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Title: Pumps and Hydraulics
Author: Rogers, Will
Language: English
As this book started as an ASCII text book there are no pictures available.
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.

*** Start of this Doctrine Publishing Corporation Digital Book "Pumps and Hydraulics" ***

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Transcriber’s Notes:

The spelling, punctuation and hyphenation are as the original except
for apparent typographical errors, which have been corrected.

  Italic text is denoted _thus_.
  Bold text is denoted =thus=.
  Bold, sans serif text, representing physical appearance e.g., of a
  ‘Vee’ shaped thread is denoted thus ^V^.
  Subscripts are denoted thus _{1}.

Some page numbers printed in the original ‘Index to Part One’ do not
appear in the body of the book . The transcriber has endeavoured to
make assumptions as to the most appropriate anchor locations. The
appearance of the original index has not been changed.

Examples (possibly relocated, by the author, into Part Two) are:

  =Air=, des., composition of, 15, 16
  =Air pump=, 13
  =Nitrogen=, what part of air, 15
  =Oxygen=, what part of air, 15

  =Value of Reidler belt-driven pump=, ills. and des., 238-240
  changed in the Index to:-
  =Valve of Riedler belt-driven pump=, ills. and des., 238-240

All references to ‘Reidler’ pumps have been corrected to ‘Riedler’
(Alois Riedler, 1850-1936, Austrian professor of engineering).



  PUMPS

  AND

  HYDRAULICS.

  IN TWO PARTS.

  Part One.



“_There are many fingers pointing to the value of a training in
science, as the one thing needful to make the man, who shall rise above
his fellows._”—FRANK ALLEN.


[Illustration: Elephant]


“_The motto marked upon our foreheads, written upon our door-posts,
channeled in the earth, and wafted upon the waves is and must be,
‘Labour is honorable and Idleness is dishonorable.’_”—CARLYLE.



  This work is respectfully dedicated to
  MAJ. ABRAM B. GARNER,
  of Newark, N. J.,

  —AND—

  ALBERTO H. CAFFEE, ESQ.,
  of New York City.

  ‘Gentlemen without fear and without reproach.’

[Illustration: _Henry R. Worthington_]



  “_Thought is the principal factor in all mechanical work; the
  mechanical effort is an incident rather than the principal equipment
  in any trade or occupation._”

  “_Any trade is easily learned by an apt scholar who uses his
  reasoning faculties and makes a study of cause and effect._”—CHAS. J.
  MASON.

  PUMPS

  —AND—

  HYDRAULICS

  —BY—

  WILLIAM ROGERS

  _Author of “Drawing and Design,” etc._


  [Illustration]


  _RELATING TO_

  HAND PUMPS; POWER PUMPS; PARTS OF PUMPS; ELECTRICALLY DRIVEN
  PUMPS; STEAM PUMPS, SINGLE, DUPLEX AND COMPOUND; PUMPING
  ENGINES, HIGH DUTY AND TRIPLE EXPANSION; THE STEAM FIRE
  ENGINE; UNDERWRITERS’ PUMPS; MINING PUMPS; AIR AND
  VACUUM PUMPS; COMPRESSORS; CENTRIFUGAL AND ROTARY
  PUMPS; THE PULSOMETER; JET PUMPS AND THE INJECTOR;
  UTILITIES AND ACCESSORIES; VALVE SETTING; MANAGEMENT;
  CALCULATIONS, RULES AND TABLES.
  _WITH ILLUSTRATIONS._

  _ALSO_

  GENERAL CONSIDERATIONS; GLOSSARY OF PUMP TERMS; HISTORICAL
  INTRODUCTION, WITH ILLUSTRATIONS; THE ELEMENTS OF HYDRO-MECHANICS,
  HYDROSTATICS AND PNEUMATICS; GRAVITY AND FRICTION;
  HYDRAULIC MEMORANDA; LAWS GOVERNING FLUIDS; WATER
  PRESSURE MACHINES; PUMPS AS HYDRAULIC MACHINES, ETC.

  PART ONE.


  PUBLISHED BY

  THEO. AUDEL & COMPANY

  72 FIFTH AVE.,
  NEW YORK, U.S.A.

  7, IMPERIAL ARCADE,
  LUDGATE CIRCUS, E.C.,
  LONDON, ENG.



  Copyrighted, 1905, by
  THEO. AUDEL & CO., NEW YORK.
  Entered at Stationers Hall, London, England.

  Protected by International Copyright in Great Britain and all
  her Colonies, and, under the provisions of the
  Berne Convention, in

  Belgium, France, Germany, Italy, Spain, Switzerland, Tunis,
  Hayti, Luxembourg, Monaco, Montinegro
  and Norway.


  Printed in the United States.



TABLE OF CONTENTS

Part ONE.

The divisions of Part One are represented by the following headings:
each subject is fully treated and illustrated on the pages shown:


            PAGES

  INTRODUCTORY CONSIDERATIONS                    1-16

  GLOSSARY OF PUMP AND HYDRAULIC TERMS          17-34

  HISTORICAL INTRODUCTION                       35-70

  ELEMENTARY HYDRAULICS                        70-104

  FLOW OF WATER UNDER PRESSURE                105-116

  WATER PRESSURE MACHINES                     117-154

  WATER WHEELS                                119-125

  TURBINE WATER WHEELS               126-135, 141-144

  TURBINE PUMPS                               136-139

  WATER PRESSURE ENGINES                      145-147

  HYDRAULIC MOTORS                            147-154

  HYDRAULIC APPARATUS                         155-184

  HYDRAULIC JACK                              159-168

  HYDRAULIC PRESS                             169-170

  HYDRAULIC ACCUMULATOR                       171-173

  HYDRAULIC RAM                               175-180

  PUMPS AS HYDRAULIC APPARATUS                181-184

  CLASSIFICATION OF PUMPS                     185-345

  HAND PUMPS                                  189-204

  POWER PUMPS                                 205-224

  BELTED PUMPS                                225-240

  THE ELECTRIC PUMP                           241-276

  THE STEAM PUMP                              227-330

  THE DUPLEX PUMP                             331-343

  UNDERWRITER FIRE PUMPS                          344

  SPECIFICATIONS OF THE NATIONAL BOARD OF FIRE
  UNDERWRITERS RELATING TO THE DUPLEX FIRE
  PUMPS                                       347-398

  READY REFERENCE INDEX TO PART ONE



“_Among the first things a practical engineer should know, and among
the last things he will, after becoming such, forget, is that in
handling water within pipes he has a fluid which, while it is flexible
to the greatest extent and is susceptible of the influence of power,
or force, of greater or less intensity, and while it may be drawn from
below and raised to the heights above, can be turned to the right or
to the left at will, and while, with a seeming docility which is as
flattering as it is deceptive, it bends itself to the will of the
engineer, still there are some things it will not do, and which all the
complicated appliances of the engineer have as yet failed to compel it
to do. When inclosed within chambers and pipes, to an extent that fills
them, it will not permit the introduction of an added atom without
bursting its bounds. While inclosed within long lines of pipes it will
not suddenly start into motion, or when in motion suddenly come to a
rest, without shocks or strains more or less disastrous; and so, while
it seems to be handled with the greatest ease, it is only in the manner
it chooses to go, and all mechanical appliances not designed with
reference to following these imperative laws are sure to meet trouble,
if not disaster. In other words, when an unyielding force meets an
unyielding resistance, their coming together means a shock to all
about._”



  INTRODUCTORY
  CONSIDERATIONS



“_Whenever a full mind meets an empty one, it is a call to teach, not
to scoff._”—ANON.


[Illustration: ORIFICES OF PIPES, ETC., SYMBOLICAL OF IRRIGATION.]


“_He who sedulously attends, pointedly asks, calmly speaks, coolly
answers and ceases when he has no more to say, is in possession of some
of the best requisites of man._”—LEVATER.



PREFACE.


It should be a matter of thankfulness to author and reader, or
rather to both instructor and student, for this is designed to be an
educational work, that the Laws of Nature are unchangeable.

From age to age and co-extensive with the globe the immutable
principles underlying and actuating the physical states of all matter
remain steadfast; gaseous bodies expand by unchanging laws which are
obeyed down to the merest atom, fluids flow by law and the earth to the
smallest particle remains firm, all things at all times responsive to
the mandates of the Author of Creation.

The silent, mighty, unanswering physical characteristics of Gravity,
Cohesion, Tenacity, furnish an agreeable contrast to the din, discord
and frequent argument, to the verge of hatred, that have too often
accompanied the efforts of mankind to co-operate with the forces
of Nature. But now, between author and reader, let it be hoped,
that in the unfolding of the subject-matter of this work that kind
consideration will be extended and that some of that peacefulness and
trust which existed on the earth, when flints were the weapons and the
gourds the only goblets, may prevail from beginning to the “finis” of
the volumes.

The author in planning the outlines of this work has aimed to keep
close to real things belonging to the practical side of hydraulics,
pumps, pumping-engines, and to the simple explanation of the Natural
Laws pertaining to their industrial application. A knowledge of the
real things in the objective world about us and the laws that govern
them in their inter-relations is of practical value to every man; all
branches of science are simply branches of one great science and all
phases of human activity are touched by it; man is so constituted that
he must have something to be interested in, and if he has no resources
within himself he looks elsewhere, and often to his own disadvantage.

And so, the author has aimed to make the subjects of this book
interesting as well as useful; 1, by their self-help arrangement; 2, by
the illustrations, and 3, by leaving very much to the further research
and investigation of the reader, as, in a well-told story, many things
are left to the imagination of the listeners.

It should be borne in mind by the reader, that the work is designed
to be seriously Educational in its plan and scope, and Progressive in
the presentation of its subject-matter; nothing has been withheld that
might add to its lasting value.

This is said in the way of an introduction to the _Table of Contents_
to which the student is referred as showing the method of treatment, in
the wide range of the theory and practice, of this important branch of
Industrial Science.

In the back of the volume may be found a _Ready Reference Index_ which
by its admirable method of arrangement affords a speedy key to the
contents of the book when occasion requires.



WHAT A STEAM PUMP WOULD SAY IF IT COULD TALK.


_The well-known pump expert, Mr. F. Meriam Wheeler_, writes us saying
that if the manufacturers of steam pumps would send out with their
pumps a card reading something like the following, it would probably
impress the men who run the pumps more forcibly than anything that
could be said or written in the ordinary way of giving instructions:

“_Please do not gorge me with oil, as it will give my steam chest
indigestion. What I like is a steady diet and thus enable my valves to
work smoothly and with durability. A very small amount of oil fed to me
steadily is the thing—it saves oil and repair bills._

“_Two or three times a year give me a good dose of kerosene, to clean
out any obstructions that may have accumulated in the passageways
of my steam chest, or on the face or working parts of the valve and
valve-seat, or on the chest piston._

“_Do all you can to help me make a full length of stroke, as it means
that I will use less steam and do better work. The adjustable collars
on the valve rod will allow you to regulate the length of my stroke to
a nicety._

“_By allowing me to make short strokes, you prevent my steam piston
from getting in its proper cushion, which it would do if it could
complete its full stroke. My steam piston is supposed to run up to the
end of the cylinder and pass across the exhaust port, cushioning on the
confined steam between said port and the cylinder cover._

“_The hand wheels on the side of my steam cylinder are for controlling
the amount of this cushion. For slow speeds these cushion valves should
be shut tight. When running at ordinary speed or a high rate of speed,
these cushion valves should be slightly opened._

“_Once in a while take a look at my water cylinder. See that the
packing of the water piston is not set up so tight that it makes me
grunt, producing unnecessary friction and wear. Or, perhaps the packing
is too loose a fit, or is worn out and needs renewing._

“_Please see that my water valves are seating properly, because if
they are not tight I cannot pump as much water as I ought to do for a
given speed. Sometimes the springs on the backs of my water valves need
renewing or looking after._

“_If you have not already provided a good suction air chamber for my
water cylinder, you ought to do it, because it will prevent the water
column in the suction pipe from slapping the face of my water piston at
the end of each stroke in a harsh manner and so produce ‘water hammer.’
A good suction air chamber, properly located, saves wear and tear, and
makes a pump quiet running._

“_Please keep me nice and clean. I may not be of as much importance as
your big engine, but there is no reason why I should not be kept free
from dirt and grease. I hate to have oil slobbered all over my steam
chest, or my stuffing-boxes left leaking._

“_You will find it pays to keep me in good condition, like a
well-groomed horse. Treat me well and I’ll serve you well and
long!!!_”—THE ENGINEER.



GLOSSARY OF PUMP AND HYDRAULIC TERMS.


  _Air-bound._ This word applies to both pump and piping and expresses
  the confinement of air between the discharge valve of the pump and
  the check-valve or the point of delivery.

  _Air-cock._ Is the same as a pet-cock and is used to relieve pipes
  that are air-bound.

  [Illustration: AIR COCK.]

  _Annular Valve._ From annular—a ring—_i. e._, a round valve with a
  hole in the middle.

  _Area._ The extent of surface, as the area of a piston.

  _Assembling._ Putting together the parts of a machine.

  _Atmospheric Pressure._ The pressure of atmospheric air, not only
  downward but in every direction, this amounts to about 14.7 lbs. per
  square inch at the sea level. Usually taken at 15 lbs. to facilitate
  calculations.

  _Auxiliary._ Something to “help out,” as an auxiliary cylinder or an
  auxiliary piston.

  _Ball Check-valve._ One in which a metal ball is used in place of a
  poppet-valve.

  [Illustration: BALL CHECK-VALVE.]

  _Balanced Valve._ A valve having an equal pressure on all sides. See
  equilibrium valve.

  _Basket._ The outer casing or netting of a foot valve which forms a
  strainer on a pump suction pipe.

  _Bends._ In pipe, the turns in lines of pipe may be angle bends
  (called “elbows“) or offset bends.

