrier.

In tunneling hard, firm rock, this is practically the entire compass
of the work: breaking away the rock from the mother mass, and,
coincidently, removing it from the workings. The opposite extreme in
conditions is met in the soft-ground tunnel, driven through material
incapable of supporting itself above the tunnel opening. Here, the
excavation of the tunneled substance is of relatively small concern,
eclipsed by the problem of preventing the surrounding material from
collapsing into the bore.

SECTIONS of the project; blast holes drilled by hand jacking.
MHT model--1/2" scale. (Smithsonian photo 49260-L.)]

In one other principal respect does tunnel engineering differ widely
from its collateral branches of civil engineering. Few other physical
undertakings are approached with anything like the uncertainty
attending a tunnel work. This is even more true in mountain tunnels,
for which test borings frequently cannot be made to determine the
nature of the material and the geologic conditions which will be

The course of tunnel work is not subject to an overall preliminary
survey; the engineer is faced with not only the inability to
anticipate general contingencies common to all engineering work, but
with the peculiar and often overwhelming unpredictability of the very
basis of his work.

Subaqueous and soft-ground work on the other hand, while still subject
to many indeterminates, is now far more predictable than during its
early history, simply because the nature of the adverse condition
prevailing eventually was understood to be quite predictable. The
steady pressures of earth and water to refill the excavated area are
today overcome with relative ease and consistency by the tunneler.

In tunneling as in no other branch of civil engineering did empiricism
so long resist the advance of scientific theory; in no other did the
"practical engineer" remain to such an extent the key figure in
establishing the success or failure of a project. The Hoosac Tunnel,
after 25 years of legislative, financial, and technical difficulties,
in 1875 was finally driven to successful completion only by the
efforts of a group who, while in the majority were trained civil
engineers, were to an even greater extent men of vast practical
ability, more at home in field than office.

DeWitt C. Haskin (see p. 234), during the inquest that followed the
death of a number of men in a blowout of his pneumatically driven
Hudson River Tunnel in 1880, stated in his own defense: "I am not a
scientific engineer, but a practical one ... I know nothing of
mathematics; in my experience I have grasped such matters as a whole;
I believe that the study of mathematics in that kind of work
[tunneling] has a tendency to dwarf the mind rather than enlighten
it...." An extreme attitude perhaps, and one which by no means adds to
Haskin's stature, but a not unusual one in tunnel work at the time. It
would not of course be fair to imply that such men as Herman Haupt,
Brunel the elder, and Greathead were not accomplished theoretical
engineers. But it was their innate ability to evaluate and control the
overlying physical conditions of the site and work that made possible
their significant contributions to the development of tunnel

Tunneling remained largely independent of the realm of mathematical
analysis long after the time when all but the most insignificant
engineering works were designed by that means. Thus, as structural
engineering has advanced as the result of a flow of new theoretical
concepts, new, improved, and strengthened materials, and new methods
of fastening, the progress of tunnel engineering has been due more to
the continual refinement of constructional techniques.


In the Museum of History and Technology has recently been established
a Hall of Civil Engineering in which the engineering of tunnels is
comprehensively treated from the historical standpoint--something not
previously done in an American museum. The guiding precept of the
exhibit has not been to outline exhaustively the entire history of
tunneling, but rather to show the fundamental advances which have
occurred between primitive man's first systematic use of fire for
excavating rock in mining, and the use in combination of compressed
air, iron lining, and a movable shield in a subaqueous tunnel at the
end of the 19th century. This termination date was selected because it
was during the period from about 1830 to 1900 that the most
concentrated development took place, and during which tunneling became
a firmly established and important branch of civil engineering and
indeed, of modern civilization. The techniques of present-day
tunneling are so fully related in current writing that it was deemed
far more useful to devote the exhibit entirely to a segment of the
field's history which is less commonly treated.

[Illustration: Figure 3.--HOOSAC TUNNEL. WORKING OF LATER STAGES with
Burleigh pneumatic drills mounted on carriages. The bottom heading is
being drilled in preparation for blasting out with nitroglycerine.
MHT model--1/2" scale. (Smithsonian photo 49260-M.)]

The major advances, which have already been spoken of as being ones of
technique rather than theory, devolve quite naturally into two basic
classifications: the one of supporting a mass of loose, unstable,
pressure-exerting material--soft-ground tunneling; and the
diametrically opposite problem of separating rock from the basic mass
when it is so firm and solid that it can support its own overbearing
weight as an opening is forced through it--rock, or hard-ground

To exhibit the sequence in a thorough manner, inviting and capable of
easy and correct interpretation by the nonprofessional viewer, models
offered the only logical means of presentation. Six tunnels were
selected, all driven in the 19th century. Each represents either a
fundamental, new concept of tunneling technique, or an important,
early application of one. Models of these works form the basis of the
exhibit. No effort was made to restrict the work to projects on
American soil. This would, in fact, have been quite impossible if an
accurate picture of tunnel technology was to be drawn; for as in
virtually all other areas of technology, the overall development
in this field has been international. The art of mining was first
developed highly in the Middle Ages in the Germanic states; the tunnel
shield was invented by a Frenchman residing in England, and the use of
compressed air to exclude the water from subaqueous tunnels was first
introduced on a major work by an American. In addition, the two main
subdivisions, rock and soft-ground tunneling, are each introduced by
a model not of an actual working, but of one typifying early classical
methods which were in use for centuries until the comparatively recent
development of more efficient systems of earth support and rock
breaking. Particular attention is given to accuracy of detail
throughout the series of eight models; original sources of descriptive
and graphic information were used in their construction wherever
possible. In all cases except the introductory model in the
rock-tunneling series, representing copper mining by early
civilizations, these sources were contemporary accounts.

The plan to use a uniform scale of reduction throughout, in order
to facilitate the viewers' interpretation, unfortunately proved
impractical, due to the great difference in the amount of area to be
encompassed in different models, and the necessity that the cases
holding them be of uniform height. The related models of the Broadway
and Tower Subways represent short sections of tunnels only 8 feet or
so in diameter enabling a relatively large scale, 1-1/2 inches to the
foot, to be used. Conversely, in order that the model of Brunel's
Thames Tunnel be most effective, it was necessary to include one of
the vertical terminal shafts used in its construction. These were
about 60 feet in depth, and thus the much smaller scale of 1/4 inch
to the foot was used. This variation is not as confusing as might be
thought, for the human figures in each model provide an immediate and
positive sense of proportion and scale.

Careful thought was devoted to the internal lighting of the models, as
this was one of the critical factors in establishing, so far as is
possible in a model, an atmosphere convincingly representative of work
conducted solely by artificial light. Remarkable realism was achieved
by use of plastic rods to conduct light to the tiny sources of tunnel
illumination, such as the candles on the miners' hats in the Hoosac
Tunnel, and the gas lights in the Thames Tunnel. No overscaled
miniature bulbs, generally applied in such cases, were used. At
several points where the general lighting within the tunnel proper has
been kept at a low level to simulate the natural atmosphere of the
work, hidden lamps can be operated by push-button in order to bring
out detail which otherwise would be unseen.

The remainder of the material in the Museum's tunneling section
further extends the two major aspects of tunneling. Space limitations
did not permit treatment of the many interesting ancillary matters
vital to tunnel engineering, such as the unique problems of
subterranean surveying, and the extreme accuracy required in the
triangulation and subsequent guidance of the boring in long mountain
tunnels; nor the difficult problems of ventilating long workings, both
during driving and in service; nor the several major methods developed
through the years for driving or constructing tunnels in other than
the conventional manner.[1]

Rock Tunneling

While the art of tunneling soft ground is of relatively recent origin,
that of rock tunneling is deeply rooted in antiquity. However,
the line of its development is not absolutely direct, but is
more logically followed through a closely related branch of
technology--mining. The development of mining techniques is a
practically unbroken one, whereas there appears little continuity or
relationship between the few works undertaken before about the 18th
century for passage through the earth.

The Egyptians were the first people in recorded history to have driven
openings, often of considerable magnitude, through solid rock. As is
true of all major works of that nation, the capability of such grand
proportion was due solely to the inexhaustible supply of human power
and the casual evaluation of life. The tombs and temples won from the
rock masses of the Nile Valley are monuments of perseverance rather
than technical skill. Neither the Egyptians nor any other peoples
before the Middle Ages have left any consistent evidence that they
were able to pierce ground that would not support itself above the
opening as would firm rock. In Egypt were established the methods of
rock breaking that were to remain classical until the first use of
gun-powder blasting in the 17th century which formed the basis of the
ensuing technology of mining.

Notwithstanding the religious motives which inspired the earliest rock
excavations, more constant and universal throughout history has been
the incentive to obtain the useful and decorative minerals hidden
beneath the earth's surface. It was the miner who developed the
methods introduced by the early civilizations to break rock away from
the primary mass, and who added the refinements of subterranean
surveying and ventilating, all of which were later to be assimilated
into the new art of driving tunnels of large diameter. The connection
is the more evident from the fact that tunnelmen are still known as


Therefore, the first model of the sequence, reflecting elemental
rock-breaking techniques, depicts a hard-rock copper mine (fig. 1).
Due to the absence of specific information about such works during the
pre-Christian eras, this model is based on no particular period or
locale, but represents in a general way, a mine in the Rio Tinto area
of Spain where copper has been extracted since at least 1000 B.C.
Similar workings existed in the Tirol as early as about 1600 B.C. Two
means of breaking away the rock are shown: to the left is the most
primitive of all methods, the hammer and chisel, which require no
further description. At the right side, the two figures are shown
utilizing the first rock-breaking method in which a force beyond that
of human muscles was employed, the age-old "fire-setting" method. The
rock was thoroughly heated by a fierce fire built against its face and
then suddenly cooled by dashing water against it. The thermal shock
disintegrated the rock or ore into bits easily removable by hand.

[Illustration: Figure 4.--HOOSAC TUNNEL. Bottom of the central shaft
showing elevator car and rock skip; pumps at far right. In the center,
the top bench is being drilled by a single column-mounted Burleigh
drill. MHT model--1/2" scale. (Smithsonian photo 49260-N.)]

The practice of this method below ground, of course, produced a
fearfully vitiated atmosphere. It is difficult to imagine whether the
smoke, the steam, or the toxic fumes from the roasting ore was
the more distressing to the miners. Even when performed by labor
considered more or less expendable, the method could be employed only
where there was ventilation of some sort: natural chimneys and
convection currents were the chief sources of air circulation. Despite
the drawbacks of the fire system, its simplicity and efficacy weighed
so heavily in its favor that its history of use is unbroken almost to
the present day. Fire setting was of greatest importance during the
years of intensive mining in Europe before the advent of explosive
blasting, but its use in many remote areas hardly slackened until the
early 20th century because of its low cost when compared to powder.
For this same reason, it did have limited application in actual tunnel
work until about 1900.

Direct handwork with pick, chisel and hammer, and fire setting were
the principal means of rock removal for centuries. Although various
wedging systems were also in favor in some situations, their
importance was so slight that they were not shown in the model.


It was possible in the model series, without neglecting any major
advancement in the art of rock tunneling, to complete the sequence of
development with only a single additional model. Many of the greatest
works of civil engineering have been those concerned directly with
transport, and hence are the product of the present era, beginning in
the early 19th century. The development of the ancient arts of route
location, bridge construction, and tunnel driving received a powerful
stimulation after 1800 under the impetus of the modern canal, highway,
and, especially, the railroad.

The Hoosac Tunnel, driven through Hoosac Mountain in the very
northwest corner of Massachusetts between 1851 and 1875, was the first
major tunneling work in the United States. Its importance is due not
so much to this as to its being literally the fountainhead of modern
rock-tunneling technology. The remarkable thing is that the work was
begun using methods of driving almost unchanged during centuries
previous, and was completed twenty years later by techniques which
were, for the day, almost totally mechanized. The basic pattern of
operation set at Hoosac, using pneumatic rock drills and efficient
explosives, remains practically unchanged today.

The general history of the Hoosac project is so thoroughly recorded
that the briefest outline of its political aspects will suffice here.
Hoosac Mountain was the chief obstacle in the path of a railroad
projected between Greenfield, Massachusetts, and Troy, New York.
The line was launched by a group of Boston merchants to provide a
direct route to the rapidly developing West, in competition with the
coastal routes via New York. The only route economically reasonable
included a tunnel of nearly five miles through the mountain--a
length absolutely without precedent, and an immense undertaking in
view of the relatively primitive rock-working methods then available.

[Illustration: Figure 5.--BURLEIGH ROCK DRILL, improved model of about
1870, mounted on frame for surface work. (Catalog and price list: The
Burleigh Rock Drill Company, 1876.)]

The bore's great length and the desire for rapid exploitation inspired
innovation from the outset of the work. The earliest attempts at
mechanization, although ineffectual and without influence on tunnel
engineering until many years later, are of interest. These took the
form of several experimental machines of the "full area" type,
intended to excavate the entire face of the work in a single operation
by cutting one or more concentric grooves in the rock. The rock
remaining between the grooves was to be blasted out. The first such
machine tested succeeded in boring a 24-foot diameter opening for 10
feet before its total failure. Several later machines proved of equal
merit.[2] It was the Baltimore and Ohio's eminent chief engineer,
Benjamin H. Latrobe, who in his _Report on the Hoosac Tunnel_
(Baltimore, Oct. 1, 1862, p. 125) stated that such apparatus contained
in its own structure the elements of failure, "... as they require
the machines to do too much and the powder too little of the work,
thus contradicting the fundamental principles upon which all
labor-saving machinery is framed ... I could only look upon it as a
misapplication of mechanical genius."

[Illustration: Figure 6.--HOOSAC TUNNEL. Flash-powder photograph of
Burleigh drills at the working face. (_Photo courtesy of State
Library, Commonwealth of Massachusetts._)]

Latrobe stated the basic philosophy of rock-tunnel work. No mechanical
agent has ever been able to improve upon the efficiency of explosives
for the shattering of rock. For this reason, the logical application
of machinery to tunneling was not in replacing or altering the
fundamental process itself, but in enabling it to be conducted with
greater speed by mechanically drilling the blasting holes to receive
the explosive.

Actual work on the Hoosac Tunnel began at both ends of the tunnel in
about 1854, but without much useful effect until 1858 when a contract
was let to the renowned civil engineer and railroad builder, Herman
Haupt of Philadelphia. Haupt immediately resumed investigations of
improved tunneling methods, both full-area machines and mechanical
rock drills. At this time mechanical rock-drill technology was in a
state beyond, but not far beyond, initial experimentation. There
existed one workable American machine, the Fowle drill, invented in
1851. It was steam-driven, and had been used in quarry work, although
apparently not to any commercial extent. However, it was far too
large and cumbersome to find any possible application in tunneling.
Nevertheless, it contained in its operating principle, the seed of a
practical rock drill in that the drill rod was attached directly to
and reciprocated by a double-acting steam piston. A point of great
importance was the independence of its operation on gravity,
permitting drilling in any direction.

While experimenting, Haupt drove the work onward by the classical
methods, shown in the left-hand section of the model (fig. 2). At
the far right an advance heading or adit is being formed by pick and
hammer work; this is then deepened into a top heading with enough
height to permit hammer drilling, actually the basic tunneling
operation. A team is shown "double jacking," i.e., using two-handed
hammers, the steel held by a third man. This was the most efficient of
the several hand-drilling methods. The top-heading plan was followed
so that the bulk of the rock could be removed in the form of a bottom
bench, and the majority of drilling would be downward, obviously the
most effective direction. Blasting was with black powder and its
commercial variants. Some liberty was taken in depicting these steps
so that both operations might be shown within the scope of the model:
in practice the heading was kept between 400 and 600 feet in advance
of the bench so that heading blasts would not interfere with the bench
work. The bench carriage simply facilitated handling of the blasted
rock. It was rolled back during blasts.

[Illustration: Figure 7.--HOOSAC TUNNEL. GROUP OF MINERS descending
the west shaft with a Burleigh drill. (_Photo courtesy of State
Library, Commonwealth of Massachusetts._)]

The experiments conducted by Haupt with machine drills produced no
immediate useful results. A drill designed by Haupt and his associate,
Stuart Gwynn, in 1858 bored hard granite at the rate of 5/8 inch per
minute, but was not substantial enough to bear up in service. Haupt
left the work in 1861, victim of intense political pressures and
totally unjust accusations of corruption and mismanagement. The
work was suspended until taken over by a state commission in 1862.
Despite frightful ineptitude and very real corruption, this period
was exceedingly important in the long history both of Hoosac Tunnel
and of rock tunneling in general.

The merely routine criticism of the project had by this time become
violent due to the inordinate length of time already elapsed and the
immense cost, compared to the small portion of work completed. This
served to generate in the commission a strong sense of urgency to
hurry the project along. Charles S. Storrow, a competent engineer, was
sent to Europe to report on the progress of tunneling there, and in
particular on mechanization at the Mont Cenis Tunnel then under
construction between France and Italy. Germain Sommeiller, its chief
engineer, had, after experimentation similar to Haupt's, invented a
reasonably efficient drilling machine which had gone into service at
Mont Cenis in March 1861. It was a distinct improvement over hand
drilling, almost doubling the drilling rate, but was complex and
highly unreliable. Two hundred drills were required to keep 16 drills
at work. But the vital point in this was the fact that Sommeiller
drove his drills not with steam, but air, compressed at the tunnel
portals and piped to the work face. It was this single factor, one of
application rather than invention, that made the mechanical drill
feasible for tunneling.

All previous effort in the field of machine drilling, on both sides
of the Atlantic, had been directed toward steam as the motive power.
In deep tunnels, with ventilation already an inherent problem, the
exhaust of a steam drill into the atmosphere was inadmissible.
Further, steam could not be piped over great distances due to serious
losses of energy from radiation of heat, and condensation. Steam
generation within the tunnel itself was obviously out of the question.
It was the combination of a practical drill, and the parallel
invention by Sommeiller of a practical air compressor that resulted in
the first workable application of machine rock drilling to tunneling.

[Illustration: Figures 8 & 9.--HOOSAC TUNNEL. CONTEMPORARY
ENGRAVINGS. As such large general areas could not be sufficiently
illuminated for photography, the Museum model was based primarily on
artists' versions of the work. (_Science Record_, 1872; _Leslie's
Weekly_, 1873.)]

The Sommeiller drills greatly impressed Storrow, and his report of
November 1862 strongly favored their adoption at Hoosac. It is curious
however, that not a single one was brought to the U.S., even on trial.
Storrow does speak of Sommeiller's intent to keep the details of the
machine to himself until it had been further improved, with a view to
its eventual exploitation. The fact is, that although workable, the
Sommeiller drill proved to be a dead end in rock-drill development
because of its many basic deficiencies. It did exert the indirect
influence of inspiration which, coupled with a pressing need for
haste, led to renewed trials of drilling machinery at Hoosac. Thomas
Doane, chief engineer under the state commission, carried this program
forth with intensity, seeking and encouraging inventors, and himself
working on the problem. The pattern of the Sommeiller drill was
generally followed; that is, the drill was designed as a separate,
relatively light mechanical element, adapted for transportation by
several miners, and attachable to a movable frame or carriage during
operation. Air was of course the presumed power. To be effective, it
was necessary that a drill automatically feed the drill rod as the
hole deepened, and also rotate the rod automatically to maintain a
round, smooth hole. Extreme durability was essential, and usually
proved the source of a machine's failure. The combination of these
characteristics into a machine capable of driving the drill rod into
the rock with great force, perhaps five times per second, was a
severe test of ingenuity and materials. Doane in 1864 had three
different experimental drills in hand, as well as various steam
and water-powered compressors.

Success finally came in 1865 with the invention of a drill by Charles
Burleigh, a mechanical engineer at the well-known Putnam Machine Works
of Fitchburg, Massachusetts. The drills were first applied in the east
heading in June of 1866. Although working well, their initial success
was limited by lack of reliability and a resulting high expense for
repairs. They were described as having "several weakest points." In
November, these drills were replaced by an improved Burleigh drill
which was used with total success to the end of the work. The era of
modern rock tunneling was thus launched by Sommeiller's insight in
initially applying pneumatic power to a machine drill, by Doane's
persistence in searching for a thoroughly practical drill, and by
Burleigh's mechanical talent in producing one. The desperate need to
complete the Hoosac Tunnel may reasonably be considered the greatest
single spur to the development of a successful drill.

The significance of this invention was far reaching. Burleigh's was
the first practical mechanical rock drill in America and, in view of
its dependability, efficiency, and simplicity when compared to the
Sommeiller drill, perhaps in the world. The Burleigh drill achieved
success almost immediately. It was placed in production by Putnam for
the Burleigh Rock Drill Company before completion of Hoosac in 1876,
and its use spread throughout the western mining regions and other
tunnel works. For a major invention, its adoption was, in relative
terms, instantaneous. It was the prototype of all succeeding
piston-type drills, which came to be known generically as "burleighs,"
regardless of manufacture. Walter Shanley, the Canadian contractor who
ultimately completed the Hoosac, reported in 1870, after the drills
had been in service for a sufficient time that the techniques for
their most efficient use were fully understood and effectively
applied, that the Burleigh drills saved about half the drilling costs
over hand drilling. The per-inch cost of machine drilling averaged 5.5
cents, all inclusive, vs. 11.2 cents for handwork. The more important
point, that of speed, is shown by the reports of average monthly
progress of the tunnel itself, before and after use of the air drills.

  _Year_     _Average monthly
              progress in feet_

  1865              55
  1866              48
  1867              99
  1868              --
  1869             138
  1870             126
  1871             145
  1872             124

[Illustration: Figure 10.--TRINITROGLYCERINE BLAST at Hoosac Tunnel.
(_Leslie's Weekly_, 1873.)]

The right portion of the model (fig. 3) represents the workings during
the final period. The bottom heading system was generally used after
the Burleigh drills had been introduced. Four to six drills were
mounted on a carriage designed by Doane. These drove the holes for
the first blast in the center of the heading in about six hours. The
full width of the heading, the 24-foot width of the tunnel, was then
drilled and blasted out in two more stages. As in the early section,
the benches to the rear were later removed to the full-tunnel height
of about 20 feet. This operation is shown by a single drill (fig. 4)
mounted on a screw column. Three 8-hour shifts carried the work
forward: drilling occupied half the time and half was spent in running
the carriage back, blasting, and mucking (clearing the broken rock).

[Illustration: Figure 11.--HOOSAC TUNNEL survey crew at engineering
office. The highest accuracy of the aboveground and underground survey
work was required to insure proper vertical and horizontal alignment
and meeting of the several separately driven sections. (_Photo
courtesy of State Library, Commonwealth of Massachusetts._)]

The tunnel's 1028-foot central shaft, completed under the Shanley
contract in 1870 to provide two additional work faces as well as a
ventilation shaft is shown at the far right side of this half of the
model. Completed so near the end of the project, only 15 percent of
the tunnel was driven from the shaft.

The enormous increase in rate of progress was not due entirely to
machine drilling. From the outset of his jurisdiction, Doane undertook
experiments with explosives as well as drills, seeking an agent more
effective than black powder. In this case, the need for speed was not
the sole stimulus. As the east and west headings advanced further and
further from the portals, the problem of ventilation grew more acute,
and it became increasingly difficult to exhaust the toxic fumes
produced by the black powder blasts.

In 1866, Doane imported from Europe a sample of trinitroglycerine,
the liquid explosive newly introduced by Nobel, known in Europe as
"glonoïn oil" and in the United States as "nitroglycerine." It already
had acquired a fearsome reputation from its tendency to decompose with
heat and age and to explode with or without the slightest provocation.
Nevertheless, its tremendous power and characteristic of almost
complete smokelessness led Doane to employ the chemist George W.
Mowbray, who had blasted for Drake in the Pennsylvania oil fields, to
develop techniques for the bulk manufacture of the new agent and for
its safe employment in the tunnel.

Mowbray established a works on the mountain and shortly developed
a completely new blasting practice based on the explosive. Its
stability was greatly increased by maintaining absolute purity in the
manufacturing process. Freezing the liquid to reduce its sensitivity
during transport to the headings, and extreme caution in its handling
further reduced the hazard of its use. At the heading, the liquid was
poured into cylindrical cartridges for placement in the holes. As with
the Burleigh drill, the general adoption of nitroglycerine was
immediate once its qualities had been demonstrated. The effect on the
work was notable. Its explosive characteristics permitted fewer blast
holes over a given frontal area of working face, and at the same time
it was capable of effectively blowing from a deeper drill hole, 42
inches against 30 inches for black powder, so that under ideal
conditions 40 percent more tunnel length was advanced per cycle of
operations. A new fuse and a system of electric ignition were
developed which permitted simultaneous detonation and resulted
in a degree of effectiveness impossible with the powder train and
cord fusing used with the black powder. Over a million pounds of
nitroglycerine were produced by Mowbray between 1866 and completion
of the tunnel.

for hoisting, pumping and air compressing machinery, and general
repair, 1871. (_Photo courtesy of State Library, Commonwealth of

Hoosac River near North Adams. The compressors were driven partially
by waterpower, derived from the river. (_Photo courtesy of State
Library, Commonwealth of Massachusetts._)]

[Illustration: Figure 14.--WEST PORTAL OF HOOSAC TUNNEL before
completion, 1868, showing six rings of lining brick. (_Photo
courtesy of State Library, Commonwealth of Massachusetts._)]

When the Shanleys took the work over in 1868, following political
difficulties attending operation by the State, the period of
experimentation was over. The tunnel was being advanced by totally
modern methods, and to the present day the overall concepts have
remained fundamentally unaltered: the Burleigh piston drill has been
replaced by the lighter hammer drill; the Doane drill carriage by the
more flexible "jumbo"; nitroglycerine by its more stable descendant
dynamite and its alternatives; and static-electric blasting machines
by more dependable magnetoelectric. But these are all in the nature of
improvements, not innovations.

Unlike the preceding model, there was good documentation for this one.
Also, the Hoosac was apparently the first American tunnel to be well
recorded photographically. Early flashlight views exist of the drills
working at the heading (fig. 6) as well as of the portals, the winding
and pumping works at the central shaft, and much of the machinery and
associated aspects of the project. These and copies of drawings of
much of Doane's experimental apparatus, a rare technological record,
are preserved at the Massachusetts State Library.

Soft-Ground Tunneling

So great is the difference between hard-rock and soft-ground tunneling
that they constitute two almost separate branches of the field. In
penetrating ground lacking the firmness or cohesion to support itself
above an opening, the miner's chief concern is not that of removing
the material, but of preventing its collapse into his excavation. The
primitive methods depending upon brute strength and direct application
of fire and human force were suitable for assault on rock, but lacked
the artifice needed for delving into less stable material. Roman
engineers were accomplished in spanning subterranean ways with masonry
arches, but apparently most of their work was done by cut-and-cover
methods rather than by actual mining.

Not until the Middle Ages did the skill of effectively working
openings in soft ground develop, and not until the Renaissance
was this development so consistently successful that it could
be considered a science.


From the earliest periods of rock working, the quest for minerals
and metals was the primary force that drove men underground. It was
the technology of mining, the product of slow evolution over the
centuries, that became the technology of the early tunnel, with no
significant modification except in size of workings.

Every aspect of 16th century mining is definitively detailed in
Georgius Agricola's remarkable _De re Metallica_, first published in
Basel in 1556. During its time of active influence, which extended
for two centuries, it served as the authoritative work on the subject.
It remains today an unparalleled early record of an entire branch
of technology. The superb woodcuts of mine workings and tools in
themselves constitute a precise description of the techniques of the
period, and provided an ideal source of information upon which to base
the first model in the soft-ground series.

STONEWORK at west portal, 1874. At top-right are the sheds where
the lining brick was produced. (_Photo courtesy of State Library,
Commonwealth of Massachusetts._)]

The model, representing a typical European mine, demonstrates the
early use of timber frames or "sets" to support the soft material of
the walls and roof. In areas of only moderate instability, the sets
alone were sufficient to counteract the earth pressure, and were
spaced according to the degree of support required. In more extreme
conditions, a solid lagging of small poles or boards was set outside
the frames, as shown in the model, to provide absolute support of the
ground. Details of the framing, the windlass, and all tools and
appliances were supplied by Agricola, with no need for interpretation
or interpolation.

The basic framing pattern of sill, side posts and cap piece, all
morticed together, with lagging used where needed, was translated
unaltered into tunneling practice, particularly in small exploratory
drifts. It remained in this application until well into the 20th

The pressure exerted upon tunnels of large area was countered during
construction by timbering systems of greater elaboration, evolved
from the basic one. By the time that tunnels of section large
enough to accommodate canals and railways were being undertaken as
matter-of-course civil engineering works, a series of nationally
distinguishable systems had emerged, each possessing characteristic
points of favor and fault. As might be suspected, the English system
of tunnel timbering, for instance, was rarely applied on the
Continent, nor were the German, Austrian or Belgian systems normally
seen in Great Britain. All were used at one time or another in this
country, until the American system was introduced in about 1855.
While the timbering commonly remained in place in mines, it would be
followed up by permanent masonry arching and lining in tunnel work.

Overhead in the museum Hall of Civil Engineering are frames
representing the English, Austrian and American systems. Nearby, a
series of small relief models (fig. 19) is used to show the sequence
of enlargement in a soft-ground railroad tunnel of about 1855, using
the Austrian system. Temporary timber support of tunnels fell from use
gradually after the advent of shield tunneling in conjunction with
cast-iron lining. This formed a perfect support immediately behind the
shield, as well as the permanent lining of the tunnel.


The interior surfaces of tunnels through ground merely unstable are
amenable to support by various systems of timbering and arching. This
becomes less true as the fluidity of the ground increases. The soft
material which normally comprises the beds of rivers can approach an
almost liquid condition resulting in a hydraulic head from the
overbearing water sufficient to prevent the driving of even the most
carefully worked drift, supported by simple timbering. The basic
defect of the timbering systems used in mining and tunneling was
that there was inevitably a certain amount of the face or ceiling
unsupported just previous to setting a frame, or placing over it the
necessary section of lagging. In mine work, runny soil could, and did,
break through such gaps, filling the working. For this reason, there
were no serious attempts made before 1825 to drive subaqueous tunnels.

In that year, work was started on a tunnel under the Thames between
the Rotherhithe and Wapping sections of London, under guidance of the
already famous engineer Marc Isambard Brunel (1769-1849), father of
I. K. Brunel. The undertaking is of great interest in that Brunel
employed an entirely novel apparatus of his own invention to provide
continuous and reliable support of the soft water-bearing clay which
formed the riverbed. By means of this "shield," Brunel was able to
drive the world's first subaqueous tunnel.[3]

[Illustration: Figure 16.--WEST PORTAL UPON COMPLETION, 1876.
(_Photo courtesy of New-York Historical Society._)]

The shield was of cast-iron, rectangular in elevation, and was
propelled forward by jackscrews. Shelves at top, bottom, and sides
supported the tunnel roof, floor, and walls until the permanent brick
lining was placed. The working face, the critical area, was supported
by a large number of small "breasting boards," held against the ground
by small individual screws bearing against the shield framework. The
shield itself was formed of 12 separate frames, each of which could be
advanced independently of the others. The height was 22 feet 3 inches:
the width 37 feet 6 inches.

The progress was piecemeal. In operation the miners would remove one
breasting board at a time, excavate in front of it, and then replace
it in the advanced position--about 6 inches forward. This was repeated
with the next board above or below, and the sequence continued until
the ground for the entire height of one of the 12 sections had been
removed. The board screws for that section were shifted to bear on the
adjacent frames, relieving the frame of longitudinal pressure. It
could then be screwed forward by the amount of advance, the screws
bearing to the rear on the completed masonry. Thus, step by step the
tunnel progressed slowly, the greatest weekly advance being 14 feet.

In the left-hand portion of the model is the shaft sunk to begin
operations; here also is shown the bucket hoist for removing the
spoil. The V-type steam engine powering the hoist was designed by
Brunel. At the right of the main model is an enlarged detail of the
shield, actually an improved version built in 1835.

The work continued despite setbacks of every sort. The financial ones
need no recounting here. Technically, although the shield principle
proved workable, the support afforded was not infallible. Four or five
times the river broke through the thin cover of silt and flooded
the workings, despite the utmost caution in excavating. When this
occurred, masses of clay, sandbags, and mats were dumped over the
opening in the riverbed to seal it, and the tunnel pumped out. I. K.
Brunel acted as superintendent and nearly lost his life on a number of
occasions. After several suspensions of work resulting from withdrawal
or exhaustion of support, one lasting seven years, the work was
completed in 1843.

Despite the fact that Brunel had, for the first time, demonstrated a
practical method for tunneling in firm and water-bearing ground, the
enormous cost of the work and the almost overwhelming problems
encountered had a discouraging effect rather than otherwise. Not for
another quarter of a century was a similar project undertaken.

The Thames Tunnel was used for foot and light highway traffic until
about 1870 when it was incorporated into the London Underground
railway system, which it continues to serve today. The roofed-over
top sections of the two shafts may still be seen from the river.

A number of contemporary popular accounts of the tunnel exist, but one
of the most thorough and interesting expositions on a single tunnel
work of any period is Henry Law's _A Memoir of the Thames Tunnel_,
published in 1845-1846 by John Weale. Law, an eminent civil engineer,
covers the work in incredible detail from its inception until the
major suspension in late 1828 when slightly more than half completed.
The most valuable aspect of his record is a series of plates of
engineering drawings of the shield and its components, which, so
far as is known, exist nowhere else. These formed the basis of the
enlarged section of the shield, shown to the right of the model of the
tunnel itself. A vertical section through the shield is reproduced
here from Law for comparison with the model (figs. 21 and 23).

[Illustration: Figure 17.--SOFT-GROUND TUNNELING. The support of
walls and roof of mine shaft by simple timbering; 16th century.
MHT model--3/4" scale. (Smithsonian photo 49260-J.)]

[Illustration: Figure 18.--SOFT-GROUND TUNNELING. The model of a 16th
century mine in the Museum of History and Technology was constructed
from illustrations in such works as G. E. von Löhneyss' _Bericht vom
Bergwerck_, 1690, as well as the better known ones from _De re

[Illustration: Figure 19.--THE SUCCESSIVE STAGES in the enlargement
of a mid-19th century railroad tunnel, using the Austrian system of
timbering. MHT model.]

[Illustration: Figure 20.--M. I. BRUNEL'S THAMES TUNNEL, 1825-1843,
the first driven beneath a body of water. MHT model--1/4" scale.
(Smithsonian photo 49260-F.)]


Various inventors attempted to improve upon the Brunel shield, aware
of the fundamental soundness of the shield principle. Almost all
bypassed the rectangular sectional construction used in the Thames
Tunnel, and took as a starting point a sectional shield of circular
cross section, advanced by Brunel in his original patent of 1818.
James Henry Greathead (1844-1896), rightfully called the father of
modern subaqueous tunneling, surmised in later years that Brunel had
chosen a rectangular configuration for actual use, as one better
adapted to the sectional type of shield. The English civil engineer,
Peter W. Barlow, in 1864 and 1868 patented a circular shield, of one
piece, which was the basis of one used by him in constructing a small
subway of 1350 feet beneath the Thames in 1869, the first work to
follow the lead of Brunel. Greathead, acting as Barlow's contractor,
was the designer of the shield actually used in the work, but it was
obviously inspired by Barlow's patents.

The reduction of the multiplicity of parts in the Brunel shield to
a single rigid unit was of immense advantage and an advance perhaps
equal to the shield concept of tunneling itself. The Barlow-Greathead
shield was like the cap of a telescope with a sharpened circular ring
on the front to assist in penetrating the ground. The diaphragm
functioned, as did Brunel's breasting boards, to resist the
longitudinal earth pressure of the face, and the cylindrical portion
behind the diaphragm bore the radial pressure of roof and walls. Here
also for the first time, a permanent lining formed of cast-iron
segments was used, a second major advancement in soft-ground tunneling
practice. Not only could the segments be placed and bolted together
far more rapidly than masonry lining could be laid up, but unlike the
green masonry, they could immediately bear the full force of the
shield-propelling screws.

Barlow, capitalizing on Brunel's error in burrowing so close to the
riverbed, maintained an average cover of 30 feet over the tunnel,
driving through a solid stratum of firm London clay which was
virtually impervious to water. As the result of this, combined with
the advantages of the solid shield and the rapidly placed iron lining,
the work moved forward at a pace and with a facility in startling
contrast to that of the Thames Tunnel, although in fairness it must be
recalled that the face area was far less.

The clay was found sufficiently sound that it could be readily
excavated without the support of the diaphragm, and normally three
miners worked in front of the shield, digging out the clay and passing
it back through a doorway in the plate. This could be closed in case
of a sudden settlement or break in. Following excavation, the shield
was advanced 18 inches into the excavated area by means of 6 screws,
and a ring of lining segments 18 inches in length bolted to the
previous ring under cover of the overlapping rear skirt of the shield.
The small annular space left between the outside of the lining and the
clay by the thickness and clearance of the skirt--about an inch--was
filled with thin cement grout. The tunnel was advanced 18 inches
during each 8-hour shift. The work continued around the clock, and the
900-foot river section was completed in only 14 weeks.[4] The entire
work was completed almost without incident in just under a year, a
remarkable performance for the world's second subaqueous tunnel.

[Illustration: Figure 21.--ENLARGED DETAIL of Brunel's tunneling
shield, vertical section. The first two and part of the third of the
twelve frames are shown. To the left is the tunnel's completed brick
lining and to the right, the individual breasting boards and screws
for supporting the face. The propelling screws are seen at top and
bottom, bearing against the lining. Three miners worked in each frame,
one above the other. MHT model--3/4" scale. (Smithsonian photo

OF WORK on the Thames Tunnel, 1827. (MHT collections.)

  OPEN TO THE PUBLIC EVERY DAY (_Sundays excepted_) _from Seven in the
  Morning, until Eight in the Evening_,


  Fig. 1 shows a transverse section of the Thames, and beneath it a
  longitudinal section of the Tunnel, as it will be when completed;
  with the ascents in the inclinations in which they will be finished.

  Fig. 2 shows the two arched entrances of the Tunnel from the shaft.

  Fig. 3 is a representation of the iron shield, and shows a workman
  in each of the compartments.

  The Entrance to the Tunnel is near to Rotherhithe Church, and nearly
  opposite to the London-Docks. The nearest landing place from the river
  is Church Stairs. The Greenwich and Deptford coaches which go the
  lower road, start hourly from Charing-cross, and Gracechurch-street,
  and pass close by the works at Rotherhithe.

  Books relative to the Tunnel may be had at the works.

  The Public may view the Tunnel every day (Sundays excepted) from
  Seven in the morning until Eight in the Evening, upon payment of
  One Shilling each Person.

  The extreme northern end of the Tunnel is for the present secured
  by a strong wall; but visitors will find a dry, warm, and gravelled
  promenade, as far as to almost the centre of the river, and
  brilliantly lighted with oil gas.

  The entrance is from Rotherhithe Street, and by a safe, commodious,
  and easy stair case.

    H. Teape & Son, Printers, Tower-hill, London.]

The long lever, x, supported the wood centering for turning the
masonry arches of the lining. (LAW, _A Memoir of the Thames

[Illustration: Figure 24.--THAMES TUNNEL. SECTION THROUGH riverbed and
tunnel following one of the break-throughs of the river. Inspection of
the damage with a diving bell. (BEAMISH, _A Memoir of the Life of Sir
Marc Isambard Brunel_.)]

The Tower Subway at first operated with cylindrical cars that nearly
filled the 7-foot bore; the cars were drawn by cables powered by small
steam engines in the shafts. This mode of power had previously been
used in passenger service only on the Greenwich Street elevated
railway in New York. Later the cars were abandoned as unprofitable and
the tunnel turned into a footway (fig. 32). This small tunnel, the
successful driving due entirely to Greathead's skill, was the
forerunner of the modern subaqueous tunnel. In it, two of the three
elements essential to such work thereafter were first applied: the
one-piece movable shield of circular section, and the segmental
cast-iron lining.

The documentation of this work is far thinner than for the Thames
Tunnel. The most accurate source of technical information is a brief
historical account in Copperthwaite's classic _Tunnel Shields and the
Use of Compressed Air in Subaqueous Works_, published in 1906.
Copperthwaite, a successful tunnel engineer, laments the fact that he
was able to turn up no drawing or original data on this first shield
of Greathead's, but he presents a sketch of it prepared in the
Greathead office in 1895, which is presumably a fair representation
(fig. 33). The Tower Subway model was built on the basis of this and
several woodcuts of the working area that appeared contemporaneously
in the illustrated press. In this and the adjacent model of Beach's
Broadway Subway, the tunnel axis has been placed on an angle to the
viewer, projecting the bore into the case so that the complete circle
of the working face is included for a more suggestive effect. This was
possible because of the short length of the work included.

Henry S. Drinker, also a tunnel engineer and author of the most
comprehensive work on tunneling ever published, treats rock tunneling
in exhaustive detail up to 1878. His notice of what he terms
"submarine tunneling" is extremely brief. He does, however, draw a
most interesting comparison between the first Thames Tunnel, built by
Brunel, and the second, built by Greathead 26 years later:

                                     (TOWER SUBWAY)

  Brickwork lining, 38 feet       Cast-iron lining of 8 feet
  wide by 22-1/2 feet high.       outside diameter.

  120-ton cast-iron shield,       2-1/2-ton, wrought-iron shield,
  accommodating 36 miners.        accommodating at most 3 men.

  Workings filled by irruption   "Water encountered at almost
  of river five times.            any time could have been
                                  gathered in a stable pail."

  Eighteen years elapsed between  Work completed in about
  start and finish of work.       eleven months.

  Cost: $3,000,000.               Cost: $100,000.

[Illustration: Figure 25.--TRANSVERSE SECTION THROUGH SHIELD, after
inundation. Such disasters, as well as the inconsistency of the
riverbed's composition, seriously disturbed the alignment of the
shield's individual sections. (LAW, _A Memoir of the Thames Tunnel_.)]

after sandbagging to close a break in the riverbed. The tunnel is
filled with silt and water. (LAW, _A Memoir of the Thames Tunnel_.)]

[Illustration: Figure 27.--INTERIOR OF THE THAMES TUNNEL shortly after
completion in 1843. (_Photo courtesy of New York Public Library
Picture Collection._)]

[Illustration: Figure 28.--THAMES TUNNEL in use by London Underground
railway. (_Illustrated London News_, 1869?)]

[Illustration: Figure 29.--PLACING A segment of cast-iron lining in
Greathead's Tower Subway, 1869. To the rear is the shield's diaphragm
or bulkhead. MHT model--1-1/2" scale. (Smithsonian photo 49260-B.)]


Almost simultaneously with the construction of the Tower Subway,
the first American shield tunnel was driven by Alfred Ely Beach
(1826-1896). Beach, as editor of the _Scientific American_ and
inventor of, among other things, a successful typewriter as early as
1856, was well known and respected in technical circles. He was not
a civil engineer, but had become concerned with New York's pressing
traffic problem (even then) and as a solution, developed plans for a
rapid-transit subway to extend the length of Broadway. He invented a
shield as an adjunct to this system, solely to permit driving of the
tunnel without disturbing the overlying streets.

An active patent attorney as well, Beach must certainly have known of
and studied the existing patents for tunneling shields, which were,
without exception, British. In certain aspects his shield resembled
the one patented by Barlow in 1864, but never built. However, work on
the Beach tunnel started in 1869, so close in time to that on the
Tower Subway, that it is unlikely that there was any influence from
that source. Beach had himself patented a shield, in June 1869, a
two-piece, sectional design that bore no resemblance to the one used.
His subway plan had been first introduced at the 1867 fair of the
American Institute in the form of a short plywood tube through which
a small, close-fitting car was blown by a fan. The car carried 12
passengers. Sensing opposition to the subway scheme from Tammany, in
1868 Beach obtained a charter to place a small tube beneath Broadway
for transporting mail and small packages pneumatically, a plan he
advocated independently of the passenger subway.

[Illustration: Figure 30.--CONTEMPORARY ILLUSTRATIONS of Tower
Subway works used as basis of the model in the Museum of History
and Technology. (_Illustrated London News_, 1869.)


[Illustration: Figure 31.--EXCAVATION IN FRONT OF SHIELD, Tower
Subway. This was possible because of the stiffness of the clay
encountered. MHT model--front of model shown in fig. 29.
(Smithsonian photo 49260-A.)]

Under this thin pretense of legal authorization, the sub-rosa
excavation began from the basement of a clothing store on Warren
Street near Broadway. The 8-foot-diameter tunnel ran eastward a short
distance, made a 90-degree turn, and thence southward under Broadway
to stop a block away under the south side of Murray Street. The total
distance was about 312 feet. Work was carried on at night in total
secrecy, the actual tunneling taking 58 nights. At the Warren Street
terminal, a waiting room was excavated and a large Roots blower
installed for propulsion of the single passenger car. The plan was
similar to that used with the model in 1867: the cylindrical car
fitted the circular tunnel with only slight circumferential clearance.
The blower created a plenum within the waiting room and tunnel area
behind the car of about 0.25 pounds per square inch, resulting in a
thrust on the car of almost a ton, not accounting for blowby. The car
was thus blown along its course, and was returned by reversing the
blower's suction and discharge ducts to produce an equivalent vacuum
within the tunnel.

(THORNBURY, _Old and New London, 1887, vol. 1, p. 126_.)]

The system opened in February of 1870 and remained in operation for
about a year. Beach was ultimately subdued by the hostile influences
of Boss Tweed, and the project was completely abandoned. Within a very
few more years the first commercially operated elevated line was
built, but the subway did not achieve legitimate status in New York
until the opening of the Interborough line in 1904. Ironically, its
route traversed Broadway for almost the length of the island.

[Illustration: Figure 33.--VERTICAL SECTION through the Greathead
shield used at the Tower Subway, 1869. The first one-piece shield of
circular section. (COPPERTHWAITE, _Tunnel Shields and the Use of
Compressed Air in Subaqueous Works_.)]

The Beach shield operated with perfect success in this brief trial,
although the loose sandy soil encountered was admittedly not a severe
test of its qualities. No diaphragm was used; instead a series of 8
horizontal shelves with sharpened leading edges extended across the
front opening of the shield. The outstanding feature of the machine
was the substitution for the propelling screws used by Brunel and
Greathead of 18 hydraulic rams, set around its circumference. These
were fed by a single hand-operated pump, seen in the center of figure
34. By this means the course of the shield's forward movement could be
controlled with a convenience and precision not attainable with
screws. Vertical and horizontal deflection was achieved by throttling
the supply of water to certain of the rams, which could be
individually controlled, causing greater pressure on one portion of
the shield than another. This system has not changed in the ensuing
time, except, of course, in the substitution of mechanically produced
hydraulic pressure for hand.

[Illustration: Figure 34.--BEACH'S Broadway Subway. Advancing the
shield by hydraulic rams, 1869. MHT model--1-1/2" scale. (Smithsonian
photo 49260-E.)]

[Illustration: Figure 35.--VERTICAL SECTION through the Beach shield
used on the Broadway Subway, showing the horizontal shelves (C), iron
cutting ring (B), hydraulic rams (D), hydraulic pump (F), and rear
protective skirt (H). (_Scientific American_, March 5, 1870.)]

Unlike the driving of the Tower Subway, no excavation was done in
front of the shield. Rather, the shield was forced by the rams into
the soil for the length of their stroke, the material which entered
being supported by the shelves. This was removed from the shelves and
hauled off. The ram plungers then were withdrawn and a 16-inch length
of the permanent lining built up within the shelter of the shield's
tail ring. Against this, the rams bore for the next advance. Masonry
lining was used in the straight section; cast-iron in the curved. The
juncture is shown in the model.

[Illustration: Figure 36.--INTERIOR of Beach Subway showing iron
lining on curved section and the pneumatically powered passenger car.
View from waiting room. (_Scientific American_, March 5, 1870.)]

Enlarged versions of the Beach shield were used in a few tunnels in
the Midwest in the early 1870's, but from then until 1886 the shield
method, for no clear reason, again entered a period of disuse finding
no application on either side of the Atlantic despite its virtually
unqualified proof at the hands of Greathead and Beach. Little precise
information remains on this work. The Beach system of pneumatic
transit is described fully in a well-illustrated booklet published
by him in January 1868, in which the American Institute model is
shown, and many projected systems of pneumatic propulsion as well
as of subterranean and subaqueous tunneling described. Beach again
(presumably) is author of the sole contemporary account of the
Broadway Subway, which appeared in _Scientific American_ following its
opening early in 1870. Included are good views of the tunnel and car,
of the shield in operation, and, most important, a vertical sectional
view through the shield (fig. 35).

It is interesting to note that optical surveys for maintenance of the
course apparently were not used. The article illustrated and described
the driving each night of a jointed iron rod up through the tunnel
roof to the street, twenty or so feet above, for "testing the


Despite the ultimate success of Brunel's Thames Tunnel in 1843, the
shield in that case afforded only moderately reliable protection
because of the fluidity of the soil driven through, and its tendency
to enter the works through the smallest opening in the shield's
defense. An English doctor who had made physiological studies of the
effects on workmen of the high air pressure within diving bells is
said to have recommended to Brunel in 1828 that he introduce an
atmosphere of compressed air into the tunnel to exclude the water
and support the work face.

This plan was first formally described by Sir Thomas Cochrane
(1775-1860) in a British patent of 1830. Conscious of Brunel's
problems, he proposed a system of shaft sinking, mining, and tunneling
in water-bearing materials by filling the excavated area with air
sufficiently above atmospheric pressure to prevent the water from
entering and to support the earth. In this, and his description of air
locks for passage of men and materials between the atmosphere and the
pressurized area, Cochrane fully outlined the essential features of
pneumatic excavation as developed since.

[Illustration: Figure 37.--THE GIANT ROOTS LOBE-TYPE BLOWER used for
propelling the car.]

In 1839, a French engineer first used the system in sinking a mine
shaft through a watery stratum. From then on, the sinking of shafts,
and somewhat later the construction of bridge pier foundations, by the
pneumatic method became almost commonplace engineering practice in
Europe and America. Not until 1879 however, was the system tried in
tunneling work, and then, as with the shield ten years earlier, almost
simultaneously here and abroad. The first application was in a small
river tunnel in Antwerp, only 5 feet in height. This project was
successfully completed relying on compressed air alone to support the
earth, no shield being used. The importance of the work cannot be
considered great due to its lack of scope.

[Illustration: Figure 38.--TESTING ALIGNMENT of the Broadway Subway at
night by driving a jointed rod up to street level. (_Scientific
American_, March 5, 1870.)]

In 1871 Dewitt C. Haskin (1822-1900), a west coast mine and railroad
builder, became interested in the pneumatic caissons then being used
to found the river piers of Eads' Mississippi River bridge at St.
Louis. In apparent total ignorance of the Cochrane patent, he evolved
a similar system for tunneling water-bearing media, and in 1873
proposed construction of a tunnel through the silt beneath the Hudson
to provide rail connection between New Jersey and New York City.

[Illustration: Figure 39.--HASKIN'S pneumatically driven tunnel
under the Hudson River, 1880. In the engine room at top left was the
machinery for hoisting, generating electricity for lighting, and air
compressing. The air lock is seen in the wall of the brick shaft.
MHT model--0.3" scale. (Smithsonian photo 49260.)]

[Illustration: Figure 40.--ARTIST'S CONCEPTION OF MINERS escaping
into the air lock during the blowout in Haskin's tunnel.]

It would be difficult to imagine a site more in need of such
communication. All lines from the south terminated along the west
shore of the river and the immense traffic--cars, freight and
passengers--was carried across to Manhattan Island by ferry and barge
with staggering inconvenience and at enormous cost. A bridge would
have been, and still is, almost out of the question due not only to
the width of the crossing, but to the flatness of both banks. To
provide sufficient navigational clearance (without a drawspan),
impracticably long approaches would have been necessary to obtain
a permissibly gentle grade.

Haskin formed a tunneling company and began work with the sinking of
a shaft in Hoboken on the New Jersey side. In a month it was halted
because of an injunction by, curiously, the D L & W Railroad, who
feared for their vast investment in terminal and marine facilities.
Not until November of 1879 was the injunction lifted and work again
commenced. The shaft was completed and an air lock located in one wall
from which the tunnel proper was to be carried forward. It was
Haskin's plan to use no shield, relying solely on the pressure of
compressed air to maintain the work faces and prevent the entry of
water. The air was admitted in late December, and the first
large-scale pneumatic tunneling operation launched. A single 26-foot,
double-track bore was at first undertaken, but a work face of such
diameter proved unmanageable and two oval tubes 18 feet high by 16
feet wide were substituted, each to carry a single track. Work went
forward with reasonable facility, considering the lack of precedent.
A temporary entrance was formed of sheet-iron rings from the air lock
down to the tunnel grade, at which point the permanent work of the
north tube was started. Immediately behind the excavation at the face,
a lining of thin wrought-iron plates was built up, to provide form for
the 2-foot, permanent brick lining that followed. The three stages are
shown in the model in about their proper relationship of progress. The
work is shown passing beneath an old timber-crib bulkhead, used for
stabilizing the shoreline.

The silt of the riverbed was about the consistency of putty and under
good conditions formed a secure barrier between the excavation and the
river above. It was easily excavated, and for removal was mixed with
water and blown out through a pipe into the shaft by the higher
pressure in the tunnel. About half was left in the bore for removal
later. The basic scheme was workable, but in operation an extreme
precision was required in regulating the air pressure in the work
area.[5] It was soon found that there existed an 11-psi difference
between the pressure of water on the top and the bottom of the working
face, due to the 22-foot height of the unlined opening. Thus, it was
impossible to maintain perfect pneumatic balance of the external
pressure over the entire face. It was necessary to strike an average
with the result that some water entered at the bottom of the face
where the water pressure was greatest, and some air leaked out at the
top where the water pressure was below the air pressure. Constant
attention was essential: several men did nothing but watch the
behavior of the leaks and adjusted the pressure as the ground density
changed with advance. Air was supplied by several steam-driven
compressors at the surface.

The air lock permitted passage back and forth of men and supplies
between the atmosphere and the work area, without disturbing the
pressure differential. This principle is demonstrated by an animated
model set into the main model, to the left of the shaft (fig. 39). The
variation of pressure within the lock chamber to match the atmosphere
or the pressurized area, depending on the direction of passage, is
clearly shown by simplified valves and gauges, and by the use of light
in varying color density. In the Haskin tunnel, 5 to 10 minutes were
taken to pass the miners through the lock so as to avoid too abrupt a
physiological change.

Despite caution, a blowout occurred in July 1880 due to air leakage
not at the face, but around the temporary entrance. One door of the
air lock jammed and twenty men drowned, resulting in an inquiry which
brought forth much of the distrust with which Haskin was regarded by
the engineering profession. His ability and qualifications were
subjected to the bitterest attack in and by the technical press. There
is some indication that, although the project began with a staff of
competent engineers, they were alienated by Haskin in the course of
work and at least one withdrew. Haskin's remarks in his own defense
indicate that some of the denunciation was undoubtedly justified. And
yet, despite this reaction, the fundamental merit of the pneumatic
tunneling method had been demonstrated by Haskin and was immediately
recognized and freely acknowledged. It was apparent at the same time,
however, that air by itself did not provide a sufficiently reliable
support for large-area tunnel works in unstable ground, and this
remains the only major subaqueous tunnel work driven with air alone.

[Illustration: Figure 41.--LOCATION OF HUDSON RIVER TUNNEL. (_Leslie's
Weekly_, 1879.)]

After the accident, work continued under Haskin until 1882 when funds
ran out. About 1600 feet of the north tube and 600 feet of the south
tube had been completed. Greathead resumed operations with a shield
for a British company in 1889, but exhaustion of funds again caused
stoppage in 1891. The tunnel was finally completed in 1904, and is
now in use as part of the Hudson and Manhattan rapid-transit system,
never providing the sought-after rail link. A splendid document of the
Haskin portion of the work is S. D. V. Burr's _Tunneling Under the
Hudson River_ published in 1885. It is based entirely upon firsthand
material and contains drawings of most of the work, including the
auxiliary apparatus. It is interesting to note that electric
illumination (arc, not incandescent, lights) and telephones were used,
unquestionably the first employment of either in tunnel work.

[Illustration: Figure 42.--ST. CLAIR TUNNEL. View of front of shield
showing method of excavation in firm strata. Incandescent electric
illumination was used. 1889-90. MHT model--1" scale. (Smithsonian
photo 49260-D.)]


The final model of the soft-ground series reflects, as did the Hoosac
Tunnel model for hard-rock tunneling, final emergence into the modern
period. Although the St. Clair Tunnel was completed over 70 years ago,
it typifies in its method of construction, the basic procedures of
subaqueous work in the present day. The Thames Tunnel of Brunel, and
Haskin's efforts beneath the Hudson, had clearly shown that by
themselves, both the shield and pneumatic systems of driving through
fluid ground were defective in practice for tunnels of large area.
Note that the earliest successful works by each method had been of
very small area, so that the influence of adverse conditions was
greatly diminished.

The first man to perceive and seize upon the benefits to be gained by
combining the two systems was, most fittingly, Greathead. Although he
had projected the technique earlier, in driving the underground City
and South London Railway in 1886, he brought together for the first
time the three fundamental elements essential for the practical
tunneling of soft, water-bearing ground: compressed-air support of the
work during construction, the movable shield, and cast-iron, permanent
lining. The marriage was a happy one indeed; the limitations of each
system were almost perfectly overcome by the qualities of the others.

The conditions prevailing in 1882 at the Sarnia, Ontario, terminal of
the Grand Trunk Railway, both operational and physical, were almost
precisely the same as those which inspired the undertaking of the
Hudson River Tunnel. The heavy traffic at this vital U.S.--Canada rail
interchange was ferried inconveniently across the wide St. Clair
River, and the bank and river conditions precluded construction of a
bridge. A tunnel was projected by the railway in that year, the time
when Haskin's tribulations were at their height. Perhaps because of
this lack of precedent for a work of such size, nothing was done
immediately. In 1884 the railway organized a tunnel company; in 1886
test borings were made in the riverbed and small exploratory drifts
were started across from both banks by normal methods of mine
timbering. The natural gas, quicksand, and water encountered soon
stopped the work.

[Illustration: Figure 43.--REAR VIEW OF ST. CLAIR SHIELD showing the
erector arm placing a cast-iron lining segment. The three motions of
the arm--axial, radial, and rotational, were manually powered.
(Smithsonian photo 49260-C.)]

It was at this time that the railway's president visited Greathead's
City and South London workings. The obvious answer to the St. Clair
problem lay in the successful conduct of this subway. Joseph Hobson,
chief engineer of the Grand Trunk and of the tunnel project, in
designing a shield, is said to have searched for drawings of the
shields used in the Broadway and Tower Subways of 1868-9, but unable
to locate any, he relied to a limited extent on the small drawings of
those in Drinker's volume. There is no explanation as to why he did
not have drawings of the City and South London shield at that moment
in use, unless one considers the rather unlikely possibility that
Greathead maintained its design in secrecy.

[Illustration: Figure 44.--OPENING OF THE ST. CLAIR TUNNEL, 1891.
(_Photo courtesy of Detroit Library, Burton Historical Collection._)]

The Hobson shield followed Greathead's as closely as any other, in
having a diaphragm with closable doors, but a modification of Beach's
sharpened horizontal shelves was also used. However, these functioned
more as working platforms than supports for the earth. The machine was
21-1/2 feet in diameter, an unprecedented size and almost twice that
of Greathead's current one. It was driven by 24 hydraulic rams.
Throughout the entire preliminary consideration of the project there
was a marked sense of caution that amounted to what seems an almost
total lack of confidence in success. Commencement of the work from
vertical shafts was planned so that if the tunnel itself failed, no
expenditure would have been made for approach work. In April 1888,
the shafts were started near both riverbanks, but before reaching
proper depth the almost fluid clay and silt flowed up faster than it
could be excavated and this plan was abandoned. After this second
inauspicious start, long open approach cuts were made and the work
finally began. The portals were established in the cuts, several
thousand feet back from each bank and there the tunneling itself
began. The portions under the shore were driven without air. When the
banks were reached, brick bulkheads containing air locks were built
across the opening and the section beneath the river, about 3,710 feet
long, driven under air pressure of 10 to 28 pounds above atmosphere.
For most of the way, the clay was firm and there was little air
leakage. It was found that horses could not survive in the compressed
air, and so mules were used under the river.

In the firm clay, excavation was carried on several feet in front of
the shield, as shown in the model (fig. 42). About twelve miners
worked at the face. However, in certain strata the clay encountered
was so fluid that the shield could be simply driven forward by the
rams, causing the muck to flow in at the door openings without
excavation. After each advance, the rams were retracted and a ring of
iron lining segments built up, as in the Tower Subway. Here, for the
first time, an "erector arm" was used for placing the segments, which
weighed about half a ton. In all respects, the work advanced with
wonderful facility and lack of operational difficulty. Considering
the large area, no subaqueous tunnel had ever been driven with such
speed. The average monthly progress for the American and Canadian
headings totaled 455 feet, and at top efficiency 10 rings or a length
of 15.3 feet could be set in a 24-hour day in each heading. The 6,000
feet of tunnel was driven in just a year; the two shields met
vis-a-vis in August of 1890.

The transition was complete. The work had been closely followed by the
technical journals and the reports of its successful accomplishment
thus were brought to the attention of the entire civil engineering
profession. As the first major subaqueous tunnel completed in America
and the first in the world of a size able to accommodate full-scale
rail traffic, the St. Clair Tunnel served to dispel the doubts
surrounding such work, and established the pattern for a mode of
tunneling which has since changed only in matters of detail.

Of the eight models, only this one was built under the positive
guidance of original documents. In the possession of the Canadian
National Railways are drawings not only of all elements of the shield
and lining, but of much of the auxiliary apparatus used in
construction. Such materials rarely survive, and do so in this case
only because of the foresight of the railway which, to avoid paying a
high profit margin to a private contractor as compensation for the
risk and uncertainty involved, carried the contract itself and,
therefore, preserved all original drawing records.

While the engineering of tunnels has been comprehensively treated in
this paper from the historical standpoint, it is well to still reflect
that the advances made in tunneling have not perceptibly removed the
elements of uncertainty but have only provided more positive and
effective means of countering their forces. Still to be faced are the
surprises of hidden streams, geologic faults, shifts of strata,
unstable materials, and areas of extreme pressure and temperature.


  AGRICOLA, GEORGIUS. _De re Metallica._ [English transl. H. C. and L.
     H. Hoover (_The Mining Magazine_, London, 1912).] Basel: Froben,

  BEACH, ALFRED ELY. _The pneumatic dispatch._ New York: The American
     News Company, 1868.

  BEAMISH, RICHARD. _A memoir of the life of Sir Marc Isambard
     Brunel._ London: Longmans, Green, Longmans and Roberts, 1862.

  BURR, S. D. V. _Tunneling under the Hudson River._ New York: John
     Wiley and Sons, 1885.

  COPPERTHWAITE, WILLIAM CHARLES. _Tunnel shields and the use of
     compressed air in subaqueous works._ New York: D. Van Nostrand
     Company, 1906.

  DRINKER, HENRY STURGESS. _Tunneling, explosive compounds and rock
     drills._ New York: John Wiley and Sons, 1878.

  LATROBE, BENJAMIN H. Report on the Hoosac Tunnel (Baltimore, October
     1, 1862). Pp. 125-139, app. 2, in _Report of the commissioners upon
     the Troy and Greenfield Railroad and Hoosac Tunnel_. Boston, 1863.

  LAW, HENRY. A memoir of the Thames Tunnel. _Weale's Quarterly Papers
     on Engineering_ (London, 1845-46), vol. 3, pp. 1-25 and vol. 5,
     pp. 1-86.

  The pneumatic tunnel under Broadway, N.Y. _Scientific American_
     (March 5, 1870), pp. 154-156.

  _Report of the commissioners upon the Troy and Greenfield Railroad
     and Hoosac Tunnel to his excellency the governor and the honorable
     the executive council of the state of Massachusetts, February 28,
     1863._ Boston, 1863.

  STORROW, CHARLES S. Report on European tunnels (Boston, November 28,
     1862). Pp. 5-122, app. 1, in _Report of the commissioners upon the
     Troy and Greenfield Railroad and Hoosac Tunnel...._ Boston, 1863.

  The St. Clair Tunnel. _Engineering News_ (in series running October
     4 to December 27, 1890).


  [1] There are two important secondary techniques for opening
      subterranean and subaqueous ways, neither a method truly of
      tunneling. One of these, of ancient origin, used mainly in the
      construction of shallow subways and utility ways, is the "cut and
      cover" system, whereby an open trench is excavated and then roofed
      over. The result is, in effect, a tunnel. The concept of the other
      method was propounded in the early 19th century but only used
      practically in recent years. This is the "trench" method, a sort
      of subaqueous equivalent of cut and cover. A trench is dredged in
      the bed of a body of water, into which prefabricated sections of
      large diameter tube are lowered, in a continuous line. The joints
      are then sealed by divers, the trench is backfilled over the tube,
      the ends are brought up to dryland portals, the water is pumped
      out, and a subterranean passage results. The Chesapeake Bay Bridge
      Tunnel (1960-1964) is a recent major work of this character.

  [2] In 1952 a successful machine was developed on this plan, with
      hardened rollers on a revolving cutting head for disintegrating
      the rock. The idea is basically sound, possessing advantages in
      certain situations over conventional drilling and blasting

  [3] In 1807 the noted Cornish engineer Trevithick commenced a small
      timbered drift beneath the Thames, 5 feet by 3 feet, as an
      exploratory passage for a larger vehicular tunnel. Due to the
      small frontal area, he was able to successfully probe about 1000
      feet, but the river then broke in and halted the work. Mine
      tunnels had also reached beneath the Irish Sea and various rivers
      in the coal regions of Newcastle, but these were so far below the
      surface as to be in perfectly solid ground and can hardly be
      considered subaqueous workings.

  [4] Unlike the Brunel tunnel, this was driven from both ends
      simultaneously, the total overall progress thus being 3 feet per
      shift rather than 18 inches. A top speed of 9 feet per day could
      be advanced by each shield under ideal conditions.

  [5] Ideally, the pressure of air within the work area of a
      pneumatically driven tunnel should just balance the hydrostatic
      head of the water without, which is a function of its total height
      above the opening. If the air pressure is not high enough, water
      will, of course, enter, and if very low, there is danger of
      complete collapse of the unsupported ground areas. If too high,
      the air pressure will overcome that due to the water and the air
      will force its way out through the ground, through increasingly
      larger openings, until it all rushes out suddenly in a "blowout."
      The pressurized atmosphere gone, the water then is able to pour
      in through the same opening, flooding the workings.

       *       *       *       *       *


  PAPER 42


  _John H. White_

                                 THE CUMBERLAND VALLEY RAILROAD    244

                               SERVICE HISTORY OF THE "PIONEER"    249

                        MECHANICAL DESCRIPTION OF THE "PIONEER"    251


_John H. White_

  _In the Museum of History and Technology_

[Illustration: Figure 1.--THE "PIONEER," BUILT IN 1851, shown here as
renovated and exhibited in the Museum of History and Technology, 1964.
In 1960 the locomotive was given to the Smithsonian Institution by the
Pennsylvania Railroad through John S. Fair, Jr. (Smithsonian photo

    _In the mid-nineteenth century there was a renewed interest in
    the light, single-axle locomotives which were proving so very
    successful for passenger traffic. These engines were built in
    limited number by nearly every well-known maker, and among the
    few remaining is the 6-wheel "Pioneer," on display in the Museum
    of History and Technology, Smithsonian Institution. This
    locomotive is a true representation of a light passenger
    locomotive of 1851 and a historic relic of the mid-nineteenth

    THE AUTHOR: _John H. White is associate curator of
    transportation in the Smithsonian Institution's Museum of
    History and Technology._

The "PIONEER" is an unusual locomotive and on first inspection would
seem to be imperfect for service on an American railroad of the 1850's.
This locomotive has only one pair of driving wheels and no truck, an
arrangement which marks it as very different from the highly successful
standard 8-wheel engine of this period. All six wheels of the _Pioneer_
are rigidly attached to the frame. It is only half the size of an
8-wheel engine of 1851 and about the same size of the 4--2--0 so common
in this country some 20 years earlier. Its general arrangement is that
of the rigid English locomotive which had, years earlier, proven
unsuitable for use on U.S. railroads.

These objections are more apparent than real, for the _Pioneer_, and
other engines of the same design, proved eminently successful when used
in the service for which they were built, that of light passenger
traffic. The _Pioneer's_ rigid wheelbase is no problem, for when it is
compared to that of an 8-wheel engine it is found to be about four feet
less; and its small size is no problem when we realize it was not
intended for heavy service. Figure 2, a diagram, is a comparison of the
_Pioneer_ and a standard 8-wheel locomotive.

Since the service life of the _Pioneer_ was spent on the Cumberland
Valley Railroad, a brief account of that line is necessary to an
understanding of the service history of this locomotive.

    _Exhibits of the "Pioneer"_

    The _Pioneer_ has been a historic relic since 1901. In the fall
    of that year minor repairs were made to the locomotive so that
    it might be used in the sesquicentennial celebration at
    Carlisle, Pennsylvania. On October 22, 1901, the engine was
    ready for service, but as it neared Carlisle a copper flue
    burst. The fire was extinguished and the _Pioneer_ was pushed
    into town by another engine. In the twentieth century, the
    _Pioneer_ was displayed at the Louisiana Purchase Exposition,
    St. Louis, Missouri, in 1904, and at the Wheeling, West
    Virginia, semicentennial in 1913. In 1927 it joined many other
    historic locomotives at the Baltimore and Ohio Railroad's "Fair
    of the Iron Horse" which commemorated the first one hundred
    years of that company. From about 1913 to 1925 the _Pioneer_
    also appeared a number of times at the Apple-blossom Festival
    at Winchester, Virginia. In 1933-1934 it was displayed at the
    World's Fair in Chicago, and in 1948 at the Railroad Fair in the
    same city. Between 1934 and March 1947 it was exhibited at the
    Franklin Institute, Philadelphia, Pennsylvania.

The Cumberland Valley Railroad

The Cumberland Valley Railroad (C.V.R.R.) was chartered on April 2,
1831, to connect the Susquehanna and Potomac Rivers by a railroad
through the Cumberland Valley in south-central Pennsylvania. The
Cumberland Valley, with its rich farmland and iron-ore deposits, was a
natural north-south route long used as a portage between these two
rivers. Construction began in 1836, and because of the level valley some
52 miles of line was completed between Harrisburg and Chambersburg by
November 16, 1837. In 1860, by way of the Franklin Railroad, the line
extended to Hagerstown, Maryland. It was not until 1871 that the
Cumberland Valley Railroad reached its projected southern terminus, the
Potomac River, by extending to Powells Bend, Maryland. Winchester,
Virginia, was entered in 1890 giving the Cumberland Valley Railroad
about 165 miles of line. The railroad which had become associated with
the Pennsylvania Railroad in 1859, was merged with that company in 1919.

By 1849 the Cumberland Valley Railroad was in poor condition; the
strap-rail track was worn out and new locomotives were needed. Captain
Daniel Tyler was hired to supervise rebuilding the line with T-rail, and
easy grades and curves. Tyler recommended that a young friend of his,
Alba F. Smith, be put in charge of modernizing and acquiring new
equipment. Smith recommended to the railroad's Board of Managers on June
25, 1851, that "much lighter engines than those now in use may be
substituted for the passenger transportation and thereby effect a great
saving both in point of fuel and road repairs...."[1] Smith may well
have gone on to explain that the road was operating 3- and 4-car
passenger trains with a locomotive weighing about 20 tons; the total
weight was about 75 tons, equalling the uneconomical deadweight of 1200
pounds per passenger. Since speed was not an important consideration (30
mph being a good average), the use of lighter engines would improve the
deadweight-to-passenger ratio and would not result in a slower schedule.

The Board of Managers agreed with Smith's recommendations and instructed
him "... to examine the two locomotives lately built by Mr. Wilmarth
and now in the [protection?] of Captain Tyler at Norwich and if in his
judgment they are adequate to our wants ... have them forwarded to the
road."[2] Smith inspected the locomotives not long after this resolution
was passed, for they were on the road by the time he made the following
report[3] to the Board on September 24, 1851:

    In accordance with a resolution passed at the last meeting of
    your body relative to the small engines built by Mr. Wilmarth I
    proceeded to Norwich to make trial of their capacity--fitness or
    suitability to the Passenger transportation of our Road--and
    after as thorough a trial as circumstances would admit (being on
    another Road than our own) I became satisfied that with some
    necessary improvements which would not be expensive (and are now
    being made at our shop) the engines would do the business of
    our Road not only in a manner satisfactory in point of speed and
    certainty but with greater ultimate economy in Expenses than has
    before been practised in this Country.

[Illustration: Figure 2.--DIAGRAM COMPARING the _Pioneer_ (shaded
drawing) with the _Columbia_, a standard 8-wheel engine of 1851.
(Drawing by J. H. White.)]


    Hudson River Railroad
    Lowell Machine Shop, 1852
    Wt. 27-1/2 tons (engine only)
    Cyl. 16-1/2 x 22 inches
    Wheel diam. 84 inches


    Cumberland Valley Railroad
    Seth Wilmarth, 1851
    12-1/2 tons
    8-1/2 x 14 inches
    54 inches

    After making the above trial of the Engines--I stated to your
    Hon. President the result of the trial--with my opinion of their
    Capacity to carry our passenger trains at the speed required
    which was decidedly in favor of the ability of the Engines. He
    accordingly agreed that the Engines should at once be forwarded
    to the Road in compliance with the Resolution of your Board. I
    immediately ordered the Engines shipped at the most favorable
    rates. They came to our Road safely in the Condition in which
    they were shipped. One of the Engines has been placed on the
    Road and I believe performed in such a manner as to convince all
    who are able to judge of this ability to perform--although the
    maximum duty of the Engines was not performed on account of some
    original defects which are now being remedied as I before

    Within ten days the Engine will be able to run regularly with a
    train on the Road where in shall be enabled to judge correctly
    of their merits.

    An accident occurred during the trial of the Small Engine at
    Norwich which caused a damage of about $300 in which condition
    the Engine came here and is now being repaired--the cost of
    which will be presented to your Board hereafter. As to the
    fault or blame of parties connected with the accident as also
    the question of responsibility for Repairs are questions for
    your disposal. I therefore leave the matter until further called

    The Expenses necessarily incurred by the trial of the Engines
    and also the Expenses of transporting the same are not included
    in the Statement herewith presented, the whole amount of which
    will not probably exceed $400.00.

These two locomotives became the Cumberland Valley Railroad's _Pioneer_
(number 13) and _Jenny Lind_ (number 14). While Smith notes that one of
the engines was damaged during the inspection trials, Joseph Winters, an
employee of the Cumberland Valley who claimed he was accompanying the
engine enroute to Chambersburg at the time of their delivery, later
recalled that both engines were damaged in transit.[4] According to
Winters a train ran into the rear of the _Jenny Lind_, damaging both it
and the _Pioneer_, the accident occurring near Middletown, Pennsylvania.
The _Jenny Lind_ was repaired at Harrisburg but the _Pioneer_, less
seriously damaged, was taken for repairs to the main shops of the
Cumberland Valley road at Chambersburg.

[Illustration: Figure 3.--"PIONEER," ABOUT 1901, showing the sandbox and
large headlamp. Note the lamp on the cab roof, now used as the
headlight. (Smithsonian photo 49272.)]

While there seems little question that these locomotives were not built
as a direct order for the Cumberland Valley Railroad, an article[5]
appearing in the _Railroad Advocate_ in 1855 credits their design to
Smith. The article speaks of a 2--2--4 built for the Macon and Western
Railroad and says in part:

    This engine is designed and built very generally upon the ideas,
    embodied in some small tank engines designed by A. F. Smith,
    Esq., for the Cumberland Valley road. Mr. Smith is a strong
    advocate of light engines, and his novel style and proportions
    of engines, as built for him a few years since, by Seth
    Wilmarth, at Boston, are known to some of our readers. Without
    knowing all the circumstances under which these engines are
    worked on the Cumberland Valley road, we should not venture to
    repeat all that we have heard of their performances, it is
    enough to say that they are said to do more, in proportion to
    their weight, than any other engines now in use.

The author believes that the _Railroad Advocate's_ claim of Smith's
design of the _Pioneer_ has been confused with his design of the
_Utility_ (figs. 6, 7). Smith designed this compensating-lever engine to
haul trains over the C.V.R.R. bridge at Harrisburg. It was built by
Wilmarth in 1854.

[Illustration: Figure 4.--MAP OF THE CUMBERLAND VALLEY Railroad as it
appeared in 1919.]

According to statements of Smith and the Board of Managers quoted on
page 244, the _Pioneer_ and the _Jenny Lind_ were not new when purchased
from their maker, Seth Wilmarth. Although of recent manufacture,
previous to June 1851, they were apparently doing service on a road in
Norwich, Connecticut. It should be mentioned that both Smith and Tyler
were formerly associated with the Norwich and Worcester Railroad and
they probably learned of these two engines through this former
association. It is possible that the engines were purchased from
Wilmarth by the Cumberland Valley road, which had bought several other
locomotives from Wilmarth in previous years. It was the practice of at
least one other New England engine builder, the Taunton Locomotive
Works, to manufacture engines on the speculation that a buyer would be
found; if no immediate buyers appeared the engine was leased to a local
road until a sale was made.[6]

[Illustration: Figure 5.--AN EARLY BROADSIDE of the Cumberland Valley

Regarding the _Jenny Lind_ and _Pioneer_, Smith reported[7] to the Board
of Managers at their meeting of March 17, 1852:

    The small tank engines which were purchased last year ... and
    which I spoke in a former report as undergoing at that time some
    necessary improvements have since that time been fairly tested
    as to their capacity to run our passenger trains and proved to
    be equal to the duty.

    The improvements proposed to be made have been completed only on
    one engine [_Jenny Lind_] which is now running regularly with
    passenger trains--the cost of repairs and improvements on this
    engine (this being the one accidentally broken on the trial)
    amounted to $476.51. The other engine is now in the shop, not
    yet ready for service but will be at an early day.

[Illustration: Figure 6.--THE "UTILITY" AS REBUILT TO AN 8-WHEEL ENGINE,
about 1863 or 1864. It was purchased by the Carlisle Manufacturing Co.
in 1882 and was last used in 1896. (Smithsonian photo 36716F.)]

[Illustration: Figure 7.--THE "UTILITY," DESIGNED BY SMITH A. F. and
constructed by Seth Wilmarth in 1854, was built to haul trains across
the bridge at Harrisburg, Pa.]

[Illustration: Figure 8.--THE EARLIEST KNOWN ILLUSTRATION of the
_Pioneer_, drawn by A. S. Hull, master mechanic of the Cumberland Valley
Railroad in 1876. It depicts the engine as it appeared in 1871.
(_Courtesy of Paul Westhaeffer._)]

The _Pioneer_ and _Jenny Lind_ achieved such success in action that the
president of the road, Frederick Watts, commented on their performance
in the annual report of the Cumberland Valley Railroad for 1851. Watts
stated that since their passenger trains were rarely more than a baggage
car and two coaches, the light locomotives "... have been found to be
admirably adapted to our business." The Cumberland Valley Railroad,
therefore, added two more locomotives of similar design in the next few
years. These engines were the _Boston_ and the _Enterprise_, also built
by Wilmarth in 1854-1855.

Watts reported the _Pioneer_ and _Jenny Lind_ cost $7,642. A standard
8-wheel engine cost about $6,500 to $8,000 each during this period. In
recent years, the Pennsylvania Railroad has stated the _Pioneer_ cost
$6,200 in gold, but is unable to give the source for this information.
The author can discount this statement for it does not seem reasonable
that a light, cheap engine of the pattern of the _Pioneer_ could cost as
much as a machine nearly twice its size.

[Illustration: Figure 9.--ANNUAL PASS of the Cumberland Valley Railroad
issued in 1863.]

[Illustration: Figure 10.--TIMETABLE OF THE Cumberland Valley Railroad
for 1878.]

Service History of the _Pioneer_

After being put in service, the _Pioneer_ continued to perform well and
was credited as able to move a 4-car passenger train along smartly at 40
mph.[8] This tranquility was shattered in October 1862 by a raiding
party led by Confederate General J. E. B. Stuart which burned the
Chambersburg shops of the Cumberland Valley Railroad. The _Pioneer_,
_Jenny Lind_, and _Utility_ were partially destroyed. The Cumberland
Valley Railroad in its report for 1862 stated:

    The Wood-shop, Machine-shop, Black-smith-shop, Engine-house,
    Wood-sheds, and Passenger Depot were totally consumed, and with
    the Engine-house three second-class Engines were much injured by
    the fire, but not so destroyed but that they may be restored to

However, no record can be found of the extent or exact nature of the
damage. The shops and a number of cars were burned so it is reasonable
to assume that the cab and other wooden parts of the locomotive were
damaged. One unverified report in the files of the Pennsylvania Railroad
states that part of the roof and brick wall fell on the _Pioneer_ during
the fire causing considerable damage. In June 1864 the Chambersburg
shops were again burned by the Confederates, but on this occasion the
railroad managed to remove all its locomotives before the raid. During
the Civil War, the Cumberland Valley Railroad was obliged to operate
longer passenger trains to satisfy the enlarged traffic. The _Pioneer_
and its sister single-axle engines were found too light for these trains
and were used only on work and special trains. Reference to table 1 will
show that the mileage of the _Pioneer_ fell off sharply for the years


(From Annual Reports of the Cumberland Valley Railroad)

    _Year_:             _Miles_

    1852                  3,182[a]
    1853                 20,722[b]
    1854                 18,087
    1855                 14,151
    1856                 20,998
    1857                 22,779
    1858                 29,094
    1859                 29,571
    1860                  4,824
    1861                  4,346
    1862                   ([c])
    1863                  5,339
    1864                    224
    1865                  2,215
    1866                 20,546
    1867                  5,709
    1868                 13,626
    1869                  1,372
    1870                    ...
    1871                  2,102
    1872                  4,002
    1873                  3,721
    1874                  3,466
    1875                    636
    1876                    870
    1877                    406
    1878                  4,433
    1879                    ...
    1880                  8,306
    1881                   ([d])
    Total               244,727[e]


     [a] Mileage 1852 for January to September (no record of mileage
     recorded in Annual Reports previous to 1852).

     [b] 15,000 to 20,000 miles per year was considered very high
     mileage for a locomotive of the 1850's.

     [c] No mileage reported for any engines due to fire.

     [d] Not listed on roster.

     [e] The Pennsylvania Railroad claims a total mileage of 255,675.
     This may be accounted for by records of mileages for 1862, 1870,
     and 1879.

In 1871 the _Pioneer_ was remodeled by A. S. Hull, master mechanic of
the railroad. The exact nature of the alterations cannot be determined,
as no drawings or photographs of the engine previous to this time are
known to exist. In fact, the drawing (fig. 8) prepared by Hull in 1876
to show the engine as remodeled in 1871 is the oldest known illustration
of the _Pioneer_. Paul Westhaeffer, a lifelong student of Cumberland
Valley R. R. history, states that according to an interview with one of
Hull's descendants the only alteration made to the _Pioneer_ during the
1871 "remodeling" was the addition of a handbrake. The road's annual
report of 1853 describes the _Pioneer_ as a six-wheel tank engine. The
report of 1854 mentions that the _Pioneer_ used link motion. These
statements are enough to give substance to the idea that the basic
arrangement has survived unaltered and that it has not been extensively
rebuilt, as was the _Jenny Lind_ in 1878.