  _Bibb-cock._ This is a plug cock having an elbow or curved outlet
  directing the outflow downward.

  [Illustration: BIBB-COCK.]

  [Illustration: BIBB COMPRESSION.]

  _Bibb Compression._ A bibb-cock having in place of the plug a stem
  with thread and handle to open by unscrewing; the valve contains
  fibrous packing and is made tight by compression.

  _Bonnets._ These are covers for the opening into valve chambers of
  pumps.

  _Boss._ Any round protuberance on a casting to support a stud or to
  strengthen a steam chest cover, etc.

  _Bushing._ A nut used in pipe fitting, threaded inside and outside to
  accommodate two sizes of pipe.

  [Illustration: BUSHING.]

  _Check Valve._ A valve through which fluid can pass only in one
  direction; used between pump and reservoir or boiler. See swing-check.

  _Check-Nut._ A second nut screwed against the first to hold it firmly
  in place; also called a lock-nut.

  _Circulating Pump._ A pump arranged to force water through the tubes
  of a surface condenser. Frequently a _centrifugal pump_ is used as a
  circulating pump.

  _Clack Valve._ This takes its name from the noise it makes in
  seating; it is made of leather with a metal weight on top, the
  leather forming a hinge on one side. In the cut the lifted valve is
  the “clack.”

  [Illustration: CLACK VALVE.]

  _Clearance._ The space or distance by which one piece clears another.
  The space between piston and cylinder head.

  _Cock._ A faucet or device for opening or closing a passage. The
  illustration shows a straight-way cock.

  [Illustration: PLAIN COCK.]

  _Column Pipe._ A column may be considered as a beam set on end and
  a column pipe may, similarly, be defined as a pipe set on end. The
  pipes leading from a water column to boiler.

  _Compression Gauge Cock._ A device having a threaded steam spindle
  and made tight by compression. The figure exhibits an outside view of
  a locomotive compression gauge cock.

  [Illustration: COMPRESSION GAUGE COCK.]

  _Corrosion._ Rusting or wasting away of the surfaces of metals.

  _Crow._ A claw with a screw attached to support and feed a drill
  brace for drilling holes in pipes.

  _Cup Leather Packing._ The leather packing used around the ram of a
  press. In section it resembles a cup—hence the name.

  [Illustration: CUP LEATHER PACKING.]

  _Cushioning._ This term applied to the operation of pumps, etc.,
  is the imprisoning of steam, water or air between the piston and
  cylinder head to prevent the piston from impact with the head.

  _Cylinder Head or Cylinder Cover._ A plate which encloses or covers
  the end of a cylinder.

  _Dead end of a pipe._ The closed end of a pipe or system of pipes.

  _Disk or Disc._ A cylinder, whose length is very short in proportion
  to its diameter; a round plate with a hole in its center.

  _Double-eye or Knuckle Joint._ A joint formed of two forks or jaws
  with a cube of iron between them, with a bolt or pin through each jaw
  and the cube at right angles. Will work freely in all positions from
  a straight line up to 45°.

  _Double seated poppet valve._ A poppet valve having two valves on one
  stem, with two seats in the same shell.

  [Illustration: DOUBLE-SEATED POPPET VALVE.]

  _Drafting water._ Another term for “raising“ water by suction, in
  distinction to “forcing water.”

  _Drip-pipe._ A device used to draw off the water of condensation from
  systems of piping, steam cylinders, heaters, etc. Drain-cocks are
  used for similar purposes.

  “_Dutchman._” A piece “fitted in” to restore a worn part or to hide a
  defect.

  _Duct._ A passage or conduit.

  _“Duty” of pumps._ This indicates the measurement of the work
  performed by pumps. “Duty trials” are careful tests of the work done
  by the larger pumping-engines.

  _Elbow._ This fitting is used for uniting two pipes together at right
  angles. The illustration shows a malleable-iron gas-pipe elbow.

  [Illustration: ELBOW.]

  _Equilibrium Valve._ A valve balanced by an equal pressure on both
  ends.

  _Expansion Joint._ A telescopic slip joint having a packed stuffing
  box, permitting the parts it connects to expand and contract under
  variations of temperature.

  [Illustration: EXPANSION JOINT.]

  _Face._ The broadest flat surface of a piece of work, or the one
  having the greatest area.

_Factor of Safety._ When a calculation of the ultimate strength of a
machine is to be made it is necessary to provide for contingencies—this
takes the form of a multiplier, and is called the factor of safety, or
the margin of safety.

_Feather, or sunk key._ A key that is fast in one piece of work, and an
easy fit in the other, as a feather in a shaft.

_Flow._ Motion of a fluid or liquid in one direction. “Flow-gate“ is a
term sometimes applied to a riser.

_Flume._ An open trough for conveying water.

[Illustration: GATE VALVE.]

[Illustration: GLOBE VALVE.]

_Gate Valve._ A valve which opens the full area of the pipe, on the
principle of a gate in a water flume.

_Globe Valve._ A valve having a round ball-like shell as shown in the
engraving.

_Gland._ The sliding bushing for holding packing into a stuffing box,
adjusted by studs and nuts.

_Goose neck._ A pipe fitting having two bends in opposite directions
which resemble the neck of a goose.

  _Gridiron Valve._ A type of slide valve familiarly called a “grid,”
  which may be circular or rectangular, consisting of alternate bars
  and spaces, sliding over a similarly formed seat, the object being
  to obtain the necessary steam way with a diminished amount of valve
  travel.

  _Hand-Nut._ A nut having wings or projections so that it may be
  screwed up by hand without the aid of a wrench.

  [Illustration: HAND-NUT.]

  _Head of water._ In hydraulics “head“ means pressure due to height of
  column of water.

  _Heat Units._ The unit of heat is the amount of heat required to
  raise one pound of water one degree, usually from 32° to 33° Fahr.

  “_Hesitates._” A pump is said to “hesitate” when the motion becomes
  uncertain.

  _Horse-power of a pump._ Is the same as is used to designate that of
  a steam engine, with this exception: the initial pressure in the pump
  remains constant throughout the stroke. Formula is the same as for a
  steam engine.

  “_Hump._” This is an arch or bend which causes an “air pocket” in a
  water-pipe line.

  _Hydrant._ A valve and spout connecting with a street main.

  _Hydraulic Belt._ An endless woolen band for raising water. The lower
  bight is immersed in water, and the upper bight passes over a roller.
  The belt travels about 1,000 feet per minute, and discharges at its
  upper turn.

  _Hydraulic Jack._ A lifting device in which a ram, a pump, and liquid
  is used instead of a screw.

  [Illustration: HYDRAULIC JACK.]

  _Hydraulic Pivot._ A “slippery liquid support” for an upright shaft,
  a film of water being introduced beneath it by pressure to support
  the weight thereof and prevent the usual friction of the shaft on its
  step.

  _Hydraulic Shears._ A machine for shearing or cutting metals, etc.,
  by the force of water pressure operating cutters.

  _Hydraulic Valve._ A valve for regulating the distribution of water
  in the cylinders of hydraulic elevators, cranes and other water
  pressure machines and devices.

  _Hydraulic Wheel._ One for raising water by applied power, as the
  Noria Scoop wheel, tympanum, etc. See illustrations in section
  relating to the history of the pump.

  _Impact._ The single instantaneous shock of a body in motion when it
  strikes against another body either in motion or at rest.

  _Leakage._ The loss of water from any cause.

  “_Lift and drop of a valve._” This term indicates the amount of
  “play” up and down, designed to be given to a valve by its designer.

  _Liner._ A piece of iron or other metal put behind or on a piece to
  take up its wear.

  _Lost Motion._ Motion that is not transmitted on account of the
  looseness of the parts, hence it is lost.

  “_Losing water._” A term used when the pump stops, caused by air
  leaking into the suction pipe, or foreign matter clogging the
  strainer at the end of the suction pipe.

  _Low pressure steam._ Steam which is either below 30 lbs., or but a
  few pounds in excess of the atmospheric pressure.

  _Lug._ That which projects like an ear, especially that by which
  anything is supported, or against which anything bears, or through
  which a belt passes.

  _Main._ A principal pipe or duct as distinguished from lesser ones,
  especially a principal pipe leading to or from a reservoir or a
  fire-main; a “forcing main” is the delivery pipe of a pump.

  _Mean gradient._ The grade of a pipe-line which should be made as
  nearly straight as possible to avoid air pockets.

  _Miner’s Inch._ The amount of water that will flow per minute through
  an opening one inch square in a plank two inches thick, under a head
  of four inches of water above the upper edge of the opening, and is
  equal to nine United States gallons.

  _Mississippi River gauge cock._ A cock without a handle or thread
  upon the stem and designed to be opened by pressure upon the top end
  of the stem as shown.

  [Illustration: MISSISSIPPI RIVER GAUGE COCK.]

  _“Modulus” of a steam pump._ The _measure_ or multiplier of power
  used in operating pumps. _Modulus_ has nearly the same meaning as
  measure.

  _Nipple._ A short connecting piece of pipe threaded upon both ends.

  [Illustration: NIPPLE.]

  _Outboard delivery pipe._ The pipe which leads, in steam vessels,
  from the condenser through the side of the ship.

  _Pipette._ A small tube used to withdraw and transfer fluids or gases
  from one vessel to another. The shape differs with the special use to
  which it is adapted: some are graduated to measure fluids accurately
  as well as to transfer them.

  _Penstock._ The barrel of a pump in which the piston plays and
  through which the water presses up; also the conduit or trough from
  the source of supply to a water wheel.

  _Pet-cock._ This is an air-cock. See air-cock.

  _Pipe-clamp._ A device for connecting one pipe to another without
  cutting the pipe and inserting a tee; a _pipe-saddle_ performs the
  same office as the above, but for larger pipes.

  _Pitcher Pump._ A hand pump which takes its name from the shape of
  its discharge.

  [Illustration: PITCHER PUMP.]

  _Plug-valve._ This is a tapering plug which turns in a shell,
  example, the _plug of a faucet_. See Cock. A _fire-plug_ is a street
  hydrant to which a hose may be attached.

  [Illustration: PLUMB BOB.]

  _Plumb-bob._ This is a device for testing whether anything stands
  exactly vertical; a _plumb-rule_ contains a plumb-bob.

  _Pressure-reducing Valve._ A valve for reducing high boiler pressure
  to low pressure, for steam heating, etc.

  [Illustration: PRESSURE REDUCING VALVE.]

  [Illustration: SECTION.]

  _Priming._ To fill a pump with water when it refuses to lift of its
  own action, is called “priming the pump.”

  _Pump-brake._ The handle or lever by which a pump is worked.

  _Pump-box._ A cap or case covering the top of a pump; the casings of
  the upper and lower valves are the _upper_ and _lower_ pump boxes.

  _Pump-chain._ An endless chain with discs forming valves at proper
  distances, working on two wheels, one above and one below, and
  passing down outside and returning upward through a wooden tube like
  a belt.

  _Pump-cheeks._ A forked piece serving as a fulcrum for the handle of
  a pump.

  _Pump-well._ A compartment extending from a ship’s bottom to the
  lower or the upper deck, as the case may be, to contain the pump
  stocks, etc. The _bilge water_ collects in the _limbers_ and is
  discharged through a spout called the _pump-dale_.

  _Rain-gauge._ A vessel graduated to measure the fall of rain in a
  given period.

  [Illustration: REDUCING COUPLING.]

  _Reducing-coupling._ A fitting for connecting two sizes of threaded
  pipe.

  _Resistance._ The force that a pump has to work against, caused by
  gravity, friction, head of water, etc.

  _Right-hand Thread._ A screw thread in which, with the threaded end
  of the bolt towards you, _the top of the nut_ must revolve from left
  to right like the hands of a watch, in order to cause the nut to
  screw upon the bolt.

  [Illustration:

  OPEN.      ROPE SOCKETS.      CLOSED.
  ]

  _Rope-socket._ A device fastened to the end of a rope by means of
  which the rope may be attached to its load. The socket may be open or
  closed.

  _Rust-joint._ A joint which is made by being filled with sifted
  cast-iron borings, mixed with sal ammoniac, sulphur and water; this
  causes the cuttings to rust and form a solid cement.

  _Sea Injection._ The pipe and valve through which sea water is
  injected into the condenser of a marine engine.

  _Screw jack or lifting jack._ A screw working in a threaded base or
  stationary nut and turned by a lever inserted into holes near the
  top, of which there are usually four. A loose plate or swivel is
  placed on top of screw.

  [Illustration: SCREW JACKS.]

  _“Slams” and “Shocks.”_ Banging, clanking and jarring noises
  indicating a derangement of the action of a pump.

  [Illustration: SLEEVE COUPLING.]

  _Sleeve-coupling._ A threaded connection for uniting the two ends of
  pipes of equal size.

  “_Slippage._” The difference between the calculated and actual work
  performed by a pump.

  _Sluice._ A water-gate; a channel to run off waste water.

  _Slurry pump._ A special pump for handling a mixture of earth water.

  _Socket-wrench._ A wrench for turning nuts, having a socket in the
  end made to a special size and shape of the nut to be turned.

  _Spanner._ Is a wrench for turning round nuts having holes or slots.

  [Illustration: SPANNER.]

  _Spline or feather._ A key made fast in a shaft.

  _Split-pin or cutter._ An iron pin divided at the end which is to be
  spread apart after inserting in the hole.

  “_Spread._” A term used to indicate the distance from center to
  center of the cylinders of a duplex pump.

  _Spring-seat._ An elastic seat for a valve.

  _Steam thrown valves._ Valves moved by steam only.

  _Steam end of a pump._ The end operated by steam.

  “_Sticking of valves._” Inability to work caused by the introduction
  into the valves of sand, soil, etc.; or it may be caused by too tight
  a fit of the moving parts, rust or corrosion.

  [Illustration: STREET ELBOW.]

  _Street elbow._ An elbow having an extension piece at one end.