By the 1870's, the _Pioneer_ was too light for the heavier cars then in
use and by 1880 it had reached the end of its usefulness for regular
service. After nearly thirty years on the road it had run 255,675 miles.
Two new passenger locomotives were purchased in 1880 to handle the
heavier trains. In 1881 the _Pioneer_ was dropped from the roster, but
was used until about 1890 for work trains. After this time it was stored
in a shed at Falling Spring, Pennsylvania, near the Chambersburg yards
of the C.V.R.R.

Mechanical Description of the _Pioneer_

[Illustration: Figure 11.--"PIONEER," ABOUT 1901, scene unknown. (_Photo
courtesy of Thomas Norrell._)]

After the early 1840's the single-axle locomotive, having one pair of
driving wheels, was largely superseded by the 8-wheel engine. The
desire to operate longer trains and the need for engines of greater
traction to overcome the steep grades of American roads called for
coupled driving wheels and machines of greater weight than the 4--2--0.
After the introduction of the 4--4--0, the single-axle engine received
little attention in this country except for light service or such
special tasks as inspection or dummy engines.

[Illustration: Figure 12.--THE "PIONEER" IN CARLISLE, PA., 1901. (_Photo
courtesy of Thomas Norrell._)]

There was, however, a renewed interest in "singles" in the early 1850's
because of W. B. Adams' experiments with light passenger locomotives in
England. In 1850 Adams built a light single-axle tank locomotive for the
Eastern Counties Railway which proved very economical for light
passenger traffic. It was such a success that considerable interest in
light locomotives was generated in this country as well as in England.
Nearly 100 single-axle locomotives were built in the United States
between about 1845-1870. These engines were built by nearly every
well-known maker, from Hinkley in Boston to the Vulcan Foundry in San
Francisco. Danforth Cooke & Co. of Paterson built a standard pattern
4--2--4 used by many roads. One of these, the _C. P. Huntington_,
survives to the present time.

The following paragraphs describe the mechanical details of the
_Pioneer_ as it appears on exhibition in the Smithsonian Institution's
new Museum of History and Technology.


The boiler is the most important and costly part of a steam locomotive,
representing one-fourth to one-third of the total cost. A poorly built
or designed boiler will produce a poor locomotive no matter how well
made the remainder of mechanism. The boiler of the _Pioneer_ is of the
wagon-top, crownbar, fire-tube style and is made of a 5/16-inch thick,
wrought-iron plate. The barrel is very small, in keeping with the size
of the engine, being only 27 inches in diameter. While some readers may
believe this to be an extremely early example of a wagon-top boiler, we
should remember that most New England builders produced few locomotives
with the Bury (dome) boiler and that the chief advocates of this later
style were the Philadelphia builders. By the early 1850's the Bury
boiler passed out of favor entirely and the wagon top became the
standard type of boiler with all builders in this country.

Sixty-three iron tubes, 1-7/8 inches by 85 inches long are used. The
original tubes may have been copper or brass since these were easier to
keep tight than the less malleable iron tubes. The present tube sheet is
of iron but was originally copper. Its thickness cannot be conveniently
measured, but it is greater than that of the boiler shell, probably
about 1/2 to 5/8 inch. While copper tubes and tube sheets were not much
used in this country after about 1870, copper was employed as recently
as 1950 by Robert Stephenson & Hawthorns, Ltd., on some small industrial

The boiler shell is lagged with wooden tongue-and-groove strips about
2-1/2 inches wide (felt also was used for insulation during this
period). The wooden lagging is covered with Russia sheet iron which is
held in place and the joints covered by polished brass bands. Russia
sheet iron is a planish iron having a lustrous, metallic gray finish.

[Illustration: Figure 14.--THE "FURY," BUILT FOR THE Boston and
Worcester Railroad in 1849 by Wilmarth. It was known as a "Shanghai"
because of its great height. (Smithsonian Chaney photo 6443.)]

[Illustration: Figure 15.--THE "NEPTUNE," BUILT FOR THE Boston and
Worcester in 1847 by Hinkley and Drury. Note the similarity of this
engine and the _Fury_.]

[Illustration: Figure 16.--THE "PIONEER" AS FIRST EXHIBITED in the Arts
and Industries building of the Smithsonian Institution prior to
restoration of the sandbox. (Smithsonian photo 48069D.)]

The steam dome (fig. 18) is located directly over the firebox, inside
the cab. It is lagged and jacketed in an identical manner to the boiler.
The shell of the dome is of 5/16-inch wrought iron, the top cap is a
cast-iron plate which also serves as a manhole cover offering access to
the boiler's interior for inspection and repair.

[Illustration: Figure 17.--"PIONEER" locomotive. (Drawing by J. H.

[Illustration: Figure 18.--"PIONEER" LOCOMOTIVE, (1) Safety valve, (2)
spring balance, (3) steam jet, (4) dry pipe, (5) throttle lever, (6)
throttle, (7) crown bar, (8) front tube sheet, (9) check valve, (10) top
rail, (11) rear-boiler bracket, (12) pedestal, (13) rocker bearing, (14)
damper, (15) grate, (16) bottom rail, (17) pump heater valve, (18)
cylinder lubricator, (19) reversing lever, (20) brake shoe, (21) mud
ring, (22) blowoff cock, (23) ashpan. (Drawing by J. H. White.)]

A round plate, 20 inches in diameter, riveted on the forward end of the
boiler, just behind the bell stand, was found when the old jacket was
removed in May 1963. The size and shape of the hole, which the plate
covers, indicate that a steam dome or manhole was located at this point.
It is possible that this was the original location of the steam dome
since many builders in the early 1850's preferred to mount the dome
forward of the firebox. This was done in the belief that there was less
danger of priming because the water was less agitated forward of the

The firebox is as narrow as the boiler shell and fits easily between the
frame. It is a deep and narrow box, measuring 27 inches by 28 inches by
about 40 inches deep, and is well suited to burning wood. A deep firebox
was necessary because a wide, shallow box suitable for coal burning,
allowed the fuel to burn so quickly it was difficult to fire the engine
effectively. With the deep, narrow firebox, wood was filled up to the
level of the fire door. In this way, the fire did not burn so furiously
and did not keep ahead of the fireman; at the same time, since it burned
so freely, a good fire was always on hand. The _Pioneer_ burned oak and
hickory.[14] For the firebox 5/16-inch thick sheet was used, for heavier
sheet would have blistered and flaked off because of the intense heat of
the fire and the fibrous quality of wrought-iron sheet of the period.
Sheet iron was fabricated from many small strips of iron rolled together
while hot. These strips were ideally welded into a homogeneous sheet,
but in practice it was found the thicker the sheet the less sure the

The fire grates are cast iron and set just a few inches above the bottom
of the water space so that the water below the grates remains less
turbulent and mud or other impurities in the water settle here. Four
bronze mud plugs and a blowoff cock are fitted to the base of the
firebox so that the sediment thus collected can be removed (figs. 17,

The front of the boiler is attached to the frame by the smokebox, which
is a cylinder, bolted on a light, cast-iron saddle (not part of the
cylinder castings nor attached to them, but bolted directly to the top
rail of the frame; it may be a hastily made repair put on at the shops
of the C.V.R.R.). The rear of the boiler is attached to the frame by two
large cast-iron brackets, one on each side of the firebox (fig. 18).
These are bolted to the top rail of the frame but the holes in the
brackets are undoubtedly slotted, so that they may slide since the
boiler will expand about 1/4 inch when heated. In addition to the crown
bars, which strengthen the crown sheet, the boiler is further
strengthened by stay bolts and braces located in the wagon top over the
firebox, where the boiler had been weakened by the large hole necessary
for the steam dome. This boiler is a remarkably light, strong, and
compact structure.


Few boiler fittings are found on the _Pioneer_ and it appears that
little was done to update the engine with more modern devices during its
many years of service. With the exception of the steam gauge, it has no
more boiler fitting than when it left the builder's shop in 1851.

The throttle valve is a simple slide valve and must have been primitive
for the time, for the balance-poppet throttle valve was in use in this
country previous to 1851. It is located directly below the steam dome
even though it was common practice to place the throttle valve at the
front of the boiler in the smokebox. Considering the cramped condition
inside the smokebox, there would seem to be little space for the
addition of the throttle valve; hence its present location. The dry pipe
projects up into the steam dome to gather the hottest, driest steam for
the cylinders. The inverted, funnel-like cap on the top of the dry pipe
is to prevent priming, as drops of water may travel up the sides of the
pipe and then to the cylinders, with the possibility of great damage.
After the steam enters the throttle valve it passes through the front
end of the valve, through the top of the boiler via the dry pipe (fig.
18), through the front tube sheet, and then to the cylinders via the
petticoat pipes. The throttle lever is a simple arrangement readily
understood from the drawings. It has no latch and the throttle lever is
held in any desired setting by the wingnut and quadrant shown in figure
18. The water level in the boiler is indicated by the three brass cocks
located on the backhead. No gauge glass is used; they were not employed
in this country until the 1870's, although they were commonly used in
England at the time the _Pioneer_ was built.

While two safety valves were commonly required, only one was used on the
_Pioneer_. The safety valve is located on top of the steam dome.
Pressure is exerted on the lever by a spring balance, fixed at the
forward end by a knife-blade bearing. The pressure can be adjusted by
the thumbscrew on the balance. The graduated scale on the balance gave a
general but uncertain indication of the boiler pressure. The valve
itself is a poppet held against the face of the valve seat by a second
knife blade attached to the lever. The ornamental column forming the
stand of the safety valve is cast iron and does much to decorate the
interior of the cab. The pipe carrying the escaping steam projects
through the cab roof. It is made of copper with a decorative brass band.
This entire mechanism was replaced by a modern safety valve for use at
the Chicago Railroad Fair (1949). Fortunately, the old valve was
preserved and has since been replaced on the engine.

The steam gauge is a later addition, but could have been put on as early
as the 1860's, since the most recent patent date that it bears is 1859.
It is an Ashcroft gauge having a handsome 4--4--0 locomotive engraved on
its silver face.

The steam jet (item 3, fig. 18) is one of the simplest yet most notable
boiler fitting of the _Pioneer_, being nothing more than a valve tapped
into the base of the steam dome with a line running under the boiler
jacket to the smokestack. When the valve is opened a jet of steam goes
up the stack, creating a draft useful for starting the fire or
enlivening it as necessary. This device was the invention of Alba F.
Smith in 1852, according to the eminent 19th-century technical writer
and engineer Zerah Colburn.[15]

The two feedwater pumps (fig. 20) are located beneath the cab deck (1,
fig. 17). They are cast-iron construction and are driven by an eccentric
on the driving-wheel axle (fig. 27). The airchamber or dome (1, fig. 27)
imparts a more steady flow of the water to the boiler by equalizing the
surges of water from the reciprocating pump plunger. A steam line (3,
fig. 18), which heats the pump and prevents freezing in cold weather, is
regulated by a valve in the cab (figs. 18, 27). Note that the line on
the right side of the cab has been disconnected and plugged.

The eccentric drive for the pumps is unusual, and the author knows of no
other American locomotive so equipped. Eastwick and Harrison, it is
true, favored an eccentric drive for feed pumps, but they mounted the
eccentric on the crankpin of the rear driving wheel and thus produced in
effect a half-stroke pump. This was not an unusual arrangement, though a
small crank was usually employed in place of the eccentric. The
full-stroke crosshead pump with which the _Jenny Lind_ (fig. 22) is
equipped, was of course the most common style of feed pump used in this
country in the 19th century.

[Illustration: Figure 19.--BACKHEAD of the _Pioneer_. (Smithsonian photo

Of all the mechanisms on a 19th-century locomotive, the feed pump was
the most troublesome. If an engineer could think of nothing else to
complain about, he could usually call attention to a defective pump and
not be found a liar. Because of this, injectors were adopted after their
introduction in 1860. It is surprising that the _Pioneer_, which was in
regular service as late as 1880 and has been under steam many times
since for numerous exhibitions, was never fitted with one of these
devices. Because its stroke is short and the plunger is in less rapid
motion, the present eccentric arrangement is more complex but less prone
to disorder than the simpler but faster crosshead pump.

[Illustration: Figure 20.--FEEDWATER PUMP of the _Pioneer_. (Smithsonian
photo 63344.)]

The check valves are placed slightly below the centerline of the boiler
(fig. 18). These valves are an unfinished bronze casting and appear to
be of a recent pattern, probably dating from the 1901 renovation. At the
time the engine was built, it was usual to house these valves in an
ornamental spun-brass casing. The smokestack is of the bonnet type
commonly used on wood-burning locomotives in this country between about
1845 and 1870. The exhaust steam from the cylinders is directed up the
straight stack (shown in phantom in fig. 27) by the blast pipe. This
creates a partial vacuum in the smokebox that draws the fire, gases,
ash, and smoke through the boiler tubes from the firebox. The force of
the exhausting steam blows them out the stack. At the top of the
straight stack is a deflecting cone which slows the velocity of the
exhaust and changes its direction causing it to go down into the
funnel-shaped outer casing of the stack. Here, the heavy embers and
cinders are collected and prevented from directly discharging into the
countryside as dangerous firebrands. Wire netting is stretched overtop
of the deflecting cone to catch the lighter, more volatile embers which
may defy the action of the cone. The term "bonnet stack" results from
the fact that this netting is similar in shape to a lady's bonnet. The
cinders thus accumulated in the stack's hopper could be emptied by
opening a plug at the base of the stack.

While the deflecting cone was regarded highly as a spark arrester and
used practically to the exclusion of any other arrangement, it had the
basic defect of keeping the smoke low and close to the train. This was a
great nuisance to passengers, as the low trailing smoke blew into the
cars. If the exhaust had been allowed to blast straight out the stack
high into the air, most of the sparks would have burned out before
touching the ground.

[Illustration: Figure 21.--"PIONEER" ON EXHIBIT in old Arts and
Industries building of the Smithsonian Institution. In this view can be
seen the bonnet screen of the stack and arrangement of the boiler-frame
braces and other details not visible from the floor. (Smithsonian photo

[Illustration: Figure 22.--"JENNY LIND," SISTER ENGINE of the _Pioneer_,
shown here as rebuilt in 1878 for use as an inspection engine. It was
scrapped in March 1905. (_Photo courtesy of E. P. Alexander._)]

[Illustration: Figure 23.--CYLINDER head with valve box removed.]

[Illustration: Figure 24.--BOTTOM of valve box with slide valve

[Illustration: Figures 25 and 26.--CYLINDER with valve box removed,
showing valve face.]


The frame of the _Pioneer_ defies an exact classification but it more
closely resembles the riveted- or sandwich-type frame than any other
(figs. 18, 27). While the simple bar frame enjoyed the greatest
popularity in the last century, riveted frames were widely used in this
country, particularly by the New England builders between about 1840 and
1860. The riveted frame was fabricated from two plates of iron, about
5/8-inch thick, cut to the shape of the top rail and the pedestal. A bar
about 2 inches square was riveted between the two plates. A careful
study of photographs of Hinkley and other New England-built engines of
the period will reveal this style of construction. The frame of the
_Pioneer_ differs from the usual riveted frame in that the top rail is
1-3/4 inches thick by 4-1/8 inches deep and runs the length of the
locomotive. The pedestals are made of two 3/8-inch plates flush-riveted
to each side of the top rail. The cast-iron shoes which serve as guides
for the journal boxes also act as spacers between the pedestal plates.

The bottom rail of the frame is a 1-1/8-inch diameter rod which is
forged square at the pedestals and forms the pedestal cap. The frame is
further stiffened by two diagonal rods running from the top of each
truck-wheel pedestal to the base of the driving-wheel pedestal, forming
a truss. Six rods, riveted to the boiler shell and bolted to the frame's
top rail, strengthen the frame laterally. Four of these rods can be seen
easily as they run from the frame to the middle of the boiler; the other
two are riveted to the underside of the boiler. The attachment of these
rods to the boiler was an undesirable practice, for the boiler shell
was thus subjected to the additional strain of the locomotive's
vibrations as it passed over the road. In later years, as locomotives
grew in size, this practice was avoided and frames were made
sufficiently strong to hold the engine's machinery in line without using
the boiler shell.

The front and rear frame beams are of flat iron plate bolted to the
frame. The rear beam had been pushed in during an accident, and instead
of its being replaced, another plate was riveted on and bent out in the
opposite direction to form a pocket for the rear coupling pin. Note that
there is no drawbar and that the coupler is merely bolted to the beams.
Since the engine only pulled light trains, the arrangement was
sufficiently strong.


The running gear is simply sprung with individual leaf springs for each
axle; it is not connected by equalizing levers. To find an American
locomotive not equipped with equalizers is surprising since they were
almost a necessity to produce a reasonably smooth ride on the rough
tracks of American railroads. Equalizers steadied the motion of the
engine by distributing the shock received by any one wheel or axle to
all the other wheels and axles so connected, thus minimizing the effects
of an uneven roadbed. The author believes that the _Pioneer_ is a
hard-riding engine.

The springs of the main drives are mounted in the usual fashion. The
rear boiler bracket (fig. 18) is slotted so that the spring hanger may
pass through for its connection with the frame. The spring of the
leading wheels is set at right angles to the frame (fig. 27) and bears
on a beam, fabricated of iron plate, which in turn bears on the journal
boxes. The springs of the trailing wheels are set parallel with the
frame and are mounted between the pedestal plates (fig. 18).

The center of the driving wheel is cast iron and has spokes of the old
rib pattern, which is a T in cross section, and was used previous to the
adoption of the hollow spoke wheel. In the mid-1830's Baldwin and others
used this rib-pattern style of wheel, except that the rib faced inside.
The present driving-wheel centers are unquestionably original. The
sister engine _Jenny Lind_ (fig. 22) was equipped with identical driving
wheels. The present tires are very thin and beyond their last turning.
They are wrought iron and shrunk to fit the wheel centers. Flush rivets
are used for further security. The left wheel, shown in figure 17, is
cracked at the hub and is fitted with an iron ring to prevent its

The truck wheels, of the hollow spoke pattern, are cast iron with
chilled treads. They were made by Asa Whitney, one of the leading
car-wheel manufacturers in this country, whose extensive plant was
located in Philadelphia. Made under Whitney's patent of 1866, these
wheels may well have been added to the _Pioneer_ during the 1871
rebuilding. Railroad wheels were not cast from ordinary cast iron, which
was too weak and brittle to stand the severe service for which they were
intended, but from a high-quality cast iron similar to that used for
cannons. Its tensile strength, which ranged from 31,000 to 36,000 psi,
was remarkably high and very nearly approached that of the best
wrought-iron plate.

The cylinders are cast iron with an 8-1/2-inch bore about half the size
of the cylinders of a standard 8-wheel engine. The cylinders are bolted
to the frame but not to the saddle, and are set at a 9 deg. angle to clear
the leading wheels and at the same time to line up with the center of
the driving-wheel axle. The wood lagging is covered with a decorative
brass jacket. Ornamental brass jacketing was extensively used on
mid-19th-century American locomotives to cover not only the cylinders
but steam and sand boxes, check valves, and valve boxes. The greater
expense for brass (Russia iron or painted sheet iron were a cheaper
substitute) was justified by the argument that brass lasted the life of
the engine, and could be reclaimed for scrap at a price approaching the
original cost; and also that when brightly polished it reflected the
heat, preventing loss by radiation, and its bright surface could be seen
a great distance, thus helping to prevent accidents at grade crossings.
The reader should be careful not to misconstrue the above arguments
simply as rationalization on the part of master mechanics more intent on
highly decorative machines than on the practical considerations

The valve box, a separate casting, is fastened to the cylinder casting
by six bolts. The side cover plates when removed show only a small
opening suitable for inspection and adjustment of the valve. The valve
box must be removed to permit repair or removal of the valve. A better
understanding of this mechanism and the layout of the parts can be
gained from a study of figures 23-26, 28 (8, 8A, and 8B).

[Illustration: Figure 27.--"PIONEER" LOCOMOTIVE. (1) Air chamber, (2)
reversing lever, (3) counterweight, (4) reversing shaft, (5) link
hanger, (6) rocker, (7) feedwater line to boiler, (8) link block, (9)
link, (10) eccentric, (11) pump plunger, (12) pump steamheater line,
(13) feedwater pump, (14) wire netting [bonnet], (15) deflecting cone,
(16) stack, (17) stack hopper. (Drawing by J. H. White.)]

[Illustration: Figure 28.--REAR ELEVATION of _Pioneer_ and detail of
valve shifter; valve face and valve. (Drawing by J. H. White.)]

Both crossheads were originally of cast iron but one of these has been
replaced and is of steel. They run into steel guides, bolted at the
forward end to the rear cylinder head and supported in the rear by a
yoke. The yoke is one of the more finished and better made pieces on the
entire engine (fig. 27). The main rod is of the old pattern, round in
cross section, and only 1-1/2 inches in diameter at the largest point.


The valve gear is of the Stephenson shifting-link pattern (see fig. 27),
a simple and dependable motion used extensively in this country between
about 1850 and 1900. The author believes that this is the original valve
gear of the _Pioneer_, since the first mention (1854) in the _Annual
Report_ of the Cumberland Valley Railroad of the style of valve gear
used by each engine, states that the _Pioneer_ was equipped with a
shifting-link motion. Assuming this to be the original valve gear of the
_Pioneer_, it must be regarded as an early application, because the
Stephenson motion was just being introduced into American locomotive
practice in the early 1850's. Four eccentrics drive the motion; two are
for forward motion and two for reverse. The link is split and made of
two curved pieces. The rocker is fabricated of several forged pieces
keyed and bolted together. On better made engines the rocker would be a
one-piece forging. The lower arm of each rocker is curiously shaped,
made with a slot so that the link block may be adjusted. Generally, the
only adjustment possible was effected by varying the length of the valve
stem by the adjusting nuts provided. A simple weight and lever attached
to the reversing shaft serve as a counterbalance for the links and thus
assist the engineer in shifting the valve motion. There are eight
positions on the quadrant of the reversing lever.

[Illustration: Figure 29.--"PIONEER" on exhibit in old Arts and
Industries building, showing the tank and backhead. (Smithsonian photo


The cab is solid walnut with a natural finish. It is very possible that
the second cab was added to the locomotive after the 1862 fire. A brass
gong used by the conductor to signal the engineer is fastened to the
underside of the cab roof. This style of gong was in use in the 1850's
and may well be original equipment.

The water tank is in two sections, one part extending below the deck,
between the frame. The tank holds 600 gallons of water. The tender holds
one cord of wood.

The small pedestal-mounted sandbox was used on several Cumberland Valley
engines including the _Pioneer_. This box was removed from the engine
sometime between 1901 and 1904. It was on the engine at the time of the
Carlisle sesquicentennial but disappeared by the time of the St. Louis
exposition. Two small sandboxes, mounted on the driving-wheel splash
guards, replaced the original box. The large headlamp (fig. 3)
apparently disappeared at the same time and was replaced by a crudely
made lamp formerly mounted on the cab roof as a backup light. Headlamps
of commercial manufacture were carefully finished and made with
parabolic reflectors, elaborate burners, and handsomely fitted cases.
Such a lamp could throw a beam of light for 1000 feet. The present lamp
has a flat cone-shaped piece of tin for a reflector.

The brushes attached to the pilot were used in the winter to brush snow
and loose ice off the rail and thus improve traction. In good weather
the brushes were set up to clear the tracks.

[Illustration: Figure 30.--RECONSTRUCTED SANDBOX replaced on the
locomotive, August 1962. (Drawing by J. H. White.)]

After the _Pioneer_ had come to the National Museum, it was decided that
some refinishing was required to return it as nearly as possible to the
state of the original engine. Replacing the sandbox was an obvious
change.[20] The brass cylinder jackets were also replaced. The cab was
stripped and carefully refinished as natural wood. The old safety valve
was replaced, as already mentioned. Rejacketing the boiler with
simulated Russia iron produced a most pleasing effect, adding not only
to the authenticity of the display but making the engine appear lighter
and relieving the somber blackness which was not characteristic of a
locomotive of the 1850's. Several minor replacements are yet to be done;
chiefly among these are the cylinder-cock linkage and a proper headlamp.

The question arises, has the engine survived as a true and accurate
representation of the original machine built in 1851? In answer, it can
be said that although the _Pioneer_ was damaged en route to the
Cumberland Valley Railroad, modified on receipt, burned in 1862, and
operated for altogether nearly 40 years, surprisingly few new appliances
have been added, nor has the general arrangement been changed.
Undoubtedly, the main reason the engine is so little changed is that its
small size and odd framing did not invite any large investment for
extensive alteration for other uses. But there can be no positive answer
as to its present variance from the original appearance as represented
in the oldest known illustration of it--the Hull drawing of 1871 (fig.
8). There are few, if any, surviving 19th-century locomotives that have
not suffered numerous rebuildings and are not greatly altered from the
original. The _John Bull_, also in the U.S. National Museum collection,
is a good example of a machine many times rebuilt in its 30 years of
service.[21] Unless other information is uncovered to the contrary, it
can be stated that the _Pioneer_ is a true representation of a light
passenger locomotive of 1851.

_Alba F. Smith_

Alba F. Smith, the man responsible for the purchase of the _Pioneer_,
was born in Lebanon, Connecticut, June 28, 1817.[9] Smith showed promise
as a mechanic at an early age and by the time he was 22 had established
leadpipe works in Norwich. His attention was drawn particularly to
locomotives since the tracks of the Norwich and Worcester Railroad
passed his shop. His attempts to develop a spark arrester for
locomotives brought Smith to the favorable attention of Captain Daniel
Tyler (1799-1882), president of the Norwich and Worcester Railroad. When
Tyler was hired by the Cumberland Valley Railroad in 1850 to supervise
the line's rebuilding, he persuaded the managers of that road to hire
Smith as superintendent of machinery.[10] Smith was appointed as
superintendent of the machine shop of the Cumberland Valley Railroad on
July 22, 1850.[11] On January 1, 1851, he became superintendent of the

In March of 1856 Smith resigned his position with the Cumberland Valley
Railroad and became superintendent of the Hudson River Railroad, where
he remained for only a year. During that time he designed the
coal-burning locomotive _Irvington_, rebuilt the Waterman condensing
dummy locomotive for use in hauling trains through city streets, and
developed a superheater.[12]

After retiring from the Hudson River Railroad he returned to Norwich and
became active in enterprises in that area, including the presidency of
the Norwich and Worcester Railroad. While the last years of Smith's life
were devoted to administrative work, he found time for mechanical
invention as well. In 1862 he patented a safety truck for locomotives,
and became president of a concern which controlled the most important
patents for such devices.[13] Alba F. Smith died on July 21, 1879, in
Norwich, Connecticut.




SETH WILMARTH, Proprietor,






_Parts connected with Railroads, including Frogs, Switches, Chairs and
Hand Cars._

MACHINISTS' TOOLS, of all descriptions, including _TURNING LATHES_, of
sizes varying from 6 feet to 50 feet in length, and weighing from 500
pounds to 40 tons each; the latter capable of turning a wheel or pulley,
_thirty feet in diameter_.


Varying from 2 feet to 60 feet in length, and weighing from 200 lbs. to
70 tons each, and will plane up to 55 feet long and 7 feet square.

Boring Mills, Vertical and Horizontal Drills, Slotting Machines,
Punching Presses, Gear and Screw Cutting Machines, &c. &c. Also,

Mill Gearing and Shafting.

JOBBING AND REPAIRS, and any kind of work usually done in Machine Shops,
executed at short notice.

Figure 13.--ADVERTISEMENT OF SETH WILMARTH appearing in Boston city
directory for 1848-1849.]

_Seth Wilmarth_

Little is known of the builder of the _Pioneer_, Seth Wilmarth, and
nothing in the way of a satisfactory history of his business is
available. For the reader's general interest the following information
is noted.[16]

Seth Wilmarth was born in Brattleboro, Vermont, on September 8, 1810. He
is thought to have learned the machinist trade in Pawtucket, Rhode
Island, before coming to Boston and working for the Boston Locomotive
Works, Hinkley and Drury proprietors. In about 1836 he opened a machine
shop and, encouraged by an expanding business, in 1841 he built a new
shop in South Boston which became known as the Union Works.[17] Wilmarth
was in the general machine business but his reputation was made in the
manufacture of machine tools, notably lathes. He is believed to have
built his first locomotive in 1842, but locomotive building never became
his main line of work. Wilmarth patterned his engines after those of
Hinkley and undoubtedly, in common with the other New England builders
of this period, favored the steady-riding, inside-connection engines.
The "Shanghais," so-called because of their great height, built for the
Boston and Worcester Railroad by Wilmarth in 1849, were among the best
known inside-connection engines operated in this country (fig. 14).
While the greater part of Wilmarth's engines was built for New England
roads, many were constructed for lines outside that area, including the
Pennsylvania Railroad, Ohio and Pennsylvania Railroad, and the Erie.

A comparison of the surviving illustrations of Hinkley and Wilmarth
engines of the 1850's reveals a remarkable similarity in their details
(figs. 14 and 15). Notice particularly the straight boiler, riveted
frame, closely set truck wheels, feedwater pump driven by a pin on the
crank of the driving wheel, and details of the dome cover. All of the
features are duplicated exactly by both builders. This is not surprising
considering the proximity of the plants and the fact that Wilmarth had
been previously employed by Hinkley.

In 1854 Wilmarth was engaged by the New York and Erie Railroad to build
fifty 6-foot gauge engines.[18] After work had been started on these
engines, and a large store of material had been purchased for their
construction, Wilmarth was informed that the railroad could not pay cash
but that he would have to take notes in payment.[19] There was at this
time a mild economic panic and notes could be sold only at a heavy
discount. This crisis closed the Union Works. The next year, 1855, Seth
Wilmarth was appointed master mechanic of the Charlestown Navy Yard,
Boston, where he worked for twenty years. He died in Malden,
Massachusetts, on November 5, 1886.

       *       *       *       *       *


   [1]  _Minutes of the Board of Managers of the Cumberland Valley
        Railroad._ This book may be found in the office of the
        Secretary, Pennsylvania Railroad, Philadelphia, Pa., June 25,
        1851. Hereafter cited as "Minutes C.V.R.R."

   [2]  Ibid.

   [3]  Minutes C.V.R.R.

   [4]  _Franklin Repository_ (Chambersburg, Pa.), August 26, 1909.

   [5]  _Railroad Advocate_ (December 29, 1855), vol. 2, p. 3.

   [6]  C. E. FISHER, "Locomotives of the New Haven Railroad," _Railway
        and Locomotive Historical Society Bulletin_ (April 1938), no.
        46, p. 48.

   [7]  Minutes C.V.R.R.

   [8]  _Evening Sentinel_ (Carlisle, Pa.), October 23, 1901.

   [9]  _Norwich Bulletin_ (Norwich, Conn.), July 24, 1879. All data
        regarding A. F. Smith is from this source unless otherwise

  [10]  _Railway Age_ (September 13, 1889), vol. 14, no. 37. Page 600
        notes that Tyler worked on C.V.R.R. 1851-1852; Smith's obituary
        (footnote 9) mentions 1849 as the year; and minutes of C.V.R.R.
        mention Tyler as early as 1850.

  [11]  Minutes C.V.R.R.

  [12]  A. F. HOLLEY, _American and European Railway Practice_ (New York:
        1861). An illustration of Smith's superheater is shown on plate
        58, figure 13.

  [13]  JOHN H. WHITE, "Introduction of the Locomotive Safety Truck,"
        (Paper 24, 1961, in _Contributions from the Museum of History
        and Technology: Papers 19-30_, U.S. National Museum Bulletin
        228; Washington: Smithsonian Institution, 1963), p. 117.

  [14]  _Annual Report_, C.V.R.R., 1853.

  [15]  ZERAH COLBURN, _Recent Practice in Locomotive Engines_ (1860),
        p. 71.

  [16]  _Railroad Gazette_ (September 27, 1907), vol. 43, no. 13, pp.
        357-360. These notes on Wilmarth locomotives by C. H. Caruthers
        were printed with several errors concerning the locomotives of
        the Cumberland Valley Railroad and prompted the preparation of
        these present remarks on the history of Wilmarth's activities.
        Note that on page 359 it is reported that only one
        compensating-lever engine was built for the C.V.R.R. in 1854,
        and not two such engines in 1852. The _Pioneer_ is incorrectly
        identified as a "Shanghai," and as being one of three such
        engines built in 1871 by Wilmarth.

  [17]  The author is indebted to Thomas Norrell for these and many of
        the other facts relating to Wilmarth's Union Works.

  [18]  _Railroad Gazette_ (October 1907), vol. 43, p. 382.

  [19]  _Boston Daily Evening Telegraph_ (Boston, Mass.), August 11,
        1854. The article stated that one engine a week was built and
        that 10 engines were already completed for the Erie.
        Construction had started on 30 others.

  [20]  The restoration work has been ably handled by John Stine of the
        Museum staff. Restoration started in October 1961.

  [21]  S. H. OLIVER, _The First Quarter Century of the Steam Locomotive
        in America_ (U.S. National Museum Bulletin 210; Washington:
        Smithsonian Institution, 1956), pp. 38-46.

       *       *       *       *       *

PAPER 42: Typographical Corrections

      Page 259: "as late as 1880 and has been under steam" (was stream).

      Page 267: "made with parabolic reflectors" (was parobolic).

       *       *       *       *       *


  PAPER 43




                          SECTION OF MATERIA MEDICA (1881-1898)    272

                               DIVISION OF MEDICINE (1898-1939)    276

             DIVISION OF MEDICINE AND PUBLIC HEALTH (1939-1957)    281

                 DIVISION OF MEDICAL SCIENCES (1957 TO PRESENT)    290

                           A NEW DIMENSION FOR THE HEALING ARTS    292

                                                   BIBLIOGRAPHY    297


  _Sami Hamarneh_

  _In The Museum of History and Technology_

MUSEUM, known for the last quarter of a century as the Arts and
Industries building. Completed in 1881, it housed the Division of
Medical Sciences from its establishment in 1881 as a Section of Materia
Medica to the time of the writing of this paper. While the medical
collection remained in the Department of Arts and Industries, by the end
of June 1912 practically all other collections belonging to the fields
of natural history and anthropology were transferred to the then new
Natural History building.]

    _This paper traces, for the first time, the history of the
    Division of Medical Sciences in the Museum of History and
    Technology from its small beginnings as a section of materia
    medica in 1881 to its present broad scope. The original
    collection of a few hundred specimens of crude drugs which had
    been exhibited at the centennial exhibition of 1876 at
    Philadelphia, has now developed into the largest collection in
    the Western Hemisphere of historical objects related to the
    healing arts._

    THE AUTHOR: _Sami Hamarneh is the curator of the Division of
    Medical Sciences in the Smithsonian Institution's Museum of
    History and Technology._

By the early 1870's, leading figures from both the health professions
and the general public had begun to realize the necessity for having the
medical sciences represented in the Smithsonian Institution. The impetus
behind this new feeling resulted from the action of a distinguished
American physician, philanthropist, and author, Joseph Meredith Toner
(1825-1896), and came almost a decade before the integration of a new
section concerned with research and the historical and educational
aspects of the healing arts in the Smithsonian Institution.

In 1872, Dr. Toner established the "Toner Lectures" to encourage efforts
towards discovering new truths "for the advancement of medical science
... for the benefit of mankind." To finance these lectures, he provided
a fund worth approximately $3,000 to be administered by a board of
trustees consisting of the Secretary of the Smithsonian Institution, the
Surgeon General of the U.S. Navy, the Surgeon General of the U.S. Army
(only in some years), and the president of the Medical Society of the
District of Columbia. The interest from this fund was to compensate
physicians and scholars who were to deliver "at least two annual memoirs
or essays" based on original research on some branch of the medical
sciences and containing information which had been verified "by
experiments or observations."[1]

The Secretary of the Smithsonian Institution agreed to have these
lectures published by the Institution in its Miscellaneous Collections.
The first lecture given by the Assistant Surgeon of the U.S. Army, "On
the Structure of Cancerous Tumors and the Mode in which Adjacent parts
are Invaded," deserves credit even by current standards of scientific
research.[2] Only 10 lectures were given between 1873 and 1890 (see
bibliography), despite the recommendation for at least two every

[Illustration: Figure 2.--DR. JOSEPH M. TONER, a leading physician in
Washington, D.C., and founder of the "Toner Lectures" for the promotion
and advancement of medical education and research. In 1873, Dr. Toner
became president of the American Medical Association and, in 1874, he
became president of the American Public Health Association. He was a
physician to St. Joseph's Male Orphan Asylum and St. Ann's Infants'
Asylum in Washington, D.C. In addition, he was instrumental in
establishing Providence Hospital in the District of Columbia. He also
provided a workable plan for the American Medical Association's library
in Washington, D.C. (1868-1871). Among his several publications are:
_Contributions to the Annals of Medical Progress and Medical Education
in the United States before and during the War of Independence_
(Washington: Government Printing Office, 1874) and _Medical Men of the
Revolution_ (1876). In 1882, he donated his large library, consisting of
44,000 books and pamphlets on topics related mainly to medicine and
history, to the Library of Congress. (_Photo courtesy of National
Library of Medicine._)]

A more direct factor, which not only contributed to the establishment of
a section on the healing arts, but also had a greater effect upon the
Smithsonian Institution than any other event since its founding, was the
1876 centennial exhibition in Philadelphia.

This magnificent international fair commemorated the hundredth
anniversary of the adoption of the Declaration of Independence. The
finest exhibits of 30 foreign countries and various States of the Union
participating in the fair were finally donated to the Smithsonian
Institution as the official depository of historical and archeological
objects for this country. As a result, the Institution's collections
increased to an extent far beyond the capacity of the first Smithsonian
building. This led to the erection of the National Museum, known for the
last two decades and until date of publication as the Arts and
Industries building, which was completed on March 4, 1881, and was used
that evening for the inaugural reception of incoming President James A.

Section of Materia Medica (1881-1898)

Throughout the 19th century, the study of _materia medica_ (dealing with
the nature and properties of drugs of various kinds and origins, their
collection and mode of administration for the treatment of diseases, and
the medicinal utilization of animal products) held an increasingly
important place among the medical sciences. In the United States, as in
other civilized countries, this topic was greatly emphasized in the
curriculum of almost every school teaching the health professions.
Today, the subject matter contained in this branch of science is taught
under the heading of several specialized fields, such as pharmacology,
pharmacognosy, and drug analysis of various types. However, when the
decision was made in 1881 to promote greater knowledge and interest in
the healing arts by creating a section devoted to such pursuits in the
U.S. National Museum, the title of Section of Materia Medica was
adopted. Added to this, was the fact that the bulk of the first
collections received in the Section was a great variety of crude drugs,
which constituted much of the material then taught in the academic
courses of _materia medica_.

The new Section was included in the Department of Arts and Industries,
then under the curatorship of Assistant Director G. Brown Goode. From
its beginning and for two decades, however, the Section of Materia
Medica was sponsored and supervised by the U.S. Navy in cooperation with
the Smithsonian Institution. For this reason, the Navy decided not to
establish a similar bureau for a health museum as did the Army in
starting the Medical Museum (of the Armed Forces Institute of Pathology)
in 1862 through the efforts of Dr. William Alexander Hammond. The
Smithsonian did, however, provide a clerk to relieve the curator of much
of the routine work. The Section's early vigorous activities were the
result of the ingenuity of the first honorary curator, Dr. James Milton
Flint (1838-1919), an Assistant Surgeon of the U.S. Navy. From the
establishment of the Section, in 1881, to 1912, Dr. Flint was curator
during separate periods for a total of nearly 25 years. For three of his
tenures (1881-1884; 1887-1891; 1895-1900), he was detailed to the
Smithsonian Institution by the Surgeon General of the U.S. Navy. During
the interim periods, other naval doctors were detailed as curators.
Finally, in 1900, Dr. Flint retired from the Navy with the rank of Rear
Admiral and volunteered to continue his services to the National Museum.
The proposal was gladly accepted and he continued as a curator until his
retirement from the Smithsonian Institution in 1912.

[Illustration: Figure 3.--REAR ADMIRAL JAMES M. FLINT, U.S. Navy surgeon
and first honorary curator of the Section of Materia Medica. (_Photo
courtesy of the Library of Congress._)]

The Section commenced with a wealth of material. After the close of the
1876 centennial exhibition, its _materia medica_ collection had been
stored with the other collections in a warehouse, awaiting an
appropriation by Congress for transfer and installation. This collection
was gradually brought into the new National Museum after that building's
completion in 1881. Many other _materia medica_ specimens were
transferred from the Department of Agriculture. In addition to these
large collections of crude drugs, generous contributions came from
several prominent pharmaceutical firms such as Parke, Davis & Company of
Detroit, Michigan; Wallace Brothers of Statesville, North Carolina; and
Schieffelin and Company of New York City. These manufacturing houses are
mentioned here because they and their agents abroad were the first to
take interest and donate to the Section, complete assortments of
contemporary remedial agents then in common use throughout the United
States and Europe, besides many hundreds of "rare and curious drugs."
Thus, in spite of difficulties encountered from bringing several
collections into the building at one time, the _materia medica_
exhibition got off to a good start.

It was Dr. Flint, the first curator, who stated in 1883 that remedial
agents used by a nation or a community are as indicative of the degree
of their cultural development and standard of living as is the nature of
their food, the character of their dwellings, and their social and
religious traditions. Therefore, he felt that collections of drugs and
medical, surgical and pharmaceutical instruments and appliances should
not be thought of or designed as instructive to the specialist only, but
should also possess a general interest for the public. Because of these
objectives, Dr. Flint added, this section was conceived as a
departmental division for the collecting and exhibiting of objects
related to medicine, surgery, pharmacology, hygiene, and all material
related to the health field at large.[4]

During his first term of curatorship (1881-1884), Dr. Flint devoted much
of his time to sorting, examining, identifying, and classifying the
_materia medica_ specimens.[5] In 1881, he issued a memorandum of
instructions to be followed by collectors of drugs and urged them to
give detailed and accurate information regarding acquired specimens so
that they might be "more than mere museum curiosities." In addition, in
1883, he prepared a brief manual of classification of the _materia
medica_ collection in the Museum as well as a useful, detailed catalog
of informational labels of the individual objects on exhibition. The
unpublished catalog is still the property of the Smithsonian Institution
Archives, Division of Medical Sciences' Library.

It was Dr. Flint's ambition to obtain a comprehensive, worldwide
collection of all substances used as remedies. Then, in order to
identify drugs from foreign countries, he tried to collect illustrated
works on medical botany and printed pharmacopoeias of all nations having
them. He rightly defined an official pharmacopoeia as "a book containing
directions for the identification and preparation of medicines prepared
and issued with the sanction of a government or organized and
authorized medical and pharmaceutical societies. Its purpose is to
establish uniformity in the nomenclature of remedies and in the
character and potency of the pharmaceutical preparations. It is enacted
by legislation, and thus becomes binding on all who prepare drugs or
sell them for medication." By soliciting the help of various American
consuls and Navy officers abroad, about 16 such official pharmacopoeias
were collected, making an almost complete international representation
of all available, official, drug standards. With these sources of
information, Dr. Flint compiled and arranged an international list of
_materia medica_ specimens, indicating the authorized preparations of
each. By so doing, the first curator of this Section took the initiative
at least in proposing and, to some extent acting, on the preparation of
an international pharmacopoeia of drugs used in existing authorized
formularies giving "official synonyms, and tables showing the
constituents and comparative strength of all preparations."[6] This
undertaking is of special importance in the history of American
pharmacy, since it was probably the first attempt of its kind in the
United States.[7] In addition, colored plates and photographs of
medicinal plants were collected, forming the nucleus of the Division's
current collection of pictorial and photographic material related to the
history of the health field.

Dr. Flint also put on exhibition 630 Chinese _materia medica_ specimens
from the 1876 Philadelphia centennial. These had been collected
originally by the Chinese Imperial Customs Commission for the centennial
and were subsequently given to this country.

In 1881, the numbered objects in the Section's register amounted to
1,574 entries. In the following year, 1,590 more specimens were added,
most of them drugs in their crude state. By the end of 1883, the total
collection had reached 4,037, out of which 3,240 individual drugs in
good condition were classified and put on display. Of these, about 500
specimens with beautiful illustrations of parts of their original plants
had been mounted for exhibition. The drug exhibitions also included
materials transferred from the Department of Agriculture in 1881, which
originally had been brought from Central America and South America for
the 1876 centennial exhibition, a variety of opium specimens from
Turkey, and a number of rare drugs listed in the official formulary
which were acquired from the Museum of Karachi in what was then India.

Dr. Flint commented in the _Smithsonian Annual Report_ for 1883 that the
collection of cinchona barks was especially complete. It was comprised
of specimens of nearly all the natural cinchona barks of South America
and every known variety of the cultivated product from the British
government plantations in India. In addition, there were specimens from
Java, Ceylon, Mexico, and Jamaica. The Indian and Jamaican barks were
accompanied by herbarium specimens of the leaf and flower (and, in some
cases, the fruit) of each variety of tree from which the bark was

In an attempt to protect specimens liable to attack by insects, a small
piece of blotting paper moistened with chloroform was inserted
underneath the stopper in each bottle. Later on, bichloride of mercury
was found to be a better insecticide.

These early collections of the Section were brought into admirable
condition and received compliments for their organization and
completeness. In the _Smithsonian Annual Report_ for 1883, the
collections were praised as "superior to any other in the United States
and scarcely excelled by any in Europe."

[Illustration: Figure 4.--DR. HENRY GUSTAV BEYER, the second honorary
curator of the Section of Materia Medica (1884-1887). (_Photo courtesy
of American Physiological Society._)]

In spite of the apparent emphasis on the displaying of drugs, the first
curator of the Section had envisioned that the exhibits eventually would
embrace the entire field of the healing arts. In the _Smithsonian Annual
Report_ for 1883, Dr. Flint noted that "in the establishment of a museum
designed to illustrate man and his environment, it is proper that the
materials and methods used for the prevention and cure of disease should
have a place." However, his plans were temporarily interrupted when his
first term as honorary curator ended in 1884.

On June 4, 1884, Dr. Henry Gustav Beyer was detailed by the Department
of the Navy to become the second honorary curator of the Section of
Materia Medica. As a young man, Dr. Beyer (1850-1918) had come from
Saxony, Germany, to the United States and, in due course, became a
naturalized citizen. He was graduated from the Bellevue Hospital
Medical College of New York City in 1876.

Because of his interest in physiological experimental research, Dr.
Beyer enrolled at the Johns Hopkins University, where he was awarded a
Ph. D. degree in 1887. Unlike his predecessor, Dr. Beyer was primarily
interested in carrying on research on the physiological action of
certain drugs and in pharmacology. This was evident from the original
scientific papers mentioned in the _Smithsonian Annual Reports_ and
published by him during the period of his curatorship from 1884 to 1887.

Despite the pressure of his postgraduate studies at Johns Hopkins
University, Dr. Beyer helped in arranging and classifying the _materia
medica_ collection without trying to extend materially the scope of the

After the term of Dr. Beyer expired in 1887, Dr. Flint returned to take
charge of the Section. Surprisingly, at this time, it seems that he
showed less enthusiasm and devotion to the work of the Museum which he
had previously served so well. It could have been a disappointment
resulting from a lack of evidence of any real progress in the Section
since he had left it three years before. Whatever the reasons may have
been, the _Smithsonian Annual Reports_ show that only a few hundred
specimens were added to the _materia medica_ collections between 1887
and 1890, bringing the total to 5,915 preserved in good condition.
Further curtailment of the Section's activities began in November 1891
when Dr. Flint was again transferred to other duties for the U.S. Navy.
From November 1891 to May 24, 1895, curatorship of the Section was
charged to five physicians of the U.S. Navy: Drs. John C. Boyd (from
November 1891 to April 6, 1892); William S. Dixon (April 1892 to January
5, 1893); C. H. White (January 1893 to July 15, 1893); C. U. Gravatt
(July 1893 to January 22, 1894); R. A. Marmion (January 22, 1894 to June
15, 1894); and to Medical Inspector Daniel McMurtrie (June 1894 to May
24, 1895). During this interim of nearly three and a half years, there
were neither literary contributions nor additions made to the
collections of the Section that were of any significance. The reason is
obvious, for all of these curators averaged less than seven months of
service which is not enough time, even for a well-trained individual, to
accomplish very much in a museum. Therefore, it is easy to imagine that
when the Secretary of the Navy detailed Dr. Flint for a third time to
take charge of the Section, he was rather discouraged. Nevertheless, at
the Cotton States and International Exposition in Atlanta, Georgia, from
September 18 to December 31, 1895, the _materia medica_ was represented
by two displays: one on mineral waters and amounts of solid constituents
in pure state; and another showing the quantities of minerals after
analysis of the composition of the human body.

A similar project was undertaken in 1897 at the Tennessee Centennial
Exposition (May 1 to October 31) in Nashville, where there were two
displays of _materia medica_. One showed several kinds of the cinchona
barks and the medicinal preparations made from them, and another
containing the commercial varieties of the alkaloids of opium.

At this time, Dr. Flint's attention turned to a new phase of medical
exhibition. He felt the need for a program of exhibits on the practice
and the historical development of the healing arts. A change of the
Section's name was deemed necessary and, thus, in 1898 the more
comprehensive title of Division of Medicine was adopted.

Division of Medicine (1898-1939)

The statement by L. Emmett Holt of the Rockefeller Institute for Medical
Research, that before 1906, the Smithsonian Institution was never a
beneficiary to medicine in any form,[9] is not entirely applicable. The
previous discussion has clearly shown that the U.S. National Museum's
cooperation with the Navy contributed materially towards encouraging and
promoting medical knowledge. Furthermore, Dr. Flint tried to bring many
of his plans for this medical division of the Museum to a practical
fulfillment. He devised a program for presenting medical history in a
way which would be of interest both to the public and to the profession.
In order to best illustrate the history of the healing art, he divided
his subject matter into five provisional classifications according to
the _Report upon the Condition and Progress of the U.S. National Museum_
during 1898:

    1. Magical medicine including exorcism, amulets, talismans,
    fetishes and incantation;

    2. Psychical medicine including faith cures, and hypnotism;

    3. Physical and external medicine including baths, exercise,
    electricity, massage, surgery, cautery, and blood-letting;

    4. Internal medicine including medications and treatment used by
    the ancient Egyptians, Greeks, Hindus, Arabians, and Chinese;

    5. Preventive medicine including beverages, food, soil, clothing
    and habitation.

It is certainly to Dr. Flint's credit that from its early conception,
first as Section of Materia Medica and thereafter as Division of
Medicine, he planned for an all-embracing exhibition and reference
collection of the medical sciences. Until the end of the 19th century
and the early years of the 20th century, crude drugs as well as
primitive and magic medicine held a more prominent place than medical
instruments in the exhibits and collections. In 1905, Flint issued his
last, known, literary contribution, "Directions for Collecting
Information and Objects Illustrating the History of Medicine," in Part S
of _Bulletin of the U.S. National Museum_, no. 39. The emphasis he put
upon this shows Dr. Flint's interest in collecting medical and
pharmaceutical objects and equipment of historical value. Consequently,
he arranged new exhibits including one on American Indian medicine. A
medical historian, Fielding H. Garrison, inspected these about 1910 and,
in his "An Introduction to the History of Medicine," wrote of their
novelty and appeal. "In the interesting exhibit of folk medicine in the
National Museum at Washington," he commented, "a buckeye or horse
chestnut (_Aesculus flavus_), an Irish potato, a rabbit's foot, a
leather strap previously worn by a horse, and a carbon from an arc light
are shown as sovereign charms against rheumatism. Other amulets in the
Washington exhibit," he added, "are the patella of a sheep and a ring
made out of a coffin nail (dug out of a graveyard) for cramps and
epilepsy, a peony root to be carried in the pocket against insanity, and
rare and precious stones for all and sundry diseases." It had been Dr.
Flint's intention, besides presenting an educational display on the
history of the medical arts, to warn the public against the perils of
quackery and the faults of folk medicine, as well as to expose evils in
drug adulteration. Today, we can see actual fulfillment of these
intentions in the present exhibit at the medical gallery which has been
executed recently on the basis of scientific, historical research.

After Dr. Flint's retirement from the Smithsonian Institution in 1912,
there was no replacement for over five years. Therefore, the Division
of Medicine was placed, for administrative purposes, under the
supervision of the curator of the newly reestablished (1912) Division of
Textiles, Frederick L. Lewton. During these years, he fought against the
dispersal of the medical and _materia medica_ collections. Thus, for
lack of a curator of its own, almost all new activities in the Division
of Medicine were curtailed until 1917.

On January 31, 1917, Lewton addressed members of the American
Pharmaceutical Association inviting them to cooperate in gathering up
and preserving at the National Museum the "many unique and irreplaceable
objects" connected with the early history of pharmacy in this country
which could still be saved.[10] Then, on March 14, 1917, an examination
was announced by the Civil Service (held May 2) for an assistant curator
for the Division of Medicine, and the position was filled by Joseph
Donner on August 16, 1917. Donner was the first full-time employee paid
by the Smithsonian Institution for the curatorship of this Division. He
held the post until January 31, 1918, when he was inducted into the
Sanitary Corps of the United States Army. No significant activities in
the Division of Medicine were reported during these few months.

Mr. Donner was followed by a second, full-time, museum officer who
promoted a great amount of good will towards the Division during his
curatorship of a little over 30 years. Dr. Charles Whitebread
(1877-1963), the first pharmacist to head the Division, joined the
Smithsonian in 1918 and remained until his retirement in 1948, the
longest service, thus far, of any individual in the Division.

Dr. Whitebread received his degree of Doctor of Pharmacy from the School
of Pharmacy at George Washington University in Washington, D.C., in
1911. He entered government service late in 1915, but it was not until
April 2, 1918, that he agreed to become assistant curator of the
Division of Medicine.

Curator Whitebread's first year was an active and challenging one, for
in this new position he began to develop a deep interest in the history
of the healing arts. He made a number of important acquisitions, most of
them pertaining to pharmaceutical products, synthetic chemicals and
crude drugs. He found that many specimens from the older drug
collections had deteriorated to such an extent as to be worthless, and
he began replacing them with freshly marketed drugs.

[Illustration: Figure 5.--CURATOR CHARLES WHITEBREAD inspecting, with
admiration, five drug containers from the Squibb collection (1945).
(_Photo courtesy of the American Pharmaceutical Association._)]

Plans were completed for the opening of new medical exhibits and
adopting, with some modifications and additions, earlier classifications
set by Dr. Flint. Dr. Whitebread grouped these into the following
classes: the evaluation of the healing arts; a picture display of
medical men prominent in American history;[11] a _materia medica_
display including the history of pharmacy; and an exhibition on
Sanitation and Public Hygiene[12] which was later to evolve into the
Hall of Health.

In 1920, Dr. Whitebread added a number of specimens of medical-dosage
forms and pharmaceutical preparations to the Division's collections. He
also acquired other gifts to complete existing exhibits illustrating the
basic principles of the various schools of medicine, such as homeopathy
and osteopathy--their methods, tools, and ways of thought.

In 1921, a tablet machine by the Arthur Colton Company of Detroit,
Michigan, was acquired, and an exhibit illustrating vaccine and serum
therapy was installed in the medical gallery. This was followed, in
1922, by a collection arranged to tell the story of the prevention and
cure of specific diseases by means of biological remedies.

During the following two years, two more exhibits related to hospital
supplies and sanitation were added to the rapidly developing Hall of
Health exhibition which was opened in 1924. A third exhibit in 1925
consisted of 96 mounted color transparencies illustrating services
provided by hospitals to promote public health. Plans for the further
development of the Hall of Health continued during 1926, and contacts
were made with organizations interested in the educational aspects of
the healing arts. As a result, several new exhibits were added. In 1926,
the American Optometric Association helped in the installation of an
exhibit on conservation of vision or the care of the eyes under the
slogan "Save your vision," as a phase of health work. Other exhibits in
the Hall at this time were: what parasites are; water pollution and how
to obtain pure water; waste disposal; ventilation and healthy housing,
and the importance of recreation; purification of milk and how to obtain
pure milk; transmission of diseases by insects and animals; how life
begins; prenatal and postnatal care and preschool care; duties of the
public health nurse; and social, oral and mental hygiene.

With the acquiring of more medical appliances and the widening of the
scope of the exhibits, more and more space was needed, and attention was
turned to the area of the medical gallery which had been occupied by the
_materia medica_ collection for almost four decades. To gain more
exhibit space, it was decided that the greater part of the crude drugs
should be removed from the exhibits and be kept as a reference
collection and for research.[13]

installed about 1924, which was illustrated by graphs and drugs
mentioned in extant records of this ancient period. (Smithsonian photo

[Illustration: Figure 7.--EXHIBIT ON MEDICAL HISTORY during the
Greco-Roman period. (Smithsonian photo 30796-D.)]

vegetable origin, displayed about mid-1930's. (Smithsonian photo

In 1926, original patent models including those related to pharmacy,
medicine, and dentistry, were transferred from the U.S. Patent Office to
the National Museum. These patent models, together with other apothecary
tools and the machines used in drug production took up most of the
available space. This unfortunate situation led Dr. Whitebread to turn
down significant medical and pharmaceutical collections offered the
Museum between 1927 and 1930. Since the patent models were devised for
inventions designed to simplify the practice of the health professions,
three cases of these models were displayed in the medical gallery in the
early 1930's. Other exhibits shown during this decade included the
deception of folk medicine with warnings against superstitions, and an
exhibition on osteopathy,[14] as well as dioramas on the manufacture of
medicines and their use in scientific medical treatment.

In the meantime, Dr. Whitebread was an active contributor to the
literature of the health field in various periodicals, as well as in
pamphlets issued by the Museum and other governmental agencies (see
bibliography). His literary contributions, guided by the exhibits he
designed and the collections he acquired, were focused on the Division's
collections, such as primitive and psychic medicine and warnings against
reliance on magic and superstitions in treatment, medical oddities, and
the utilization of drugs of animal origin, both past and present.

Division of Medicine and Public Health (1939-1957)

After taking charge of the Division of Medicine in 1918, Dr. Whitebread
gave special attention to public health displays. His activities in this
area were accelerated after 1924 when the health exhibit at the
Smithsonian Institution was inaugurated. As the exhibits in this field
increased, the Division, in 1939, took the more comprehensive title of
Division of Medicine and Public Health. Also, in 1939, Dr. Whitebread
was promoted to the rank of associate curator.

[Illustration: Figure 9.--EXHIBIT ON METHODS OF TREATMENT of diseases
through mental impressions and psychic conditions as displayed about
1925. (Smithsonian photo 30796-B.)]

magic, and faith healing in the light of scientific medicine, completed
in 1962, is in sharp contrast with that shown in figure 9.]

He continued his efforts to collect more specimens of interest to
medical history and to contribute to the literature. Among exhibited
specimens in 1941 were a powder paper-crimping machine, a portable drug
crusher, an odd device for spreading plaster on cloth, a pill-coating
apparatus, various suppository molds, a lozenge cutter, and an ingenious
Seidlitz powder machine. The derivation of medicinal drugs from animal,
vegetable, and mineral sources was also depicted, as were synthetic
materials and their intermediates. Basic prescription materials were
displayed, and rows of glass-enclosed cases held samples of crude
botanical drugs from almost every part of the globe with explanatory
cards giving brief, concise descriptions. The exhibition provided
medical and pharmaceutical students about to take state-board
examinations, the opportunity to study the subject in detail, especially
the enormous collection of _materia medica_ samples.[15] Also in 1941,
Eli Lilly and Company donated an exhibit on the medical treatment of
various types of anemia. In the same year, a diorama including a
hypochlorinator for purification of water on a farm was installed in the
gallery. In 1942, the first Emerson iron lung (developed in 1931 by John
Haven Emerson) for artificial respiration was acquired by the Division.
The Division acquired, in 1944, the first portable x-ray machine known
to have been operated successfully on the battlefield, as well as other
x-ray equipment and early medicine chests.

[Illustration: Figure 11.--OLD PUBLIC HEALTH EXHIBITION installed in the
gallery about 1924. (Smithsonian photo 19952.)]

[Illustration: Figure 12.--THE HALL OF HEALTH, reestablished and opened
in November 1957. (Smithsonian photo 44931.)]

[Illustration: Figure 13.--EARLY EXHIBIT ON HOMEOPATHY showing its
history, methods and remedies which was installed about 1929.
(Smithsonian photo 27049.)]

Without a doubt, the most outstanding accession in the field of
pharmaceutical history during Dr. Whitebread's years of service was the
acquisition of the E. R. Squibb and Sons old apothecary shop. Most of
the baroque fixtures, including the stained-glass windows with
Hessian-Nassau coats of arms and wrought-iron frames, were part of the
mid-18th-century cathedral pharmacy "Muenster Apotheke" in Freiburg im
Breisgau, Germany. It was offered for sale in September 1930 by Dr. Jo
Mayer of Wiesbaden, Germany, who was an enthusiastic collector of
antiques, especially those related to the health professions. Earlier
that year, a historian of pharmacy and chemistry, Fritz Ferchl of
Mittenwald, Germany, had published a series of scholarly and informative
articles on the Meyer collection in which the outstanding specimens were
beautifully portrayed and thoroughly described (see bibliography).

As a result of Dr. Mayer's efforts to sell his collection, the impact of
Ferchl's illustrated articles, and the uniqueness of the collection, E.
R. Squibb and Sons purchased it in 1932 and brought it to the United
States "with the thought that it would provide for American pharmacy,
its teachers and students, a museum illuminating the history, growth,
and development of pharmacy, its interesting background and struggle
through the ages." It was displayed at the Century of Progress
exposition held in Chicago during 1933 and 1934; subsequently, it was
assembled in the Squibb Building in New York City as a private museum
where, for about 10 years, it was visited by many interested in
pharmacy, ceramics, and art. Charles H. LaWall, who was originally
engaged to prepare a descriptive catalog on the exhibit, gave it the
title "The Squibb Ancient Pharmacy."

Late in 1943, E. R. Squibb and Sons offered the collection as a gift to
the American Pharmaceutical Association if the latter would provide
museum space for it. The offer was accepted, but the Association
finally found it difficult to spare the needed space for the collection
and decided to take up the matter with the U.S. National Museum.

[Illustration: Figure 14.--THIS EARLY EXHIBIT ON OSTEOPATHY was
renovated several times prior to the early 1940's. (Smithsonian photo

At this point, it should be stated that since 1883 the members of the
American Pharmaceutical Association have been keenly interested in
having the National Museum serve as the custodian for all collected
objects and records of historical interest to pharmacy. In 1944, the
Association officially offered to deposit on permanent loan, the
Squibb's pharmacy collection in the Smithsonian Institution with the
understanding that a suitable place would be provided for prompt and
permanent display. The offer was accepted, and during April and May of
1945, the entire collection was transferred to the Smithsonian
Institution, and construction to recreate the original two rooms for the
old, 18th-century, European "Apotheke" was underway.

By August 1946, the exhibit was completed. In the large room where the
pharmacist met his customers, the shelves were filled with 15th-to
19th-century, European pharmaceutical antiques. These included
Renaissance mortars; 16th-and 17th-century nested weights; beautiful
Italian, French, Swiss, and German majolica and faience drug jars; Dutch
and English delft; drug containers made of flint or opal glass with
fused-enamel labels with alchemical symbols; rare, 16th-century, wooden
drug containers, each with the coat of arms of the city in which each
was made; and two glass-topped, display tables contained franchises
issued and signed by Popes or state rulers, medical edicts,
dispensatories, herbals, pharmacopoeias, and pharmaceutical utensils.

On the walls in the small laboratory room, which also had been used as a
workshop and a study, were a stuffed crocodile, shark's head, tortoise,
fish, and salamander, parts of which were utilized as remedial agents.
Their presence provided tangible evidence that the pharmacy dispensed
genuine drugs and not substitutes.

The pharmaceutical profession in this country hailed the outstanding
exhibition, and the November 1946 issue of the _Journal of the American
Pharmaceutical Association, Practical Pharmacy Edition_, devoted its
front cover to depicting one corner of the study and laboratory room of
the shop.[16] Also, in a letter dated January 2, 1947, addressed to Dr.
Alexander Wetmore, then Secretary of the Smithsonian Institution, Dr.
Robert P. Fischelis, the secretary of the American Pharmaceutical
Association, considered the completion of the deposited exhibition a
triumph and "as one of the highlights of the accomplishments of the
Association in 1946."

[Illustration: Figure 15.--LATE 16TH-CENTURY, wooden drug container with
coat-of-arms, in the Squibb collection. The inscription _Ungula Alcis_
(the hoof of the elk) suggests a superstitious attitude in medical
practice and the wide use of animal organs in medical treatment.
(_Courtesy of the American Pharmaceutical Association._)]

From 1946 to 1948, the Division's collection was further enriched with
a number of historical specimens, among which was a "grosse Flamme"
x-ray machine with induction-coil tube and stand developed by Albert B.
Koett. It is one of the earliest American-made machines of its kind,
producing a 12-inch spark, the largest usable at that time with
180,000-volt capacity, and a forerunner of later autotransformers. Other
accessions included two 19th-century drug mills, an electric belt used
in quackery, two medicine chests, three sets of Hessian crucibles used
in a pioneer drugstore in Colorado, a drunkometer, mineral ores, and
purely produced chemical elements.

[Illustration: Figure 16.--A RARE, ANTWERP, 16th-century drug jar in the
Squibb collection deposited by the American Pharmaceutical Association.]

In the spring of 1948, Associate Curator Whitebread retired after 30
years of service with the U.S. National Museum. He was a pioneer in the
field of health museums and during his curatorship had developed a
moribund section into a Division of field-wide importance. Dr.
Whitebread was succeeded by George S. Thomas, also a pharmacist, who
served as associate curator from August 1948 until early 1952.

[Illustration: Figure 17.--THE APOTHECARY SHOP as seen in the Arts and
Industries building (1946-1964). (_Courtesy of the American
Pharmaceutical Association._)]

[Illustration: Figure 18.--VIEW OF THE LABORATORY AND STUDY ROOM of the
apothecary shop. On the left, the German-Swiss bronze mortar and pestle
(1686) sign and above it an 18th-century German painting on canvas of
Christ, "the apothecary of the soul." The drug containers represent "the
fruits of the spirit," faith, patience, charity, etc., and the scales
represent justice. Underneath is the verse from Matthew, 11:28, "Come
unto me, all ye that labour and are heavy laden, and I will give you
rest." (_Courtesy of the American Pharmaceutical Association._)]

During his almost-three and a half years of service, Thomas acquired
hearing-aid appliances from which he designed an exhibit on the
development of these aids, surgical sutures, early samples of
Aureomycin, and a static-electricity machine made by Henkel about 1840.
He also published three short articles under the title, "Now and Then,"
in the _National Capital Pharmacist_ (1950), no. 1, pp. 8-9; no. 2, pp.
18-19, 29; and no. 3, pp. 15-16. In early 1952, Dr. Arthur O. Morton
presented to the Division, a Swiss-made keratometer which he had
purchased in 1907, and it is believed to be one of the first used in the
United States to measure the curves of the cornea.

The achievements of the Division reached their highest point, thus far,
in significantly increasing the national collection, as well as in
contributing to the scientific, historical, and professional literature,
under the curatorships of George B. Griffenhagen (December 8, 1952, to
June 27, 1959) and John B. Blake (July 1, 1957, to September 2, 1961).
Their reorganization of exhibits and collections, their competence and
industry, fulfilled the hopes, plans, and purposes laid down by earlier
curators for the Division.

Immediately after assuming the responsibilities of the Division and
throughout 1953, Mr. Griffenhagen (M.S. in pharmaceutical chemistry from
the University of Southern California) undertook to develop the
collections still further. He increased the emphasis not only on
historical pharmacy, but also on medicine, surgery, and dentistry. He
also renovated the exhibits in the medical gallery.

In 1954, several antibiotics were donated to the Division including a
mold of _Penicillium notatum_ prepared and presented to the Smithsonian
Institution by Sir Alexander Fleming (1881-1955), the discoverer of
penicillium (1929), and a few Petri dishes used by botanist Benjamin M.
Daggar who, while working for Lederle Laboratories, developed Aureomycin
(chlortetracycline) in 1948. The Forest D. Dodrill--G.M.R. mechanical
heart (1952), the first machine reported to be used successfully for the
complete bypass of one side of the human heart during a surgical
operation,[17] was presented to the Smithsonian Institution.

The following year, 1955, the Division acquired one of the earliest
Einthoven string galvanometers (named after the Dutch physiologist Willem
Einthoven, 1860-1927) made in the United States in 1914 by Charles F.
Hindle for an electrocardiograph. Also added to the Division's
collections was the electrocardiograph used by Dr. Frank E. Wilson of
the United States, a pioneer educator in this field. Two temporary
exhibits on allergy and surgical dressings were installed in the
gallery. In the same year, Curator Griffenhagen published _Early
American Pharmacies_, a catalog on 28 pharmacy restorations in this

In 1956, among many publications of interest in the fields of medical
and pharmaceutical history, was Curator Griffenhagen's _Pharmacy
Museum_, with a foreword by Laurence V. Coleman, who termed it a useful
catalog and "a good reflection of the history of the museum movement at
large." A third x-ray tube of Wilhelm Konrad Roentgen (1845-1922) was
added to the collection in 1957 as well as a complete set of
hospital-ward fixtures of about 1900 from the Massachusetts General
Hospital, rare patent medicines, 18th-century microscopes, and a
13th-century mortar and pestle made in Persia.

In 1957, Mr. Griffenhagen published a series of illustrated articles in
the _Journal of the American Pharmaceutical Association, Practical
Pharmacy Edition_, which were later reprinted by the Association in a
booklet entitled, _Tools of the Apothecary_. In it, he described several
pharmaceutical specimens in the collection and their place in history.

Division of Medical Sciences (1957 to Present)

The U.S. National Museum was reorganized on July 1, 1957, into two
units, the Natural History Museum and the Museum of History and
Technology. At the same time, and in view of the widening scope of the
Division, its more scientifically based planning, and the constantly
increasing collection with equal emphasis on all branches of the healing
arts, the Division's title was changed to the Division of Medical
Sciences--the title it still bears in 1964. With the reorganization, the
Department of Engineering and Industries, under which the Division fell
administratively, was renamed the Department of Science and Technology
of the Museum of History and Technology. It was also the first time
since its establishment in 1881 that the Division had two curators, for
on July 1, 1957, Dr. John B. Blake joined the staff.

[Illustration: Figure 19.--CURATORS JOHN B. BLAKE AND GEORGE
GRIFFENHAGEN examine the newly acquired (1957) electromagnetic,
Morton-Wimshurst-Holz Influence Machine. It was manufactured by the
Bowen Company of Providence, Rhode Island (1889). With the discovery of
x-ray, it was used for making x-ray photographs until early in the 20th

As a result of these changes, the Division was subdivided into a Section
of Pharmaceutical History and Health and a Section of Medical and Dental
History. The former was planned to encompass the collections of _materia
medica_, pharmaceutical equipment, and all material related to the
history of pharmacy, toxicology, pharmacology, and biochemistry, as well
as the Hall of Health which was opened November 2, 1957, and which
emphasizes man's progressing knowledge of his body and the functions of
its major organs.[18] The latter Section was planned to include all that
belongs to the development of surgery, medicine, dentistry, and nursing,
especially in relation to hospitals.

In October 1957, the Division acquired a collection of rare, ceramic,
drug jars which included two, 13th-century, North Syrian and Persian,
albarello-shaped, majolica jars; a 15th-century, Hispano-Moresque drug
container; and a 16th-century, Italian faience, dragon-spout ewer.
During the following two years, Curator Griffenhagen periodically toured
museums and medical and pharmaceutical institutions in this country,
South America, and Europe gathering specimens and information for the
Division and for publication, respectively. However, on June 27, 1959,
he resigned his curatorship to join the staff of the American
Pharmaceutical Association in Washington, D.C. Dr. Blake became the
curator in charge of the Division and Mr. Griffenhagen was succeeded on
September 24, 1959, by the author of this paper as associate curator in
charge of the Section of Pharmaceutical History and Health.

Dr. Blake, as curator of the Section of Medical and Dental History,
acquired a large number of valuable and varied specimens for the
Division's collections. They included optometric refracting instruments,
an early 1920's General Electric, portable, x-ray machine, the Charles
A. Lindbergh and Alexis Carrel pump (designed in 1935 to perfuse
life-sustaining fluids to the organs of the body), the Sewell heart pump
(1950) to control delivery of air pressure and suction to the pumping
mechanism, and a large and valuable collection of dental equipment
formerly at the universities of Pennsylvania and Illinois. Dr. Blake
wrote the explanatory material and supervised the design and production
of the majority of exhibits in the renovated hall of medical and dental
history. He also contributed several scholarly articles and a book (see
bibliography) on the history of the healing arts and public health in
particular. He resigned on September 2, 1961, to join the staff of the
National Library of Medicine as chief of the History of Medicine
Division, and was succeeded by the author as curator of the Division.
From the summer of 1962 to April 1964, the Division benefited from the
expert advice of Dr. Alfred R. Henderson as consultant in the
preparation and designing of the surgical and medical exhibits of the
Museum of History and Technology.

During the period from 1961 to May 1964, the Division's collections
expanded greatly through its medical, dental, and pharmaceutical
acquisitions. Specimens of antiques acquired from 1961 through 1963
numbered up to 1,539 and included gifts from leading institutions and
individual philanthropists. The scope of these gifts and acquisitions
ranges from electronic resuscitators, microscopes, x-ray equipment, and
spectacles, to patent medicines, amulets, apothecary tools, dental
instruments, and office material of practitioners.

OPTOMETERS, and refraction, completed in 1960. It features a cross
section of the Division's large collection of eyeglasses. (Smithsonian
photo 47943-D.)]

In the last decade, the interest in the national endeavor for promoting
research and scholarship in the history of medicine has increased
greatly. It was most appropriate, therefore, for the Smithsonian
Institution to play host on May 2 for two sessions of the 37th annual
meeting of the American Association for the History of Medicine held in
the Washington, D.C., area from April 30 through May 2, 1964. In
welcoming the members to the morning session in the auditorium of the
new Museum of History and Technology, Frank A. Taylor, director of the
United States National Museum, expressed the feeling that the meeting of
the Association was, in a sense, a dedication of the new auditorium and
an opportunity for the Smithsonian to reaffirm its deep interest and
commitment in fostering research and furthering the appreciation of
scholarly endeavor in the history of the healing arts.

A New Dimension For the Healing Arts

"One day the United States will have a National Museum of science,
engineering, and industry, as most large nations have." This was the
prediction made in 1946 by the director of the U.S. National Museum, Mr.
Frank A. Taylor, then curator of the Division of Engineering.[19] It was
in 1963, that the new $36,000,000 building of the Museum of History
and Technology was completed, and opened to the public in 1964. The
offices of the Division of Medical Sciences as well as the reference and
study collections were moved to the fifth floor of the new building. The
exhibits, however, will be displayed in the gallery at the southwest
corner of the first floor. These exhibits, it is hoped, will show a new
dimension and an unprecedented approach in displaying the development of
the healing arts throughout the ages and the instruments and equipment
associated with health professions. They also present the expanding
objectives and plans of the Division's growth as an integral part of the
Smithsonian Institution. Conveniently, the exhibits form four, closely
connected halls in one large gallery which will be open to the public in
the summers of 1965 to 1966.

INSTRUMENTS and the early 20th-century sphygmomanometers which was
completed in 1960. (Smithsonian photo 47943-M.)]

1. THE HALL OF HEALTH displays models and graphic and historical exhibit
materials to demonstrate the function of the various healthy organs of
the human body. The main topics emphasized are: embryology and
childbirth; tooth structure; the heart and blood circulation;
respiration; the endocrine glands; kidneys and the urinary-excretory
system; the brain and the nervous system; the ear; and vision and the
use of eyeglasses.

The most appreciated exhibit of all in this Hall is the "transparent
woman" figure which rotates, automatically, every 15 minutes with a
recorded message describing the function of each major organ of the body
at the same time that the organ is electronically lighted, so that the
viewer can see its place in the body.

[Illustration: Figure 22.--HEARING-AID EXHIBIT designed in 1962. It
includes otologist Julius Lempert's personal memorabilia and original
surgical instruments used in the fenestration operation for restoring
hearing. (Smithsonian photo 49345-C.)]

2. THE HALL OF MEDICINE AND DENTISTRY will depict the history of these
two sciences with exhibits of the equipment used through the centuries.
In the medical field, early trephining and other surgical instruments
will be displayed along with a diorama of an 1805 surgical operation
performed by Dr. Philip Syng Physick in the amphitheater of the
Pennsylvania Hospital. Diagnostic instruments such as stethoscopes,
endoscopes, speculums, and blood-pressure measuring devices will be
exhibited with a series of microscopes illustrating the development of
these instruments. Exhibits of original galvanometers and other
apparatus will trace the development of cardiography. The early use of
anesthesia will be shown by apparatus of William Morton and Crawford W.
Long, American pioneers in this field. The development of the devices of
modern medicine and surgery will be shown by exhibits of the iron lung
and x-ray tubes, including a tube used by W. K. Roentgen. Medicine
chests and surgical kits of different periods will graphically summarize
the state of medical science in the period each represents.

Exhibits on the development of dentistry and dental surgery will display
examples of tooth-filling and extracting tools, drilling apparatus from
the early hand and foot engines to the first ultrasonic cutting
instrument (1954), and the original contra-angle, hydraulic and
air-turbine handpiece model[20] which revolutionized the field of
instrumentation for dental surgery (with speeds of 200,000 to 400,000
rpm). This hydraulic turbine of Dr. Robert J. Nelson and associates of
the National Bureau of Standards set the design pattern for the
remarkable and successful high-speed, air-turbine handpiece developed by
Paul H. Tanner and Oscar P. Nagel of the U.S. Naval Dental School in
1956. Also underway is the reconstruction of the offices of famous
dentists such as G. V. Black and the father of American orthodontia,
Edward H. Angle, using their original equipment and instruments. In
addition, an exhibit is planned to include x-ray tubes and the electric
dental engine, the first to be operated in a human mouth by the pioneer
dentist on dental skiagraphy, Charles E. Kells (1856-1928).[21]

[Illustration: Figure 23.--EXHIBIT ON NURSING BOTTLES and measures to
promote child health to counteract the once-common diseases of
childhood. This display was completed in 1962. (Smithsonian photo

3. THE HALL OF PHARMACEUTICAL HISTORY will feature exhibits on the
reconstruction of two pharmacy shops: an 18th-century apothecary shop,
originally from Germany, with a very elegant collection of drug jars,
decorated medicinal bottles, balances, mortars and pestles, and other
tools and documents pertaining to the apothecary art, and a late
19th-century American drugstore with shelves filled with patent
medicines and drug containers of various sizes and shapes. The window
will also feature symbols of pharmacy and beautiful show globes.
Displays will show the development of antibiotics and the early tools
used in the manufacture of the so-called "miracle drugs," including a
mold from Sir Alexander Fleming, the discoverer of penicillin. In
addition, a platform will be reconstructed to display a variety of
pharmaceutical apparatus used in the preparation and manufacture of
drugs, such as tablet and capsule machines and drug mills and
percolators. Recently, with the assistance of Professor Glenn
Sonnedecker, the Division acquired a fine collection of pharmaceutical
equipment and devices from the School of Pharmacy of the University of

[Illustration: Figure 24.--THE ORIGINS OF DRUGS from the three natural
kingdoms, drug synthesis, and the increase in the manufacture of
vitamins. This display was completed in 1962 and is now on display at
the Museum of History and Technology. (Smithsonian photo P6316.)]

Since the Division houses the largest collection of _materia medica_ in
the country, a representative cross section of crude drugs will be
displayed in alphabetical order as well as a display illustrating the
role of cinchona and antimalarial drugs in the fight against disease. An
exhibit will portray the "origin of drugs" from the three natural
kingdoms, animal, vegetable, and mineral, together with synthetic drugs
including the manufacture of vitamins.

Plans are being made for an elaborate exhibit of weights and balances
used in many countries throughout the centuries, their impact on
accuracy of dosage and weighing of drugs, and their use in the
apothecary art.

The Division will also display pictorial and printed materials, as well
as artifacts from all periods and all countries. These collections are
intended to help in presenting a more complete picture of the story of
the medical sciences for educational purposes and research, and to
increase man's knowledge in fighting disease and promoting health.

Thus, from a few hundred specimens of crude drugs in the Section of
Materia Medica of 83 years ago, there has developed a Museum Division
today which embraces the evolution of the health professions through the
ages. This Division now has the largest collection in the Western
Hemisphere of historical objects which are related to the healing arts.
The reference collections are available to the researcher and scholar,
and the exhibits are intended for pleasure and educational purposes in
these fields. The plans for expansion have no limitation as we keep pace
with man's progress in the medical sciences and continue to collect
materials that contributed to the historical development in the fight
against diseases and the attempts to secure better health for everyone.


    The _Annual report of the Board of Regents of the Smithsonian
    Institution_ from 1872 to date and the _Proceedings of the
    United States National Museum_ from 1881 to date were used
    extensively as sources in this survey. In the latter, see in
    particular, the year 1881, pp. 545-546; 1882, pp. 1-2; and 1884,
    pp. 431-475.

ATKINSON, WILLIAM B. _The physicians and surgeons of the United States._
Philadelphia, 1878. [On Dr. Toner.]

BLAKE, JOHN B. Dental history and the Smithsonian Institution. _Journal
of the American College of Dentists_ (1961), vol. 28, pp. 125-127.

---- _Public health in the town of Boston, 1630-1822._ Cambridge, Mass.:
Harvard University Press, 1959.

[BRAISTED, WILLIAM C.] The biography of Dr. Beyer. Page 94 in
_Dictionary of American medical biography_, by HOWARD A. KELLY and
WALTER L. BURRAGE; NEW YORK: D. Appleton and Co., 1928.

CLARK, LEILA F. The library of the Smithsonian Institution. _Science_
(1946), vol. 104, p. 143.

COLEMAN, LAURENCE VAIL. _The museum in America: A critical study._ 3
vols. Baltimore: Waverly Press, 1939. [Printed for the American
Association of Museums, Washington, D.C.] See vol. 1, pp. 3, 11-12,
32-33, 143-146, 222, 318; vol. 3, p. 471.

DAUKES, S. H. _The medical museum: modern developments, organization and
technical methods based on a new system of visual teaching._ London:
Wellcome Foundation Ltd., 1929.

DODRILL, FOREST D., and others. Pulmonary volvuloplasty under direct
vision using the mechanical heart for a complete bypass of the right
heart in a patient with congenital pulmonary stenosis. _Journal of
Thoracic Surgery_ (1953), vol. 26, pp. 584-595.

---- Temporary mechanical substitution for the left ventricle in man.
_Journal of the American Medical Association_ (1952), vol. 150, pp.

DUNGLISON, ROBLEY. _A dictionary of medical science._ Rev. ed. Pp.
629-630. Philadelphia: Lea, 1874.

EDWARDS, J. J., and EDWARDS, M. J. _Medical museum technology._ London:
Oxford University Press, 1959. [See in particular, pp. 33-62, 142-159.]

FERCHL, FRITZ. Die Moerser der Sammlung Jo Mayer--Wiesbaden; Libri rari
et curiosi der Sammlung Dr. Jo Mayer--Wiesbaden; Bildnisse und Bilder
der Sammlung Jo Mayer--Wiesbaden; Kuriositaeten und Antiquitaeten der
Sammlung Jo Mayer--Wiesbaden; and Glaeser, Majoliken und Faensen der
Sammlung Jo Mayer--Wiesbaden. _Pharmazeutische Zeitung_ (Berlin, 1930),
vol. 75: January 4, no. 2, pp. 19-24; February 15, no. 14, pp. 219-223;
March 8, no. 20, pp. 309-314; April 19, no. 32, pp. 487-489; and June
21, no. 50, pp. 735-740.