  _“Stroke” of pump._ The distance traveled by the piston in one motion.

  [Illustration: STUD-BOLT.]

  _Stud-bolt._ A piece of round bar metal with a thread upon each end.
  A represents thread for nut; B body of bolt and C thread to fit in
  casting.

  [Illustration: STUB-END.]

  _Stub-end._ Either end of a connecting rod.

  [Illustration: STRAINER.]

  _Strainer._ A device for separating solid particles from the liquid
  which contains them.

  _Stuffing box._ A recess to receive the packing around piston rods,
  plungers and valve stems.

  _Submerged pump._ A pump which works under water.

  “_Sucking wind._” A leakage of air into the suction part of a pump.

  _Supplemental piston._ The piston which operates the main valve in
  the steam pump.

  [Illustration: SWING CHECK VALVE.]

  _Swing check valve._ One which swings upon a pivot or hinge in
  opening and closing.

  [Illustration: SWITCH COCK.]

  _Switch cock or valve._ A device for conducting exhaust steam into
  the smoke stack or atmosphere. A three-way cock.

  [Illustration: SYPHON COCK.]

  _Syphon Cock._ A cock having a combined chamber which is partially
  filled with water of condensation, attached to a steam gauge to keep
  steam from entering and damaging the works of the instrument.

  [Illustration: THUMB-NUT.]

  _Thumb-nut._ The same as a wing-nut, but a smaller size of the two,
  shown above, applied to hand-vice.

  _Tobin-bronze._ An alloy of copper, tin and zinc treated in a special
  manner; it is non-corrosive, has great tensile strength and can be
  forged at a cherry red heat.

  “_Trailing Water._” Water can be trailed, _i.e._, carried through
  pipes to pumps a very great distance so long as “the lift” is not
  over 25 to 33 feet.

  “_Trompe._” The term used to designate a water-blast—a form of pump.

  _Turbine._ A water wheel driven by the impact or reaction of streams
  of water flowing through it or by the impact and reaction combined;
  it is also distinguished by the manner in which it discharges the
  water, as _outward, vertical or central discharge_ turbine wheels.

  _Turbine-pump._ A pump in which water is raised by the action of a
  turbine wheel driven by exterior power in the opposite direction from
  that in which it is turned when used as a motor.

  [Illustration: TUBE-PLUG.]

  _Tube-plug._ A tube stopper to be used in case of a leak in a boiler
  tube; it consists of two wood pistons joined together so that the
  leak will come between them. Tube plugs are frequently made of turned
  tapered cast iron, one of which is to be driven into each end of a
  leaking tube.

  [Illustration: UNION.]

  _Union._ A fitting designed to unite the two screwed ends of a pipe,
  with a single nut to secure them.

  _Vacuum._ A void space; an inclosed chamber from which the air (or
  other gas) has been very nearly removed, as by an air pump.

  _Valve._ Any device or appliance used to control the flow of a
  liquid, vapor, or gas, or loose material, through a pipe, outlet
  or inlet; the term includes air, gas, steam and water-cocks of all
  kinds; water-gates, air-gates, etc. One hundred and fifty of such
  devices are named by Knight in his “Mechanical Dictionary.”

  _Viscosity._ Glutinous, adhering, or sticky, as tar, gums, molasses.
  Internal friction or resistance to change of shape.

  ^V^ _thread._ A thread on a rod or bolt cut in the form of a letter
  ^V^.

  _Washer._ A circular piece of leather, rubber, metal, or other
  material with a hole in its center, through which a rod or bolt may
  pass.

  _Water Arch._ A chamber of plates or of pipes over the furnace door
  of brick set boilers to take the place of the usual cast iron or fire
  brick arch, and connected with the boiler to supply it with water.
  The feed water is often introduced through the water arch.

  _Water-bellows._ A form of pump, like a bellows—of great antiquity.

  _Water-cap._ The cover for discharge valves on a steam pump.

  _Water-end._ The pump end of a steam-pump; in distinction from the
  steam end.

  _Water-hammer._ A noise caused by the pulsative motion of water
  inside a steam pipe, resembling the blows of a hammer.

  _Water Ram._ A hydraulic ram.

  _Working Barrel._ The water end of a pump.

  _Whirlpool-chamber._ A chamber attached to the discharge end of the
  centrifugal pump in which the whirling water gradually loses its
  rotation, thereby reducing friction.

  _Wing-nut._ An iron nut having a wing at each side. Sometimes called
  a “butterfly nut.”

  [Illustration: YOKE.]

  _Yoke._ A branch pipe, or a two-way coupling for pipes, particularly
  twin hot and cold-water pipes that unite in their discharge.

  ^Y^.—A pipe fitting for uniting two pipes at an angle of 45°.



HISTORICAL INTRODUCTION.


The very small degree of antiquity to which machine tools can lay claim
appears forcibly in the sparse records of the state of the mechanic
arts a century ago.

[Illustration: GOURD, CAULDRON AND PIPKIN.]

A few tools of a rude kind, such as trip-hammers (worked by water
wheels), and a few special ones, which aimed at accuracy but were of
limited application, such as “mills” for boring cannon, or “engines”
for cutting the teeth of clock wheels, were almost their only
representatives.

The transmission of power was unthought of, except for the very limited
distances which were possible with the ill-fitted “gudgeons” and
“lanterns and trundles” of the old millwrights.

The steam-engine, however, changed all this; on the one hand the
hitherto unheard of accuracy of fit required by its working parts
created a demand for tools of increased power and precision, and on
the other it rendered the use of such tools possible in almost any
situation.

Thus, acting and re-acting on each other, machine tools and steam
engines have grown side by side, although the first steps were costly
and difficult to a degree which is not now easy to realize. James Watt,
for instance, in 1779 was fain to be content with a cylinder for his
“fire-engine,” of which, though it was but 18 inches in the bore, the
diameter in one place exceeded that at another by about 3/8 of an inch;
its piston was not unnaturally leaky; though he packed it with “paper,
cork, putty, pasteboard and old hat.”

_The early history of the pumping-engine is the history of the
steam-engine_, for originally and for many years the only way in which
the steam-engine was utilized was for pumping water out of the coal
mines of England and from the low lands of the Netherlands.

In 1698 Capt. Thomas Savery secured Letters Patent for a machine for
raising water by steam. It consisted of two boilers and two receivers
for the steam, with valves and the needful pipes. One of the receivers
being filled with steam, its communication with the boiler was then cut
off and the steam condensed with cold water outside of it; into the
vacuum thus formed the atmosphere forced the water from below, when
the steam was again caused to press upon the water and drive it still
higher.

This engine was used extensively for draining mines and the water was,
in some instances, made to turn a water wheel, by which lathes and
other machinery were driven.

In 1705 Thomas Newcomen, with his associates, patented an engine which
combined, for the first time, the cylinder and piston and separate
boiler. _This soon became extensively introduced for draining mines
and collieries_, and the engines grew to be of gigantic size, with
cylinders 60 inches in diameter and other parts in proportion.

This engine was, in course of years, used in connection with the
Cornish pump, whose performance in raising water from mines came to be
a matter of the nicest scientific investigation, and adopted as the
standard for the duty or work, by which to compare the multitudinous
experimental machines very soon introduced by many inventors.

But there is an earlier history which long antedates the achievements
of Savery, Newcomen and Watt, which belongs, however, principally to
the domain of hydraulics. Before proceeding to discuss the advancements
made within the memory of men now living, it may be well to take
a glance backward and occupy a few pages with their appropriate
illustrations, with the facts recorded in history.

It were vain to even try, to trace the advances made toward the mammoth
city pumping stations, from the early beginning hereafter described,
which have inspired the words recorded by J. F. Holloway, M. E.:

  “In looking upon the ponderous pumping engines which lift a volume of
  water equal to the flow of a river, sending it with each throbbing
  beat of their pulsating plungers through the arteries and veins
  that now reach out in every direction in our great cities, bringing
  health, comfort, cleanliness and protection to every home therein, we
  cannot but wonder what is the history of their beginning, what the
  process of their evolution out from the crude appliances of long ago.

  Just who the first man was, and by what stream he sat gazing on his
  parched fields, on which the cloudless skies of the Orient shed no
  rain, and where the early rising sun with eager haste lapped up the
  dew drops which the more kindly night in pity over his hard lot had
  shed, and who, looking on his withering grain stalks on the one side
  and the life-giving waters which flowed by on the other, first caught
  the inspiring thought that if one could only be brought to the other,
  how great would be the harvest, we shall never know. Knowing, as we
  do, that such still is the problem that confronts the toiler on the
  plains of that far-off Eastern land where man’s necessities first
  prompted man’s invention, it does not require a great stretch of the
  imagination to conceive of such a situation, and to believe that,
  acting on the impulse of the moment, he called his mate, and tying
  thongs to the feet of a sheep-skin and standing on either side of the
  brook, with alternate swingings of the suspended skin they lifted
  the waters of the stream to the thirsty field, making its blanched
  furrows to bloom with vegetation, and at the same time introducing to
  the world the first hydraulic apparatus ever invented, and certainly
  the first hydraulic ram ever used.”

The figures shown on the opening page of this section of the work
represent the very first utensils used for collecting and containing
water. The _gourd or calabash_ was undoubtedly the very first; it was
common among the ancient Romans, Mexicans and Egyptians, and in the
most modern times continues to be in use in Africa, South America and
other warm countries. The New Zealanders possessed _no other vessels_
for holding liquids, and the same remark is applicable to numerous
other savage tribes.

Although not strictly connected with the subject, it may be observed
that the gourd is probably the original vessel for _heating water,
cooking, etc._ In these and other applications the neck is sometimes
used as a handle and an opening made into the body by removing a
portion of it, as shown in the engraving, its exterior being kept
moistened by water while on the fire, while others apply a coating of
clay to protect it from the effects of the flame. When in process of
time vessels for heating water were formed wholly of clay, they were
fashioned after the cauldron as shown.

[Illustration: FIGS. 47-52.]

The above illustrations are representations of ancient vases; it is
curious to note their conformation to the figure of the gourd. The
first three on the left are from Thebes. _Golden ewers_ of a similar
form were used by rich Egyptians for containing water to wash the hands
and feet of their guests.

Similar shaped vessels of the Greeks, Romans and other people might be
easily produced.


In Egypt, India, Chaldea and China the _clepsydra or water-clocks_
date back beyond all records. Plutarch mentions them in his life of
Alcibiades who flourished in the Fifth Century B. C. when they were
employed in the tribunals at Athens to measure the time to which the
orators were limited in their addresses to the judges. Julius Cæsar
found the Britons in possession of them.

[Illustration: FIG. 53.—WATER-CLOCK.]

_The clepsydra is a device for measuring time_ by the amount of water
discharged from a vessel through a small aperture, the quantity
discharged in a given unit of time, as an hour being first determined.
In the earlier clepsydras the hours were measured by the sinking of the
surface of the water in the vessel containing it. In others the water
ran from one vessel to another, there being in the lower a cork or
piece of light wood which as the vessel filled, rose and thus indicated
the hour. In later clepsydras the hour has been indicated by a dial.

Fig. 53 shows a water-clock described by Hero of Alexandria, Egypt,
made _to govern the quantities of fluids flowing from a vessel_. The
note below gives the exact wording of the description which has come
down to us.

  “A vessel containing wine, and provided with an open spout, stands
  upon a pedestal: it is required by shifting a weight to cause the
  spout to pour forth a given quantity,—sometimes, for instance,
  a half cotyle (1/4 pint), sometimes a cotyle (1/2 pint), and in
  short, whatever quantity we please. A B (fig. 53), is the vessel
  into which wine is to be poured: near the bottom is a spout D: the
  neck is closed by the partition E F, and through E F is inserted a
  tube, G H, reaching nearly to the bottom of the vessel, but so as to
  allow of the passage of water. K L M N is the pedestal on which the
  vessel stands, and O X another tube reaching within a little of the
  partition and extending into the pedestal in which water is placed
  so as to cover the orifice O, of the tube. Fix a rod, P R, one-half
  within, and the other without the pedestal, moving like the beam of a
  lever about the point S; and from the extremity P of the rod suspend
  a water-clock, T, having a hole in the bottom. The spout D having
  been first closed, the vessel should be filled through the tube G H
  before water is poured into the pedestal, that the air may escape
  through the tube X O; then pour water into the pedestal, through a
  hole, until the orifice O is closed, and set the spout D free. It is
  evident that the wine will not flow, as there is no opening through
  which air can be introduced: but if we depress the extremity R of
  the rod, a portion of the water-clock will be raised from the water,
  and, the vent O being uncovered, the spout D will run until the water
  suspended in the water-clock has flowed back and closed the vent O.
  If, when the water-clock is filled again, we depress the extremity R
  still further, the liquid suspended in the water-clock will take a
  longer time to flow out, and there will be a longer discharge from
  D: and if the water-clock be entirely raised above the water, the
  discharge will last considerably longer. To avoid the necessity of
  depressing the extremity R of the rod with the hand, take a weight Q,
  sliding along the outer portion of the rod, R W, and able, if placed
  at R, to lift the whole water-clock; if at a distance from R, some
  smaller portion of it. Then, having obtained by trial the quantities
  which we wish to flow from D, we must make notches in the rod R W and
  register the quantities; so that, when we wish a given quantity to
  flow out, we have only to bring the weight to the corresponding notch
  and leave the discharge to take place.”


THE SYPHON.

_The Syphon_ is a bent pipe or tube with legs of unequal length, used
for drawing liquid out of a vessel by causing it to rise in the tube
over the rim or top. For this purpose the shorter leg is inserted in
the liquid, and the air is exhausted by being drawn through the longer
leg. The liquid then rises by the pressure of the atmosphere and fills
the tube and the flow begins from the lower end.