FLINT, JAMES M. Classification and arrangement of the materia medica
collection. _Proceedings of the United States National Museum_ (1881),
vol. 4, app. no. 6.

---- Classification of the materia medica collection of the United
States National Museum, and catalogue of specimens. _Proceedings of the
United States National Museum_ (1883), vol. 6, app. 19, pp. 431-475.

---- Directions for collecting information and objects illustrating the
history of medicine. Part S of _Bulletin of the United States National
Museum_ (1905). No. 39.

---- Memoranda for collectors of drugs for the materia medica section of
the National Museum. _Proceedings of the United States National Museum_
(1881), vol. 4, app. 8.

FOLEY, MATTHEW O. Smithsonian Institution devotes much space to hospital
exhibit. _Hospital Management_ (April 1929), pp. 271-287.

GALDSTON, IAGO. Research in the United States. _Ciba Symposia_
(June-July 1946), vol. 8, nos. 3 and 4, p. 366.

GARRISON, FIELDING H. _An introduction to the history of medicine._ 2d
ed. p. 38. Philadelphia: Saunders, 1917.

GEBHARD, BRUNO. From medicine show to health museum. _Ciba Symposia_
(March 1947), vol. 8, no. 12, p. 579.

GOODE, GEORGE BROWN. _The Smithsonian Institution (1846-1896): The
history of its first half century._ Pp. 325-329, 362-363. Washington,

GRIFFENHAGEN, GEORGE. _Pharmacy museums._ Madison, Wis.: American
Institute of the History of Pharmacy, 1956.

---- and HUGHES, CALVIN H. The history of the mechanical heart. _Annual
report of the Board of Regents of the Smithsonian Institution for the
year ended June 30, 1955_ (Washington, 1956), pp. 339-356.

HAMARNEH, SAMI. At the Smithsonian ... exhibits on pharmaceutical dosage
forms. _Journal of the American Pharmaceutical Association_ (1962), new
ser., vol. 2, pp. 478-479.

----For the collector, facts and artifacts. _Pharmacy in History_
(1961), vol. 6, p. 48.

---- Historical and educational exhibits on dentistry at the Smithsonian
Institution. _Journal of the American-Dental Association_ (July 1962),
vol. 65, pp. 111-114.

---- New dental exhibits at the Smithsonian Institution. _Journal of the
American Dental Association_ (May 1963), vol. 66, pp. 676-678.

HAYNES, WILLIAM. Out of alchemy into chemistry. _The Scientific Monthly_
(November 1952), vol. 75, p. 268.

HOLT, L. EMMETT. A sketch of the development of the Rockefeller
Institute for Medical Research. _Science_ (July 6, 1906), new ser., vol.
24, no. 601, p. 1.

HOWELL, WILLIAM H. The American Physiological Society during its first
twenty-five years. Pp. 21-22 [biography of Dr. Beyer] in _History of the
American Physiological Society semicentennial, 1881-1937_; Baltimore,

[KLEIN, ALLEN.] He directs pharmacy exhibits at the Smithsonian
Institution. _Modern Pharmacy_ (July 1941), vol. 25, pp. 20-21.

LAWALL, CHARLES H. Ancient pharmacy on display. _Pacific Drug Review_
(1933), vol. 45, p. 18.

---- _The curious lore of drugs and medicines._ Garden City, N.Y.:
Garden City Publishing Co., Inc., 1927. [See p. 453 on Division of
Medical Sciences' collection.]

LEWTON, FREDERICK L. A national pharmaceutical collection. _Journal of
the American Pharmaceutical Association_ (1919), vol. 8, pp. 45-46.

---- The opportunity for developing historical pharmacy collections at
the National Museum. _Journal of the American Pharmaceutical
Association_ (1917), vol. 6, pp. 259-262.

LONG, ESMOND R. The Army Medical Museum. _Military Medicine_ (May 1963),
vol. 128, pp. 367-369.

MONELL, S. H. "Dental Skiagraphy" (pp. 313-336 in _A system in x-ray
methods and medical uses of light hot-air, vibration and high-frequency
currents_ by Monell; New York: Pelton, 1902).

MURRAY, DAVID. _Museums, their history and their use._ Glasgow:
MacLehose, 1904. [See vol. 1, pp. 13-77.]

turbine, contra-angle handpiece. _Journal of the American Dental
Association_ (September 1953), vol. 47, pp. 324-329.

_Official Catalogue of the Cotton States and International Exposition_:
Atlanta, Georgia, September 18 to December 31, 1895. Atlanta: Claflin
and Mellichamp, 1895. [See p. 204.]

PACKARD, FRANCES R. _History of medicine in the United States._ New
York, 1931. [See vol. 1, pp. 5-6, 37-51, 168-176, 602-607 on Dr. Toner.]

PICKARD, MADGE E. Government and science in the United States:
Historical background. _Journal of the History of Medicine and Allied
Sciences_ (1946), vol. 1, nos. 2 and 3, pp. 265-266, 289, 446-447, 478.

PURTLE, HELEN R. Notes on the Medical Museum of the Armed Forces
Institute of Pathology. _Bulletin of the Medical Library Association_
(1956), vol. 44, no. 3, pp. 300-305.

RATHBUN, RICHARD. _A descriptive account of the building recently
erected for the Departments of Natural History of the United States
National Museum._ (U.S. National Museum Bulletin 80.) Washington, 1913.
[See pp. 7-15.]

RHEES, WILLIAM J. _The Smithsonian Institution; documents relative to
its origin and history, 1835-1899._ 2 vols. (Smithsonian Miscellaneous
Collections: vol. 42, _1835-1881_; vol. 43, _1881-1899_.) Washington,

SHUFELDT, R. W. Suggestions for a national museum of medicine. _Medical
Record_ (March 22, 1919), pp. 4-5. [Also reprinted, 1919, by William
Wood and Co., New York.]

SIGERIST, HENRY E. _Primitive and archaic medicine._ (Vol. 1 of _A
history of medicine_, by Sigerist.) New York: Oxford University Press,
1951. [See pp. 525-531.]

SILVER, EDWIN H. Description of the exhibit on conservation of vision
placed in the United States Museum at Washington, D.C. _The Optical
Journal and Review of Optometry_ (February 3, 1927), vol. 59, no. 5, pp.

[SONNEDECKER, GLENN.] Apothecary shop nears completion. _Journal of the
American Pharmaceutical Association, Practical Pharmacy Edition_ (1946),
vol. 7, pp. 157.

---- Dr. Charles Whitebread, pharmacist and museum curator. _Journal of
the American Pharmaceutical Association, Practical Pharmacy Edition_
(1946), vol. 7, p. 203.

---- Old apothecary shop. _Journal of the American Pharmaceutical
Association, Practical Pharmacy Edition_ (1945), vol. 6, pp. 184-187.

---- Old apothecary shop opened. _Journal of the American Pharmaceutical
Association, Practical Pharmacy Edition_ (1946), vol. 7, p. 427.

TAYLOR, FRANK A. A national museum of science, engineering and industry.
_The Scientific Monthly_ (1946), vol. 63, pp. 359.

---- The background of the Smithsonian's Museum of Engineering and
Industries. _Science_ (1946), vol. 104, no. 2693, pp. 130-132.

Toner Lectures:

   1. J. J. WOODWARD. On the structure of cancerous tumors and the
   mode in which adjacent parts are invaded. No. 266 in _Smithsonian
   Miscellaneous Collections_, vol. 15; Washington, 1878. [Lecture
   given on March 28, 1873.]

   2. C. E. BROWN-SEQUARD. Dual character of the brain. No. 291 in
   _Smithsonian Miscellaneous Collections_, vol. 15; Washington,
   1878. [Lecture given on April 22, 1874.]

   3. J. M. DA COSTA. On strain and over-action of the heart. No.
   279 in _Smithsonian Miscellaneous Collections_, vol. 15;
   Washington, 1878. [Lecture given on May 14, 1874.]

   4. H. C. WOOD. A study of the nature and mechanism of fever. No.
   282 in _Smithsonian Miscellaneous Collections_, vol. 15;
   Washington, 1878. [Lecture given on January 20, 1875.]

   5. WILLIAM W. KEEN. On the surgical complications and sequels of
   the continued fevers. No. 300 in _Smithsonian Miscellaneous
   Collections_, vol. 15; Washington, 1878. [Lecture given on
   February 17, 1876.]

   6. WILLIAM ADAMS. Subcutaneous surgery: Its principles, and its
   recent extension in practice. No. 302 in _Smithsonian
   Miscellaneous Collections_, vol. 15; Washington, 1878. [Lecture
   given on September 13, 1876.]

   7. EDWARD O. SHAKESPEARE. The nature of reparatory inflammation
   in arteries after ligatures, acupressure, and torsion. No. 321 in
   _Smithsonian Miscellaneous Collections_, vol. 16; Washington,
   1880. [Lecture given on June 27, 1878.]

   8. GEORGE E. WARING. Suggestions for the sanitary drainage of
   Washington City. No. 349 in _Smithsonian Miscellaneous
   Collections_, vol. 26; Washington, 1883. [Lecture given on May
   26, 1880.]

   9. CHARLES K. MILLS. Mental over-work and premature disease among
   public and professional men. No. 594 in _Smithsonian
   Miscellaneous Collections_, vol. 34; Washington, 1893. [Lecture
   given on March 19, 1884.]

   10. HARRISON ALLEN. A clinical study of the skull. No. 708 in
   _Smithsonian Miscellaneous Collections_, vol. 34; Washington,
   1893. [Lecture given on May 29, 1889.]

TRUE, WEBSTER P. _The Smithsonian Institution._ (Vol. 1 of the
Smithsonian Scientific Series.) Washington, 1929.

URDANG, GEORGE, and NITARDY, F. W. _The Squibb ancient pharmacy._ New
York, 1940. [Out of print, but remaining catalogs were given to the
Division of Medicine to "be reserved for pharmaceutical educators,
foreign dignitaries, pharmacists of national and international
reputation, and pharmaceutical historians," according to a letter from
Mr. Nitardy in 1945.]

WHITEBREAD, CHARLES. Animal pharmaceuticals of the past and present.
_Journal of the American Pharmaceutical Association_ (1933), vol. 22,
pp. 431-437.

---- An old apothecary shop of 1750. _National Capital Pharmacist_
(September 1946), vol. 8, pp. 11-13, 35.

---- Early American pharmaceutical inventions. _Journal of the American
Pharmaceutical Association_ (1937), vol. 26, pp. 918-928.

---- _Handbook of the health exhibits of the United
States National Museum._ Baltimore: Lord Baltimore Press [1924].

---- Health superstitions. _Journal of the American Pharmaceutical
Association, Practical Pharmacy Edition_ (1942), vol. 3, pp. 268-274.

---- Medicine making as depicted by museum dioramas. _Journal of the
American Pharmaceutical Association_ (January 1936), vol. 25, pp. 40-46.

---- Superstition, credulity and skepticism. _Journal of the American
Pharmaceutical Association_ (1933), vol. 22, pp. 1140-1145.

---- The Indian medical exhibit of the Division of Medicine in the
United States National Museum. Article 10 in vol. 67 of _Proceedings of
the U.S. National Museum_; Washington, 1926.

---- The magic, psychic, ancient Egyptian, Greek, and Roman medical
collections of the Division of Medicine in the United States National
Museum. Article 15 in vol. 65 of _Proceedings of the U.S. National
Museum_; Washington, 1925.

---- The odd origin of medical discoveries. _Journal of the American
Pharmaceutical Association, Practical Pharmacy Edition_ (1943), vol. 4,
p. 321.

---- The United States National Museum pharmaceutical collection, its
aims, problems, and accomplishments. _Journal of the American
Pharmaceutical Association_ (1930), vol. 19, pp. 1125-1126.

WINTERS, S. R. Magic medicine. _Hygeia_ (July 1937), vol. 15, pp.

       *       *       *       *       *


  [1] _Annual Report of the Board of Regents of the Smithsonian
      Institution for the Year 1882_ [hereinafter referred to as the
      _Smithsonian Annual Report_], pp. 101-103; and introductory
      "advertisement" to the lectures published by the Smithsonian
      Institution in its Miscellaneous Collections (see bibliography).

  [2] Dr. J. J. Woodward's lecture explained the progress of medical
      knowledge of morbid growth and cancerous tumors from 1865 to 1872.
      It cautioned that uncertain methods of diagnosis at that time
      allowed charlatans and uneducated practitioners to report cures of
      cancer in instances where nonmalignant growths were "removed by
      their caustic pastes and plasters."

  [3] The two longest intervals were in preparing the last two lectures:
      the ninth in 1884, and the tenth, 1889. Both came after the
      establishment in 1881 of the Section of Materia Medica in the U.S.
      National Museum, to display the development and progress of the
      health professions.

  [4] _Annual Report of the Secretary of the Navy for the year 1883_,
      pp. 190, 614-615.

  [5] For classifying chemical compounds, Dr. Flint relied on the work
      of H. E. Roscoe and C. Schorlemmez, _A Treatise on Chemistry_, 2
      vols. (New York: D. Appleton, 1878-1800.)

  [6] _Annual Report of the Secretary of the Navy for the year 1882_,
      vol. 2, part 2, pp. 100, 228, 656-657. Dr. Flint in his article
      "Report on Pharmacopoeias of All Nations," ibid., pp. 655-680,
      remarks that there were then 19 official pharmacopoeias in the
      world, besides three semiofficial formularies in certain
      localities in Italy. The pharmacopoeias collected represent
      Austria, Belgium, France, Germany, Great Britain, Greece, Holland,
      India, Mexico, Norway, Portugal, Spain, Sweden, Switzerland (two),
      and the United States.

  [7] The _Universal Formulary_, by R. Eglesfeld Griffith, first edited
      in March 1850 (3rd ed. rev. and enlarged by John M. Maisch,
      Philadelphia: Lea, 1874) should not be considered an international
      drug standard. It was mainly concerned with compiling a great
      number of formulas and recipes, methods of preparing and
      administering official and other medicines, and tables on weights
      and measures for utilization by the U.S. practitioners of the

  [8] Other elaborate arrangements were also made to improve and expand
      the Section's activities and services, though some have never
      materialized. For example, a herbarium was suggested from which
      specimens could be obtained for display of the actual drug with
      painted pictures of its plant next to it. Consideration was given
      to displaying enlarged drawings to show the minute structure of
      the specimen for better identification. In addition, an exhibition
      of several 10-liter vessels of the most popular mineral waters was
      planned. The amount of saline substances which analysis had shown
      to be present in each vessel was to be listed in a table to be
      attached to that vessel, or the same amount of minerals was to be
      put in a small bottle beside it. This plan was carried out to the
      best advantage at the Cotton States and International Exposition
      held in 1895 in Atlanta, Georgia.

  [9] HOLT, "A Sketch of the Development of the Rockefeller Institute
      for Medical Research," p. 1. A similar comment was voiced by
      GALDSTON, "Research in the United States," p. 366.

  [10] _Journal of the American Pharmaceutical Association_ (1918), vol.
      7, pp. 376-377, 466.

  [11] Two decades later, Dr. Whitebread designed a panel showing
      photographs of famous medical pioneers of all nationalities. See
      his article, "The Odd Origin of Medical Discoveries," p. 321.

  [12] GEBHARD, "From Medicine Show to Health Museum," p. 579. The
      original plan for this Hall of Health was to feature exhibits on
      public health for popular educational purposes, including an
      illustrated exhibit on hospital care. See FOLEY, "Smithsonian
      Institution Devotes Much Space to Hospital Exhibit," pp. 43-44.

  [13] Lack of space notwithstanding, valuable accessions were added
      about 1930, including a collection of early x-ray tubes and
      personal memorabilia of Drs. William T. G. Morton (1819-1868),
      Crawford W. Long (1815-1878), and William Gorgas (1854-1920).

  [14] D. RILEY MOORE published a series of short reports under the
      title "Committee on Osteopathic Exhibits in the U.S. National
      Museum," in the _Journal of the American Osteopathic Association_
      (1933-1946), vols. 33-46, regarding the exhibit on osteopathy.

  [15] [KLEIN], "He Directs Pharmacy Exhibits at the Smithsonian
      Institution," pp. 20-21.

  [16] Several other journals reported the exhibition with
      illustrations: _Drug Topics_ (July 8, 1946), vol. 90, no. 2, pp.
      2, 79; _National Capital Pharmacist_ (September 1945), vol. 7, p.
      11, and (September 1946), vol. 8, pp. 11-13; and _The Scientific
      Monthly_ (November 1952), vol. 75, p. 268.

  [17] DODRILL, and others, "Temporary Mechanical Substitution for the
      Left Ventricle in Man," pp. 642-644, and "Pulmonary Volvuloplasty
      under Direct Vision using the Mechanical Heart for a Complete
      Bypass of the Right Heart in a Patient with Congenital Pulmonary
      Stenosis," pp. 584-595.

  [18] For the design, expert arrangement of the exhibits, and the
      legends that accompany each exhibit in the Hall of Health, we are
      indebted to Drs. Bruno Gebhard, Richards H. Shryock, Thomas G.
      Hull, James Laster, Walle J. H. Nauta, Leslie W. Knott, Theodore
      Wiprud, and other physicians, dentists, and scholars who have
      offered their advice, assistance, and expert skills.

  [19] TAYLOR, "A National Museum of Science, Engineering and Industry,"
      p. 359.

  [20] NELSON, PELANDER, and KUMPULA, "Hydraulic Turbine, Contra-angle
      Handpiece," pp. 324-329.

  [21] MONELL, "Dental Skiagraphy," pp. 313-336.

       *       *       *       *       *

Paper 43 - Transcriber's Note

Page 277: "the basis of scientific, historical"
             was "the bases of scientific, historical"

       *       *       *       *       *


  PAPER 44



  Victor F. Lenzen and Robert P. Multhauf

                                   GALILEO, HUYGENS, AND NEWTON    304

                                            FIGURE OF THE EARTH    306

                                       EARLY TYPES OF PENDULUMS    309


                             REPSOLD-BESSEL REVERSIBLE PENDULUM    320


                          VON STERNECK AND MENDENHALL PENDULUMS    331

                           ABSOLUTE VALUE OF GRAVITY AT POTSDAM    338

                                 APPLICATION OF GRAVITY SURVEYS    342

                                                        SUMMARY    346

_Victor F. Lenzen and Robert P. Multhauf_


[Illustration: Figure 1.--A STUDY OF THE FIGURE OF THE EARTH WAS one of
the earliest projects of the French Academy of Sciences. In order to
test the effect of the earth's rotation on its gravitational force, the
Academy in 1672 sent Jean Richer to the equatorial island of Cayenne to
compare the rate of a clock which was known to have kept accurate time
in Paris. Richer found that the clock lost 2 minutes and 28 seconds at
Cayenne, indicating a substantial decrease in the force of gravity on
the pendulum. Subsequent pendulum experiments revealed that the period
of a pendulum varied not only with the latitude but also regionally,
under the influence of topographical features such as mountains. It
became clear that the measurement of gravity should be made a part of
the work of the geodetic surveyor.]

    _The history of gravity pendulums dates back to the time of
    Galileo. After the discovery of the variation of the force of
    gravity over the surface of the earth, gravity measurement
    became a major concern of physics and geodesy. This article
    traces the history of the development of instruments for this

    THE AUTHORS: _Victor F. Lenzen is Professor of Physics,
    Emeritus, at the University of California at Berkeley and Robert
    P. Multhauf is Chairman of the Department of Science and
    Technology in the Smithsonian Institution's Museum of History
    and Technology._

The intensity of gravity, or the acceleration of a freely falling body,
is an important physical quantity for the several physical sciences. The
intensity of gravity determines the weight of a standard pound or
kilogram as a standard or unit of force. In physical experiments, the
force on a body may be measured by determining the weight of a known
mass which serves to establish equilibrium against it. Thus, in the
absolute determination of the ampere with a current balance, the force
between two coils carrying current is balanced by the earth's
gravitational force upon a body of determinable mass. The intensity of
gravity enters into determinations of the size of the earth from the
angular velocity of the moon, its distance from the earth, and Newton's
inverse square law of gravitation and the laws of motion. Prediction
of the motion of an artificial satellite requires an accurate knowledge
of gravity for this astronomical problem.

The gravity field of the earth also provides data for a determination of
the figure of the earth, or geoid, but for this problem of geodesy
relative values of gravity are sufficient. If g is the intensity of
gravity at some reference station, and [Delta]g is the difference
between intensities at two stations, the values of gravity in geodetic
calculations enter as ratios ([Delta]g)/g over the surface of the earth.
Gravimetric investigations in conjunction with other forms of
geophysical investigation, such as seismology, furnish data to test
hypotheses concerning the internal structure of the earth.

Whether the intensity of gravity is sought in absolute or relative
measure, the most widely used instrument for its determination since the
creation of classical mechanics has been the pendulum. In recent
decades, there have been invented gravity meters based upon the
principle of the spring, and these instruments have made possible the
rapid determination of relative values of gravity to a high degree of
accuracy. The gravity meter, however, must be calibrated at stations
where the absolute value of gravity has been determined by other means
if absolute values are sought. For absolute determinations of gravity,
the pendulum historically has been the principal instrument employed.
Although alternative methods of determining absolute values of gravity
are now in use, the pendulum retains its value for absolute
determinations, and even retains it for relative determinations, as is
exemplified by the Cambridge Pendulum Apparatus and that of the Dominion
Observatory at Ottawa, Ontario.

The pendulums employed for absolute or relative determinations of
gravity have been of two basic types. The first form of pendulum used as
a physical instrument consisted of a weight suspended by a fiber, cord,
or fine wire, the upper end of which was attached to a fixed support.
Such a pendulum may be called a "simple" pendulum; the enclosure of the
word simple by quotation marks is to indicate that such a pendulum is an
approximation to a simple, or mathematical pendulum, a conceptual object
which consists of a mass-point suspended by a weightless inextensible
cord. If l is the length of the simple pendulum, the time of swing
(half-period in the sense of physics) for vibrations of infinitely small
amplitude, as derived from Newton's laws of motion and the hypothesis
that weight is proportional to mass, is T = [pi][sqrt](l/g).

The second form of pendulum is the compound, or physical, pendulum. It
consists of an extended solid body which vibrates about a fixed axis
under the action of the weight of the body. A compound pendulum may be
constituted to oscillate about one axis only, in which case it is
nonreversible and applicable only for relative measurements. Or a
compound pendulum may be constituted to oscillate about two axes, in
which case it is reversible (or "convertible") and may be used to
determine absolute values of gravity. Capt. Henry Kater, F.R.S., during
the years 1817-1818 was the first to design, construct, and use a
compound pendulum for the absolute determination of gravity. He
constructed a convertible pendulum with two knife edges and with it
determined the absolute value of gravity at the house of Henry Browne,
F.R.S., in Portland Place, London. He then constructed a similar
compound pendulum with only one knife edge, and swung it to determine
relative values of gravity at a number of stations in the British Isles.
The 19th century witnessed the development of the theory and practice of
observations with pendulums for the determination of absolute and
relative values of gravity.

Galileo, Huygens, and Newton

The pendulum has been both an objective and an instrument of physical
investigation since the foundations of classical mechanics were
fashioned in the 17th century.[1] It is tradition that the youthful
Galileo discovered that the period of oscillation of a pendulum is
constant by observations of the swings of the great lamp suspended from
the ceiling in the cathedral of Pisa.[2] The lamp was only a rough
approximation to a simple pendulum, but Galileo later performed more
accurate experiments with a "simple" pendulum which consisted of a heavy
ball suspended by a cord. In an experiment designed to confirm his laws
of falling bodies, Galileo lifted the ball to the level of a given
altitude and released it. The ball ascended to the same level on the
other side of the vertical equilibrium position and thereby confirmed a
prediction from the laws. Galileo also discovered that the period of
vibration of a "simple" pendulum varies as the square root of its
length, a result which is expressed by the formula for the time of
swing of the ideal simple pendulum. He also used a pendulum to measure
lapse of time, and he designed a pendulum clock. Galileo's experimental
results are important historically, but have required correction in the
light of subsequent measurements of greater precision.

Mersenne in 1644 made the first determination of the length of the
seconds pendulum,[3] that is, the length of a simple pendulum that beats
seconds (half-period in the sense of physics). Subsequently, he proposed
the problem to determine the length of the simple pendulum equivalent in
period to a given compound pendulum. This problem was solved by Huygens,
who in his famous work _Horologium oscillatorium_ ... (1673) set forth
the theory of the compound pendulum.[4]

Huygens derived a theorem which has provided the basis for the
employment of the reversible compound pendulum for the absolute
determination of the intensity of gravity. The theorem is that a given
compound pendulum possesses conjugate points on opposite sides of the
center of gravity; about these points, the periods of oscillation are
the same. For each of these points as center of suspension the other
point is the center of oscillation, and the distance between them is the
length of the equivalent simple pendulum. Earlier, in 1657, Huygens
independently had invented and patented the pendulum clock, which
rapidly came into use for the measurement of time. Huygens also created
the theory of centripetal force which made it possible to calculate the
effect of the rotation of the earth upon the observed value of gravity.

The theory of the gravity field of the earth was founded upon the laws
of motion and the law of gravitation by Isaac Newton in his famous
_Principia_ (1687). It follows from the Newtonian theory of gravitation
that the acceleration of gravity as determined on the surface of the
earth is the resultant of two factors: the principal factor is the
gravitational attraction of the earth upon bodies, and the subsidiary
factor is the effect of the rotation of the earth. A body at rest on the
surface of the earth requires some of the gravitational attraction for
the centripetal acceleration of the body as it is carried in a circle
with constant speed by the rotation of the earth about its axis. If the
rotating earth is used as a frame of reference, the effect of the
rotation is expressed as a centrifugal force which acts to diminish the
observed intensity of gravity.

       *       *       *       *       *


ABSOLUTE GRAVITY: the value of the acceleration of gravity, also
expressed by the length of the seconds pendulum.

RELATIVE GRAVITY: the value of the acceleration of gravity relative to
the value at some standard point.

SIMPLE PENDULUM: see theoretical pendulum.

THEORETICAL PENDULUM: a heavy bob (point-mass) at the end of a
weightless rod.

SECONDS PENDULUM: a theoretical or simple pendulum of such length that
its time of swing (half-period) is one second. (This length is about one

GRAVITY PENDULUM: a precisely made pendulum used for the measurement of

COMPOUND PENDULUM: a pendulum in which the supporting rod is not
weightless; in other words, any actual pendulum.

CONVERTIBLE PENDULUM: a compound pendulum having knife edges at
different distances from the center of gravity. Huygens demonstrated
(1673) that if such a pendulum were to swing with equal periods from
either knife edge, the distance between those knife edges would be equal
to the length of a theoretical or simple pendulum of the same period.

REVERSIBLE PENDULUM: a convertible pendulum which is also symmetrical in

INVARIABLE PENDULUM: a compound pendulum with only one knife edge, used
for relative measurement of gravity.

       *       *       *       *       *

From Newton's laws of motion and the hypothesis that weight is
proportional to mass, the formula for the half-period of a simple
pendulum is given by T = [pi][sqrt](l/g). If a simple pendulum beats
seconds, 1 = [pi][sqrt]([lambda]/g), where [lambda] is the length of the
seconds pendulum. From T = [pi][sqrt](l/g) and 1 = [pi][sqrt]([lambda]/g),
it follows that [lambda] = l/T^{2}. Then g = [pi]^{2}[lambda]. Thus, the
intensity of gravity can be expressed in terms of the length of the
seconds pendulum, as well as by the acceleration of a freely falling
body. During the 19th century, gravity usually was expressed in terms of
the length of the seconds pendulum, but present practice is to express
gravity in terms of g, for which the unit is the gal, or one centimeter
per second per second.

[Illustration: Figure 2.--THIS DRAWING, FROM RICHER'S _Observations
astronomiques et physiques faites en l'isle de Caienne_ (Paris, 1679),
shows most of the astronomical instruments used by Richer, namely, one
of the two pendulum clocks made by Thuret, the 20-foot and the 5-foot
telescopes and the large quadrant. The figure may be intended as a
portrait of Richer. This drawing was done by Sebastian Le Clerc, a young
illustrator who made many illustrations of the early work of the Paris

Figure of the Earth

A principal contribution of the pendulum as a physical instrument has
been the determination of the figure of the earth.[5] That the earth
is spherical in form was accepted doctrine among the ancient Greeks.
Pythagoras is said to have been the first to describe the earth as a
sphere, and this view was adopted by Eudoxus and Aristotle.

The Alexandrian scientist Eratosthenes made the first estimate of the
diameter and circumference of a supposedly spherical earth by an
astronomical-geodetic method. He measured the angle between the
directions of the rays of the sun at Alexandria and Syene (Aswan),
Egypt, and estimated the distance between these places from the length
of time required by a caravan of camels to travel between them. From the
central angle corresponding to the arc on the surface, he calculated the
radius and hence the circumference of the earth. A second measurement
was undertaken by Posidonius, who measured the altitudes of stars at
Alexandria and Rhodes and estimated the distance between them from the
time required to sail from one place to the other.

With the decline of classical antiquity, the doctrine of the spherical
shape of the earth was lost, and only one investigation, that by the
Arabs under Calif Al-Mamun in A.D. 827, is recorded until the 16th
century. In 1525, the French mathematician Fernel measured the length of
a degree of latitude between Paris and Amiens by the revolutions of the
wheels of his carriage, the circumference of which he had determined. In
England, Norwood in 1635 measured the length of an arc between London
and York with a chain. An important forward step in geodesy was the
measurement of distance by triangulation, first by Tycho Brahe, in
Denmark, and later, in 1615, by Willebrord Snell, in Holland.

Of historic importance, was the use of telescopes in the triangulation
for the measurement of a degree of arc by the Abbe Jean Picard in
1669.[6] He had been commissioned by the newly established Academy of
Sciences to measure an arc corresponding to an angle of 1 deg., 22', 55"
of the meridian between Amiens and Malvoisine, near Paris. Picard proposed
to the Academy the measurement of the meridian of Paris through all of
France, and this project was supported by Colbert, who obtained the
approval of the King. In 1684, Giovanni-Domenico Cassini and De la Hire
commenced a trigonometrical measure of an arc south of Paris;
subsequently, Jacques Cassini, the son of Giovanni-Domenico, added the
arc to the north of Paris. The project was completed in 1718. The length
of a degree of arc south of Paris was found to be greater than the
length north of Paris. From the difference, 57,097 toises[7] minus
56,960 toises, it was concluded that the polar diameter of the earth is
larger than the equatorial diameter, i.e., that the earth is a prolate
spheroid (fig. 3).

[Illustration: Figure 3.--MEASUREMENTS OF THE LENGTH of a degree of
latitude which were completed in different parts of France in 1669 and
1718 gave differing results which suggested that the shape of the earth
is not a sphere but a prolate spheroid (1). But Richer's pendulum
observation of 1672, as explained by Huygens and Newton, indicated that
its shape is that of an oblate spheroid (2). The disagreement is
reflected in this drawing. In the 1730's it was resolved in favor of the
latter view by two French geodetic expeditions for the measurement of
degrees of latitude in the equatorial and polar regions (Ecuador--then
part of Peru--and Lapland).]

Meanwhile, Richer in 1672 had been sent to Cayenne, French Guiana, to
make astronomical observations and to measure the length of the seconds
pendulum.[8] He took with him a pendulum clock which had been adjusted
to keep accurate time in Paris. At Cayenne, however, Richer found that
the clock was retarded by 2 minutes and 28 seconds per day (fig. 1). He
also fitted up a "simple" pendulum to vibrate in seconds and measured
the length of this seconds pendulum several times every week for 10
months. Upon his return to Paris, he found that the length of the
"simple" pendulum which beat seconds at Cayenne was 1-1/4 Paris lines[9]
shorter than the length of the seconds pendulum at Paris. Huygens
explained the reduction in the length of the seconds pendulum--and,
therefore, the lesser intensity of gravity at the equator with respect
to the value at Paris--in terms of his theory of centripetal force as
applied to the rotation of the earth and pendulum.[10]

A more complete theory was given by Newton in the _Principia_.[11]
Newton showed that if the earth is assumed to be a homogeneous, mutually
gravitating fluid globe, its rotation will result in a bulging at the
equator. The earth will then have the form of an oblate spheroid, and
the intensity of gravity as a form of universal gravitation will vary
with position on the surface of the earth. Newton took into account
gravitational attraction and centrifugal action, and he calculated the
ratio of the axes of the spheroid to be 230:229. He calculated and
prepared a table of the lengths of a degree of latitude and of the
seconds pendulum for every 5 deg. of latitude from the equator to the
pole. A discrepancy between his predicted length of the seconds pendulum
at the equator and Richer's measured length was explained by Newton in
terms of the expansion of the scale with higher temperatures near the

Newton's theory that the earth is an oblate spheroid was confirmed by
the measurements of Richer, but was rejected by the Paris Academy of
Sciences, for it contradicted the results of the Cassinis, father and
son, whose measurements of arcs to the south and north of Paris had led
to the conclusion that the earth is a prolate spheroid. Thus, a
controversy arose between the English scientists and the Paris Academy.
The conflict was finally resolved by the results of expeditions sent by
the Academy to Peru and Sweden. The first expedition, under Bouguer, La
Condamine, and Godin in 1735, went to a region in Peru, and, with the
help of the Spaniard Ullo, measured a meridian arc of about 3 deg. 7'
near Quito, now in Ecuador.[12] The second expedition, with Maupertuis
and Clairaut in 1736, went to Lapland within the Arctic Circle and
measured an arc of about 1 deg. in length.[13] The northern arc of 1 deg.
was found to be longer than the Peruvian arc of 1 deg., and thus it was
confirmed that the earth is an oblate spheroid, that is, flattened at
the poles, as predicted by the theory of Newton.

[Illustration: Figure 4.--THE DIRECT USE OF A CLOCK to measure the force
of gravity was found to be limited in accuracy by the necessary
mechanical connection of the pendulum to the clock, and by the
unavoidable difference between the characteristics of a clock pendulum
and those of a theoretical (usually called "simple") pendulum, in which
the mass is concentrated in the bob, and the supporting rod is

After 1735, the clock was used only to time the swing of a detached
pendulum, by the method of "coincidences." In this method, invented by
J. J. Mairan, the length of the detached pendulum is first accurately
measured, and the clock is corrected by astronomical observation. The
detached pendulum is then swung before the clock pendulum as shown here.
The two pendulums swing more or less out of phase, coming into
coincidence each time one has gained a vibration. By counting the number
of coincidences over several hours, the period of the detached pendulum
can be very accurately determined. The length and period of the detached
pendulum are the data required for the calculation of the force of

The period from Eratosthenes to Picard has been called the spherical era
of geodesy; the period from Picard to the end of the 19th century has
been called the ellipsoidal period. During the latter period the earth
was conceived to be an ellipsoid, and the determination of its
ellipticity, that is, the difference of equatorial radius and polar
radius divided by the equatorial radius, became an important geodetic
problem. A significant contribution to the solution of this problem was
made by determinations of gravity by the pendulum.

An epoch-making work during the ellipsoidal era of geodesy was
Clairaut's treatise, _Theorie de la figure de la terre_.[14] On the
hypothesis that the earth is a spheroid of equilibrium, that is, such
that a layer of water would spread all over it, and that the internal
density varies so that layers of equal density are coaxial spheroids,
Clairaut derived a historic theorem: If [gamma]_{E}, [gamma]_{P} are the
values of gravity at the equator and pole, respectively, and c the
centrifugal force at the equator divided by [gamma]_{E}, then the
ellipticity [alpha] = (5/2)c - ([gamma]_{P} - [gamma]_{E})/[gamma]_{E}.

Laplace showed that the surfaces of equal density might have any nearly
spherical form, and Stokes showed that it is unnecessary to assume any
law of density as long as the external surface is a spheroid of
equilibrium.[15] It follows from Clairaut's theorem that if the earth is
an oblate spheroid, its ellipticity can be determined from relative
values of gravity and the absolute value at the equator involved in c.
Observations with nonreversible, invariable compound pendulums have
contributed to the application of Clairaut's theorem in its original and
contemporary extended form for the determination of the figure and
gravity field of the earth.

Early Types of Pendulums

The pendulum employed in observations of gravity prior to the 19th
century usually consisted of a small weight suspended by a filament
(figs. 4-6). The pioneer experimenters with "simple" pendulums changed
the length of the suspension until the pendulum beat seconds. Picard in
1669 determined the length of the seconds pendulum at Paris with a
"simple" pendulum which consisted of a copper ball an inch in diameter
suspended by a fiber of pite from jaws (pite was a preparation of the
leaf of a species of aloe and was not affected appreciably by moisture).

A celebrated set of experiments with a "simple" pendulum was conducted
by Bouguer[16] in 1737 in the Andes, as part of the expedition to
measure the Peruvian arc. The bob of the pendulum was a double
truncated cone, and the length was measured from the jaw suspension to
the center of oscillation of the thread and bob. Bouguer allowed for
change of length of his measuring rod with temperature and also for the
buoyancy of the air. He determined the time of swing by an elementary
form of the method of coincidences. The thread of the pendulum was swung
in front of a scale and Bouguer observed how long it took the pendulum
to lose a number of vibrations on the seconds clock. For this purpose,
he noted the time when the beat of the clock was heard and,
simultaneously, the thread moved past the center of the scale. A
historic aspect of Bouguer's method was that he employed an "invariable"
pendulum, that is, the length was maintained the same at the various
stations of observation, a procedure that has been described as having
been invented by Bouguer.

Since T = [pi][sqrt](l/g), it follows that (T_{1})^{2}/(T_{2})^{2} =
g_{2}/g_{1}. Thus, if the absolute value of gravity is known at one
station, the value at any other station can be determined from the ratio
of the squares of times of swing of an invariable pendulum at the two
stations. From the above equation, if T_{1} is the time of swing at a
station where the intensity of gravity is g, and T_{2} is the time at a
station where the intensity is g + [Delta]g, then [Delta]g/g =
(T_{1})^{2}/(T_{2})^{2} - 1.

Bouguer's investigations with his invariable pendulum yielded methods
for the determination of the internal structure of the earth. On the
Peruvian expedition, he determined the length of the seconds pendulum at
three stations, including one at Quito, at varying distances above sea
level. If values of gravity at stations of different elevation are to be
compared, they must be reduced to the same level, usually to sea level.
Since gravity decreases with height above sea level in accordance with
the law of gravitation, a free-air reduction must be applied to values
of gravity determined above the level of the sea. Bouguer originated the
additional reduction for the increase in gravity on a mountain or
plateau caused by the attraction of the matter in a plate. From the
relative values of gravity at elevated stations in Peru and at sea
level, Bouguer calculated that the mean density of the earth was 4.7
times greater than that of the _cordilleras_.[17] For greater accuracy
in the study of the internal structure of the earth, in the 19th century
the Bouguer plate reduction came to be supplemented by corrections for
irregularities of terrain and by different types of isostatic reduction.

La Condamine, who like Bouguer was a member of the Peruvian expedition,
conducted his own pendulum experiments (fig. 4). He experimented in 1735
at Santo Domingo en route to South America,[18] then at various stations
in South America, and again at Paris upon his return to France. His
pendulum consisted of a copper ball suspended by a thread of pite. For
experimentation the length initially was about 12 feet, and the time of
swing 2 seconds, but then the length was reduced to about 3 feet with
time of swing 1 second. Earlier, when it was believed that gravity was
constant over the earth, Picard and others had proposed that the length
of the seconds pendulum be chosen as the standard. La Condamine in 1747
revived the proposal in the form that the length of the seconds pendulum
at the equator be adopted as the standard of length. Subsequently, he
investigated the expansion of a toise of iron from the variation in the
period of his pendulum. In 1755, he observed the pendulum at Rome with
Boscovich. La Condamine's pendulum was used by other observers and
finally was lost at sea on an expedition around the world. The knowledge
of the pendulum acquired by the end of the 18th century was summarized
in 1785 in a memoir by Boscovich.[19]

the length of the pendulum devised on the basis of a series of
preliminary experiments by C. M. de la Condamine who, in the course of
the French geodetic expedition to Peru in 1735, devoted a 3-month
sojourn on the island of Santo Domingo to pendulum observations by
Mairan's Method. In this arrangement, shown here, a vertical rod of
ironwood is used both as the scale and as the support for the apparatus,
having at its top the brass pendulum support (A) and, below, a
horizontal mirror (O) which serves to align the apparatus vertically
through visual observation of the reflection of the pointer projecting
from A. The pendulum, about 37 inches long, consists of a thread of pite
(a humidity-resistant, natural fiber) and a copper ball of about 6
ounces. Its exact length is determined by adjusting the micrometer (S)
so that the ball nearly touches the mirror. It will be noted that the
clock pendulum would be obscured by the scale. La Condamine seems to
have determined the times of coincidence by visual observation of the
occasions on which "the pendulums swing parallel." (Portion of plate 1,
_Memoires publies par la Societe francaise de Physique_, vol. 4.)]

[Illustration: Figure 6.--THE RESULT of early pendulum experiments was
often expressed in terms of the length of a pendulum which would have a
period of one second and was called "the seconds pendulum." In 1792, J.
C. Borda and J. D. Cassini determined the length of the seconds pendulum
at Paris with this apparatus. The pendulum consists of a platinum ball
about 1-1/2 inches in diameter, suspended by a fine iron wire. The
length, about 12 feet, was such that its period would be nearly twice as
long as that of the pendulum of the clock (A). The interval between
coincidences was determined by observing, through the telescope at the
left, the times when the two pendulums emerge together from behind the
screen (M). The exact length of the pendulum was measured by a platinum
scale (not shown) equipped with a vernier and an auxiliary copper scale
for temperature correction.

When, at the end of the 18th century, the French revolutionary
government established the metric system of weights and measures, the
length of the seconds pendulum at Paris was considered, but not adopted,
as the unit of length. (Plate 2, _Memoires publies par la Societe
francaise de Physique_, vol. 4.)]

The practice with the "simple" pendulum on the part of Picard, Bouguer,
La Condamine and others in France culminated in the work of Borda and
Cassini in 1792 at the observatory in Paris[20] (fig. 6). The
experiments were undertaken to determine whether or not the length of
the seconds pendulum should be adopted as the standard of length by the
new government of France. The bob consisted of a platinum ball 16-1/6
Paris lines in diameter, and 9,911 grains (slightly more than 17 ounces)
in weight. The bob was held to a brass cup covering about one-fifth of
its surface by the interposition of a small quantity of grease. The cup
with ball was hung by a fine iron wire about 12 Paris feet long. The
upper end of the wire was attached to a cylinder which was part of a
wedge-shaped knife edge, on the upper surface of which was a stem on
which a small adjustable weight was held by a screw thread. The knife
edge rested on a steel plate. The weight on the knife-edge apparatus was
adjusted so that the apparatus would vibrate with the same period as the
pendulum. Thus, the mass of the suspending apparatus could be neglected
in the theory of motion of the pendulum about the knife edge.

[Illustration: Figure 7.--RESULTS OF EXPERIMENTS in the determination of
the length of the seconds pendulum at Koenigsberg by a new method were
reported by F. W. Bessel in 1826 and published in 1828. With this
apparatus, he obtained two sets of data from the same pendulum, by using
two different points of suspension. The pendulum was about 10 feet long.
The distance between the two points of suspension (_a_ and _b_) was 1
toise (about six feet). A micrometric balance (_c_) below the bob was
used to determine the increase in length due to the weight of the bob.
He projected the image of the clock pendulum (not shown) onto the
gravity pendulum by means of a lens, thus placing the clock some
distance away and eliminating the disturbing effect of its motion.
(Portion of plate 6, _Memoires publies par la Societe francaise de
Physique_, vol. 4.)]

In the earlier suspension from jaws there was uncertainty as to the
point about which the pendulum oscillated. Borda and Cassini hung their
pendulum in front of a seconds clock and determined the time of swing by
the method of coincidences. The times on the clock were observed when
the clock gained or lost one complete vibration (two swings) on the
pendulum. Suppose that the wire pendulum makes n swings while the clock
makes 2n + 2. If the clock beats seconds exactly, the time of one
complete vibration is 2 seconds, and the time of swing of the wire
pendulum is T = (2n + 2)/n = 2(1 + 1/n). An error in the time caused by
uncertainty in determining the coincidence of clock and wire pendulum is
reduced by employing a long interval of observation 2n. The whole
apparatus was enclosed in a box, in order to exclude disturbances from
currents of air. Corrections were made for buoyancy, for amplitude of
swing and for variations in length of the wire with temperature. The
final result was that the length of the seconds pendulum at the
observatory in Paris was determined to be 440.5593 Paris lines, or
993.53 mm., reduced to sea level 993.85 mm. Some years later the methods
of Borda were used by other French investigators, among whom was Biot
who used the platinum ball of Borda suspended by a copper wire 60 cm.

Another historic "simple" pendulum was the one swung by Bessel (fig. 7)
for the determination of gravity at Koenigsberg 1825-1827.[21] The
pendulum consisted of a ball of brass, copper, or ivory that was
suspended by a fine wire, the upper end of which was wrapped and
unwrapped on a horizontal cylinder as support. The pendulum was swung
first from one point and then from another, exactly a "toise de
Peru"[22] higher up, the bob being at the same level in each case (fig.
7). Bessel found the period of vibration of the pendulum by the method
of coincidences; and in order to avoid disturbances from the comparison
clock, it was placed at some distance from the pendulum under

Bessel's experiments were significant in view of the care with which he
determined the corrections. He corrected for the stiffness of the wire
and for the lack of rigidity of connection between the bob and wire. The
necessity for the latter correction had been pointed out by Laplace, who
showed that through the circumstance that the pull of the wire is now on
one side and now on the other side of the center of gravity, the bob
acquires angular momentum about its center of gravity, which cannot be
accounted for if the line of the wire, and therefore the force that it
exerts, always passed through the center. In addition to a correction
for buoyancy of the air considered by his predecessors, Bessel also took
account of the inertia of the air set in motion by the pendulum.

[Illustration: Figure 8.--MODE OF SUSPENSION of Bessel's pendulum is
shown here. The iron wire is supported by the thumbscrew and clamp at
the left, but passes over a pin at the center, which is actually the
upper terminal of the pendulum. Bessel found this "cylinder of
unrolling" superior to the clamps and knife edges of earlier pendulums.
The counterweight at the right is part of a system for supporting the
scale in such a way that it is not elongated by its own weight.

With this apparatus, Bessel determined the ratio of the lengths of the
two pendulums and their times of vibration. From this the length of the
seconds pendulum was calculated. His method eliminated the need to take
into account such sources of inaccuracy as flexure of the pendulum wire
and imperfections in the shape of the bob. (Portion of plate 7,
_Memoires publies par la Societe francaise de Physique_, vol. 4.)]

[Illustration: Figure 9.--FRIEDRICH WILHELM BESSEL (1784-1846), German
mathematician and astronomer. He became the first superintendent of the
Prussian observatory established at Koenigsberg in 1810, and remained
there during the remainder of his life. So important were his many
contributions to precise measurement and calculation in astronomy that
he is often considered the founder of the "modern" age in that science.
This characteristic also shows in his venture into geodesy, 1826-1830,
one product of which was the pendulum experiment reported in this

The latter effect had been discovered by Du Buat in 1786,[23] but his
work was unknown to Bessel. The length of the seconds pendulum at
Koenigsberg, reduced to sea level, was found by Bessel to be 440.8179
lines. In 1835, Bessel determined the intensity of gravity at a site in
Berlin where observations later were conducted in the Imperial Office of
Weights and Measures by Charles S. Peirce of the U.S. Coast Survey.

Kater's Convertible and Invariable Pendulums

The systematic survey of the gravity field of the earth was given a
great impetus by the contributions of Capt. Henry Kater, F.R.S. In 1817,
he designed, constructed, and applied a convertible compound pendulum
for the absolute determination of gravity at the house of Henry Browne,
F.R.S., in Portland Place, London.[24] Kater's convertible pendulum
(fig. 11) consisted of a brass rod to which were attached a flat
circular bob of brass and two adjustable weights, the smaller of which
was adjusted by a screw. The convertibility of the pendulum was
constituted by the provision of two knife edges turned inwards on
opposite sides of the center of gravity. The pendulum was swung on each
knife edge, and the adjustable weights were moved until the times of
swing were the same about each knife edge. When the times were judged to
be the same, the distance between the knife edges was inferred to be the
length of the equivalent simple pendulum, in accordance with Huygens'
theorem on conjugate points of a compound pendulum. Kater determined the
time of swing by the method of coincidences (fig. 12). He corrected for
the buoyancy of the air. The final value of the length of the seconds
pendulum at Browne's house in London, reduced to sea level, was
determined to be 39.13929 inches.

The convertible compound pendulum had been conceived prior to its
realization by Kater. In 1792, on the occasion of the proposal in Paris
to establish the standard of length as the length of the seconds
pendulum, Baron de Prony had proposed the employment of a compound
pendulum with three axes of oscillation.[25] In 1800, he proposed the
convertible compound pendulum with knife edges about which the pendulum
could complete swings in equal times. De Prony's proposals were not
accepted and his papers remained unpublished until 1889, at which time
they were discovered by Defforges. The French decision was to experiment
with the ball pendulum, and the determination of the length of the
seconds pendulum was carried out by Borda and Cassini by methods
previously described. Bohnenberger in his _Astronomie_ (1811),[26] made
the proposal to employ a convertible pendulum for the absolute
determination of gravity; thus, he has received credit for priority in
publication. Capt. Kater independently conceived of the convertible
pendulum and was the first to design, construct, and swing one.

[Illustration: Figure 10.--HENRY KATER (1777-1835), English army officer
and physicist. His scientific career began during his military service
in India, where he assisted in the "great trigonometrical survey."
Returned to England because of bad health, and retired in 1814, he
pioneered (1818) in the development of the convertible pendulum as an
alternative to the approximation of the "simple" pendulum for the
measurement of the "seconds pendulum." Kater's convertible pendulum and
the invariable pendulum introduced by him in 1819 were the basis of
English pendulum work. (_Photo courtesy National Portrait Gallery,

After his observations with the convertible pendulum, Capt. Kater
designed an invariable compound pendulum with a single knife edge but
otherwise similar in external form to the convertible pendulum[27] (fig.
13). Thirteen of these Kater invariable pendulums have been reported as
constructed and swung at stations throughout the world.[28] Kater
himself swung an invariable pendulum at a station in London and at
various other stations in the British Isles. Capt. Edward Sabine,
between 1820 and 1825, made voyages and swung Kater invariable pendulums
at stations from the West Indies to Greenland and Spitzbergen.[29] In
1820, Kater swung a Kater invariable pendulum at London and then sent it
to Goldingham, who swung it in 1821 at Madras, India.[30] Also in 1820,
Kater supplied an invariable pendulum to Hall, who swung it at London
and then made observations near the equator and in the Southern
Hemisphere, and at London again in 1823.[31] The same pendulum, after
its knives were reground, was delivered to Adm. Luetke of Russia, who
observed gravity with it on a trip around the world between 1826 and

[Illustration: Figure 11.--THE ATTEMPT TO APPROXIMATE the simple
(theoretical) pendulum in gravity experiments ended in 1817-18 when
Henry Kater invented the compound convertible pendulum, from which the
equivalent simple pendulum could be obtained according to the method of
Huygens (see text, p. 314). Developed in connection with a project to
fix the standard of English measure, Kater's pendulum was called
"compound" because it was a solid bar rather than the fine wire or
string with which earlier experimenters had tried to approximate a
"weightless" rod. It was called convertible because it is alternately
swung from the two knife edges (_a_ and _b_) at opposite ends. The
weights (_f_ and _g_) are adjusted so that the period of the pendulum is
the same from either knife edge. The distance between the two knife
edges is then equal to the length of the equivalent simple pendulum.]

[Illustration: Figure 12.--THE KATER CONVERTIBLE PENDULUM in use is
placed before a clock, whose pendulum bob is directly behind the
extended "tail" of the Kater pendulum. A white spot is painted on the
center of the bob of the clock pendulum. The observing telescope, left,
has a diaphragm with a vertical slit of such width that its view is just
filled by the tail of the Kater pendulum when it is at rest. When the
two pendulums are swinging, the white spot on the clock pendulum can be
seen on each swing except that in which the two pendulums are in
coincidence; thus, the coincidences are determined. (Portion of plate 5,
_Memoires publies par la Societe francaise de Physique_, vol. 4.)]

[Illustration: Figure 13.--THIS DRAWING ACCOMPANIED John Goldingham's
report on the work done in India with Kater's invariable pendulum. The
value of gravity obtained, directly or indirectly, in terms of the
simple pendulum, is called "absolute." Once absolute values of gravity
were established at a number of stations, it became possible to use the
much simpler "relative" method for the measurement of gravity at new
stations. Because it has only one knife edge, and does not involve the
adjustments of the convertible pendulum, this one is called
"invariable." In use, it is first swung at a station where the absolute
value of gravity has been established, and this period is then compared
with its period at one or more new stations. Kater developed an
invariable pendulum in 1819, which was used in England and in Madras,
India, in 1821.]

While the British were engaged in swinging the Kater invariable
pendulums to determine relative values of the length of the seconds
pendulum, or of gravity, the French also sent out expeditions. Capt. de
Freycinet made initial observations at Paris with three invariable brass
pendulums and one wooden one, and then carried out observations at Rio
de Janeiro, Cape of Good Hope, Ile de France, Rawak (near New Guinea),
Guam, Maui, and various other places.[33] A similar expedition was
conducted in 1822-1825 by Captain Duperry.[34]

During the years from 1827 to 1840, various types of pendulum were
constructed and swung by Francis Baily, a member of the Royal
Astronomical Society, who reported in 1832 on experiments in which no
less than 41 different pendulums were swung in vacuo, and their
characteristics determined.[35] In 1836, Baily undertook to advise the
American Lt. Charles Wilkes, who was to head the United States
Exploring Expedition of 1838-1842, on the procurement of pendulums for
this voyage. Wilkes ordered from the London instrument maker, Thomas
Jones, two unusual pendulums, which Wilkes described as "those
considered the best form by Mr. Baily for traveling pendulums," and
which Baily, himself, described as "precisely the same as the two
invariable pendulums belonging to this [Royal Astronomical] Society,"
except for the location of the knife edges.

[Illustration: Figure 14.--VACUUM CHAMBER FOR USE with the Kater
pendulum. Of a number of extraneous effects which tend to disturb the
accuracy of pendulum observations the most important is air resistance.
Experiments reported by the Greenwich (England) observatory in 1829 led
to the development of a vacuum chamber within which the pendulum was

The unusual feature of these pendulums was in their symmetry of mass as
well as of form. They were made of bars, of iron in one case, and of
brass in the other, and each had two knife edges at opposite ends
equidistant from the center. Thus, although they resembled reversible
pendulums, their symmetry of mass prevented their use as such, and they
were rather equivalent to four separate invariable pendulums.[36]

Wilkes was taught the use of the pendulum by Baily, and conducted
experiments at Baily's house, where the latter had carried out the work
reported on in 1832. The subsequent experiments made on the U.S.
Exploring Expedition were under the charge of Wilkes, himself, who made
observations on 11 separate occasions, beginning with that in London
(1836) and followed by others in New York, Washington, D.C., Rio de
Janeiro, Sydney, Honolulu, "Pendulum Peak" (Mauna Loa), Mount Kanoha,
Nesqually (Oregon Territory), and, finally, two more times in
Washington, D.C. (1841 and 1845).

Wilkes' results were communicated to Baily, who appears to have found
the work defective because of insufficient attention to the maintenance
of temperature constancy and to certain alterations made to the
pendulums.[37] The results were also to have been included in the
publications of the Expedition, but were part of the unpublished 24th
volume. Fortunately they still exist, in what appears to be a printer's

The Kater invariable pendulums were used to investigate the internal
constitution of the earth. Airy sought to determine the density of the
earth by observing the times of swing of pendulums at the top and bottom
of a mine. The first experiments were made in 1826 at the Dolcoath
copper mine in Cornwall, and failed when the pendulum fell to the
bottom. In 1854, the experiments were again undertaken in the Harton
coalpit, near Sunderland.[39] Gravity at the surface was greater than
below, because of the attraction of a shell equal to the depth of the
pit. From the density of the shell as determined from specimens of rock,
Airy found the density of the earth to be 6-1/2 times greater than that
of water. T. C. Mendenhall, in 1880, used a Kater convertible pendulum
in an invariable manner to compare values of gravity on Fujiyama and at
Tokyo, Japan.[40] He used a "simple" pendulum of the Borda type to
determine the absolute value of gravity at Tokyo. From the values of
gravity on the mountain and at Tokyo, and an estimate of the volume of
the mountain, he estimated the mean density of the earth as 5.77 times
greater than that of water.

In 1879, Maj. J. Herschel, R.E., stated:

    The years from 1840 to 1865 are a complete blank, if we except
    Airy's relative density experiments in 1854. This pause was
    broken simultaneously in three different ways. Two pendulums of
    the Kater pattern were sent to India; two after Bessel's design
    were set to work in Russia; and at Geneva, Plantamour's zealous
    experiments with a pendulum of the same kind mark the
    commencement of an era of renewed activity on the European

With the statement that Kater invariable pendulums nos. 4 and 6 (1821)
were used in India between 1865 and 1873, we now consider the other
events mentioned by Herschel.

[Illustration: Figure 15.--ONE OF FRANCIS BAILY'S PENDULUMS (62-1/2
inches long), shown on the left, is now in the possession of the Science
Museum, London, and, right, two views of a similar pendulum (37-5/8
inches long) made in the late 19th century by Edward Kuebel, Washington,
D.C., which is no. 316,876 in the collection of the U.S. National
Museum. Among a large number of pendulums tried by Baily in London
(1827-1840), was one which resembles the reversible pendulum
superficially, but which is actually an invariable pendulum having knife
edges at both ends. The purpose was apparently economy, since it is
equivalent to two separate invariable pendulums. This is the type of
pendulum used on the U.S. Exploring Expedition of 1838-1842. It is not
known what use was made of the Kuebel pendulum.]

Repsold-Bessel Reversible Pendulum

As we have noted, Bessel made determinations of gravity with a ball
("simple") pendulum in the period 1825-1827 and in 1835 at Koenigsberg
and Berlin, respectively. In the memoir on his observations at
Koenigsberg, he set forth the theory of the symmetrical compound pendulum
with interchangeable knife edges.[42] Bessel demonstrated theoretically
that if the pendulum were symmetrical with respect to its geometrical
center, if the times of swing about each axis were the same, the effects
of buoyancy and of air set in motion would be eliminated. Laplace had
already shown that the knife edge must be regarded as a cylinder and not
as a mere line of support. Bessel then showed that if the knife edges
were equal cylinders, their effects were eliminated by inverting the
pendulum; and if the knife edges were not equal cylinders, the
difference in their effects was canceled by interchanging the knives and
again determining the times of swing in the so-called erect and inverted
positions. Bessel further showed that it is unnecessary to make the
times of swing exactly equal for the two knife edges.

The simplified discussion for infinitely small oscillations in a vacuum
is as follows: If T_{1} and T_{2} are the times of swing about the knife
edges, and if h_{1} and h_{2} are distances of the knife edges from the
center of gravity, and if k is the radius of gyration about an axis
through the center of gravity, then from the equation of motion of a
rigid body oscillating about a fixed axis under gravity

  (T_{1})^{2} = [pi]^{2}(k^{2} + (h_{1})^{2})/gh_{1},

  (T_{2})^{2} = [pi]^{2}(k^{2} + (h_{2})^{2})/gh_{2}.


  (h_{1}(T_{1})^{2} - h_{2}(T_{2})^{2})/(h_{1} - h_{2})

  = ([pi]^{2}/g)(h_{1} + h_{2})

  = [tau]^{2}.

[tau] is then the time of swing of a simple pendulum of length h_{1} +
h_{2}. If the difference T_{1} - T_{2} is sufficiently small,

  [tau] = (h_{1}T_{1} - h_{2}T_{2})/(h_{1} - h_{2}).

Prior to its publication by Bessel in 1828, the formula for the time of
swing of a simple pendulum of length h_{1} + h_{2} in terms of T_{1},
T_{2} had been given by C. F. Gauss in a letter to H. C. Schumacher
dated November 28, 1824.[43]

The symmetrical compound pendulum with interchangeable knives, for which
Bessel gave a posthumously published design and specifications,[44] has
been called a reversible pendulum; it may thereby be distinguished from
Kater's unsymmetrical convertible pendulum. In 1861, the Swiss Geodetic
Commission was formed, and in one of its first sessions in 1862 it was
decided to add determinations of gravity to the operations connected
with the measurement--at different points in Switzerland--of the arc of
the meridian traversing central Europe.[45] It was decided further to
employ a reversible pendulum of Bessel's design and to have it
constructed by the firm of A. Repsold and Sons, Hamburg. It was also
decided to make the first observations with the pendulum in Geneva;
accordingly, the Repsold-Bessel pendulum (fig. 16) was sent to Prof. E.
Plantamour, director of the observatory at Geneva, in the autumn of

The Swiss reversible pendulum was about 560 mm. in length (distance
between the knife edges) and the time of swing was approximately 3/4
second. At the extremities of the stem of the pendulum were movable
cylindrical disks, one of which was solid and heavy, the other hollow
and light. It was intended by the mechanicians that equality of times of
oscillation about the knife edges would be achieved by adjusting the
position of a movable disk. The pendulum was hung by a knife edge on a
plate supported by a tripod and having an attachment from which a
measuring rod could be suspended so that the distance between the knife
edges could be measured by a comparator. Plantamour found it
impracticable to adjust a disk until the times of swing about each knife
edge were equal. His colleague, Charles Cellerier,[47] then showed that
if (T_{1} - T_{2})/T_{1} is sufficiently small so that one can neglect
its square, one can determine the length of the seconds pendulum from
the times of swing about the knife edges by a theory which uses the
distances of the center of gravity from the respective knife edges.
Thus, a role for the position of the center of gravity in the theory of
the reversible pendulum, which had been set forth earlier by Bessel, was
discovered independently by Cellerier for the Swiss observers of

In 1866, Plantamour published an extensive memoir "Experiences faites a
Geneve avec le pendule a reversion." Another memoir, published in 1872,
presented further results of determinations of gravity in Switzerland.
Plantamour was the first scientist in western Europe to use a
Repsold-Bessel reversible pendulum and to work out methods for its

The Russian Imperial Academy of Sciences acquired two Repsold-Bessel
pendulums, and observations with them were begun in 1864 by Prof.
Sawitsch, University of St. Petersburg, and others.[48] In 1869, the
Russian pendulums were loaned to the India Survey in order to enable
members of the Survey to supplement observations with the Kater
invariable pendulums nos. 4 and 6 (1821). During the transport of the
Russian apparatus to India, the knives became rusted and the apparatus
had to be reconditioned. Capt. Heaviside of the India Survey observed
with both pendulums at Kew Observatory, near London, in the spring of
1874, after which the Russian pendulums were sent to Pulkowa (Russia)
and were used for observations there and in the Caucasus.

The introduction of the Repsold-Bessel reversible pendulum for the
determination of gravity was accompanied by the creation of the first
international scientific association, one for geodesy. In 1861, Lt. Gen.
J. J. Baeyer, director of the Prussian Geodetic Survey, sent a
memorandum to the Prussian minister of war in which he proposed that the
independent geodetic surveys of the states of central Europe be
coordinated by the creation of an international organization.[49] In
1862, invitations were sent to the various German states and to other
states of central Europe. The first General Conference of the
association, initially called _Die Mittel-Europaeische Gradmessung_, also
_L'Association Geodesique Internationale_, was held from the 15th to
the 22d of October 1864 in Berlin.[50] The Conference decided upon
questions of organization: a general conference was to be held
ordinarily every three years; a permanent commission initially
consisting of seven members was to be the scientific organ of the
association and to meet annually; a central bureau was to be established
for the reception, publication, and distribution of reports from the
member states.

[Illustration: Figure 16.--FROM A DESIGN LEFT BY BESSEL, this portable
apparatus was developed in 1862 by the firm of Repsold in Hamburg, whose
founder had assisted Bessel in the construction of his pendulum
apparatus of 1826. The pendulum is convertible, but differs from Kater's
in being geometrically symmetrical and, for this reason, Repsold's is
usually called "reversible." Just to the right of the pendulum is a
standard scale. To the left is a "vertical comparator" designed by
Repsold to measure the distance between the knife edges of the pendulum.
To make this measurement, two micrometer microscopes which project
horizontally through the comparator are alternately focused on the knife
edges and on the standard scale.]

Under the topic "Astronomical Questions," the General Conference of 1864
resolved that there should be determinations of the intensity of gravity
at the greatest possible number of points of the geodetic network, and
recommended the reversible pendulum as the instrument of
observation.[51] At the second General Conference, in Berlin in 1867, on
the basis of favorable reports by Dr. Hirsch, director of the
observatory at Neuchatel, of Swiss practice with the Repsold-Bessel
reversible pendulum, this instrument was specifically recommended for
determinations of gravity.[52] The title of the association was changed
to _Die Europaeische Gradmessung_; in 1886, it became _Die Internationale
Erdmessung_, under which title it continued until World War I.

On April 1, 1866, the Central Bureau of _Die Europaeische Gradmessung_
was opened in Berlin under the presidency of Baeyer, and in 1868 there
was founded at Berlin, also under his presidency, the Royal Prussian
Geodetic Institute, which obtained regular budgetary status on January
1, 1870. A reversible pendulum for the Institute was ordered from A.
Repsold and Sons, and it was delivered in the spring of 1869. The
Prussian instrument was symmetrical geometrically, as specified by
Bessel, but different in form from the Swiss and Russian pendulums. The
distance between the knife edges was 1 meter, and the time of swing
approximately 1 second. The Prussian Repsold-Bessel pendulum was swung
at Leipzig and other stations in central Europe during the years
1869-1870 by Dr. Albrecht under the direction of Dr. Bruhns, director of
the observatory at Leipzig and chief of the astronomical section of the
Geodetic Institute. The results of these first observations appeared in
a publication of the Royal Prussian Geodetic Institute in 1871.[53]

Results of observations with the Russian Repsold-Bessel pendulums were
published by the Imperial Academy of Sciences. In 1872, Prof. Sawitsch
reported the work for western Europeans in "Les variations de la
pesanteur dans les provinces occidentales de l'Empire russe."[48] In
November 1873, the Austrian Geodetic Commission received a
Repsold-Bessel reversible pendulum and on September 24, 1874, Prof.
Theodor von Oppolzer reported on observations at Vienna and other
stations to the Fourth General Conference of _Die Europaeische
Gradmessung_ in Dresden.[54] At the fourth session of the Conference, on
September 28, 1874, a Special Commission, consisting of Baeyer, as
chairman, and Bruhns, Hirsch, von Oppolzer, Peters, and Albrecht, was
appointed to consider (under Topic 3 of the program): "Observations for
the determination of the intensity of gravity," the question, "Which
Pendulum-apparatuses are preferable for the determination of many

After the adoption of the Repsold-Bessel reversible pendulum for gravity
determinations in Europe, work in the field was begun by the U.S. Coast
Survey under the superintendency of Prof. Benjamin Peirce. There is
mention in reports of observations with pendulums prior to Peirce's
direction to his son Charles on November 30, 1872, "to take charge of
the Pendulum Experiments of the Coast Survey and to direct and inspect
all parties engaged in such experiments and as often as circumstances
will permit, to take the field with a party...."[55] Systematic and
important gravity work by the Survey was begun by Charles Sanders
Peirce. Upon receiving notice of his appointment, the latter promptly
ordered from the Repsolds a pendulum similar to the Prussian instrument.
Since the firm of mechanicians was engaged in making instruments for
observations of the transit of Venus in 1874, the pendulum for the
Coast Survey could not be constructed immediately. Meanwhile, during the
years 1873-1874, Charles Peirce conducted a party which made
observations of gravity in the Hoosac Tunnel near North Adams, and at
Northampton and Cambridge, Massachusetts. The pendulums used were
nonreversible, invariable pendulums with conical bobs. Among them was a
silver pendulum, but similar pendulums of brass were used also.[56]

[Illustration: Figure 17.--REPSOLD-BESSEL REVERSIBLE PENDULUM apparatus
as made in 1875, and used in the gravity work of the U.S. Coast and
Geodetic Survey. Continental geodesists continued to favor the general
use of convertible pendulums and absolute determinations of gravity,
while their English colleagues had turned to invariable pendulums and
relative determinations, except for base stations. Perhaps the first
important American contribution to gravity work was C. S. Peirce's
demonstration of the error inherent in the Repsold apparatus through
flexure of the stand.]

[Illustration: Figure 18.--CHARLES SANDERS PEIRCE (1839-1914), son of
Benjamin Peirce, Perkins Professor of Astronomy and Mathematics at
Harvard College. C. S. Peirce graduated from Harvard in 1859. From 1873
to 1891, as an assistant at the U.S. Coast and Geodetic Survey, he
accomplished the important gravimetric work described in this article.
Peirce was also interested in many other fields, but above all in the
logic, philosophy, and history of science, in which he wrote
extensively. His greatest fame is in philosophy, where he is regarded as
the founder of pragmatism.]

In 1874, Charles Peirce expressed the desire to be sent to Europe for at
least a year, beginning about March 1, 1875, "to learn the use of the
new convertible pendulum and to compare it with those of the European
measure of a Degree and the Swiss and to compare" his "invariable
pendulums in the manner which has been used by swinging them in London
and Paris."[57]

Charles S. Peirce, assistant, U.S. Coast Survey, sailed for Europe on
April 3, 1875, on his mission to obtain the Repsold-Bessel reversible
pendulum ordered for the Survey and to learn the methods of using it for
the determination of gravity. In England, he conferred with Maxwell,
Stokes, and Airy concerning the theory and practice of research with
pendulums. In May, he continued on to Hamburg and obtained delivery from
the Repsolds of the pendulum for the Coast Survey (fig. 17). Peirce then
went to Berlin and conferred with Gen. Baeyer, who expressed doubts of
the stability of the Repsold stand for the pendulum. Peirce next went to
Geneva, where, under arrangements with Prof. Plantamour, he swung the
newly acquired pendulum at the observatory.[58]

In view of Baeyer's expressed doubts of the rigidity of the Repsold
stand, Peirce performed experiments to measure the flexure of the stand
caused by the oscillations of the pendulum. His method was to set up a
micrometer in front of the pendulum stand and, with a microscope, to
measure the displacement caused by a weight passing over a pulley, the
friction of which had been determined. Peirce calculated the correction
to be applied to the length of the seconds pendulum--on account of the
swaying of the stand during the swings of the pendulum--to amount to
over 0.2 mm. Although Peirce's measurements of flexure in Geneva were
not as precise as his later measurements, he believed that failure to
correct for flexure of the stand in determinations previously made with
Repsold pendulums was responsible for appreciable errors in reported
values of the length of the seconds pendulum.

The Permanent Commission of _Die Europaeische Gradmessung_ met in Paris,
September 20-29, 1875. In conjunction with this meeting, there was held
on September 21 a meeting of the Special Commission on the Pendulum. The
basis of the discussion by the Special Commission was provided by
reports which had been submitted in response to a circular sent out by
the Central Bureau to the members on February 26, 1874.[59]

Gen. Baeyer stated that the distance of 1 meter between the knife edges
of the Prussian Repsold-Bessel pendulum made it unwieldy and unsuited
for transport. He declared that the instability of the stand also was a
source of error. Accordingly, Gen. Baeyer expressed the opinion that
absolute determinations of gravity should be made at a control station
by a reversible pendulum hung on a permanent, and therefore stable
stand, and he said that relative values of gravity with respect to the
control station should be obtained in the field by means of a Bouguer
invariable pendulum. Dr. Bruhns and Dr. Peters agreed with Gen. Baeyer;
however, the Swiss investigators, Prof. Plantamour and Dr. Hirsch
reported in defense of the reversible pendulum as a field instrument, as
did Prof. von Oppolzer of Vienna. The circumstance that an invariable
pendulum is subject to changes in length was offered as an argument in
favor of the reversible pendulum as a field instrument.

Peirce was present during these discussions by the members of the
Special Commission, and he reported that his experiments at Geneva
demonstrated that the oscillations of the pendulum called forth a
flexure of the support which hitherto had been neglected. The observers
who used the Swiss and Austrian Repsold pendulums contended, in
opposition to Peirce, that the Repsold stand was stable.

The outcome of these discussions was that the Special Commission
reported to the Permanent Commission that the Repsold-Bessel reversible
pendulum, except for some small changes, satisfied all requirements for
the determination of gravity. The Special Commission proposed that the
Repsold pendulums of the several states be swung at the Prussian
Eichungsamt in Berlin where, as Peirce pointed out, Bessel had made his
determination of the intensity of gravity with a ball pendulum in 1835.
Peirce was encouraged to swing the Coast Survey reversible pendulum at
the stations in France, England, and Germany where Borda and Cassini,
Kater, and Bessel, respectively, had made historic determinations. The
Permanent Commission, in whose sessions Peirce also participated, by
resolutions adopted the report of the Special Commission on the

During the months of January and February 1876, Peirce conducted
observations in the Grande Salle du Meridien at the observatory in Paris
where Borda, Biot, and Capt. Edward Sabine had swung pendulums early in
the 19th century. He conducted observations in Berlin from April to June
1876 and, by experiment, determined the correction for flexure to be
applied to the value of gravity previously obtained with the Prussian
instrument. Subsequent observations were made at Kew. After his return
to the United States on August 26, 1876, Peirce conducted experiments at
the Stevens Institute in Hoboken, New Jersey, where he made careful
measurements of the flexure of the stand by statical and dynamical
methods. In Geneva, he had secured the construction of a vacuum chamber
in which the pendulum could be swung on a support which he called the
Geneva support. At the Stevens Institute, Peirce swung the
Repsold-Bessel pendulum on the Geneva support and determined the effect
of different pressures and temperatures on the period of oscillation of
the pendulum. These experiments continued into 1878.[61]

Meanwhile, the Permanent Commission met October 5-10, 1876, in Brussels
and continued the discussion of the pendulum.[62] Gen. Baeyer reported
on Peirce's experiments in Berlin to determine the flexure of the stand.
The difference of 0.18 mm. in the lengths of the seconds pendulum as
determined by Bessel and as determined by the Repsold instrument agreed
with Peirce's estimate of error caused by neglect of flexure of the
Repsold stand. Dr. Hirsch, speaking for the Swiss survey, and Prof. von
Oppolzer, speaking for the Austrian survey, contended, however, that
their stands possessed sufficient stability and that the results found
by Peirce applied only to the stands and bases investigated by him. The
Permanent Commission proposed further study of the pendulum.

The Fifth General Conference of _Die Europaeische Gradmessung_ was held
from September 27 to October 2, 1877, in Stuttgart.[63] Peirce had
instructions from Supt. Patterson of the U.S. Coast Survey to attend
this conference, and on arrival presented a letter of introduction from
Patterson requesting that he, Peirce, be permitted to participate in the
sessions. Upon invitation from Prof. Plantamour, as approved by Gen.
Ibanez, president of the Permanent Commission, Peirce had sent on July
13, 1877, from New York, the manuscript of a memoir titled "De
l'Influence de la flexibilite du trepied sur l'oscillation du pendule a
reversion." This memoir and others by Cellerier and Plantamour
confirming Peirce's work were published as appendices to the proceedings
of the conference. As appendices to Peirce's contribution were published
also two notes by Prof. von Oppolzer. At the second session on September
29, 1877, when Plantamour reported that the work of Hirsch and himself
had confirmed experimentally the independent theoretical work of
Cellerier and the theoretical and experimental work of Peirce on
flexure, Peirce described his Hoboken experiments.

During the discussions at Stuttgart on the flexure of the Repsold stand,
Herve Faye, president of the Bureau of Longitudes, Paris, suggested that
the swaying of the stand during oscillations of the pendulum could be
overcome by the suspension from one support of two similar pendulums
which oscillated with equal amplitudes and in opposite phases. This
proposal was criticized by Dr. Hirsch, who declared that exact
observation of passages of a "double pendulum" would be difficult and
that two pendulums swinging so close together would interfere with each
other. The proposal of the double pendulum came up again at the meeting
of the Permanent Commission at Geneva in 1879.[64] On February 17, 1879,
Peirce had completed a paper "On a Method of Swinging Pendulums for the
Determination of Gravity, Proposed by M. Faye." In this paper, Peirce
presented the results of an analytical mechanical investigation of
Faye's proposal. Peirce set up the differential equations, found the
solutions, interpreted them physically, and arrived at the conclusion
"that the suggestion of M. Faye ... is as sound as it is brilliant and
offers some peculiar advantages over the existing method of swinging

In a report to Supt. Patterson, dated July 1879, Peirce stated: "I think
it is important before making a new pendulum apparatus to experiment
with Faye's proposed method."[65] He wrote further: "The method proves
to be perfectly sound in theory, and as it would greatly facilitate the
work it is probably destined eventually to prevail. We must
unfortunately leave to other surveys the merit of practically testing
and introducing the new method, as our appropriations are insufficient
for us to maintain the leading position in this matter, which we
otherwise might take." Copies of the published version of Peirce's
remarks were sent to Europe. At a meeting of the Academy of Sciences in
Paris on September 1, 1879, Faye presented a report on Peirce's
findings.[66] The Permanent Commission met September 16-20, 1879, in
Geneva. At the third session on September 19, by action of Gen. Baeyer,
copies of Peirce's paper on Faye's proposed method of swinging pendulums
were distributed. Dr. Hirsch again commented adversely on the proposal,
but moved that the question be investigated and reported on at the
coming General Conference. The Permanent Commission accepted the
proposal of Dr. Hirsch, and Prof. Plantamour was named to report on the
matter at the General Conference. At Plantamour's request, Charles
Cellerier was appointed to join him, since the problem essentially was a
theoretical one.

The Sixth General Conference of _Die Europaeische Gradmessung_ met
September 13-16, 1880, in Munich.[67] Topic III, part 7 of the program
was entitled "On Determinations of Gravity through pendulum
observations. Which construction of a pendulum apparatus corresponds
completely to all requirements of science? Special report on the

The conference received a memoir by Cellerier[68] on the theory of the
double pendulum and a report by Plantamour and Cellerier.[69]
Cellerier's mathematical analysis began with the equations of Peirce and
used the latter's notation as far as possible. His general discussion
included the results of Peirce, but he stated that the difficulties to
be overcome did not justify the employment of the "double pendulum." He
presented an alternative method of correcting for flexure based upon a
theory by which the flexure caused by the oscillation of a given
reversible pendulum could be determined from the behavior of an
auxiliary pendulum of the same length but of different weight. This
method of correcting for flexure was recommended to the General
Conference by Plantamour and Cellerier in their joint report. At the
fourth session of the conference on September 16, 1880, the problem of
the pendulum was discussed and, in consequence, a commission consisting
of Faye, Helmholtz, Plantamour (replaced in 1882 by Hirsch), and von
Oppolzer was appointed to study apparatus suitable for relative
determinations of gravity.

The Permanent Commission met September 11-15, 1882, at The Hague,[70]
and at its last session appointed Prof. von Oppolzer to report to the
Seventh General Conference on different forms of apparatus for the
determination of gravity. The Seventh Conference met October 15-24,
1883, in Rome,[71] and, at its eighth session, on October 22, received a
comprehensive, critical review from Prof. von Oppolzer entitled "Ueber
die Bestimmung der Schwere mit Hilfe verschiedener Apparate."[72] Von
Oppolzer especially expounded the advantages of the Bessel reversible
pendulum, which compensated for air effects by symmetry of form if the
times of swing for both positions were maintained between the same
amplitudes, and compensated for irregular knife edges by making them
interchangeable. Prof. von Oppolzer reviewed the problem of flexure of
the Repsold stand and stated that a solution in the right direction
was the proposal--made by Faye and theoretically pursued by Peirce--to
swing two pendulums from the same stand with equal amplitudes and in
opposite phases, but that the proposal was not practicable. He concluded
that for absolute determinations of gravity, the Bessel reversible
pendulum was highly appropriate if one swung two exemplars of different
weight from the same stand for the elimination of flexure. Prof. von
Oppolzer's important report recognized that absolute determinations were
less accurate than relative ones, and should be conducted only at
special places.

The discussions initiated by Peirce's demonstration of the flexure of
the Repsold stand resulted, finally, in the abandonment of the plan to
make absolute determinations of gravity at all stations with the
reversible pendulum.

[Illustration: Figure 19.--THREE PENDULUMS USED IN EARLY WORK at the
U.S. Coast and Geodetic Survey. Shown on the left is the Peirce
invariable; center, the Peirce reversible; and, right, the Repsold
reversible. Peirce designed the cylindrical pendulum in 1881-1882 to
study the effect of air resistance according to the theory of G. G.
Stokes on the motion of a pendulum in a viscous field. Three examples of
the Peirce pendulums are in the U.S. National Museum.]

Peirce and Defforges Invariable, Reversible Pendulums

The Repsold-Bessel reversible pendulum was designed and initially used
to make absolute determinations of gravity not only at initial stations
such as Kew, the observatory in Paris, and the Smithsonian Institution
in Washington, D.C., but also at stations in the field. An invariable
pendulum with a single knife edge, however, is adequate for relative
determinations. As we have seen, such invariable pendulums had been used
by Bouguer and Kater, and after the experiences with the Repsold
apparatus had been recommended again by Baeyer for relative
determinations. But an invariable pendulum is subject to uncontrollable
changes of length. Peirce proposed to detect such changes in an
invariable pendulum in the field by combining the invariable and
reversible principles. He explained his proposal to Faye in a letter
dated July 23, 1880, and he presented it on September 16, 1880, at the
fourth session of the sixth General Conference of _Die Europaeische
Gradmessung_, in Munich.[73]

As recorded in the Proceedings of the Conference, Peirce wrote:

    But I obviate it in making my pendulum both invariable and
    reversible. Every alteration of the pendulum will be revealed
    immediately by the change in the difference of the two periods
    of oscillation in the two positions. Once discovered, it will be
    taken account of by means of new measures of the distance
    between the two supports.

Peirce added that it seemed to him that if the reversible pendulum
perhaps is not the best instrument to determine absolute gravity, it is,
on condition that it be truly invariable, the best to determine relative
gravity. Peirce further stated that he would wish that the pendulum be
formed of a tube of drawn brass with heavy plugs of brass equally drawn.
The cylinder would be terminated by two hemispheres; the knives would be
attached to tongues fixed near the ends of the cylinder.

During the years 1881 and 1882, four invariable, reversible pendulums
were made after the design of Peirce at the office of the U.S. Coast and
Geodetic Survey in Washington, D.C. The report of the superintendent for
the year 1880-1881 states:

    A new pattern of the reversible pendulum has been invented,
    having its surface as nearly as convenient in the form of an
    elongated ellipsoid. Three of these instruments have been
    constructed, two having a distance of one meter between the
    knife edges and the third a distance of one yard. It is proposed
    to swing one of the meter pendulums at a temperature near 32 deg.
    F. at the same time that the yard is swung at 60 deg. F., in order
    to determine anew the relation between the yard and the meter.[74]

The report for 1881-1882 mentions four of these Peirce pendulums.