The general method of use is to fill the tube in the first place with
the liquid, and then, stopping the mouth of the longer leg, to insert
the shorter leg in the vessel; upon removal of the stop, the liquid
will immediately begin to run. The flow depends upon the difference
in vertical height of the two columns of the liquids, measured
respectively from the bend of the tube, to the level of the water in
the vessel and to the open end of the tube. The flow ceases as soon as,
by the lowering of the level in the vessel, these columns become of
equal height or when this level descends to the end of the shorter leg.

The atmospheric pressure is essential to the support of the column of
liquid from the vessel up to the top of the bend of the tube, and this
height is consequently limited; at sea height the maximum height is a
little less than 34 feet for water, but this varies according to _the
density of the fluid_.

[Illustration:

  FIGS. 54      55      56      57      58      59]

_Syphons are necessary in numerous manipulations of the laboratory_,
and modern researches in chemistry have given rise to several beautiful
devices for charging them, and also for interrupting and renewing their
action. When corrosive liquids or those of high temperatures are to
be transferred by syphons, it is often inconvenient, and sometimes
dangerous to put them in operation by the lungs. Moreover cocks and
valves of metal are acted on by acids, and in some cases would affect
or destroy the properties of the fluids themselves.

Fig. 54 shows how hot or corrosive liquids may be drawn off from a wide
mouthed bottle or jar. The short leg of a syphon is inserted through
the cork, and also a small tube, through which the operator blows, and
by the pressure of his breath forces the liquid through the syphon.

Fig. 55 represents a syphon sometimes employed by chemists. When used,
the short leg is first placed in the fluid to be decanted, the flame of
a lamp or candle is then applied to the underside of the bulb; the heat
rarefies the air, and consequently drives out the greater part of it
through the discharging orifice. The finger is applied to this orifice,
and as the bulb becomes cool the atmosphere drives up the liquid into
the void and puts the instrument in operation.

Fig. 56 is a syphon charged by pouring a quantity of the fluid to be
decanted into the funnel, the bent pipe attached to which terminates
near the top of the discharging leg. The fluid in descending through
this leg bears down the air within it, on the principle of the trompe,
and the atmosphere drives up the liquid in the reservoir through the
short leg.

Fig. 57 is a glass syphon for decanting acids, &c. It is charged by
sucking, and to guard against the contents entering the mouth, a bulb
is blown on the sucking tube. The accumulation of a liquid in this bulb
being visible, the operator can always withdraw his lips in time to
prevent his tasting it.

Fig. 58 is designed to retain its contents when not in use, so that on
plunging the short leg deep into a liquid the instrument will operate.
This effect however will not follow if the end of the discharging leg
descend below the bend near it, and if its orifice be not contracted
nearly to that of a capillary tube.

Fig. 59 is a syphon by which liquids may be drawn at intervals, viz.,
by raising and lowering the end of the discharging leg according to the
surface of the liquid in the cistern.

[Illustration: FIG. 60.]

Figs. 60, 61, 62 are syphons described by Hero of Alexandria who lived
120 B. C.; the descriptions of the figures are the translation of the
original.

Let A B C D (Fig. 60) be a vessel open at the top, and through its
bottom pass a tube, either an inclosed pipe as E F G, or a bent syphon
G H K. When the vessel A B C D is filled, and the water runs over,
a discharge will begin and continue till the vessel is empty, if the
interior opening is so near the bottom of the vessel as only to leave a
passage for the water.

As before, let there be a vessel, A B (Fig. 61), containing water.
Through its bottom insert a tube, C D, soldered into the bottom and
projecting below. Let the aperture C of the syphon approach to the
mouth of the vessel A B, and let another tube, E F, inclose the tube C
D, the distance between the tubes being everywhere equal, and the mouth
of the outer tube being closed by a plate, E G, a little above the
mouth C. If we exhaust, by suction through the mouth D, the air in the
tube C D, we shall draw into it the water in the vessel A B, so that it
will flow out through the projection of the syphon until the water is
exhausted. For the air contained between the liquid and the tube E F,
being but little, can pass into the tube C D, and the water can then
be drawn after it. And the water will not cease flowing because of the
projection of the syphon below:—if, indeed, the tube E F were removed,
the discharge would cease on the surface of the water arriving at C, in
spite of the projection below; but when E F is entirely immersed no air
can enter the syphon in place of that drawn off, since the air which
enters the vessel takes the place of the water as it passes out.

[Illustration: FIG. 61.]

Let A B C (Fig. 62), be a bent syphon, or tube, of which the leg A B is
plunged into a vessel D E containing water. If the surface of the water
is in F G, the leg of the syphon, A B, will be filled with water as
high as the surface, that is, up to H, the portion H B C remaining full
of air. If, then we draw off the air by suction through the aperture
C, the liquid also will follow. And if the aperture C be level with
the surface of the water, the syphon, though full, will not discharge
the water, but will remain full: so that, although it is contrary to
nature for water to rise, it has risen so as to fill the tube A B C;
and the water will remain in equilibrium, like the beams of a balance,
the portion H B being raised on high, and the portion B C suspended.
But if the outer mouth of the syphon be lower than the surface F G,
as at K, the water flows out, for the liquid in K B, being heavier,
overpowers and draws toward it the liquid B H. The discharge, however,
continues only until the surface of the water is on a level with the
mouth K, when, for the same reason as before, the efflux ceases. But
if the outer mouth of the tube be lower than K, as at L, the discharge
continues until the surface of the water reaches the mouth A.

[Illustration: FIG. 62.]

_The Syringe_ is an instrument of very high antiquity and was probably
the first machine consisting of a cylinder and piston that was
especially designed to force liquids. In the closed end a short conical
pipe is attached whose dimensions are adapted to the particular purpose
for which the instrument is to be used. The piston is solid and covered
with a piece of soft leather, hemp, woolen listing, or any similar
substance that readily imbibes moisture, in order to prevent air or
water from passing between it and the sides of the cylinder. When the
end of the pipe is placed in a liquid and the piston drawn back, the
atmosphere drives the liquid into the cylinder; whence it is expelled
through the same orifice by pushing the piston down: in the former case
the syringe acts as a sucking pump: in the latter as a forcing one.
They are formed of silver, brass, pewter, glass, and sometimes of wood.
For some purposes the small pipe is dispensed with, the end of the
cylinder being closed by a perforated plate, as in those instruments
with which gardeners syringe their plants.


WELLS.

Long before pumping devices were conceived, wells existed as the
invention of prehistoric man. Herewith is a sectional view of _Joseph’s
Well_ to be seen at the present time at Cairo, Egypt. Scientists think
it the production of the same people that built the pyramids and the
unrivaled monuments of Thebes, Dendaroh and Ebsambone. The magnitude
of the well and the skill displayed in its construction is perfectly
unique.

[Illustration: JOSEPH’S WELL.]

This stupendous well is an oblong square, twenty four feet by eighteen,
being sufficiently capacious to admit within its mouth a moderate
sized house. It is excavated (of these dimensions) through solid rock
to the depth of one hundred and sixty-five feet, where it is enlarged
into a capacious chamber, in the bottom of which is formed a basin or
reservoir, to receive the water raised from below (for this chamber is
not the bottom of the well). On one side of the reservoir another shaft
is continued, one hundred and thirty feet lower, where it emerges
through the rock into a bed of gravel, in which the water is found, the
whole depth being two hundred and ninety-seven feet; the lower shaft is
not in the same vertical line with the upper one, nor is it so large,
being fifteen feet by nine.

[Illustration: TWELFTH CENTURY.]

[Illustration: ASIATIC PULLEY AND BUCKET.]

As the water is first raised into the basin, by means of machinery
propelled by horses or oxen within the chamber, it may be asked, how
are these animals conveyed to that depth in this tremendous pit, and
by what means do they ascend? A spiral passage-way is cut through
the rock, from the surface of the ground to the chamber, independent
of the well, round which it winds with so gentle a descent, that
persons sometimes ride up or down upon asses or mules. It is six feet
four inches wide, and seven feet two inches high. Between it and the
interior of the well, a wall of rock is left, to prevent persons
falling into, or even looking down it (which in some cases would be
equally fatal), except through certain openings or windows, by means of
which it is faintly lighted from the interior of the well. The animals
descend by this passage to drive the machinery that raises the water
from the lower shaft into the reservoir or basin, from which it is
again elevated by similar machinery and other oxen on the surface of
the ground. In the lower shaft a path is also cut down to the water,
but as no partition is left between it and the well, it is extremely
perilous for strangers to descend.

  NOTE.—However old and numerous wells with stairs in them may be,
  most of the ancient ones were constructed without them; hence the
  necessity of some mode of raising the water. From the earliest ages,
  a _vessel suspended by a cord_, has been used by all nations—a device
  more simple and more extensively employed than any other, and one
  which was undoubtedly the germ of the most useful hydraulic machine
  of the ancients. The figures shown on this and a few succeeding pages
  are from the collection made by Ewbank—to whom reference has been
  made in another portion of this work.

[Illustration: PULLEY AND TWO BUCKETS. (ANCIENT.)]

The square openings represented on each side of the upper shaft are
sections of the spiral passage, and the zig-zag lines indicate its
direction. The wheels at the top carry endless ropes, the lower parts
of which reach down into the water; to these, earthenware vases are
secured by ligatures (see A A) at equal distances through the whole of
their length, so that when the machinery moves these vessels ascend
full of water on one side of the wheels, discharge it into troughs as
they pass over them and descend in an inverted position on the other
side.

[Illustration: CHINESE WINDLASS.]

This celebrated production of former times, as will be perceived,
resembles an enormous hollow screw, the center of which forms the well
and the threads a winding stair-case around it. To erect of granite,
a flight of “geometrical” or “well stairs,” two or three hundred
feet high, on the surface of the ground, would require extraordinary
skill, although in its execution every aid from rules, measures, and
the light of day, would guide the workmen at every step; but to begin
such a work at the top, and construct it _downwards_ by excavation
alone, in the dark bowels of the earth, is a more arduous undertaking,
especially as deviations from the correct lines could not be remedied;
yet in Joseph’s well, the partition of rock between the pit and the
passage-way, and the uniform inclination of the latter, seem to have
been ascertained with equal precision, as if the whole had been
constructed of cut stone on the surface. Was the pit, or the passage,
formed first; or were they simultaneously carried on, and the excavated
masses from both borne up the passage, are unanswered questions.

[Illustration: ANGLO-SAXON CRANE.]

The extreme thinness of the partition wall, excited the astonishment of
M. Jomard, whose account of the well is inserted in the second volume
of Memoirs in Napoleon’s great work on Egypt. It is, according to him,
but sixteen centimetres thick, [about six inches!] He justly remarks
that it must have required singular care to leave and preserve so small
a portion while excavating the rock from both sides of it. It would
seem no stronger in proportion, than sheets of paste-board placed on
edge, to support one end of the stairs of a modern built house, for it
should be borne in mind, that the massive roof of the spiral passage
_next the well_, has nothing but this film of rock to support it, or
to prevent from falling, such portions as are loosened by fissures, or
such, as from changes in the direction of the strata, are not firmly
united to the general mass. But this is not all: thin and insufficient
as it may seem, the bold designer has pierced it through its whole
extent with semi-circular openings, to admit light from the well: those
on one side are shown in the engraving.

[Illustration: SWAPE OR SWEEP, A. D. 1493.]

Aqueducts, fountains, cisterns and wells, are in numerous instances
the only remains of some of the most celebrated cities of the ancient
world. Of Heliopolis, Syene and Babylon in Egypt; of Tyre, Sidon,
Palmyra, Nineveh, Carthage, Utica, Barca, and many others. “The
features of nature,” says Dr. Clarke, “continue the same, though works
of art may be done away: the ‘beautiful gate’ of the Jerusalem temple
is no more, but Siloah’s fountain still flows, and Kedron still murmurs
in the valley of Jehoshaphat.” According to Chateaubriand, the Pool of
Bethesda, a reservoir, one hundred and fifty feet by forty, constructed
of large stones cramped with iron, and lined with flints embedded in
cement, is the only specimen remaining of the ancient architecture of
that city.

  NOTE.—Roman wells are found in every country which that people
  conquered. Their armies had constant recourse to them when other
  sources of water failed. Pompey and Cæsar often preserved their
  troops from destruction by having provided them. It was Pompey’s
  superior knowledge in thus obtaining water, which enabled him to
  overthrow Mithridates, by retaining possession of an important post.

[Illustration: PICOTAH OF HINDOSTAN.]

  NOTE.—The operation of this primitive device may be thus
  described—Near the well or tank, a piece of wood is fixed, forked at
  the top; in this fork another piece of wood is fixed to form a swape,
  which is formed by a peg, and steps cut out at the bottom, that the
  person who works the machine may easily get up and down. Commonly,
  the lower part of the swape is the trunk of a tree; to the upper end
  is fixed a pole, at the end of which hangs a leather bucket. A man
  gets up the steps to the top of the swape, and supports himself by
  a bamboo screen erected by the sides of the machine. He plunges the
  bucket into the water, and draws it up by his weight; while another
  person stands ready to empty it.

Ephesus, too, is no more; and the temple of Diana, that according
to Pliny was 220 years in building, and upon which was lavished the
talent and treasure of the east; the pride of all Asia, also one of the
wonders of the world, has vanished, while the fountains which furnished
the citizens with water, remain as fresh and perfect as ever. Cisterns
have been discovered in the oldest citadels in Greece. The _fountains
of Bounarbashi_ are perhaps the _only_ objects remaining that can be
relied on, in locating the palace of Priam and the site of ancient
Troy. And the well near the outer walls of the temple of the sun at
Palmyra, will, in all probability, furnish men with water, when other
relics of Tadmor in the wilderness have disappeared; a great number of
the wells of the ancient world still supply man with water, although
their history generally, is lost in the night of time.