A description of the Peirce invariable, reversible pendulums was given
by Assistant E. D. Preston in "Determinations of Gravity and the
Magnetic Elements in Connection with the United States Scientific
Expedition to the West Coast of Africa, 1889-90."[75] The invariable,
reversible pendulum, Peirce no. 4, now preserved in the Smithsonian
Institution's Museum of History and Technology (fig. 34), may be taken
as typical of the meter pendulums: In the same memoir, Preston gives the
diameter of the tube as 63.7 mm., thickness of tube 1.5 mm., weight
10.680 kilograms, and distance between the knives 1.000 meter.

The combination of invariability and reversibility in the Peirce
pendulums was an innovation for relative determinations. Indeed, the
combination was criticized by Maj. J. Herschel, R.E., of the Indian
Survey, at a conference on gravity held in Washington in May 1882 on the
occasion of his visit to the United States for the purpose of
connecting English and American stations by relative determinations with
three Kater invariable pendulums. These three pendulums have been
designated as nos. 4, 6 (1821), and 11.[76]

[Illustration: Figure 20.--SUPPORT FOR THE PEIRCE PENDULUM, 1889. Much
of the work of C. S. Peirce was concerned with the determination of the
error introduced into observations made with the portable apparatus by
the vibration of the stand with the pendulum. He showed that the popular
Bessel-Repsold apparatus was subject to such an error. His own pendulums
were swung from a simple but rugged wooden frame to which a hardened
steel bearing was fixed.]

Another novel characteristic of the Peirce pendulums was the mainly
cylindrical form. Prof. George Gabriel Stokes, in a paper "On the Effect
of the Internal Friction of Fluids on the Motion of Pendulums"[77] that
was read to the Cambridge Philosophical Society on December 9, 1850, had
solved the hydrodynamical equations to obtain the resistance to the
motions of a sphere and a cylinder in a viscous fluid. Peirce had
studied the effect of viscous resistance on the motion of his
Repsold-Bessel pendulum, which was symmetrical in form but not
cylindrical. The mainly cylindrical form of his pendulums (fig. 19)
permitted Peirce to predict from Stokes' theory the effect of viscosity
and to compare the results with experiment. His report of November 20,
1889, in which he presented the comparison of experimental results with
the theory of Stokes, was not published.[78]

Peirce used his pendulums in 1883 to establish a station at the
Smithsonian Institution that was to serve as the base station for the
Coast and Geodetic Survey for some years. Pendulum Peirce no. 1 was
swung at Washington in 1881 and was then taken by the party of
Lieutenant Greely, U.S.A., on an expedition to Lady Franklin Bay where
it was swung in 1882 at Fort Conger, Grinnell Land, Canada. Peirce nos.
2 and 3 were swung by Peirce in 1882 at Washington, D.C.; Hoboken, New
Jersey; Montreal, Canada; and Albany, New York. Assistant Preston took
Peirce no. 3 on a U.S. eclipse expedition to the Caroline Islands in
1883. Peirce in 1885 swung pendulums nos. 2 and 3 at Ann Arbor,
Michigan; Madison, Wisconsin; and Ithaca, New York. Assistant Preston in
1887 swung Peirce nos. 3 and 4 at stations in the Hawaiian Islands, and
in 1890 he swung Peirce nos. 3 and 4 at stations on the west coast of

The new pattern of pendulum designed by Peirce was also adopted in
France, after some years of experience with a Repsold-Bessel pendulum.
Peirce in 1875 had swung his Repsold-Bessel pendulum at the observatory
in Paris, where Borda and Cassini, and Biot, had made historic
observations and where Sabine also had determined gravity by comparison
with Kater's value at London. During the spring of 1880, Peirce made
studies of the supports for the pendulums of these earlier
determinations and calculated corrections to those results for
hydrodynamic effects, viscosity, and flexure. On June 14, 1880, Peirce
addressed the Academy of Sciences, Paris, on the value of gravity at
Paris, and compared his results with the corrected results of Borda and
Biot and with the transferred value of Kater.[80]

In the same year the French Geographic Service of the Army acquired a
Repsold-Bessel reversible pendulum of the smaller type, and Defforges
conducted experiments with it.[81] He introduced the method of measuring
flexure from the movement of interference fringes during motion of the
pendulum. He found an appreciable difference between dynamical and
statical coefficients of flexure and concluded that the "correction
formula of Peirce and Cellerier is suited perfectly to practice and
represents exactly the variation of period caused by swaying of the
support, on the condition that one uses the statical coefficient."
Defforges developed a theory for the employment of two similar pendulums
of the same weight, but of different length, and hung by the same
knives. This theory eliminated the flexure of the support and the
curvature of the knives from the reduction of observations.

Pendulums of 1-meter and of 1/2-meter distance between the knife edges
were constructed from Defforges' design by Brunner Brothers in Paris
(fig. 21). These Defforges pendulums were cylindrical in form with
hemispherical ends like the Peirce pendulums, and were hung on knives
that projected from the sides of the pendulum, as in some unfinished
Gautier pendulums designed by Peirce in 1883 in Paris.

[Illustration: Figure 21.--REVERSIBLE PENDULUM APPARATUS of Defforges,
as constructed by Brunner, Paris, about 1887. The clock and telescope
used to observe coincidences are not shown. The telescope shown is part
of an interferometer used to measure flexure of the support. One mirror
of the interferometer is attached to the pendulum support; the other to
the separate masonry pillar at the left.]

[Illustration: Figure 22.--BECAUSE OF THE GREATER SIMPLICITY of its use,
the invariable pendulum superseded the convertible pendulum towards the
end of the 19th century, except at various national base stations (Kew,
Paris, Potsdam, Washington, D.C., etc.). Shown here are, right to left,
a pendulum of the type used by Peirce at the Hoosac Tunnel in 1873-74,
the Mendenhall 1/2-second pendulum of 1890, and the pendulum designed by
Peirce in 1881-1882.]

[Illustration: Figure 23.--THE OVERALL SIZE of portable pendulum
apparatus was greatly reduced with the introduction of this 1/2-second
apparatus in 1887, by the Austrian military officer, Robert von
Sterneck. Used with a vacuum chamber not shown here, the apparatus is
only about 2 feet high. Coincidences are observed by the reflection of a
periodic electric spark in two mirrors, one on the support and the other
on the pendulum itself.]

[Illustration: Figure 24.--THOMAS C. MENDENHALL (1841-1924). Although
largely self-educated, he became the first professor of physics and
mechanics at the Ohio Agricultural and Mechanical College (later Ohio
State University), and was subsequently connected with several other
universities. In 1878, while teaching at the Tokyo Imperial University
in Japan, he made gravity measurements between Tokyo and Fujiyama from
which he calculated the mean density of the earth. While superintendent
of the U.S. Coast and Geodetic Survey, 1889-94, he developed the
pendulum apparatus which bears his name.]

Von Sterneck and Mendenhall Pendulums

While scientists who had used the Repsold-Bessel pendulum apparatus
discussed its defects and limitations for gravity surveys, Maj. Robert
von Sterneck of Austria-Hungary began to develop an excellent apparatus
for the rapid determination of relative values of gravity.[82] Maj. von
Sterneck's apparatus contained a nonreversible pendulum 1/4-meter in
length, and 1/2-second time of swing. The pendulum was hung by a single
knife edge, which rested on a plate that was supported by a tripod. The
pendulum was swung in a chamber from which air was exhausted and which
could be maintained at any desired temperature. Times of swing were
determined by the observation of coincidences of the pendulum with
chronometer signals. In the final form a small mirror was attached to
the knife edge perpendicular to the plane of vibration of the pendulum
and a second fixed mirror was placed close to it so that the two mirrors
were parallel when the pendulum was at rest. The chronometer signals
worked a relay that gave a horizontal spark which was reflected into the
telescope from the mirrors. When the pendulum was at rest, the image of
the spark in both mirrors appeared on the horizontal cross wire in the
telescope, and during oscillation of the pendulum the two images
appeared in that position upon coincidence. In view of the reduced size
of the pendulum, the chamber in which it was swung was readily portable,
and with an improved method of observing coincidences, relative
determinations of gravity could be made with rapidity and accuracy.

By 1887 Maj. von Sterneck had perfected his apparatus, and it was widely
adopted in Europe for relative determinations of gravity. He used his
apparatus in extensive gravity surveys and also applied it in the silver
mines in Saxony and Bohemia, by the previously described methods of
Airy, for investigations into the internal constitution of the earth.

On July 1, 1889, Thomas Corwin Mendenhall became superintendent of the
U.S. Coast and Geodetic Survey. Earlier, he had been professor of
physics at the University of Tokyo and had directed observations of
pendulums for the determination of gravity on Fujiyama and at Tokyo.
Supt. Mendenhall, with the cooperation of members of his staff in
Washington, designed a new pendulum apparatus of the Von Sterneck type,
and in October 1890 he ordered construction of the first model.[83]

Like the Von Sterneck apparatus, the Mendenhall pendulum apparatus
employed a nonreversible, invariable pendulum 1/4-meter in length and of
slightly more than 1/2-second in time of swing. Initially, the knife
edge was placed in the head of the pendulum and hung on a fixed plane
support, but after some experimentation Mendenhall attached the plane
surface to the pendulum and hung it on a fixed knife edge. An apparatus
was provided with a set of three pendulums, so that if discrepancies
appeared in the results, the pendulum at fault could be detected. There
was also a dummy pendulum which carried a thermometer. A pendulum was
swung in a receiver in which the pressure and temperature of the air
were controlled. The time of swing was measured by coincidences with the
beat of a chronometer. The coincidences were determined by an optical
method with the aid of a flash apparatus.

[Illustration: Figure 25.--MENDENHALL'S 1/4-METER (1/2-SECOND)
APPARATUS. Shown on the left is the flash apparatus and, on the right,
the vacuum chamber within which the pendulum is swung. The flash
apparatus consists of a kerosene lantern and a telescope, mounted on a
box containing an electromagnetically operated shutter. The operation of
the shutter is controlled by a chronograph (not shown), so that it emits
a slit of light at regular intervals. The telescope is focused on two
mirrors within the apparatus, one fixed, the other attached to the top
of the pendulum. It is used to observe the reflection of the flashes
from these mirrors. When the two reflections are aligned, a
"coincidence" is marked on the chronograph tape. The second telescope
attached to the bottom of the vacuum chamber is for observing the
amplitude of the pendulum swing.]

The flash apparatus was contained in a light metal box which supported
an observing telescope and which was mounted on a stand. Within the box
was an electromagnet whose coils were connected with a chronometer
circuit and whose armature carried a long arm that moved two shutters,
in both of which were horizontal slits of the same size. The shutters
were behind the front face of the box, which also had a horizontal slit.
A flash of light from an oil lamp or an electric spark was emitted from
the box when the circuit was broken, but not when it was closed. When
the circuit was broken a spring caused the arm to rise, and the shutters
were actuated so that the three slits came into line and a flash of
light was emitted. A small circular mirror was set in each side of the
pendulum head, so that from either face of the pendulum the image of the
illuminated slit could be reflected into the field of the observing
telescope. A similar mirror was placed parallel to these two mirrors and
rigidly attached to the support. The chronometer signals broke the
circuit, causing the three slits momentarily to be in line, and when the
images of the slit in the two mirrors coincided, a coincidence was
observed. A coincidence occurred whenever the pendulum gained or lost
one oscillation on the beat of the chronometer. The relative intensity
of gravity was determined by observations with the first Mendenhall
apparatus at Washington, D.C., at stations on the Pacific Coast and in
Alaska, and at the Stevens Institute, Hoboken, New Jersey, between March
and October 1891.

[Illustration: Figure 26.--VACUUM RECEIVER within which the Mendenhall
pendulum is swung. The pressure is reduced to about 50 mm. to reduce the
disturbing effect of air resistance. When the apparatus is sealed, the
pendulum is lifted on the knife edge by the lever _q_ and is started to
swing by the lever _r_. The arc of swing is only about 1 deg. The
stationary mirror is shown at _g_. The pendulum shown in outline in the
center, is only about 9.7 inches long.]

Under Supt. Mendenhall's direction a smaller, 1/4-second, pendulum
apparatus was also constructed and tested, but did not offer advantages
over the 1/2-second apparatus, which therefore continued in use.

In accordance with Peirce's theory of the flexure of the stand under
oscillations of the pendulum, determinations of the displacement of the
receiver of the Mendenhall apparatus were part of a relative
determination of gravity by members of the Coast and Geodetic Survey.
Initially, a statical method was used, but during 1908-1909 members of
the Survey adapted the Michelson interferometer for the determinations
of flexure during oscillations from the shift of fringes.[84] The first
Mendenhall pendulums were made of bronze, but about 1920 invar was
chosen because of its small coefficient of expansion. About 1930, Lt. E.
J. Brown of the Coast and Geodetic Survey made significant improvements
in the Mendenhall apparatus, and the new form came to be known as the
Brown Pendulum Apparatus.[85]

[Illustration: Figure 27.--THE MICHELSON INTERFEROMETER. The horizontal
component of the force acting on the knife edge through the swinging
pendulum causes the support to move in unison with the pendulum, and
thereby affects the period of the oscillation. This movement is the
so-called flexure of the pendulum support, and must be taken into
account in the most accurate observations.

In 1907, the Michelson interferometer was adapted to this purpose by the
U.S. Coast and Geodetic Survey. As shown here, the interferometer,
resting on a wooden beam, is introduced into the path of a light beam
reflected from a mirror on the vacuum chamber. Movement of that mirror
causes a corresponding movement in the interference fringes in the
interferometer, which can be measured.]

The original Von Sterneck apparatus and that of Mendenhall provided for
the oscillation of one pendulum at a time. After the adoption of the Von
Sterneck pendulum in Europe, there were developed stands on which two or
four pendulums hung at the same time. This procedure provided a
convenient way to observe more than one invariable pendulum at a station
for the purpose of detecting changes in length. Prof. M. Haid of
Karlsruhe in 1896 described a four-pendulum apparatus,[86] and Dr.
Schumann of Potsdam subsequently described a two-pendulum

[Illustration: Figure 28.--APPARATUS WHICH WAS DEVELOPED IN 1929 by the
Gulf Research and Development Company, Harmarville, Pennsylvania. It was
designed to achieve an accuracy within one ten-millionth of the true
value of gravity, and represents the extreme development of pendulum
apparatus for relative gravity measurement. The pendulum was designed so
that the period would be a minimum. The case (the top is missing in this
photograph) is dehumidified and its temperature and electrostatic
condition are controlled. Specially designed pendulum-lifting and
-starting mechanisms are used. The problem of flexure of the case is
overcome by the Faye-Peirce method (see text) in which two dynamically
matched pendulums are swung simultaneously, 180 deg. apart in phase.]

The multiple-pendulum apparatus then provided a method of determining
the flexure of the stand from the action of one pendulum upon a second
pendulum hung on the same stand. This method of determining the
correction for flexure was a development from a "Wippverfahren" invented
at the Geodetic Institute in Potsdam. A dynamometer was used to impart
periodic impulses to the stand, and the effect was observed upon a
pendulum initially at rest. Refinements of this method led to the
development of a method used by Lorenzoni in 1885-1886 to determine the
flexure of the stand by action of an auxiliary pendulum upon the
principal pendulum. Dr. Schumann, in 1899, gave a mathematical theory of
such determinations,[88] and in his paper cited the mathematical methods
of Peirce and Cellerier for the theory of Faye's proposal at Stuttgart
in 1877 to swing two similar pendulums on the same support with equal
amplitudes and in opposite phases.

[Illustration: Figure 29.--THE GULF PENDULUM is about 10.7 inches long,
and has a period of .89 second. It is made of fused quartz which is
resistant to the influence of temperature change and to the earth's
magnetism. Quartz pendulums are subject to the influence of
electrostatic charge, and provision is made to counteract this through
the presence of a radium salt in the case. The bearings are made of
Pyrex glass.]

In 1902, Dr. P. Furtwaengler[89] presented the mathematical theory of
coupled pendulums in a paper in which he referred to Faye's proposal of
1877 and reported that the difficulties predicted upon its application
had been found not to occur. Finally, during the gravity survey of
Holland in the years 1913-1921, in view of instability of supports
caused by the mobility of the soil, F. A. Vening Meinesz adopted Faye's
proposed method of swinging two pendulums on the same support.[90] The
observations were made with the ordinary Stueckrath apparatus, in which
four Von Sterneck pendulums swung two by two in planes perpendicular to
each other. This successful application of the method--which had been
proposed by Faye and had been demonstrated theoretically to be sound by
Peirce, who also published a design for its application--was rapidly
followed for pendulum apparatus for relative determinations by
Potsdam,[91] Cambridge (England),[92] Gulf Oil and Development
Company,[93] and the Dominion Observatory at Ottawa.[94] Heiskanen and
Vening Meinesz state:

    The best way to eliminate the effect of flexure is to use two
    synchronized pendulums of the same length swinging on the same
    apparatus in the same plane and with the same amplitudes but in
    opposite phases; it is clear then the flexure is zero.[95]

In view of the fact that the symmetrical reversible pendulum is named
for Bessel, who created the theory and a design for its application by
Repsold, it appears appropriate to call the method of eliminating
flexure by swinging two pendulums on the same support the Faye-Peirce
method. Its successful application was made possible by Maj. von
Sterneck's invention of the short, 1/4-meter pendulum.

[Illustration: Figure 30.--THE ACCUMULATED DATA OF GRAVITY observations
over the earth's surface have indicated that irregularities such as
mountains do not have the effect which would be expected in modifying
gravity, but are somehow compensated for. The most satisfactory solution
to this still unanswered question has been the theory of isostasy,
according to which variations in the density of the material in the
earth's crust produce a kind of hydrostatic equilibrium between its
higher and lower parts, as they "float" on the earth's fluid core. The
metals of different density floating in mercury in this diagram
illustrate isostasy according to the theory of Pratt and Hayford.]

Absolute Value of Gravity at Potsdam

The development of the reversible pendulum in the 19th century
culminated in the absolute determination of the intensity of gravity at
Potsdam by Kuehnen and Furtwaengler of the Royal Prussian Geodetic
Institute, which then became the world base for gravity surveys.[96]

We have previously seen that in 1869 the Geodetic Institute--founded by
Lt. Gen. Baeyer--had acquired a Repsold-Bessel reversible pendulum which
was swung by Dr. Albrecht under the direction of Dr. Bruhns.
Dissatisfaction with this instrument was expressed by Baeyer in 1875 to
Charles S. Peirce, who then, by experiment and mathematical analysis of
the flexure of the stand under oscillations of the pendulum, determined
that previously reported results with the Repsold apparatus required
correction. Dr. F. R. Helmert, who in 1887 succeeded Baeyer as director
of the Institute, secured construction of a building for the Institute
in Potsdam, and under his direction the scientific study of the
intensity of gravity was pursued with vigor. In 1894, it was discovered
in Potsdam that a pendulum constructed of very flexible material yielded
results which differed markedly from those obtained with pendulums of
greater stiffness. Dr. Kuehnen of the Institute discovered that the
departure from expectations was the result of the flexure of the
pendulum staff itself during oscillations.[97]

Peirce, in 1883, had discovered that the recesses cut in his pendulums
for the insertion of tongues that carried the knives had resulted in the
flexure of the pendulum staff.[98] By experiment, he also found an even
greater flexure for the Repsold pendulum. In order to eliminate this
source of error, Peirce designed a pendulum with knives that extended
from each side of the cylindrical staff, and he received authorization
from the superintendent of the Coast and Geodetic Survey to arrange for
the construction of such pendulums by Gautier in Paris. Peirce, who had
made his plans in consultation with Gautier, was called home before the
pendulums were completed, and these new instruments remained

In a memoir titled "Effect of the flexure of a pendulum upon its period
of oscillation,"[99] Peirce determined analytically the effect on the
period of a pendulum with a single elastic connection between two rigid
parts of the staff. Thus, Peirce discovered experimentally the flexure
of the staff and derived for a simplified case the effect on the period.
It is not known if he ever found the integrated effect of the continuum
of elastic connections in the pendulum. Lorenzoni, in 1896, offered a
solution to the problem, and Almansi, in 1899, gave an extended
analysis. After the independent discovery of the problem at the Geodetic
Institute, Dr. Helmert took up the problem and criticized the theories
of Peirce and Lorenzoni. He then presented his own theory of flexure in
a comprehensive memoir.[100] In view of the previous neglect of the
flexure of the pendulum staff in the reduction of observations, Helmert
directed that the Geodetic Institute make a new absolute determination
of the intensity of gravity at Potsdam. For this purpose, Kuehnen and
Furtwaengler used the following reversible pendulums which had been
constructed by the firm of A. Repsold and Sons in Hamburg:

    1. The seconds pendulum of the Geodetic Institute procured in

    2. A seconds pendulum from the Astronomical Observatory, Padua.

    3. A heavy, seconds pendulum from the Imperial and Royal
    Military-Geographical Institute, Vienna.

    4. A light, seconds pendulum from the Imperial and Royal
    Military-Geographical Institute.

    5. A 1/2-second, reversible pendulum of the Geodetic Institute
    procured in 1892.

Work was begun in 1898, and in 1906 Kuehnen and Furtwaengler published
their monumental memoir, "Bestimmung der Absoluten Groesze der
Schwerkraft zu Potsdam mit Reversionspendeln."

The acceleration of gravity in the pendulum room of the Geodetic
Institute was determined to be 981.274 +- 0.003 cm/sec^{2}. In view of the
exceptionally careful and thorough determination at the Institute,
Potsdam was accepted as the world base for the absolute value of the
intensity of gravity. The absolute value of gravity at some other
station on the Potsdam system was determined from the times of swing of
an invariable pendulum at the station and at Potsdam by the relation
(T_{1})^{2}/(T_{2})^{2} = g_{2}/g_{1}. Thus, in 1900, Assistant G. R.
Putnam of the Coast and Geodetic Survey swung Mendenhall pendulums at
the Washington base and at Potsdam, and by transfer from Potsdam
determined the intensity of gravity at the Washington base to be 980.112
cm/sec^{2}.[101] In 1933, Lt. E. J. Brown made comparative measurements
with improved apparatus and raised the value at the Washington base to
980.118 cm/sec^{2}.[102]

In view of discrepancies between the results of various relative
determinations, the Coast and Geodetic Survey in 1928 requested the
National Bureau of Standards to make an absolute determination for
Washington. Heyl and Cook used reversible pendulums made of fused silica
having a period of approximately 1 second. Their result, published in
1936, was interpreted to indicate that the value at Potsdam was too high
by 20 parts in 1 million.[103] This estimate was lowered slightly by Sir
Harold Jeffreys of Cambridge, England, who recomputed the results of
Heyl and Cook by different methods.[104]

[Illustration: Figure 31.--MAP SHOWING THE DISTRIBUTION of gravity
stations throughout the United States as of December 1908.]

[Illustration: Figure 32.--MAP SHOWING THE DISTRIBUTION of gravity
stations throughout the United States in 1923.]

In 1939, J. S. Clark published the results of a determination of gravity
with pendulums of a non-ferrous Y-alloy[105] at the National Physical
Laboratory at Teddington, England, and, after recomputation of results
by Jeffreys, the value was found to be 12.8 parts in 1 million less than
the value obtained by transfer from Potsdam. Dr. Hugh L. Dryden of the
National Bureau of Standards, and Dr. A. Berroth of the Geodetic
Institute at Potsdam, have recomputed the Potsdam data by different
methods of adjustment and concluded that the Potsdam value was too high
by about 12 parts in a million.[106] Determination of gravity at
Leningrad by Russian scientists likewise has indicated that the 1906
Potsdam value is too high. In the light of present information, it
appears justifiable to reduce the Potsdam value of 981.274 by .013
cm/sec^{2} for purposes of comparison. If the Brown transfer from
Potsdam in 1933 was taken as accurate, the value for the Washington base
would be 980.105 cm/sec^{2}. In this connection, it is of interest to
note that the value given by Charles S. Peirce for the comparable
Smithsonian base in Washington, as determined by him from comparative
methods in the 1880's and reported in the _Annual Report of the
Superintendent of the Coast and Geodetic Survey for the year 1890-1891_,
was 980.1017 cm/sec^{2}.[107] This value would appear to indicate that
Peirce's pendulums, observations, and methods of reduction of data were
not inferior to those of the scientists of the Royal Prussian Geodetic
Institute at Potsdam.

Doubts concerning the accuracy of the Potsdam value of gravity have
stimulated many new determinations of the intensity of gravity since the
end of World War II. In a paper published in June 1957, A. H. Cook,
Metrology Division, National Physical Laboratory, Teddington, England,

    At present about a dozen new absolute determinations are in
    progress or are being planned. Heyl and Cook's reversible
    pendulum apparatus is in use in Buenos Aires and further
    reversible pendulum experiments have been made in the All Union
    Scientific Research Institute of Metrology, Leningrad (V N I I M)
    and are planned at Potsdam. A method using a very long pendulum
    was tried out in Russia about 1910 and again more recently and
    there are plans for similar work in Finland. The first
    experiment with a freely falling body was that carried out by
    Volet who photographed a graduated scale falling in an enclosure
    at low air pressure. Similar experiments have been completed in
    Leningrad and are in progress at the Physikalisch-Technische
    Bundesanstalt (Brunswick) and at the National Research Council
    (Ottawa), and analogous experiments are being prepared at the
    National Physical Laboratory and at the National Bureau of
    Standards. Finally, Professor Medi, Director of the Istituto
    Nazionale di Geofisica (Rome), is attempting to measure the
    focal length of the paraboloidal surface of a liquid in a
    rotating dish.[108]

Application of Gravity Surveys

We have noted previously that in the ancient and early modern periods,
the earth was presupposed to be spherical in form. Determination of the
figure of the earth consisted in the measurement of the radius by the
astronomical-geodetic method invented by Eratosthenes. Since the earth
was assumed to be spherical, gravity was inferred to be constant over
the surface of the earth. This conclusion appeared to be confirmed by
the determination of the length of the seconds pendulum at various
stations in Europe by Picard and others. The observations of Richer in
South America, the theoretical discussions of Newton and Huygens, and
the measurements of degrees of latitude in Peru and Sweden demonstrated
that the earth is an oblate spheroid.

Deductions as to the distribution of matter in the earth can be made
from gravity measurements. This globe shows worldwide variations in
gravity as they now appear from observations at sea (in submarines) as
well as on land. It is based on data from the Institute of Geodesy at
Ohio State University.]

The theory of gravitation and the theory of central forces led to the
result that the intensity of gravity is variable over the surface of the
earth. Accordingly, determinations of the intensity of gravity became
of value to the geodesist as a means of determining the figure of the
earth. Newton, on the basis of the meager data available to him,
calculated the ellipticity of the earth to be 1/230 (the ellipticity is
defined by (a-b)/a, where a is the equatorial radius and b the polar
radius). Observations of the intensity of gravity were made on the
historic missions to Peru and Sweden. Bouguer and La Condamine found
that at the equator at sea level the seconds pendulum was 1.26
Paris-lines shorter than at Paris. Maupertuis found that in northern
Sweden a certain pendulum clock gained 59.1 seconds per day on its rate
in Paris. Then Clairaut, from the assumption that the earth is a
spheroid of equilibrium, derived a theorem from which the ellipticity of
the earth can be derived from values of the intensity of gravity.

[Illustration: Figure 34.--AN EXHIBIT OF GRAVITY APPARATUS at the
Smithsonian Institution. Suspended on the wall, from left to right, are
the invariable pendulums of Mendenhall (1/2-second), Peirce (1873-1874),
and Peirce (1881-1882); the double pendulum of Edward Kuebel (see fig.
15, p. 319), and the reversible pendulum of Peirce. On the display
counter, from left to right, are the vacuum chamber, telescope and flash
apparatus for the Mendenhall 1/4-second apparatus. Shown below these are
the four pendulums used with the Mendenhall apparatus, the one on the
right having a thermometer attached. At bottom, right, is the Gulf
apparatus (cover removed) mentioned in the text, shown with one quartz

Early in the 19th century a systematic series of observations began to
be conducted in order to determine the intensity of gravity at stations
all over the world. Kater invariable pendulums, of which 13 examples
have been mentioned in the literature, were used in surveys of gravity
by Kater, Sabine, Goldingham, and other British pendulum swingers. As
has been noted previously, a Kater invariable pendulum was used by Adm.
Luetke of Russia on a trip around the world. The French also sent out
expeditions to determine values of gravity. After several decades of
relative inactivity, Capts. Basevi and Heaviside of the Indian Survey
carried out an important series of observations from 1865 to 1873 with
Kater invariable pendulums and the Russian Repsold-Bessel pendulums. In
1881-1882 Maj. J. Herschel swung Kater invariable pendulums nos. 4, 6
(1821), and 11 at stations in England and then brought them to the
United States in order to make observations which would connect American
and English base stations.[109]

The extensive sets of observations of gravity provided the basis of
calculations of the ellipticity of the earth. Col. A. R. Clarke in his
_Geodesy_ (London, 1880) calculated the ellipticity from the results of
gravity surveys to be 1/(292.2 +- 1.5). Of interest is the calculation by
Charles S. Peirce, who used only determinations made with Kater
invariable pendulums and corrected for elevation, atmospheric effect,
and expansion of the pendulum through temperature.[110] He calculated
the ellipticity of the earth to be 1/(291.5 +- 0.9).

The 19th century witnessed the culmination of the ellipsoidal era of
geodesy, but the rapid accumulation of data made possible a better
approximation to the figure of the earth by the geoid. The geoid is
defined as the average level of the sea, which is thought of as extended
through the continents. The basis of geodetic calculations, however, is
an ellipsoid of reference for which a gravity formula expresses the
value of normal gravity at a point on the ellipsoid as a function of
gravity at sea level at the equator, and of latitude. The general
assembly of the International Union of Geodesy and Geophysics, which was
founded after World War I to continue the work of _Die Internationale
Erdmessung_, adopted in 1924 an international reference ellipsoid,[111]
of which the ellipticity, or flattening, is Hayford's value 1/297. In
1930, the general assembly adopted a correlated International Gravity
Formula of the form

[gamma] = [gamma]_{E}(1 + [beta]sin^{2} [phi] + [epsilon]sin^{2} 2[phi])

where [gamma] is normal gravity at latitude [phi], [gamma]_{E} is the
value of gravity at sea level at the equator, [beta] is a parameter
which is computed on the basis of Clairaut's theorem from the flattening
value of the meridian, and [epsilon] is a constant which is derived
theoretically. The plumb line is perpendicular to the geoid, and the
components of angle between the perpendiculars to geoid and reference
ellipsoid are deflections of the vertical. The geoid is above the
ellipsoid of reference under mountains and it is below the ellipsoid on
the oceans, where the geoid coincides with mean sea level. In physical
geodesy, gravimetric data are used for the determination of the geoid
and components of deflections of the vertical. For this purpose, one
must reduce observed values of gravity to sea level by various
reductions, such as free-air, Bouguer, isostatic reductions. If g_{0} is
observed gravity reduced to sea level and [gamma] is normal gravity
obtained from the International Gravity Formula, then

  [Delta]g = g_{0} - [gamma]

is the gravity anomaly.[112]

In 1849, Stokes derived a theorem whereby the distance N of the geoid
from the ellipsoid of reference can be obtained from an integration of
gravity anomalies over the surface of the earth. Vening Meinesz further
derived formulae for the calculation of components of the deflection of
the vertical.

Geometrical geodesy, which was based on astronomical-geodetic methods,
could give information only concerning the external form of the figure
of the earth. The gravimetric methods of physical geodesy, in
conjunction with methods such as those of seismology, enable scientists
to test hypotheses concerning the internal structure of the earth.
Heiskanen and Vening Meinesz summarize the present-day achievements of
the gravimetric method of physical geodesy by stating[113] that it
alone can give:

    1. The flattening of the reference ellipsoid.

    2. The undulations N of the geoid.

    3. The components of the deflection of the vertical [xi] and
    [eta] at any point, oceans and islands included.

    4. The conversion of existing geodetic systems to the same world
    geodetic system.

    5. The reduction of triangulation base lines from the geoid to
    the reference ellipsoid.

    6. The correction of errors in triangulation in mountainous
    regions due to the effect of the deflections of the vertical.

    7. Geophysical applications of gravity measurements, e.g., the
    isostatic study of the earth's interior and the exploration of
    oil fields and ore deposits.

With astronomical observations or with existing triangulations, the
gravimetric method can accomplish further results. Heiskanen and Vening
Meinesz state:

    It is the firm conviction of the authors that the gravimetric
    method is by far the best of the existing methods for solving
    the main problems of geodesy, i.e., to determine the shape of
    the geoid on the continents as well as at sea and to convert the
    existing geodetic systems to the world geodetic system. It can
    also give invaluable help in the computation of the reference


Since the creation of classical mechanics in the 17th century, the
pendulum has been a basic instrument for the determination of the
intensity of gravity, which is expressed as the acceleration of a freely
falling body. Basis of theory is the simple pendulum, whose time of
swing under gravity is proportional to the square root of the length
divided by the acceleration due to gravity. Since the length of a simple
pendulum divided by the square of its time of swing is equal to the
length of a pendulum that beats seconds, the intensity of gravity also
has been expressed in terms of the length of the seconds pendulum. The
reversible compound pendulum has served for the absolute determination
of gravity by means of a theory developed by Huygens. Invariable
compound pendulums with single axes also have been used to determine
relative values of gravity by comparative times of swing.

The history of gravity pendulums begins with the ball or "simple"
pendulum of Galileo as an approximation to the ideal simple pendulum.
Determinations of the length of the seconds pendulum by French
scientists culminated in a historic determination at Paris by Borda and
Cassini, from the corrected observations with a long ball pendulum. In
the 19th century, Bessel found the length of the seconds pendulum at
Koenigsberg and Berlin by observations with a ball pendulum and by
original theoretical considerations. During the century, however, the
compound pendulum came to be preferred for absolute and relative

Capt. Henry Kater, at London, constructed the first convertible compound
for an absolute determination of gravity, and then he designed an
invariable compound pendulum, examples of which were used for relative
determinations at various stations in Europe and elsewhere. Bessel
demonstrated theoretically the advantages of a reversible compound
pendulum which is symmetrical in form and is hung by interchangeable
knives. The firm of A. Repsold and Sons in Hamburg constructed pendulums
from the specifications of Bessel for European gravity surveys.

Charles S. Peirce in 1875 received delivery in Hamburg of a
Repsold-Bessel pendulum for the U.S. Coast Survey and observed with it
in Geneva, Paris, Berlin, and London. Upon an initial stimulation from
Baeyer, founder of _Die Europaeische Gradmessung_, Peirce demonstrated by
experiment and theory that results previously obtained with the Repsold
apparatus required correction, because of the flexure of the stand under
oscillations of the pendulum. At the Stuttgart conference of the
geodetic association in 1877, Herve Faye proposed to solve the problem
of flexure by swinging two similar pendulums from the same support with
equal amplitudes and in opposite phases. Peirce, in 1879, demonstrated
theoretically the soundness of the method and presented a design for its
application, but the "double pendulum" was rejected at that time. Peirce
also designed and had constructed four examples of a new type of
invariable, reversible pendulum of cylindrical form which made possible
the experimental study of Stokes' theory of the resistance to motion of
a pendulum in a viscous fluid. Commandant Defforges, of France, also
designed and used cylindrical reversible pendulums, but of different
length so that the effect of flexure was eliminated in the reduction of
observations. Maj. Robert von Sterneck, of Austria-Hungary, initiated a
new era in gravity research by the invention of an apparatus with a
short pendulum for relative determinations of gravity. Stands were then
constructed in Europe on which two or four pendulums were hung at the
same time. Finally, early in the present century, Vening Meinesz found
that the Faye-Peirce method of swinging pendulums hung on a Stueckrath
four-pendulum stand solved the problem of instability due to the
mobility of the soil in Holland.

The 20th century has witnessed increasing activity in the determination
of absolute and relative values of gravity. Gravimeters have been
perfected and have been widely used for rapid relative determinations,
but the compound pendulums remain as indispensable instruments.
Mendenhall's replacement of knives by planes attached to nonreversible
pendulums has been used also for reversible ones. The Geodetic Institute
at Potsdam is presently applying the Faye-Peirce method to the
reversible pendulum.[115] Pendulums have been constructed of new
materials, such as invar, fused silica, and fused quartz. Minimum
pendulums for precise relative determinations have been constructed and
used. Reversible pendulums have been made with "I" cross sections for
better stiffness. With all these modifications, however, the foundations
of the present designs of compound pendulum apparatus were created in
the 19th century.

       *       *       *       *       *


    [1] The basic historical documents have been collected, with a
        bibliography of works and memoirs published from 1629 to the end
        of 1885, in _Collection de memoires relatifs a la physique,
        publies par la Societe francaise de Physique_ [hereinafter
        referred to as _Collection de memoires_]: vol. 4, _Memoires sur
        le pendule, precedes d'une bibliographie_ (Paris:
        Gauthier-Villars, 1889); and vol. 5, _Memoires sur le pendule_,
        part 2 (Paris: Gauthier-Villars, 1891). Important secondary
        sources are: C. WOLF, "Introduction historique," pp. 1-42 in
        vol. 4, above; and GEORGE BIDDELL AIRY, "Figure of the Earth,"
        pp. 165-240 in vol. 5 of _Encyclopaedia metropolitana_ (London,

    [2] Galileo Galilei's principal statements concerning the pendulum
        occur in his _Discourses Concerning Two New Sciences_, transl.
        from Italian and Latin into English by Henry Crew and Alfonso de
        Salvio (Evanston: Northwestern University Press, 1939), pp.
        95-97, 170-172.

    [3] P. MARIN MERSENNE, _Cogitata physico-mathematica_ (Paris, 1644),
        p. 44.

    [4] CHRISTIAAN HUYGENS, _Horologium oscillatorium, sive de motu
        pendulorum ad horologia adaptato demonstrationes geometricae_
        (Paris, 1673), proposition 20.

    [5] The historical events reported in the present section are from
        AIRY, "Figure of the Earth."

    [6] ABBE JEAN PICARD, _La Mesure de la terre_ (Paris, 1671). JOHN W.
        OLMSTED, "The 'Application' of Telescopes to Astronomical
        Instruments, 1667-1669," _Isis_ (1949), vol. 40, p. 213.

    [7] The toise as a unit of length was 6 Paris feet or about 1,949

    [8] JEAN RICHER, _Observations astronomiques et physiques faites en
        l'isle de Caienne_ (Paris, 1679). JOHN W. OLMSTED, "The
        Expedition of Jean Richer to Cayenne 1672-1673," _Isis_ (1942),
        vol. 34, pp. 117-128.

    [9] The Paris foot was 1.066 English feet, and there were 12 lines to
        the inch.

   [10] CHRISTIAAN HUYGENS, "De la cause de la pesanteur," _Divers
        ouvrages de mathematiques[mathematiques] et de physique par MM.
        de l'Academie Royale[Royal] des Sciences_ (Paris, 1693), p. 305.

   [11] ISAAC NEWTON, _Philosophiae naturalis principia mathematica_
        (London, 1687), vol. 3, propositions 18-20.

   [12] PIERRE BOUGUER, _La figure de la terre, determinee par les
        observations de Messieurs Bouguer et de La Condamine, envoyes
        par ordre du Roy au Perou, pour observer aux environs de
        l'equateur_ (Paris, 1749).

   [13] P. L. MOREAU DE MAUPERTUIS, _La figure de la terre determinee par
        les observations de Messieurs de Maupertuis, Clairaut, Camus, Le
        Monnier, l'Abbe Outhier et Celsius, faites par ordre du Roy au
        cercle polaire_ (Paris, 1738).

   [14] Paris, 1743.

   [15] GEORGE GABRIEL STOKES, "On Attraction and on Clairaut's Theorem,"
        _Cambridge and Dublin Mathematical Journal_ (1849), vol. 4, p.

   [16] See _Collection de memoires_, vol. 4, p. B-34, and J. H. POYNTING
        and SIR J. J. THOMSON, _Properties of Matter_ (London, 1927), p.

   [17] POYNTING and THOMSON, ibid., p. 22.

   [18] CHARLES M. DE LA CONDAMINE, "De la mesure du pendule a Saint
        Domingue," _Collection de memoires_, vol. 4, pp. 3-16.

   [19] PERE R. J. BOSCOVICH, _Opera pertinentia ad Opticam et
        Astronomiam_ (Bassani, 1785), vol. 5, no. 3.

   [20] J. C. BORDA and J. D. CASSINI DE THURY, "Experiences pour
        connaitre la longueur du pendule qui bat les secondes a Paris,"
        _Collection de memoires_, vol. 4, pp. 17-64.

   [21] F. W. BESSEL, "Untersuchungen ueber die Laenge des einfachen
        Secundenpendels," _Abhandlungen der Koeniglichen Akademie der
        Wissenschaften zu Berlin, 1826_ (Berlin, 1828).

   [22] Bessel used as a standard of length a toise which had been made
        by Fortin in Paris and had been compared with the original of
        the "toise de Peru" by Arago.

   [23] L. G. DU BUAT, _Principes d'hydraulique_ (Paris, 1786). See
        excerpts in _Collection de memoires_, pp. B-64 to B-67.

   [24] CAPT. HENRY KATER, "An Account of Experiments for Determining the
        Length of the Pendulum Vibrating Seconds in the Latitude of
        London," _Philosophical Transactions of the Royal Society of
        London_ (1818), vol. 108, p. 33. [Hereinafter abbreviated _Phil.

   [25] M. G. DE PRONY, "Methode pour determiner la longueur du pendule
        simple qui bat les secondes," _Collection de memoires_, vol. 4,
        pp. 65-76.

   [26] _Collection de memoires_, vol. 4, p. B-74.

   [27] _Phil. Trans._ (1819), vol. 109, p. 337.

   [28] JOHN HERSCHEL, "Notes for a History of the Use of Invariable
        Pendulums," _The Great Trigonometrical Survey of India_
        (Calcutta, 1879), vol. 5.