We are now to examine the modes practised by the ancients, in obtaining
water from wells. In all cases of moderate depth, the most simple and
efficient, was to form an inclined plane or passage, from the surface
of the ground to the water; a method by which the principal advantages
of an open spring on the surface were retained, and one by which
domestic animals could procure water for themselves without the aid or
attendance of man.

But when in process of time, these became too deep for exterior
passages of this kind to be convenient or practicable, the wells
themselves were enlarged, and stairs for descending to the water,
constructed within them.

  HISTORICAL NOTE.—One of the most appalling facts that is recorded
  of suffering from thirst occurred in 1805. A caravan proceeding
  from Timbuctoo to Talifet, was disappointed in not finding water
  at the usual watering places; when, horrible to relate, all the
  persons belonging to it, two thousand in number, besides eighteen
  hundred camels _perished by thirst_! Occurrences like this, account
  for the vast quantities of human and other bones, which are found
  heaped together in various parts of the desert. While the crusaders
  besieged Jerusalem, great numbers perished of thirst, for the Turks
  had filled the wells in the vicinity. Memorials of their sufferings
  may yet be found in the heraldic bearings of their descendants. The
  charge of a foraging party “for water,” we are told, “was an office
  of distinction;” hence, some of the commanders on these occasions,
  subsequently adopted _water buckets_ in their coats of arms, as
  emblems of their labors in Palestine.

Wells with stairs by which to descend to the water, are still common.
The inhabitants of Arkeko in Abyssinia, are supplied with water from
six wells, which are twenty feet deep and fifteen in diameter. The
water is collected and carried up a broken ascent by men, women and
children. Fryer in his Travels in India speaks of “deep wells many
fathoms underground, with stately stone stairs.” Near the village of
Futtehpore, is a large well, ninety feet in circumference, with a broad
stone staircase which is about thirty feet deep to descend to the
water. The fountain of Siloam is reached by a descent of thirty steps
cut in the solid rock, and the inhabitants of Libya, where the wells
often contain little water, “draw it out in little buckets, made of the
shank bones of camels.”

Wells with stairs are not only of very remote origin, but they appear
to have been used by all the nations of antiquity. They were common
chiefly, among the Greeks and Romans.

[Illustration: ITALIAN MODE OF RAISING WATER TO THE UPPER FLOORS OF A
HOUSE.]

As a matter of interest some six or eight representations of the early
forms of wells, have been introduced; but little need to be written
relating to them—the cuts with the titles speak for themselves and also
indicate their manner of use. (See note.)

_In Syria and Palestine_ at the present time the antique bucket and
rope, in modified form, is still used in raising water from wells for
irrigation. The buckets are attached to the ropes at regular intervals
and pass over large drums going down empty and rising full. They
discharge at the top into a large open trough, which conveys the water
to the irrigating ditches.

[Illustration: ROMAN SCREW.—FIG. 72.]

A method much used where rivers are available is the wheel and bucket,
in which the buckets are mounted on the rim of a large wheel which is
of a diameter equal to the height to which the water is to be raised.
The processes although extremely crude are well adapted to countries
where labor is inexpensive as the running expense of the devices is
very small.

  NOTE.—The source from which many of these have been derived is
  “_Eubank’s Hydraulics_,” to which work credit is gladly given for
  nearly all the historical data so far used in this volume. The author
  of the book named gave many years of research into the early records
  of all relating to hydraulics and water machines and kindred subjects.


WATER-LIFTING INVENTIONS.

_The raising of water is one of the early arts_; beginning in ancient
times with devices of the crudest form it has followed the progress
of civilization with ever-increasing importance. In the present era,
it demands engineering ability of the highest order and the finest of
machinery.

Important epochs in the gradual inventions relating to pumps and
hydraulics are: (1) The “force pump,” due to Ctesibius 200 B. C.;
(2) the “double-acting pump,” invented by La Hire in 1718; (3) the
“hydraulic ram,” by Whitehurst in 1772; (4) the “hydraulic press,”
introduced by Joseph Bramah in 1802.

Most of the machines hitherto noticed, raise water by means of flexible
cords or chains, and are generally applicable to wells of great depth.
We now enter upon the examination of another variety, which, with one
exception (the chain of pots), are composed of inflexible materials,
and raise water to limited heights only.

In preceding machines, the “mechanical powers” are distinct from the
hydraulic apparatus, _i. e._, the wheels, pulleys, windlass, capstan,
etc., form no essential part of the machines proper for raising the
water, but are merely employed to transmit motion to them; whereas
those we are now about to describe, are made in the form of levers,
wheels, etc., and are propelled as such.

The Roman Screw delineated upon the opposite page, if not the earliest
hydraulic engine that was composed of _tubes_, or in the construction
of which they were introduced, is certainly the oldest one known of
that description; in its mode of operation it differs essentially from
all other ancient tube machines; in the latter the tubes merely serve
as conduits for the ascending water, and as such are at rest; while in
the screw it is the tubes themselves in motion that raises the liquid.

Fig. 73 represents one of the earliest forms of _a double gutter_,
placed across a trough or reservoir designed to receive the water. A
partition is formed in the center, and two openings made through the
bottom on each of its sides, through which the water that is raised
escapes. The machine is worked by one or more men, who alternately
plunge the ends into the water, and thus produce a continuous discharge.

[Illustration: FIG. 73.]

Sometimes, openings are made in the bottom next the laborers, and
covered by flaps, to admit the water without the necessity of wholly
immersing those ends; machines of this kind probably date from remote
antiquity; they are obviously modifications of the _Jantu_ of Hindostan
and other parts of Asia. The jantu is a machine extensively used in
parts of India, to raise water for the irrigation of land, and is thus
described: “It consists of a hollow trough of wood, about fifteen
feet long, six inches wide, and ten inches deep, and is placed on a
horizontal beam lying on bamboos fixed in the bank of a pond or river.

One end of the trough as shown in the figure rests upon the bank where
a gutter is prepared to carry off the water, and the other end is
dipped in the water, by a man standing on a stage, plunging it in with
his foot. A long bamboo with a large weight of earth at the farther
end of it, is fastened to the end of the jantu near the river, and
passing over the gallows, poises up the jantu full of water, and causes
it to empty itself into the gutter. This machine raises water three
feet, but by placing a series of them one above another, it may be
raised to any height, the water being discharged into small reservoirs,
sufficiently deep to admit the jantu above, to be plunged low enough to
fill it;” water is thus conveyed over rising ground to the distance of
a mile and more. In some parts of Bengal, they have different methods
of raising water, but the principle is the same.

_The Tympanum._ This is a water raising current wheel originally made
in the form of a drum, hence the name. It is now a circular open frame
wheel, fitted with radial partitions as shown in Fig. 74, so curved
as to point upward on the rising side of the wheel and downward on
the descending side. The wheel is so suspended that its lower edge
is just submerged and is turned by the current (or by other power),
the partitions scooping up a quantity of water which, as the wheel
revolves, runs back to the axis of the wheel where it is discharged; or
it may discharge at some point of the periphery; while one of the most
ancient forms of water lifting machines it is still used in drawing
works.

[Illustration: FIG. 74.]

A little study of the figure (74) will explain its operation.

S, is the shaft; G G, the gutters; A, a trough to take away the water.
The arrow indicates the direction in which the wheel turns; each
gutter, as it revolves scoops up a portion of water and elevates it,
till by the inclination to the axle, it flows towards the latter, and
is discharged through one end of it.

The prominent defect of the tympanum arises from the water being always
at the extremity of a radius of the wheel, by which its resistance
increases as it ascends to a level with the axis, being raised at the
end of levers which virtually lengthen till the water is discharged
from them; this has been remedied by making the arms curving as shown
in the _Scoop Wheel_ (Fig. 75.) As this revolves in the direction of
the arrow the extremities of the partitions dip into the water and
scoop it up and as they ascend discharge it into a trough placed under
one end of the shaft which is hollowed into as many compartments as
there are partitions or scoops.

[Illustration: FIG. 75.]

Fig. 76 represents a sectional view of _an improved tympanum_; this was
invented by De La Faye; the illustration will be readily understood. As
shown in Figs. 74 and 75 the wheel is driven by the current of a stream
impinging upon what in later times came to be known as boards or floats
on the circumference of the wheel.

[Illustration: FIG. 76.]

Within the enclosure are arranged four scrolls of suitable proportions,
dipping the water, at one end, and emptying it out at the center of the
wheel as more clearly shown in Figs. 74 and 75.

_The Noria or Egyptian Wheel._ The tympanum has been described as an
assemblage of gutters, and the _Noria_ may be considered as a number of
revolving swapes. It consists of a series of poles united like the arms
of a wheel to a horizontal shaft. To the extremity of each, a vessel
is attached which fills as it dips into the water, and is discharged
into a reservoir or gutter at the upper part of the circle which it
describes. Hence, the former raises water only through half a diameter,
while this elevates it through a whole one. (Fig. 77.)

The Chinese make the noria, in what would seem to have been its
primitive form, and with an admirable degree of economy, simplicity,
and skill. With the exception of the axle and two posts to support it,
the whole is of bamboo, and not a nail used in its construction. Even
the vessels, are often joints of the same, being generally about four
feet long and two or three inches in diameter. They are attached to
the poles by ligatures at such an angle, as to fill nearly when in the
water, and to discharge their contents when at, or near the top.

The periphery of the wheel is composed of three rings of unequal
diameter and so arranged as to form a frustrum of a cone. The smallest
one, to which the open ends of the tubes are attached, being next
the bank over which the water is conveyed. By this arrangement their
contents are necessarily discharged into the gutter as they pass the
end of it. When employed to raise water from running streams they are
propelled by the current in the usual way—the paddles being formed of
woven bamboo. The sizes of these wheels, vary from twenty to seventy
feet in diameter; some raise over three hundred tons of water in
twenty-four hours. A writer mentions others which raise a hundred and
fifty tons to the height of forty feet during the same time.

  NOTE.—The mode of constructing and moving the noria by the Romans,
  is thus described by Vitruvius, who lived about the beginning of
  the Christian Era. “When water is to be raised higher than by the
  tympanum, a wheel is made round on axis of such a magnitude as the
  height to which the water is to be raised requires. Around the
  extremity of the side of the wheel, square buckets cemented with
  pitch and wax are fixed; so that when the wheel is turned by the
  walking of men, the filled buckets being raised to the top and
  turning again toward the bottom, discharge of themselves what they
  have brought into the reservoir.”

[Illustration: FIG. 77.]

_The Persian Wheel._ Two prominent defects exist in the noria. First,
part of the water escapes after being raised nearly to the required
elevation. Second, a large portion is raised _higher_ than the
reservoir placed to receive it, into which it is discharged after the
vessels begin to descend; to obviate this _the Persian wheel_ was
devised.

The vessels in which the water is raised, instead of being fastened
to the rim, or forming part of it, as in the preceding figures, are
suspended from pins, on which they turn, and thereby retain a vertical
position through their entire ascent; and when at the top are inverted
by their lower part coming in contact with a pin or roller attached to
the edge of the gutter or reservoir, as represented in the figure. By
this arrangement no water escapes in rising, nor is it elevated any
higher than the edge of the reservoir; hence, the defects in the noria
are avoided. It is believed, to have been used in Europe ever since the
time of the Romans.

[Illustration: FIG. 78.]


GAINING AND LOSING BUCKETS.

In the latter part of the Sixteenth, or beginning of the Seventeenth
Century a machine which is entitled to particular notice on account of
its being, as claimed, the first one of the kind to be _self-acting_,
for raising water was in use in Italy. It is ascribed to Gironimo
Finugio who put one in operation at Rome in 1616.

[Illustration]

Between the illustration and the following description its operation
may be clearly understood. On a pulley S, are suspended by a rope
two buckets A and B, of unequal dimensions. The smaller one B, is
made heavier than A when both are empty, but lighter when they are
filled. It is required to raise by them part of the water from the
spring or reservoir E, into the cistern Z. As the smaller Bucket B,
by its superior gravity, descends into E, (a flap valve in its bottom
admitting the water), it consequently raises A into the position
represented in the figure. A pipe F, then conveys water from the
reservoir into A, the orifice or bore of which pipe is so proportioned,
that both vessels are filled _simultaneously_. The larger bucket then
preponderates, descending to O, and B at the same time rising to the
upper edge of Z, when the projecting pins O O, catch against others on
the lower sides of the buckets, and overturn them at the same moment.
The bails or handles are attached by swivels to the sides, a little
above their center of gravity. As soon as both buckets are emptied,
B again preponderates, and the operation is repeated without any
attendance, so long as there is water in E and the apparatus continues
in order.

In Moxon’s machine, the buckets were filled by two separate tubes of
unequal bore; the orifices being covered by valves to prevent the
escape of water while the buckets were in motion; these valves were
opened and closed by means of cords attached to the buckets. The efflux
through F in the figure, may easily be stopped as soon as A begins to
descend, by the action of either bucket on the end of a lever attached
to a valve, or by other obvious contrivances. The water discharged
from A, runs to waste through a channel provided for that purpose.
These machines are of limited application, since they require a fall
for the descent of A, equal to the elevation to which the liquid is
raised in B. They may however be modified to suit locations where a
less descent only can be obtained. Thus, by connecting the rope of B to
the periphery of a large wheel, while that of A is united to a smaller
one on the same axis, water may be raised higher than the larger
bucket falls, but the quantity raised will of course be proportionally
diminished. In the face of these securing advantages it has fallen into
disuse; it was much too complex and cumbersome, and of too limited
application.

The principle of self-action in all these machines is no modern
discovery, for it was described by Hero of Alexandria, who applied it
to the opening and closing the doors of a temple, and to other purposes.


THE PULLEY AND WINDLASS.

In those vast periods preceding the dawn of history, water was _as
heavy and as necessary_ for the use of mankind and animals as it
is to-day; the toil and labor in securing it must indeed have been
hard. Doubtless, the first inventions of the primitive man were first
made—perhaps, after weapons of defence—to relieve himself of the
painful endeavor of supplying the precious liquid.

There are reasons which render it probable that the _single pulley_ was
devised to raise water and earth from wells; the latter are not only of
the highest antiquity but they are the only known works of man in early
times in which the pulley could have been required or applied. That it
preceded the invention of ships and the erection of lofty buildings
of stone, is all but certain; but for what purpose, save for raising
of water, the pulley could have been previously required it would be
difficult to divine; it seems to have been the first addition made to
those primitive implements, the cord and the bucket.

By it _the friction of the rope_ in rubbing against the curb and
the consequent loss of a portion of the power expended in raising
the water, were avoided, and by it also a beneficial _change in the
direction of the power_ was attained; instead of being exerted in an
ascending direction, it is applied more conveniently and efficiently in
a descending motion as shown in the various figures and illustrations
in the preceding pages.

But the grand advantage of the pulley in the early ages was this:—by it
the vertical direction in which men exerted their strength, could be
directly changed into a horizontal line, by which change _animals could
be employed_.

The wells of Asia, frequently varying from two to three, and even four
hundred feet in depth, obviously required more than one person to raise
the contents of an ordinary sized vessel; and where numbers of people
depended on such wells, not merely to supply their domestic wants,
but for the purposes of irrigation, the substitution of animals in
place of men to raise water, became a matter almost of necessity, and
was certainly adopted at a very early period. In employing an ox for
this purpose, the simplest way and one which deviated the least from
their accustomed method, was merely to attach the end of the rope to
the yoke, after passing it over a pulley fixed sufficiently high above
the mouth of the well, and then driving the animal a distance equal to
its depth, in a direct line from it, when the bucket charged with the
liquid would be raised from the bottom.

Although it may never be known to whom the world is indebted for the
_windlass_, there are circumstances which point to the construction
of wells and raising of water from them, as among the first uses to
which it as well as the pulley, was applied. The windlass possesses
an important advantage over the single pulley in lifting weights, or
overcoming any resistance since the intensity of the force transmitted
through it can be modified, either by varying the length of the crank,
or the circumference of the roller on which the rope is coiled.
Sometimes a single vessel and rope, but frequently two, are employed
as shown in several of the preceding illustrations; one of these
is the _Chinese Windlass_. This furnishes the means of increasing
mechanical energy to almost any extent, and as it is used to raise
water from some of those prodigiously deep wells already noticed, a
figure of it, page 47, has been inserted. The roller consists of two
parts of unequal diameters, to the extremities of which the ends of the
rope are fastened on opposite sides, so as to wind round both parts
in different directions. As the load to be raised is suspended to a
pulley, every turn of the roller raises a portion of the rope equal to
the circumference of the thicker part, but at the same time lets down
a portion equal to that of the smaller; consequently the weight is
raised at each turn, through a space equal only to half the difference
between the circumferences of the two parts of the roller. The action
of this machine is therefore slow, but the mechanical advantages are
proportionately great.

[Illustration: FIG. 79.]

The _fusee windlass_ is shown in Fig. 79. This is an early invention
designed to overcome in a mechanical method the greater weight which
the rope hung at its extremity has, as compared to what it is when
nearly wound up. At the bottom of the well the rope then being at its
heaviest period is wound upon the small end of the fusee; and as the
length diminishes it coils round the larger part. (See Fig. 79), which
is however inaccurately drawn—as the bucket is at the top of the well;
it should have been represented as suspended from the large end of the
fusee.

The value of a device like this will be appreciated when the great
depth of some wells is considered and the consequent additional weight
of the chains. In the fortress of Dresden is a well eighteen hundred
feet deep; at Augustburgh is a well in which half an hour is required
to raise the bucket; and at Nuremburgh another, sixteen hundred feet
deep. In all these, the water is raised by chains, and the weight of
the one used in the latter is stated to be upwards of a ton.

_The tympanum and noria_ in all their modifications have been
considered as originating in the gutter or _jantu_, and _the swape_;
while the machine we are now to examine is evidently derived from
the primitive _cord and bucket_. The first improvement of the latter
was the introduction of a pulley or sheave over which the cord was
directed—the next was the addition of another vessel, so as to have one
at each end of the rope, and the last and most important consisted in
uniting the ends of the rope, and securing to it a number of vessels at
equal distances through the whole of its length—and the _chain of pots_
was the result. (See Fig. 80.)

[Illustration: FIG. 80.]

The general construction of this machine will appear from an
examination of those which are employed to raise water from Joseph’s
well at Cairo, represented on page 45. Above the mouth of each shaft a
vertical wheel is placed, over which two endless ropes pass and are
suspended from it. These are kept parallel to, and at a short distance
from each other, by rungs secured to them at regular intervals, so
that when thus united, they form an endless ladder of ropes. The rungs
are sometimes of wood, but more frequently of cord like the shrouds of
a ship, and the whole is of such a length that the lowest part hangs
two or three feet below the surface of the water that is to be raised.
Between the rungs, earthenware vases (of the design shown at A A) are
secured by cords round the neck, and also round a knob formed on the
bottom for that purpose.


WHEEL AND AXLE.

In all the preceding machines the roller is used in a _horizontal_
position; but at some unknown period of past ages, another modification
was devised, one by which the power could be applied at any distance
from the center. Instead of placing the roller as before, over the
well’s mouth, it was removed a short distance from it, and secured in a
vertical position, by which it was converted into the wheel or capstan.
One or more horizontal bars were attached to it, of a length adapted
to the power employed, whether of men or animals; and an alternating
rotary movement imparted to it, as in the common wheel or capstan,
represented in the figure. It appears that machines of this kind, and
worked by _men_ were common in Europe previous to, and at the time he
wrote. Sometimes the shaft was placed in the edge of the well, so that
the person who moved it walked round the latter, and thus occupied less
space.

[Illustration: FIG. 81.]


SUCCESSIVE INVENTIONS.

With the wide acceptance in practical use of the Duplex steam pump,
may be dated the beginning of the modern inventive period of pumping
machinery; this introduction of the Duplex pump was only one of five
successive advances which it were well for the student to memorize:

  1. The Cornish,

  2. The Rotative,

  3. The Direct Acting,

  4. The Duplex, and

  5. The Compounded Steam Pump.

The Cornish engines have been alluded to in connection with the
Newcomen engine. Probably no large pumping engines in the past have
held, and deservedly so, as high repute as have the Cornish engines
when used for deep mine pumping. Their construction, with the rude
appliances at hand, is not only a marvel but as well a high tribute
to the ingenuity of those who designed them and to the skill of the
workmen who built them. A rather full illustrated description of this
almost unexcelled machine will be found later on in the book.

_The next class of large steam pumping-engines which have played an
important part in the history of hydraulic engineering may be grouped
together as “rotative engines.”_ What is here meant by the term
“rotative” is engines in which there are parts which make complete and
continuous rotary motion and in which are used, in some way or another,
shafts, cranks and fly-wheels.

These engines vary greatly in their design and in the details of their
construction. They are of varying sizes, including some of the largest
and most expensive in the world. As a general thing they are employed
in supplying towns and cities with water, and in some cases freeing
shallow mines of water. The application of the power of the steam used
in the steam cylinders in this class of engines to drive the plungers
or pistons in the pumps, varies greatly, both as to the general design
upon which they are built, and in the detail of their construction. In
some instances it is through the use of long or short beams or bell
cranks, sometimes through gearing, and occasionally through the plunger
or piston of the pump direct; but in all cases the limit of the stroke
of the steam piston, and of the pump plunger, is governed by a crank on
a revolving shaft.

Attached to the revolving shaft is _a fly-wheel_ of greater or less
diameter and weight, which, in addition to assisting the crank to
pass the center at each end of its stroke, _is employed to store up
at the beginning of each stroke of the steam piston, whatever excess
of power or impulse there may be imparted to it, beyond that required
to steadily move the water column, and to give out again, toward the
latter part of the stroke, when the power of the steam is of itself
below that required to move the water column, the power previously
stored in it_. In this respect the function of a revolving fly-wheel on
a rotative engine is the same as is the weighted plunger in the Cornish
engine; both being used for the purpose of permitting the steam to be
cut off at a portion of its stroke in the steam cylinder, and expanded
during the rest of the stroke.

In short, these devices, as employed in both the classes of pumping
engines described, were used in order that the best economy in the
consumption of steam by means of early cutoff and a high grade of
expansion, might be attained.

The succeeding class of pumps to be described, driven by steam are
_direct acting steam-pumps_.

What is here meant as “direct-acting,” is a steam-driven pump in which
there are no revolving parts, such as shafts, cranks and fly-wheels;
_pumps in which the power of the steam in the steam cylinder is
transferred to the piston or plunger in the pump in a direct line_, and
through the use of a continuous rod or connection. (Fig. 82.)

_The introduction of the direct-acting steam-pump marked a point of
deviation_, and it entered the field almost without a rival, and at a
time when economy was overshadowed by its convenience.

In the brief description given of these three most prominent classes
of pumping engines, no attempt has been made to describe any of the
peculiarities of their general construction, beyond what was necessary
to describe their action and the principles upon which they operate.

[Illustration: FIG. 82.]

In pumps of this construction there are no weights in the moving
parts other than that required to produce sufficient strength in
such part for the work they are expected to perform, and, as there
is consequently no opportunity to store up power in one part of the
stroke, to be given out at another, it is impossible to cut off the
steam in the steam cylinder during any part of its stroke. The uniform
and steady action of the direct-acting steam-pump is dependent alone
on the use of a steady uniform pressure of steam through the entire
stroke of the piston against a steady, uniform resistance of water
pressure in the pump; the difference between the power exerted in the
steam cylinders over the resistance in the pump governing the rate of
speed at which the piston or plunger of the pump will move. The length
of the stroke of the steam piston, within the steam cylinders of this
class of pumps, is limited and controlled alone by the admission,
suppression and release of the steam used in the cylinders.

  NOTE.—Up to the introduction of the direct-acting steam pump, all
  the other pumping machinery of the world then in use was the outcome
  of evolution. It had been developed by slow stages, in which one
  engineer after another aided by the experience of others and of
  his own, supplemented by his inventive faculties, added here and
  there slight improvements to which other engineers, with increased
  experience, were enabled to add still other improvements, so that
  each new engine constructed under more favorable circumstances, and
  with increasing expenditures, was supposed to excel all previously
  built; until at this time we have, as it is fair to suppose, pumping
  engines which combine all the wisdom of the past, and which leave
  little or no room for further improvements in their respective
  classes.

The history of the _Direct-Acting Steam Pump_ differs from all others
from the fact that it was the invention of one man, and was in the main
perfected during his lifetime. It was so strikingly different from all
that had preceded it, that there was nothing in the way of precedent,
either in ancient or modern practice, of which the inventor could avail
himself by which to aid or guide him to success.

The date of the first patent on these pumps was September 7, 1841. It
was issued on a small pump used for supplying feed water to a steam
boiler, and consisted of one steam cylinder connected to a force pump,
and so arranged that by the use of levers, trips, springs, and other
connections between the piston rod and the slide valve, the movement
of the piston rod controlled the movements of the slide valve to an
extent that not only regulated the length of the stroke of the piston,
but reversed its motion. This pump was placed alongside of the steam
boiler, and was so connected by means of pipes and levers and floats
within the boiler, that when the water fell below the proper level in
the boiler, it would start the pump, and stop it when the water rose
too high.

  NOTE.—At the head of a list consisting of two names only, who, on the
  foremost pages of “The American Society of Mechanical Engineers,”
  are recorded as the “Honorary Members in Perpetuity” of that large
  society, and standing as well at the head of that long and increasing
  list of members who have accomplished their work on earth, may be
  seen the name of _Henry Rossiter Worthington_, the inventor and
  original builder of the “direct-acting steam pump.”

Feeling how incomplete was an invention which did not provide against
the intermittent action of the pump, Mr. Worthington devoted much time
and study to correct this trouble, and a few years later he brought
out an improved pump which, in its simplicity of parts, certainty
of action, and cheapness of construction more than rivaled the
original invention itself. This pump is now universally known as the
“_Direct-Acting Duplex Steam Pump_.”

In the main, the construction of the steam ends and the water ends of
the duplex pump differs but slightly from those of the single-acting
pump, but the mechanism which operates the steam valves is different,
and the effect on the water column was marvelously different; the
principle upon which it operates is this:

Two pumps of similar construction are placed side by side, a lever
attached to the piston rod of each pump connects to the slide valve of
the opposite steam cylinder; thus the movement of each piston, instead
of operating its own slide valve as in the single pump, operates the
slide valve of the opposite cylinder. The effect of this arrangement
is, that as the piston or plunger of one pump arrives near the end of
its stroke, the plunger or piston of the other begins its movement,
thus alternately taking up the load of the water column, producing a
regular, steady, onward flow of water, without the unusual strains
induced by such a column when suddenly arrested or started in motion.

While the “duplex steam pump” overcame one of the greatest objections
to the former single pump, there still remained in this class
of pumping machinery one other difficulty. It did not use steam
expansively.

This not only debarred it from competing with other engines where a
large quantity of water was required to be raised, and where the cost
of fuel was an item of importance, but as well prevented the pump from
taking rank among the hydraulic appliances required in supplying towns
and cities.

This objection was one which seemed insurmountable, steam in them could
not be used economically. Applied to the propulsion of the plunger or
piston of this pump it must be of sufficient quantity, and pressure,
to overcome the height of the column of water on the pump, together
with its friction through the pump and its connections, _at the very
beginning of the stroke_; and it must be maintained, both as to its
volume, and its pressure up to the very last part of the stroke. Any
diminution, either of volume or pressure, during any part of the stroke
would simply bring the pump to a stop. This apparent inability to cut
off the steam in the steam cylinder, and to complete the stroke of the
pump by the aid of the steam remaining in the cylinder, and by its
expansive force, had debarred this pump from coming into general use
for large water works. How this, the only remaining objection to their
use for such purposes, was overcome, forms an interesting chapter in
the history of the “_Direct-Acting Steam Pump_.”