   [29] CAPT. EDWARD SABINE, "An Account of Experiments to Determine the
        Figure of the Earth," _Phil. Trans._ (1828), vol. 118, p. 76.

   [30] JOHN GOLDINGHAM, "Observations for Ascertaining the Length of the
        Pendulum at Madras in the East Indies," _Phil. Trans._ (1822),
        vol. 112, p. 127.

   [31] BASIL HALL, "Letter to Captain Kater Communicating the Details of
        Experiments made by him and Mr. Henry Foster with an Invariable
        Pendulum," _Phil. Trans._ (1823), vol. 113, p. 211.

   [32] See _Collection de memoires_, vol. 4, p. B-103.

   [33] Ibid., p. B-88.

   [34] Ibid., p. B-94.

   [35] FRANCIS BAILY, "On the Correction of a Pendulum for the Reduction
        to a Vacuum, Together with Remarks on Some Anomalies Observed in
        Pendulum Experiments," _Phil. Trans._ (1832), vol. 122, pp.
        399-492. See also _Collection de memoires_, vol. 4, pp. B-105,
        B-112, B-115, B-116, and B-117.

   [36] One was of case brass and the other of rolled iron, 68 in. long,
        2 in. wide, and 1/2 in. thick. Triangular knife edges 2 in. long
        were inserted through triangular apertures 19.7 in. from the
        center towards each end. These pendulums seem not to have
        survived. There is, however, in the collection of the U.S.
        National Museum, a similar brass pendulum, 37-5/8 in. long (fig.
        15) stamped with the name of Edward Kuebel (1820-96), who
        maintained an instrument business in Washington, D.C., from
        about 1849. The history of this instrument is unknown.

   [37] See Baily's remarks in the _Monthly Notices of the Royal
        Astronomical Society_ (1839), vol. 4, pp. 141-143. See also
        letters mentioned in footnote 38.

   [38] This document, together with certain manuscript notes on the
        pendulum experiments and six letters between Wilkes and Baily,
        is in the U.S. National Archives, Navy Records Gp. 37. These
        were the source materials for the information presented here on
        the Expedition. We are indebted to Miss Doris Ann Esch and Mr.
        Joseph Rudmann of the staff of the U.S. National Museum for
        calling our attention to this early American pendulum work.

   [39] G. B. AIRY, "Account of Experiments Undertaken in the Harton
        Colliery, for the Purpose of Determining the Mean Density of the
        Earth," _Phil. Trans._ (1856), vol. 146, p. 297.

   [40] T. C. MENDENHALL, "Measurements of the Force of Gravity at Tokyo,
        and on the Summit of Fujiyama," _Memoirs of the Science
        Department, University of Tokyo_ (1881), no. 5.

   [41] J. T. WALKER, _Account of Operations of The Great Trigonometrical
        Survey of India_ (Calcutta, 1879), vol. 5, app. no. 2.

   [42] BESSEL, op. cit. (footnote 21), article 31.

   [43] C. A. F. PETERS, _Briefwechsel zwischen C. F. Gauss und H. C.
        Schumacher_ (Altona, Germany, 1860), _Band_ 2, p. 3. The
        correction required if the times of swing are not exactly the
        same is said to have been given also by Bohnenberger.

   [44] F. W. BESSEL, "Construction eines symmetrisch geformten Pendels
        mit reciproken Axen, von Bessel," _Astronomische Nachrichten_
        (1849), vol. 30, p. 1.

   [45] E. PLANTAMOUR, "Experiences faites a Geneve avec le pendule a
        reversion," _Memoires de la Societe de Physique et d'histoire
        naturelle de Geneve, 1865_ (Geneva, 1866), vol. 18, p. 309.

   [46] Ibid., pp. 309-416.

   [47] C. CELLERIER, "Note sur la Mesure de la Pesanteur par le
        Pendule," _Memoires de la Societe de Physique et d'histoire
        naturelle de Geneve, 1865_ (Geneva, 1866), vol. 18, pp. 197-218.

   [48] A. SAWITSCH, "Les variations de la pesanteur dans les provinces
        occidentales de l'Empire russe," _Memoirs of the Royal
        Astronomical Society_ (1872), vol. 39, p. 19.

   [49] J. J. BAEYER, _Ueber die Groesse und Figur der Erde_ (Berlin,

   [50] _Comptes-rendus de la Conference Geodesique Internationale reunie
        a Berlin du 15-22 Octobre 1864_ (Neuchatel, 1865).

   [51] Ibid., part III, subpart E.

   [52] _Bericht ueber die Verhandlungen der vom 30 September bis 7
        October 1867 zu Berlin abgehaltenen allgemeinen Conferenz der
        Europaeischen Gradmessung_ (Berlin, 1868). See report of fourth
        session, October 3, 1867.

   [53] C. BRUHNS and ALBRECHT, "Bestimmung der Laenge des
        Secundenpendels in Bonn, Leiden und Mannheim,"
        _Astronomisch-Geodaetische Arbeiten im Jahre 1870_ (Leipzig:
        Veroeffentlichungen des Koeniglichen Preussischen Geodaetischen
        Instituts, 1871).

   [54] _Bericht ueber die Verhandlungen der vom 23 bis 28 September 1874
        in Dresden abgehaltenen vierten allgemeinen Conferenz der
        Europaeischen Gradmessung_ (Berlin, 1875). See report of second
        session, September 24, 1874.

   [55] CAROLYN EISELE, "Charles S. Peirce--Nineteenth-Century Man of
        Science," _Scripta Mathematica_ (1959), vol 24, p. 305. For the
        account of the work of Peirce, the authors are greatly indebted
        to this pioneer paper on Peirce's work on gravity. It is worth
        noting that the history of pendulum work in North America goes
        back to the celebrated Mason and Dixon, who made observations of
        "the going rate of a clock" at "the forks of the river
        Brandiwine in Pennsylvania," in 1766-67. These observations were
        published in _Phil. Trans._ (1768), vol. 58, pp. 329-335.

   [56] The pendulums with conical bobs are described and illustrated in
        E. D. PRESTON, "Determinations of Gravity and the Magnetic
        Elements in Connection with the United States Scientific
        Expedition to the West Coast of Africa, 1889-90," _Report of the
        Superintendent of the Coast and Geodetic Survey for 1889-90_
        (Washington, 1891), app. no. 12.

   [57] EISELE, op. cit. (footnote 55), p. 311.

   [58] The record of Peirce's observations in Europe during 1875-76 is
        given in C. S. PEIRCE, "Measurements of Gravity at Initial
        Stations in America and Europe," _Report of the Superintendent
        of the Coast Survey for 1875-76_ (Washington, 1879), pp. 202-337
        and 410-416. Peirce's report is dated December 13, 1878, by
        which time the name of the Survey had been changed to U.S. Coast
        and Geodetic Survey.

   [59] _Verhandlungen der vom 20 bis 29 September 1875 in Paris
        Vereinigten Permanenten Commission der Europaeischen
        Gradmessung_ (Berlin, 1876).

   [60] Ibid. See report for fifth session, September 25, 1875.

   [61] The experiments at the Stevens Institute, Hoboken, were reported
        by Peirce to the Permanent Commission which met in Hamburg,
        September 4-8, 1878, and his report was published in the general
        _Bericht_ for 1878 in the _Verhandlungen der vom 4 bis 8
        September 1878 in Hamburg Vereinigten Permanenten Commission der
        Europaeischen Gradmessung_ (Berlin, 1879), pp. 116-120.
        Assistant J. E. Hilgard attended for the U.S. Coast and Geodetic
        Survey. The experiments are described in detail in C. S. PEIRCE,
        "On the Flexure of Pendulum Supports," _Report of the
        Superintendent of the U.S. Coast and Geodetic Survey for
        1880-81_ (Washington, 1883), app. no. 14, pp. 359-441.

   [62] _Verhandlungen der vom 5 bis 10 Oktober 1876 in Brussels
        Vereinigten Permanenten Commission der Europaeischen
        Gradmessung_ (Berlin, 1877). See report of third session,
        October 7, 1876.

   [63] _Verhandlungen der vom 27 September bis 2 Oktober 1877 zu
        Stuttgart abgehaltenen fuenften allgemeinen Conferenz der
        Europaeischen Gradmessung_ (Berlin, 1878).

   [64] _Verhandlung der vom 16 bis 20 September 1879 in Genf Vereinigten
        Permanenten Commission der Europaeischen Gradmessung_ (Berlin,

   [65] _Assistants' Reports, U.S. Coast and Geodetic Survey, 1879-80._
        Peirce's paper was published in the _American Journal of
        Science_ (1879), vol. 18, p. 112.

   [66] _Comptes-rendus de l'Academie des Sciences_ (Paris, 1879), vol.
        89, p. 462.

   [67] _Verhandlungen der vom 13 bis 16 September 1880 zu Muenchen
        abgehaltenen sechsten allgemeinen Conferenz der Europaeischen
        Gradmessung_ (Berlin, 1881).

   [68] Ibid., app. 2.

   [69] Ibid., app. 2a.

   [70] _Verhandlungen der vom 11 bis zum 15 September 1882 im Haag
        Vereinigten Permanenten Commission der Europaeischen
        Gradmessung_ (Berlin, 1883).

   [71] _Verhandlungen der vom 15 bis 24 Oktober 1883 zu Rom abgehaltenen
        siebenten allgemeinen Conferenz der Europaeischen Gradmessung_
        (Berlin, 1884). Gen. Cutts attended for the U.S. Coast and
        Geodetic Survey.

   [72] Ibid., app. 6. See also, _Zeitschrift fuer Instrumentenkunde_
        (1884), vol. 4, pp. 303 and 379.

   [73] Op. cit. (footnote 67).

   [74] _Report of the Superintendent of the U.S. Coast and Geodetic
        Survey for 1880-81_ (Washington, 1883), p. 26.

   [75] _Report of the Superintendent of the U.S. Coast and Geodetic
        Survey for 1889-90_ (Washington, 1891), app. no. 12.

   [76] _Report of the Superintendent of the U.S. Coast and Geodetic
        Survey for 1881-82_ (Washington, 1883).

   [77] _Transactions of the Cambridge Philosophical Society_ (1856),
        vol. 9, part 2, p. 8. Also published in _Mathematical and
        Physical Papers_ (Cambridge, 1901), vol. 3, p. 1.

   [78] Peirce's comparison of theory and experiment is discussed in a
        report on the Peirce memoir by WILLIAM FERREL, dated October 19,
        1890, Martinsburg, West Virginia. _U.S. Coast and Geodetic
        Survey, Special Reports, 1887-1891_ (MS, National Archives,

   [79] The stations at which observations were conducted with the Peirce
        pendulums are recorded in the reports of the Superintendent of
        the U.S. Coast and Geodetic Survey from 1881 to 1890.

   [80] _Comptes-rendus de l'Academie des Sciences_ (Paris, 1880), vol.
        90, p. 1401. HERVE FAYE's report, dated June 21, 1880, is in the
        same _Comptes-rendus_, p. 1463.

   [81] COMMANDANT C. DEFFORGES, "Sur l'Intensite absolue de la
        pesanteur," _Journal de Physique_ (1888), vol. 17, pp. 239, 347,
        455. See also, DEFFORGES, "Observations du pendule," _Memorial
        du Depot general de la Guerre_ (Paris, 1894), vol. 15. In the
        latter work, Defforges described a pendulum "reversible
        inversable," which he declared to be truly invariable and
        therefore appropriate for relative determinations. The knives
        remained fixed to the pendulums, and the effect of interchanging
        knives was obtained by interchanging weights within the pendulum

   [82] Papers by MAJ. VON STERNECK in _Mitteilungen des K. u. K.
        Militaer-geographischen Instituts, Wien_, 1882-87; see, in
        particular, vol. 7 (1887).

   [83] T. C. MENDENHALL, "Determinations of Gravity with the New
        Half-Second Pendulum...," _Report of the Superintendent of the
        U.S. Coast and Geodetic Survey for 1890-91_ (Washington, 1892),
        part 2, pp. 503-564.

   [84] W. H. BURGER, "The Measurement of the Flexure of Pendulum
        Supports with the Interferometer," _Report of the Superintendent
        of the U.S. Coast and Geodetic Survey for 1909-10_ (Washington,
        1911), app. no. 6.

   [85] E. J. BROWN, _A Determination of the Relative Values of Gravity
        at Potsdam and Washington_ (Special Publication No. 204, U.S.
        Coast and Geodetic Survey; Washington, 1936).

   [86] M. HAID, "Neues Pendelstativ," _Zeitschrift fuer
        Instrumentenkunde_ (July 1896), vol. 16, p. 193.

   [87] DR. R. SCHUMANN, "Ueber eine Methode, das Mitschwingen bei
        relativen Schweremessungen zu bestimmen," _Zeitschrift fuer
        Instrumentenkunde_ (January 1897), vol. 17, p. 7. The design for
        the stand is similar to that of Peirce's of 1879.

   [88] DR. R. SCHUMANN, "Ueber die Verwendung zweier Pendel auf
        gemeinsamer Unterlage zur Bestimmung der Mitschwingung,"
        _Zeitschrift fuer Mathematik und Physik_ (1899), vol. 44, p. 44.

   [89] P. FURTWAENGLER, "Ueber die Schwingungen zweier Pendel mit
        annaehernd gleicher Schwingungsdauer auf gemeinsamer Unterlage,"
        _Sitzungsberichte der Koeniglicher Preussischen Akademie der
        Wissenschaften zu Berlin_ (Berlin, 1902) pp. 245-253. Peirce
        investigated the plan of swinging two pendulums on the same
        stand (_Report of the Superintendent of the U.S. Coast and
        Geodetic Survey for 1880-81_, Washington, 1883, p. 26; also in
        CHARLES SANDERS PEIRCE, _Collected Papers_, 6.273). At a
        conference on gravity held in Washington during May 1882, Peirce
        again advanced the method of eliminating flexure by hanging two
        pendulums on one support and oscillating them in antiphase
        ("Report of a conference on gravity determinations held in
        Washington, D.C., in May, 1882," _Report of the Superintendent
        of the U.S. Coast and Geodetic Survey for 1881-82_, Washington,
        1883, app. no. 22, pp. 503-516).

   [90] F. A. VENING MEINESZ, _Observations de pendule dans les Pays-Bas_
        (Delft, 1923).

   [91] A. BERROTH, "Schweremessungen mit zwei und vier gleichzeitig auf
        demselben Stativ schwingenden Pendeln," _Zeitschrift fuer
        Geophysik_, vol. 1 (1924-25), no. 3, p. 93.

   [92] "Pendulum Apparatus for Gravity Determinations," _Engineering_
        (1926), vol. 122, pp. 271-272.

   [93] MALCOLM W. GAY, "Relative Gravity Measurements Using Precision
        Pendulum Equipment," _Geophysics_ (1940), vol. 5, pp. 176-191.

   [94] L. G. D. THOMPSON, "An Improved Bronze Pendulum Apparatus for
        Relative Gravity Determinations," [published by] _Dominion
        Observatory_ (Ottawa, 1959), vol. 21, no. 3, pp. 145-176.

   [95] W. A. HEISKANEN and F. A. VENING MEINESZ, _The Earth and its
        Gravity Field_ (McGraw: New York, 1958).

   [96] F. KUEHNEN and P. FURTWAENGLER, _Bestimmung der Absoluten Groesze
        der Schwerkraft zu Potsdam mit Reversionspendeln_ (Berlin:
        Veroeffentlichungen des Koeniglichen Preussischen Geodaetischen
        Instituts, 1906), new ser., no. 27.

   [97] Reported by Dr. F. Kuehnen to the fifth session, October 9, 1895,
        of the Eleventh General Conference, _Die Internationale
        Erdmessung_, held in Berlin from September 25 to October 12,
        1895. A footnote states that Assistant O. H. Tittmann, who
        represented the United States, subsequently reported Peirce's
        prior discovery of the influence of the flexure of the pendulum
        itself upon the period (_Report of the Superintendent of the
        U.S. Coast and Geodetic Survey for 1883-84_, Washington, 1885,
        app. 16, pp. 483-485).

   [98] _Assistants' Reports, U.S. Coast and Geodetic Survey, 1883-84_
        (MS, National Archives, Washington).

   [99] C. S. PEIRCE, "Effect of the Flexure of a Pendulum Upon its
        Period of Oscillation," _Report of the Superintendent of the
        U.S. Coast and Geodetic Survey for 1883-84_ (Washington, 1885),
        app. no. 16.

  [100] F. R. HELMERT, _Beitraege zur Theorie des Reversionspendels_
        (Potsdam: Veroeffentlichungen des Koeniglichen Preussischen
        Geodaetischen Instituts, 1898).

  [101] J. A. DUERKSEN, _Pendulum Gravity Data in the United States_
        (Special Publication No. 244, U.S. Coast and Geodetic Survey;
        Washington, 1949).

  [102] Ibid., p. 2. See also, E. J. BROWN, loc. cit. (footnote 85).

  [103] PAUL R. HEYL and GUY S. COOK, "The Value of Gravity at
        Washington," _Journal of Research, National Bureau of Standards_
        (1936), vol. 17, p. 805.

  [104] SIR HAROLD JEFFREYS, "The Absolute Value of Gravity," _Monthly
        Notices of the Royal Astronomical Society, Geophysical
        Supplement_ (London, 1949), vol. 5, p. 398.

  [105] J. S. CLARK, "The Acceleration Due to Gravity," _Phil. Trans._
        (1939), vol. 238, p. 65.

  [106] HUGH L. DRYDEN, "A Reexamination of the Potsdam Absolute
        Determination of Gravity," _Journal of Research, National Bureau
        of Standards_ (1942), vol. 29, p. 303; and A. BERROTH, "Das
        Fundamentalsystem der Schwere im Lichte neuer
        Reversionspendelmessungen," _Bulletin Geodesique_ (1949), no.
        12, pp. 183-204.

  [107] T. C. MENDENHALL, op. cit. (footnote 83), p. 522.

  [108] A. H. COOK, "Recent Developments in the Absolute Measurement of
        Gravity," _Bulletin Geodesique_ (June 1, 1957), no. 44, pp.

  [109] See footnote 89.

  [110] C. S. PEIRCE, "On the Deduction of the Ellipticity of the Earth,
        from Pendulum Experiments," _Report of the Superintendent of the
        U.S. Coast and Geodetic Survey for 1880-81_ (Washington, 1883),
        app. no. 15, pp. 442-456.

  [111] HEISKANEN and VENING MEINESZ, op. cit. (footnote 95), p. 74.

  [112] Ibid., p. 76.

  [113] Ibid., p. 309.

  [114] Ibid., p. 310.

  [115] K. REICHENEDER, "Method of the New Measurements at Potsdam by
        Means of the Reversible Pendulum," _Bulletin Geodesique_ (March
        1, 1959), no. 51, p.72.

       *       *       *       *       *

Paper 44 - Transcriber's Note

Formatting of equations has been altered from the original: variables
are shown without italics; to display them 'in line'; and brackets have
been added to clarify expressions where necessary.

Typographical errors and inconsistencies have been corrected as follows:

  Page 320: 'difference T_{1} - T_{2} is sufficiently' had 'sufficlently.'

  Page 321: 'faites à Genève avec le pendule à réversion' had 'reversion.'

  Page 326: 'Schwere mit Hilfe verschiedener Apparate' had 'verschiedene.'

  Page 328: 'between the yard and the meter.' closing quote mark deleted.

  Page 334: 'Mendenhall apparatus were part of' 'was' changed to 'were.'

  Page 342: 'of the Geodetic Institute at Potsdam' had 'Postdam.'

  Page 345: 'The gravimetric methods of physical' had 'mtehods.'

  Footnote 1 'Société française de Physique' had 'Française.'

  Footnote 3 'Cogitata physico-mathematica' had 'physica.'

  Footnote 10 'mathématiques et de physique par MM. de l'Académie Royale'
      had 'mathematiques,' 'Royal.'

  Footnote 12 'par ordre du Roy au Pérou, pour observer'
      had 'Perou, pour observir.'

  Footnote 19 'Opticam et Astronomiam' had 'Astronomian.'

  Footnote 20 'connaître la longueur du pendule qui'
      had 'connaitre la longuer.'

  Footnote 21 'Abhandlungen der Königlichen Akademie' had 'Königliche.'

  Footnote 25 'pour déterminer la longueur du pendule' had 'longeur.'

  Footnote 41 'Survey of India (Calcutta, 1879)' had 'Surey.'

  Footnotes 45 and 47 'Société de Physique et d'histoire'
      had 'd'historire.'

  Footnote 49 'Über die Grösse und Figur der Erde' had 'Grosse.'

  Footnote 53 'Bestimmung der Länge' had 'Lange';
      'Astronomisch-Geodätische Arbeiten' had 'Astronomische';
      'Veröffentlichungen des Königlichen' had 'Königliche.'

  Footnote 55 '(1768), vol. 58, pPage 3$1:-335.' had '329-235.'

  Footnote 66 'Comptes-rendus de l'Académie' had 'L'Académie.'

  Footnote 81 'Sur l'Intensité absolue' had 'l'Intensite.'

  Footnote 89 'Sitzungsberichte der Königlicher' had 'Königliche.'

  Footnote 100 'Veröffentlichungen des Königlichen'
      had 'Veröffentlichungen Königliche.'

  Capitalisation of 'Von'/'von' has been regulaized to 'von' for all
      personal names, except at the beginning of a sentence, and when
      referring to the Von Sterneck pendulum.

       *       *       *       *       *



  Adams, W. B., 252
  Agricola, Georgius, 215, 216
  Airy, G. B., 319, 324, 332
  Albrecht, Karl Theodore, 322, 338
  Aldini, Giovanni, 124
  Al-Mamun, seventh calif of Bagdad, 306
  Almansi, Emilio, 339
  Ames Manufacturing Company, 5, 7
  Ampère, André Marie, 127, 129
  Anckerswärd, Col. Michael, 157
  Angle, Edward H., 295
  Arago, Dominique François Jean, 129
  Aristarchus of Samos, 54
  Aristotle, 179, 306
  Astor, John Jacob, 141


  Baeyer, Adolf, 193
  Baeyer, J. J., 321, 322, 324-327, 338, 346
  Baily, Francis, 317
  Baldwin, Matthias William, 264
  Baltimore, Lord. _See_ Calvert.
  Barlow, Peter W., 221, 227
  Bartlett, Charles A., 8
  Basevi, James Palladio, 345
  Battison, E. A., 18
  Beach, Alfred Ely, 224, 227-229, 231, 237
  Bechil, Achild, 179
  Bemis, Will, 20-22, 27
  Bennet, Abraham, 124
  Bennett, Frank M., 139, 150, 165
  Benz, Carl, 6, 7
  Bergh, Christian, 145
  Berroth, A., 342
  Berthelot, Marcellin, 189
  Bertolla, Alessandro, 65
  Bertolla, Bartolomeo Antonio, 31, 34, 36-41, 47, 51, 52, 57-59, 62, 63
  Berzelius, Jöns Jakob, 133, 182
  Bessel, Friedrich Wilhelm, 313, 314, 319, 320, 324, 325, 338, 346
  Besson, Jacques, 107
  Bettany, G. T., 136
  Beyer, Dr. Henry Gustav, 275, 276
  Biddle, James, 141
  Biot, Jean Baptiste, 135, 325, 329
  Black, G. V., 295
  Black and Bell, plant at Stratford, 182
  Blake, John B., 290, 291
  Bohnenberger, Johann Gottlieb Friedrich, 315
  Bollman, W., and Company, 91, 92
  Bollman, Wendel, 79, 80-83, 85, 88-92, 94-97
  Borda, J. C., 311, 312, 315, 325, 329, 346
  Borghesi, Father Francesco, 31-59, 70, 71
  Boscovitch, Père R. J., 310, 311
  Boston Locomotive Works, 260
  Bouguer, Pierre, 307, 309-311, 327, 343, 345
  Boussingault, Jean Baptiste, 185
  Boyd, John C., 276
  Boyle, Robert, 178, 179
  Brackenridge, S. M., 145
  Brahe, Tycho, 54, 306
  Brand, H., 178, 179
  Brewington, M. V., 155
  Brown, Adam and Noah, 141, 142, 145
  Brown, Alexander Crosby, 165
  Brown, E. J., 334, 339
  Brown, Noah, 141, 150, 151
  Browne, Charles, 157
  Browne, Henry, 304, 314
  Browns' yard, 142, 144
  Bruhns, C., 322, 324, 338
  Brunel, I. K., 217, 218
  Brunel, Marc Isambard (the elder), 204, 205, 217, 218, 221, 224, 229,
     231, 236
  Brunner Brothers (Paris), 329
  Buchner, Hans, 197, 200
  Burleigh, Charles, 212, 213
  Burleigh Rock Drill Company, 212
  Burr, S. D. V., 236
  Butzjäger, Johann Georg, 36, 37


  Calvert, George, Lord Baltimore, 156
  Calvin, Melvin, 200
  Canning, Stratford, 139
  Carlisle, Anthony, 124
  Carrel, Alexis, 291
  Casciarolo, Vicenzo, 179
  Cassini, Giovanni-Domenico, 306, 307
  Cassini, Jacques, 306
  Cassini de Thury, J. D., 311, 312, 315, 325, 329, 346
  Cavallo, Tiberio, 124
  Cavendish, Henry, 123
  Cellérier, Charles, 320, 321, 325, 326, 329, 336
  Chapman, Fredrik Henrik af, 156, 166
  Charles II of England, 152, 153
  Charles VI, Emperor of Austria, 32
  Chevreul, Michel, 189
  Clairaut, Alexis Claude, 308, 309, 343, 345
  Clark, J. S., 342
  Clark, John, 91
  Clarke, A. R., 345
  Cles, Baron of, 57, 59
  Coast and Harbor Defense Company, 141
  Coast Defense Society, 141, 142
  Cochrane, Sir Thomas, 231, 232
  Colbert, Jean Baptiste, 306
  Colburn, Zerah, 259
  Colden, C. D., 149
  Coleman, Laurence V., 290
  Colgan, P., 10
  Colton, Arthur, and Company, 278
  Cook, A. H., 342
  Cook, Guy S., 339, 342
  Copernicus, 54
  Copperthwaite, William Charles, 224
  Cori, Carl F., 200
  Cori, Gerti T., 200
  Crookes, William, 192
  Cummings, James, 125, 127-129, 133-136


  Dagger, Benjamin M., 290
  Danforth Cooke & Co., 252
  Danish Greenland Company, 150
  Danish Royal Archives, 139, 150
  Davy, Sir Humphry, 185
  Dearborn, Henry, 141, 142
  Deats, William, 9
  Decatur, Stephen, 141
  Defforges, C., 314, 329, 346
  De Freycinet, Louis Claude de Saulses, 317
  De Hevesy, George, 198, 200
  De la Hire, Gabriel Philippe, 306
  De la Vega, Garcilaso, 185
  De Prony, M. G., 314
  Deptford Yard (England), 165
  De Saussure, Théodore, 185
  Di Noris, Cristoforo Sizzo, 59
  Dixon, William S., 276
  Doane, Thomas, 210, 212, 213, 215
  Dodrill, Forest D., 290
  Donner, Joseph, 277
  Douglas, W. & B., Company, 113
  Drake, Edwin L., 213
  Drinker, Henry S., 224, 237
  Drury, Gardner P., 260
  Dryden, Hugh L., 342
  Du Buat, L. G., 314
  Duperry, Capt. Louis Isidore, 317
  Duryea, Charles, 3-13, 15, 16, 19-21, 26, 27
  Duryea, J. Frank, 3-7, 9-13, 15-23, 26, 27
  Duryea Motor Corporation, 5
  Duryea Motor Wagon Company, 3, 27
  Duryea Power Company, 5


  Eastwick, Andrew M., 259
  Eckford, Henry, 142
  Einthoven, Willem, 290
  Emerson, John Haven, 285
  Emmet, ----, 144
  Eratosthenes, 306, 308, 342
  Erman, Paul, 128, 129, 132, 133
  Eudoxus of Cnidus, 306
  Euler-Chelpin, Hans von, 197, 200
  Evans, Samuel, 141, 145
  Evelyn, John, 32


  Faraday, Michael, 125
  Faye, Hervé, 325-327, 336-338, 346, 347
  Ferchl, Fritz, 285
  Fernel, Jean, 306
  Fernelius, Jean, 179
  Feulgen, Robert, 193
  Fink, Albert, 79, 91
  Fischelis, Robert P., 287
  Fischer, Emil, 193
  Fleming, Sir Alexander, 290, 295
  Flint, James Milton, 273-278
  Fox, Josiah, 157
  Francis I, Emperor of the Holy Roman Empire, 42, 44, 52, 58
  Fulton, Robert, 139, 141, 142, 144, 147, 149, 150, 157, 159, 165
  Furtwängler, P., 337-339


  Gahn, Johann Gottlieb, 182
  Galilei, Galileo, 304, 305, 346
  Galvani, Luigi, 124
  Garfield, James A., 272
  Garrison, Fielding H., 277
  Gauss, C. F., 320
  Gautier, P., 339
  Gay-Lussac, Joseph Louis, 125, 182
  Gilbert, L. W., 127-129, 132
  Gobley, Nicolas Théodore, 191
  Godin, Louis, 307
  Goldingham, John, 316, 345
  Goode, G. Brown, 273
  Graham, Thomas, 182, 183, 185
  Gravatt, C. U., 276
  Greathead, James Henry, 204, 218, 221, 224, 229, 231, 235-237
  Greely, A. W., 329
  Griffenhagen, George B., 290, 291
  Grubenmann, Hans, 85
  Grubenmann, Johann Ulrich, 85
  Gulf Oil and Development Company, 338
  Gurley, Ralph R. (USN), 150, 151
  Gustav III of Sweden, 156, 157
  Gwynn, Stuart, 210


  Hahn, Father Philipp Matthäus, 33
  Haid, M., 335
  Hall, Basil, 316
  Hammond, William Alexander, 273
  Hankwitz, Gottfried, 180
  Harden, Arthur, 197, 200
  Harrington, Frank, 7
  Harrison, Joseph, Jr., 259
  Hartford Machine Screw Company, 6
  Hartmann, Immanuel Peter, 181
  Haskin, DeWitt C., 204, 232, 234-236
  Haupt, Herman, 96, 204, 209, 210
  Hawley, C. E., 6, 11
  Hawthorn, Leslie, and Company (Scotland), 166
  Heaviside, W. J., 321, 345
  Heiskanen, W. A., 338, 345, 346
  Hellot, Jean, 180
  Helmert, F. R., 338, 339
  Helmholtz, Hermann von, 326
  Henderson, Alfred R., 291
  Henkel, Silon, 290
  Henry II, King of France, 179
  Herschel, John, 319, 328, 345
  Heyl, Paul R., 339, 342
  Hindle, Charles F., 290
  Hinkley, Holmes, 252, 260, 263
  Hirsch, Adolph, 322, 324-326
  Hittorf, Wilhelm, 181
  Hobson, Joseph, 237
  Hoefer, Ferdinand, 179
  Holmberg, Wilhelm, 178
  Holt, L. Emmett, 276
  Hoppe-Seyler, Felix, 193
  Howard, George W., & Company, 8
  Hull, A. S., 251, 268
  Humboldt, Alexander von, 185
  Huygens, Christiaan, 179, 304, 305, 307, 314, 342, 346


  Ibañez, Carlos, 325
  Incas, 185


  Jefferson, Thomas, 145
  Jeffreys, Sir Harold, 342
  Jones, Jacob, 141
  Jones, Thomas, 318
  Jones, William, 147


  Kater, Henry, 304, 314-320, 325, 327, 329, 345, 346
  Kells, Charles E., 295
  Klein, Father ----, 33
  Kletwich, Johann Christopher, 179
  Knight, ----, 83
  Koett, Albert B., 287
  Koppe, Émile, 181
  Kornberg, Arthur, 200
  Kossel, Albrecht, 200
  Kraft, Johann Daniel, 179
  Kramer, Dr. ----, 181
  Kühnen, F., 338, 339
  Kunckel, Johann, 179


  La Condamine, Charles Marie de, 307, 310, 311, 343
  Lange, W., 199
  Laplace, Marquis Pierre Simon de, 309, 313, 320
  Latrobe, Benjamin H., 82, 83, 85, 87-91, 208, 209
  Laurie, J., 157
  Lavoisier, Antoine Laurent, 181, 185
  Law, Henry, 218
  LaWall, Charles H., 285
  Laws, John Bennet, 186
  Lederle Laboratories, 290
  Leibnitz, Gottfried Wilhelm von, 179
  Lennox, Charles, third Duke of Richmond, 185
  Leonhardi, Johann Gottfried, 179
  Levine, Phoebus Aaron Theodor, 193
  Lewis, Jacob, 141
  Lewis, Morgan, 141
  Lewton, Frederick L., 277
  Liebig, Justus, 183, 185, 186
  Liebreich, Oscar, 191
  Lilly, Eli, and Company, 283
  Lindbergh, Charles A., 291
  Lipmann, Fritz, 200
  Lippi, Fra Lippo, 42
  London, E. S., 193
  Long, Crawford W., 294
  Long, Stephen H., 85
  Longomontanus, Christian Severin, 54
  Lorenzoni, Giuseppe, 336, 339
  Lütke, Count Feodor Petrovich, 316, 345


  Macquer, Peter Joseph, 180
  Marestier, Jean Baptiste, 147, 149, 159, 162
  Marggraf, Andreas Sigismund, 180
  Maria Theresa, Empress of Austria, 31, 41, 42, 44, 57, 58
  Mariners' Museum, 165
  Markham, Erwin F., 8, 9, 15, 16, 19-22, 27
  Marmion, R. A., 276
  Marsh, James, 145
  Marshall, Charles, 11, 16
  Maudslay, Henry, 106, 113
  Maupertius, P. L. Moreau de, 308, 343
  Maxwell, James Clerk, 324
  May, Arthur J., 139
  Mayer, Jo, 285
  McMurtrie, Daniel, 276
  Medi, Enrico, 342
  Meigs, M. C., 96
  Meineke, ----, 128
  Mendenhall, Thomas Corwin, 319, 331, 332, 334, 347
  Merrick, C. E., 10
  Mersenne, P. Marin, 305
  Meton, 48
  Meyerhof, Otto, 194, 200
  Miescher, Johann Friedrich, 192
  Miller, Patrick, 156, 157
  Mitchill, Samuel L., 141, 142
  Monauni, Giovanni Battista, 40, 52
  Monroe, James, 145
  Montgéry, M., 147, 149-152, 159
  Morgan, "Mr.", 144
  Morris, Tasker and Company, 94
  Morris, Thomas, 141, 142
  Morton, Arthur O., 290
  Morton, William, 294
  Mount Clair shops, 83, 89, 92
  Mowbray, George W., 213, 215
  Muspratt, James, 186


  Nagel, Oscar P., 295
  Nason, Joseph, 114
  National Maritime Museum (England), 147, 156, 165
  Nelson, Robert J., 295
  Nesbitt, Mr. and Mrs. D. H., 13
  Newton, Sir Isaac, 303-305, 307, 308, 342, 343
  Nicholson, William, 124
  Nietzsche, Friedrich, 186, 187, 189
  Nobel, Alfred B., 213
  North, Simeon, arms factory, 114
  Norwood, Richard, 306


  Ochoa, Severo, 200
  Oersted, Hans Christian, 125-130, 132-136
  Ohm, Georg Simon, 123, 135
  Oken, Lorenz, 132
  Olson, Carl G., 118
  Oppolzer, Theodor von, 322, 324-327
  Owen, H. S., 5


  Page, Irving, 4
  Parke, Davis & Company, 273
  Parmelee, L. J., 10
  Patapsco Bridge and Iron Works, 92, 95
  Patrick, Mr. and Mrs. ----, 13
  Patterson, Carlile Pollock, 325, 326
  Peirce, Charles Sanders, 314, 322-329, 332, 336-339, 342, 345-347
  Pelouze, Théophile Juste, 189
  Pepys, Samuel, 155
  Perry, Oliver, 141
  Peters, C. A. F., 322, 324
  Petty, Sir William, 152, 153, 155, 166
  Pfaff, Christian Heinrich, 132
  Philolaus, 54
  Phoenix Iron Works, 92
  Physick, Philip Syng, 294
  Picard, Abbé Jean, 306, 308-311, 342
  Plantamour, E., 319-321, 324-326
  Poggendorf, Johann Christian, 127-129, 132-134, 136
  Poissant, A. A., 10
  Pope Manufacturing Company, 6, 12
  Porter, David, 144
  Posidonius, 306
  Pratt, Thomas W., 91
  Preston, E. D., 328, 329
  Ptolemy, 54
  Purcell, William, 147
  Putnam, G. R., 339
  Putnam Machine Works, 212
  Pythagoras, 54, 306


  Quare, Daniel, 32


  Raschig, Christoph Eusebius, 129
  Rasmussen, Kjeld, 150
  Reed, D. A., 27
  Reeves, Samuel J., 92, 95
  Repsold, A., and Sons (Hamburg), 320, 322, 338, 339, 346
  Richer, Jean, 307, 342
  Richmond, Duke of. _See_ Lennox.
  Riciolus, 54
  Rigsarkivet (Denmark), 147
  Ritter, Johann Wilhelm, 129
  Roebling, John A., 83, 90
  Roentgen, Wilhelm Konrad, 290, 294
  Rouelle, Guillaume François, 181
  Royal Society of London, 152
  Russell, John W., & Sons Company, 9, 10, 18, 20
  Russell, William J., 9, 10, 15, 18
  Rutgers, Henry, 141, 142


  Sabine, Capt. Edward, 315, 325, 329, 345
  San Cajetano, Brother David à, 33
  San Daniele, Father Aurelianus à, 33
  Savage Factory, 88
  Savart, Felix, 135
  Sawitsch, A., 321, 322
  Scheele, Karl W., 182
  Schieffelin and Company, 273
  Schmiedeberg, Oswald, 193
  Schrader, Gerhard, 199
  Schrötter, Anton, 181
  Schumacher, H. C., 320
  Schumann, R., 335, 336
  Schweigger, Johann Salomo Christoph, 127-130, 132-134, 136
  Seebeck, T., 128, 135
  Shanley, Walter, 212
  Shanley Bros., 215
  Shea, T., 10
  Smith, ---- (Captain, USN), 144
  Smith, Alba F., 244, 246, 247, 259
  Smith, Sir Sidney (RN), 155
  Smith Carriage Company, 8
  Snell, Willebrord, 306
  Snow, ----, 8
  Soemmering, S. T., 125
  Sommeiller, Germain, 210
  Sonnedecker, Glenn, 296
  Speter, M., 127, 128
  Squibb, E. R., and Sons, 285, 286
  Statens Sjöhistoriska Museum (Sweden), 147
  Stephenson, Robert, 90
  Stephenson, Robert, & Hawthorns, Ltd., 253
  Sterneck, Robert von, 331, 332, 335, 338, 346
  Stevens, J., Arms and Tool Company, 4
  Stevens-Duryea Company, 4
  Stewart, Charles, 145
  Stiles, George, 144
  Stokes, George Gabriel, 324, 328, 329, 345, 346
  Stoklasa, Julius, 186
  Storrow, Charles S., 210
  Stoudinger, Charles, 144
  Strecker, Adolf Friedrich, 191
  Stuart, Charles B., 139, 150
  Stuart, J. E. B., 249
  Sully, Henry, 32
  Swaine, Jack, 26
  Symington, William, 157


  Tanner, Paul H., 295
  Taunton Locomotive Works, 247
  Taylor, Frank A., 292
  Tegmeyer, John H., 91
  Thames Iron-works Company (England), 165
  Thenard, Louis Jacques, 125
  Thomas, George S., 287
  Thudichum, Ludwig, 192
  Todd, Lord Alexander, 200
  Tompion, Thomas, 32
  Toner, Joseph Meredith, 271
  Tovazzi, Giangrisostomo, 57, 58
  Town, Ithiel, 85
  Tromsdorff, Johann Bartholomacus, 125
  Tweed, William Marcy (Boss), 229
  Tyler, Daniel, 244, 253
  Tyler, David B., 139


  Ulloa, Antonio de, 308
  Union Works, 260
  Uppercu, Inglis M., 27


  Vander Woerd, Charles, 116, 117
  Van Marum, Martin, 123
  Vening Meinesz, F. A., 337, 338, 345-347
  Volet, Charles, 342
  Volta, Alessandro, 123, 124, 127
  Vulcan Foundry, 252


  Wallace Brothers, 273
  Ward, Frederick A., 120
  Warrington, Samuel, 141
  Warwick, George, 18
  Watts, Frederick, 249
  Weale, John, 218
  Wernwag, Lewis, 89
  Westhaeffer, Paul, 251
  Wetmore, Dr. Alexander, 287
  Wetschgi, Emanuel, 108
  Wetschgi, Manuel, 108, 111
  Whipple, Squire, 79, 83, 87, 91, 95
  Whistler, George W., 83
  White, C. H., 276
  Whitebread, Charles, 277, 278, 281, 283, 285, 287
  Whitney arms factory, 114
  Wilkes, Charles, 317, 318
  Wilkinson, David, 113
  Williamson, Dowe, 32
  Williamson, Joseph, 32
  Willm, Edmond, 182
  Willstätter, Richard, 191
  Wilmarth, Seth, 244, 246, 247, 249, 260
  Wilson, Frank E., 290
  Wilstack, Paul, 155
  Winans, Ross, 83
  Winters, Joseph, 244
  Winters, Father S. X., S. J., 42
  Winz, Johann Christian, 36, 37
  Wisshofer, Peter, 36, 37
  Wolcott, Oliver, 141, 142
  Wollaston, W. H., 125
  Wright, Benjamin, 83
  Wurtz, Adolphe, 185, 191


  Youle, John, foundry, 142


  Zamboni, Giuseppe, 132

       *       *       *       *       *

Transcriber's Notes (Index)

    "Emmet, ----, 144" (was Emmett).

       *       *       *       *       *

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