It was when this question had assumed a most formidable, importance,
that the principle of _using steam in compound steam engines_ had
engaged the careful consideration of the most eminent engineers of this
and other countries; _its adjustment to the Duplex pumps was made_,
and while it was easily done, owing to their peculiar construction,
its application produced a most wonderful result in their working, and
their speedy introduction for water works use.

  NOTE.—At this time the man who had invented and built the little
  steam pump for the canal boat, who had watched its growth and
  development, supplemented one device after another to help it on
  through the trial period of its existence, had merged it at last
  into the dual or duplex stage of its advancement, had added to it
  the compound feature, had seen it expanding in size and importance
  until, growing up and out of the day of small things, it had come to
  take its well-earned place alongside those old and massive machines
  whose invention and origin was lost amid the musty records of the
  past—it was, at this time, and of which any man might well have been
  proud, that his lifelong labors came to an end Dec. 18., 1880, at the
  Everett House, New York City.



  ELEMENTARY
  HYDRAULICS



ELEMENTARY HYDRAULICS.


There are three physical states or conditions of matter, which are the
_solid_, _liquid_ and _gaseous_, which in this connection apply to Ice,
Water and Steam. _A solid_ offers resistance both to change of shape
and to change of bulk.

_A Fluid_ offers no resistance to change of shape. Again fluids can be
divided into _liquids_ and vapors or gases. Water is the most familiar
example of a liquid. A liquid can be poured out in drops while a gas or
vapor flows in a stream or streams.

_Gas_ is a term at first used as meaning the same as the name _air_,
but is now restricted to fluids supposed to be permanently elastic, as
oxygen, hydrogen, etc., in distinction from vapor such as steam which
become liquid upon a reduction of temperature.

It is important to note that experiment proves that every vapor becomes
a gas at a sufficiently high temperature or low pressure, while, on
the other hand, every gas becomes a vapor at sufficiently low and
high pressures. In present popular usage the term gas applies to any
substance in the aeriform elastic condition.

_Hydraulics_ is that branch of science or of engineering which treats
of the motion of liquids, especially of water and of the laws by which
it is regulated.

As a science, hydraulics includes _hydrodynamics_ or the principles of
mechanics applicable to the motion of water.

As a branch of engineering, hydraulics consists in the practical
application of the mechanics of fluids, to the control and management
of water, with reference to the wants of man, including water works,
hydraulic machines, pumps, water wheels, etc.

The term hydraulics, so familiar in daily use, is formed from two Greek
words meaning: 1, water; 2, a pipe; hence, it will be observed with
interest how close the original meaning follows the development of the
science in its practical adaptation; there is always the “pipe” or
holding vessel and the “water” or its equivalent.

From the same elementary word meaning water, in the Greek language,
has been formed very many other words in common use, for example
hydrophobia, hydrogen, hydrant, hygrometer, etc., as well as the
following:

_Hydromechanics_ is that branch of natural philosophy which treats
of the mechanics of liquid bodies, or in other words, of their laws
of equilibrium and motion. Hydromechanics comprises properly those
phenomena of liquids by which these bodies differ from solids or from
bodies at large; hence, its foundation is laid in the properties that
distinguish the liquid from other states of bodies, viz.: the presence
of cohesion, with great mobility of parts, and perfect elasticity.

_Hydrostatics_ is that branch of science which relates to the pressure
and equilibrium of non-elastic fluids, as water, mercury, etc.;
thus, the hydrostatic press is a machine in which great force with
slow motion is action communicated to a large plunger by means of
water forced into the cylinder in which it moves, by a forcing pump.
_Statics_ treats of forces that keep bodies at rest or in equilibrium,
the water through which the force operates in the hydrostatic press
always remaining at rest serves as a good illustration.

_Pneumatics_ is that branch of science, which relates to air, or gases
in general or their properties; also of employing (compressed) air or
other gas as a motive power. The use of pneumatic pumping machinery is
constantly increasing, especially of the direct pressure types; under
the section of this work relating to Air Pumps additional data will be
presented.

_Hydropneumatics_ is defined as involving the combined action of
water and air, or gas, as shown, for example, in the hydropneumatic
accumulator. The word is a compound formed of the Greek words meaning
water and air.

_Semi-liquids._ All the results stated in reference to water are
further modified in those semi-liquids which have greater or less
viscidity, as pitch, syrup, fixed oils, etc. Viscosity may be defined
as the quality of flowing slowly, thus the viscosity of such liquids as
have been named is very great as compared with that of a mobile liquid
like alcohol.


HYDRODYNAMICS.

_Water, considered from a chemical standpoint_, is a compound substance
consisting of hydrogen and oxygen, in the proportion of two _volumes_
of the former gas to one volume of the latter; or _by weight_ it is
composed of two parts of hydrogen united with sixteen parts of oxygen.
It should be noted that the union of these two gases is effected by
_chemical action_ and not by _mechanical mixture_. Pure water is
transparent, inodorous and tasteless.

Under ordinary conditions water passes the liquid form only at
temperatures lying between 32° F. and 212° F.; it assumes a solid form,
that of ice or snow at 32° F., and it takes the form of vapor or steam
at 212° F.

_There are four notable temperatures for water_, namely:

   32° F., or   0° C. = the freezing point under one atmosphere.
   39°·1   or   4°    = the point of maximum density.
   62°     or  16°·66 = the standard temperature.
  212°     or 100°    = the boiling point, under one atmosphere.

The temperature 62° F. is the temperature of water used in calculating
the specific gravity of bodies, with respect to the gravity or density
of water as a basis, or as unity.

_Weight of one cubic foot of Pure Water._

  At 32° F.                      = 62·418 pounds.
  At 39°·1.                      = 62·425    „
  At 62° (Standard temperature)  = 62·355    „
  At 212°                        = 59·640    „

The weight of a cubic foot of water is, it may be added, about 1000
ounces (exactly 998·8 ounces), at the temperature of maximum density.

The weight of a cylindrical foot of water at 62° F. is 48·973 pounds.

_Weight of one cubic inch of Pure Water._

  At 32° F. = ·03612 pound, or 0·5779 ounce.
  At 37°·1  = ·036125  „     „ 0·5780   „
  At 62°    = ·03608   „     „ 0·5773   „ or 252·595 grains.
  At 212°   = ·03451   „     „ 0·5522   „

The weight of one cylindrical inch of pure water at 62° F. is ·02833
pounds, or 0·4533 ounce.

_Volume of one pound of Pure Water._

  At 32° F. = ·016021 cubic foot, or 27·684 cubic inches.
  At 39°·1  = ·016019       „      „ 27·680       „
  At 62°    = ·016037       „      „ 27·712       „
  At 212°   = ·016770       „      „ 28·978       „

The volume of one ounce of pure water at 62° F. is 1·732 cubic inches.

The weight of water is usually taken in round numbers, for ordinary
calculations, at 62·4 lbs. per cubic foot, which is the weight at 52°·3
F.; or it is taken at 62-1/2 lbs. per cubic foot.

Salt water boils at a higher temperature than fresh water owing to its
greater density, and because the boiling point of water is increased
by any substance that enters into chemical combination with it. The
density of water decreases as the temperature increases, since heat
destroys cohesion and expands the particles, causing them to occupy
greater space, where precision is not required; the pressure on a
square foot at different ocean depths are approximate, in the following


TABLE.

  Depth in feet. | Pressure on sq. foot.
  ===============+======================
         8       |       500  lbs.
        16       |      1000  „
        24       |      1500  „
        32       |      2000  „
        40       |      2500  „
        48       |      3000  „
        56       |      3500  „
        64       |      4000  „
        72       |      4500  „
        80       |      5000  „
        88       |      5500  „
        96       |      6000  „
  ---------------+----------------------

  1 mile, or 5,280 feet,   330,000 lbs.
  5 miles,               1,650,000  „

This table is based upon an allowance of 62-1/2 lbs. of water to the
cubic foot, thus 8 feet × 62-1/2 = 500, etc.


HYDRAULIC DATA.

_Water is practically non-elastic._ A pressure of 30,000 lbs. to the
square inch has been applied and its contraction has been found to
be less than one-twelfth. Experiment appears to show that for each
atmosphere of pressure it is condensed 47-1/2 millionth of its bulk.

The mechanical properties of liquids are determined on the hypothesis
that liquids are incompressible; according to known general principles
this is found to be for all practical purposes true, yet liquids are
more compressible than solids. If water be confined in a perfectly
rigid cylindrical vessel, its compression would equal 1/300000 of its
length for every pound per unit of area of the end pressure.

Water is nearly 100 times as compressible as steel, yet for almost all
practical purposes, liquids may be considered as non-elastic bodies
without involving sensible error.

_The pressure upon the horizontal base of any vessel containing a
fluid, is equal to the weight of a column of the fluid, found by
multiplying the area of the base into the perpendicular height of the
column, whatever be the shape of the vessel._

This follows, since here the distance of the center of gravity of the
base from the surface of the fluid, is the same as the perpendicular
height of the column. With a given base and height, therefore, the
pressure is the same whether the vessel is larger or smaller above,
whether its figure is regular or irregular, whether it rises to the
given height in a broad open funnel, or is carried up in a slender tube.

Hence, _any quantity of water, however small, may be made to balance
any quantity, however great_. This is called the _hydrostatic paradox_.
The experiment is usually performed by means of a water-bellows,
as represented in Fig. 84. When the pipe AD is filled with water,
the pressure upon the surface of the bellows, and consequently the
force with which it raises the weights laid on it, will be equal to
the weight of a cylinder of water, whose base is the surface of the
bellows, and height that of the column AD. Therefore, by making the
tube small, and the bellows large, the power of a given quantity of
water, however small, may be increased indefinitely. The pressure of
the column of water in this case corresponds to the force applied by
the piston in the hydrostatic press.

[Illustration: FIG. 84.]

We have already seen that the pressure on the bottom of a vessel
depends neither on the form of the vessel nor on the quantity of the
liquid, but simply on the height of the liquid above the bottom. But
the pressure thus exerted must not be confounded with the pressure
which the vessel itself exerts on the body which supports it. The
latter is always equal to the combined weight of the liquid and the
vessel in which it is contained, while the former may be either smaller
or greater than this weight, according to the form of the vessel. This
fact is often termed the _hydrostatic paradox_, because at first sight
it appears paradoxical.

CD (Fig. 85) is a vessel composed of two cylindrical parts of unequal
diameters, and filled with water to _a_. From what has been said
before, the bottom of the vessel CD supports the same pressure as if
its diameter were everywhere the same as that of its lower part; and it
would at first sight seem that the scale MN of the balance, in which
the vessel CD is placed, ought to show the same weight as if there
had been placed in it a cylindrical vessel having the same weight of
water, and having the diameter of the part D. But the pressure exerted
on the bottom of the vessel is not all transmitted to the scale MN;
for the _upward_ pressure upon the surface _n o_ of the vessel is
precisely equal to the weight of the _extra_ quantity of water which a
cylindrical vessel would contain, and balances an equal portion of the
_downward_ pressure on _m_. Consequently the pressure on the plate MN
is simply equal to the weight of the vessel CD and of the water which
it contains.

[Illustration: FIG. 85.]

  _Pressure exerted anywhere upon a mass of liquid is transmitted
  undiminished in all directions, and acts with the same force on all
  equal surfaces, and in a direction at right angles to those surfaces._

To get a clearer idea of the truth of this principle, let us conceive
a vessel of any given form in the sides of which are placed various
cylindrical apertures, all of equal size, and closed by movable
pistons. Let us, further, imagine this vessel to be filled with liquid
and unaffected by the action of gravity; the pistons will, obviously,
have no tendency to move. If now a weight of P pounds be placed upon
the piston A (Fig. 86), which has a surface A, it will be pressed
inwards, and the pressure will be transmitted to the internal faces of
each of the pistons B, C, D, and E, which will each be forced outwards
by a pressure P, their surfaces being equal to that of the first
piston. Since each of the pistons undergoes a pressure, P, equal to
that on A, let us suppose two of the pistons united so as to constitute
a surface 2_a_; it will have to support a pressure 2P. Similarly, if
the piston were equal to 3_a_, it would experience a pressure of 3P;
and if its area were 100 or 1,000 times that of _a_, it would sustain a
pressure of 100 or 1,000 times P. In other words, the pressure on any
part of the internal walls of the vessel would be proportional to the
surface.

The principle of the equality of pressure is assumed as a consequence
of the constitution of fluids.

By the following experiment it can be shown that pressure is
transmitted in all directions; a cylinder provided with a piston is
fitted into a hollow sphere (Fig. 87). in which small cylindrical jets
are placed perpendicular to the sides. The sphere and the cylinder
being both filled with water, when the piston is moved the liquid
spouts forth from all the orifices, and not merely from that which is
opposite to the piston.

[Illustration: FIG. 86.]

[Illustration: FIG. 87.]

The reason why a satisfactory quantitative experimental demonstration
of the principle of the equality of pressure cannot be given is that
the influence of the weight of the liquid and of the friction of the
pistons cannot be altogether eliminated.

  NOTE.—_The influence of the weight (or gravity) of water and its
  fractional resistance in practical use_ is so great upon all the
  processes of numbers and of the application of the natural laws
  governing the operation of fluids, as stated under the heading of
  Hydraulic Data, that separate pages will hereafter be found devoted
  to a more extended explanation of this subject of gravity and
  friction of water.

Yet an approximate verification may be effected by the experiment
represented in Fig. 88. Two cylinders of different diameters are
joined by a tube and filled with water. On the surface of the liquid
are two pistons, P and p, which hermetically close the cylinders, but
move without friction. Let the area of the large piston, P, be, for
instance, thirty times that of the smaller one, p. That being assumed,
let a weight, say of two pounds, be placed upon the small piston; this
pressure will be transmitted to the water and to the large piston, and
as this pressure amounts to two pounds on each portion of its surface
equal to that of the small piston, the large piston must be exposed
to an upward pressure thirty times as much, or of sixty pounds. If
now, this weight be placed upon the large piston, both will remain in
equilibrium; but if the weight is greater or less, this is no longer
the case.

[Illustration: FIG. 88.]

It is important to observe that in speaking of the transmission of
pressure to the sides of the containing vessel, these pressures must
always be supposed to be perpendicular to the sides.


_Equilibrium or state of rest of superposed liquids._ In order that
there should be equilibrium when several heterogeneous liquids are
superposed in the same vessel, each of them must satisfy the conditions
necessary for a single liquid, and further there will be a stable
state of rest only when the liquids are arranged in the order of their
decreasing densities from the bottom upwards.

The last condition is experimentally demonstrated by means of the
_phial of four elements_. This consists of a long narrow bottle
containing mercury, water, colored red, saturated with carbonate of
potash, alcohol, and petroleum. When the phial is shaken the liquids
mix, but when it is allowed to rest they separate; the mercury sinks
to the bottom, then comes the water, then the alcohol, and then the
petroleum. This is the order of the decreasing densities of the bodies.
The water is saturated with carbonate of potash to prevent its mixing
with the alcohol.

This separation of the liquids is due to the same cause as that which
enables solid bodies to float on the surface of a liquid of greater
density than their own. It is also on this account that fresh water, at
the mouths of rivers, floats for a long time on the denser salt water
of the sea; and it is for the same reason that cream, which is lighter
than milk, rises to the surface.

  _The pressure upon any particle of a fluid of uniform density is
  proportioned to its depth below the surface._

[Illustration: FIG. 89.]

_Example 1._ Let the column of fluid ABCD Fig. (1) be perpendicular
to the horizon. Take any points, _x_ and _y_, at different depths,
and conceive the column to be divided into a number of equal spaces
by horizontal planes. Then, since the density of the fluid is uniform
throughout, the pressure upon _x_ and _y_, respectively, must be in
proportion to the number of equal spaces above them, and consequently
in proportion to their depths.

_Example 2._ Let the column be of the same perpendicular height as
before, but inclined as is Fig. (2); then its quantity, and of course
its weight, is _increased_ in the same ratio as its length exceeds its
height; but since the column is partly supported by the plane, like any
other heavy body, the force of gravity acting upon it is _diminished_
on this account in the same ratio as its length exceeds its height;
therefore as much as the pressure on the base would be augmented by
the increased length of the column, just so much it is lessened by the
action of the inclined plane; and the pressure on any part of C_c_
will be, as before, proportioned to its perpendicular depth; and the
pressure of the inclined column AC_ac_ will be the same as that of the
perpendicular column ABCD.

  _Fluids rise to the same level in the opposite arms of a recurved
  tube._

[Illustration: FIG. 90.]

Let ABC, (Fig. 90) be a recurved tube: if water be poured into one arm
of the tube, it will rise to the same height in the other arm. For, the
pressure acting upon the lowest part at B, in opposite directions, is
proportioned to its depth below the surface of the fluid. Therefore,
these depths must be equal, that is, the height of the two columns
must be equal, in order that the fluid at B may be at rest; and unless
this part is at rest, the other parts of the column cannot be at rest.
Moreover, since the equilibrium depends on nothing else than the
_heights of_ the respective columns, therefore, the opposite columns
may differ to any degree in quantity, shape, or inclination to the
horizon. Thus, if vessels and tubes very diverse in shape and capacity,
as in Fig. p. 84 be connected with a reservoir, and water be poured
into any one of them, it will rise to the same level in them all.

The reason of this fact will be further understood from the application
of the principle of _equal momenta_, for it will be seen that the
velocity of the columns, when in motion, will be as much greater in the
smaller than in the larger columns, as the quantity of matter is less;
and hence the opposite momenta will be constantly equal.

Hence, water conveyed in aqueducts or running in natural channels, will
rise just as high as its source. Between the place where the water
of an aqueduct is delivered and the spring, the ground may rise into
hills and descend into valleys, and the pipes which convey the water
may follow all the undulations of the country, and the water will run
freely, provided no pipe is laid higher than the spring.


_Pressure of water due to its weight._ The pressure on any particle of
water is proportioned to its depth below the surface. The pressure of
still water in pounds per square inch against the sides of any pipe,
channel, or vessel of any shape whatever, is due solely to the “head”
or height of the level surface of the water above the point at which
the pressure is considered and is equal to ·43302 lbs. per square foot,
every foot of head or 62·355 lbs. per square foot for every foot of
head at 62° F.

The pressure per square inch is equal in all directions downwards,
upwards or sideways and is independent of the shape or size of the
containing vessel; for example, the pressure on a plug forced inward on
a square inch of the surface of water is suddenly communicated to every
square inch of the vessel’s surface, however great and to every inch of
the surface of any body immersed in it.

[Illustration: Various shapes of vessel.]

It is this principle which operates with such astonishing effect in
hydrostatic presses, of which familiar examples are found in the
hydraulic pumps, by the use of which boilers are tested. By the mere
weight of a man’s body when leaning on the extremity of a lever, a
pressure may be produced of upwards of 20 tons; it is the simplest and
most easily applicable of all contrivances for increasing human power,
and it is only limited by want of materials of sufficient strength to
utilize it.


UNIVERSAL GRAVITATION.

_Gravity or Gravitation_ is that species of attraction, or force by
which, all bodies or particles of matter in the universe tend towards
each other; it is also called _attraction of gravitation and universal
gravity_; gravity, in a more limited, sense is the tendency of a mass
of matter toward a center of attraction especially the tendency of a
body toward the center of the earth.

This influence is conveyed from one body to another without any
perceptible interval of time. If the action of gravitation is not
instantaneous, it comes very nearly to it by moving more than fifty
millions of times faster than light.

Gravity extends to all known bodies in the universe, from the smallest
to the greatest; by it all bodies are drawn toward the center of the
earth, _not because there is any peculiar property or power in the
center_, but because the earth being a sphere, the _aggregate_ effect
of the attractions exerted by all its parts upon any body exterior to
it, is such as to influence that body toward the center.

This property manifests itself, not only in the motion of falling
bodies, but in the _pressure_ exerted by one portion of matter upon
another which sustains it; and bodies descending freely under its
influence, whatever be their figure, dimensions or texture, all are
_equally accelerated_ in right lines perpendicular to the plane of
the horizon. The apparent _inequality_ of the action of gravity upon
different species of matter near the surface of the earth arises
entirely from the resistance which they meet with in their passage
through the air. When this resistance is removed (as in the exhausted
receiver of an air-pump), the inequality likewise disappears.

_The law of gravity_, discovered by Sir Isaac Newton, toward the end of
the seventeenth century, may be stated as follows:

   _Every particle of matter in the universe attracts every other
  particle with a force whose direction is that of a line joining the
  two particles considered, and whose magnitude is directly as the
  product of the masses and inversely as the square of the distance
  between them._

As a groundwork for this great generalization, Newton employed the
results of two of the greatest astronomers who preceded him, Copernicus
and Kepler. About 1500 A. D. Copernicus perceived and announced that
the apparent rotation of the heavens about the earth could be explained
by supposing the earth to rotate on an axis once in twenty-four hours.
Previous to this time the earth had been regarded as the center of the
universe. He also showed that nearly all the motions of the planets,
including the earth, could be explained on the assumption that these
revolved in circular orbits about the sun, whose position in the
circle, however, was slightly eccentric.

Thus, building somewhat upon the labors of the two parties named,
Newton was the first to prove the law of the forces which would account
for the motions of all the bodies in the solar system.


LAWS OF FALLING BODIES.

Since a body falls to the ground in consequence of the earth’s
attraction on _each_ of its molecules, it follows that, all other
things being equal, all bodies, great and small, light and heavy,
ought to fall with equal rapidity, and a lump of sand without cohesion
should during its fall retain its original form as perfectly as if it
were compact stone. The fact that a stone falls more rapidly than a
feather is due solely to the unequal resistances opposed by the air to
the descent of these bodies; _in a vacuum all bodies fall with equal
velocity_.

_In a vacuum, however, liquids fall like solids without separation
of their molecules._ The _water-hammer_, a model used in scientific
schools, illustrates this: the instrument consists of a thick glass
tube about a foot long, half filled with water, the air having been
expelled by ebullition previous to closing one extremity with the
blow-pipe. When such a tube is suddenly inverted, the water falls
in one undivided mass against the other extremity of the tube, and
produces a sharp metallic sound, resembling that which accompanies the
shock of two solid bodies coming suddenly together.

  NOTE.—The resistance opposed by the air to falling bodies is
  especially remarkable in the case of liquids. The Staubbach in
  Switzerland is a good illustration; an immense mass of water is seen
  falling over a high precipice, but before reaching the bottom it is
  shattered by the air into the finest mist. See Parker’s Philosophy,
  pp. 69-70.

It has been ascertained, by experiment, that from rest, a body falling
freely will descend 16-1/12 feet in the first second of time, and will
then have acquired a velocity, which being continued uniformly, will
carry it through 32-1/6 feet in the next second. Therefore if the
first series of numbers be expressed in seconds, 1″, 2″, 3″, &c., the
velocities in feet will be 32-1/6, 64-1/3, 96-1/2, &c.; the spaces
passed through as 16-1/12, 64-1/3, 144-3/4, &c., and the spaces for
each second, 16-1/2, 48-1/4, 80-5/12, &c.


TABLE.

_Showing the Relation of Time, Space and Velocity._

  ----------+-----------+--------+------------+------+-----------------
   Time in  | Velocity  |        |Space fallen|      |   Whole space
  seconds of|acquired at|Squares.|  through   |Space.|fallen through in
  the body’s|the end of |        |  in that   |      | the last second
    fall.   |that time. |        |   time.    |      |  of the fall.
  ----------+-----------+--------+------------+------+-----------------
       1    |   32·16   |    1   |    16·08   |   1  |      16·08
       2    |   64·33   |    4   |    64·33   |   3  |      48·25
       3    |   96·5    |    9   |   144·75   |   5  |      80·41
       4    |  128·66   |   16   |   257·33   |   7  |     112·58
       5    |  160·83   |   25   |   402·08   |   9  |     144·75
       6    |  193·     |   36   |   579·     |  11  |     176·91
       7    |  225·17   |   49   |   788·08   |  13  |     209·08
       8    |  257·33   |   64   |  1029·33   |  15  |     241·25
       9    |  289·5    |   81   |  1302·75   |  17  |     273·42
      10    |  321·66   |  100   |  1946·08   |  19  |     305·58
            |           |        |            |      |
  ----------+-----------+--------+------------+------+-----------------

Experience has shown that the measurement of all physical quantities
may be expressed in terms of three fundamental magnitudes. Those
commonly chosen for this purpose are _time_, _length and mass_ _or
quantity of matter_. It may be assumed that our ideas of time and space
are sufficiently exact for all practical purposes. The subject of
matter, however, requires more particular consideration. Of the three
magnitudes named, matter alone is directly cognizable by the senses,
and invested with a variety of interesting properties.

For present purposes matter may be defined as anything that can be
weighed, and the quantity of matter as proportional to its weight;
_i. e._, its attraction towards the earth. The _weight_ of a body is
the force it exerts in consequence of its gravity, and is measured by
its mechanical effects, such as bending a spring. We weigh a body by
ascertaining the force required _to hold it up_, or to keep it from
descending. Hence, weights are nothing more than _measures of the force
of gravity_ in different bodies.

  Again, Gravitation, the most feeble of physical actions between
  small masses, is almost imperceptible; yet it is an energy abundant
  in proportion to the quantity of matter in the universe, and fully
  competent, by its gradual condensing agency, to account for the
  origination of planetary systems and their movements. It is not
  strange, therefore, that by some physicists this energy is supposed
  to be the beginning of that of which all other forms of force are
  residues or metamorphoses. Gravity is the name especially given to
  its terrestrial manifestations. _A particle or body without a sphere
  or spheroid, solid or hollow, is attracted to the center of the mass
  of such body; within a hollow sphere, it will remain at rest at any
  point._ At different depths below the earth’s surface, a body will be
  attracted with a force diminishing as the distance from its center
  decreases. The slight variation in the gravitating force of the same
  falling body at different heights is in practice usually disregarded.
  The weight of a body, as the measure of its gravitating tendency,
  must vary both with mass and with the force acting on it; hence, from
  the form of the earth, the same body at the sea level _will weigh
  less and less as it is removed from either pole toward the equator_.
  An elevation above the sea level gives a like result. A stone falls
  through a less distance in a given time on a mountain than in the
  valley below, less at the equator than at either pole. The loss of
  weight in these cases cannot be tested by lever scales, in which
  this loss is equal on both sides; but it may be by the spring
  balance, in which bodies are weighed by the pull they exert against
  the elasticity of a coiled wire. The effect of centrifugal force,
  increasing from the pole to the equator, co-operates with increasing
  removal from the earth’s center to lessen weight; the result of the
  combined action of these two causes is, that a body weighing 195 lbs.
  at either pole will weigh but 194 over the equator. _The line of a
  falling body, called also the line of direction_, is interesting as
  being that direction in space at any point of the earth’s surface
  with reference to which all other directions are named, and by which
  they are to be determined.

A few points remain to be named. _The flow of water is the result
of the force of gravity_; the importance of this fact and its wide
influence cannot be over stated; the gently falling dew, the mighty
currents in the unfathomable depths of the ocean, as well as the
rivulet merrily falling over the rocks to a lower level are all subject
to the laws of terrestrial gravity.

The upper surface of a liquid in a vessel exposed to the atmosphere is
called _the free surface_ and is pressed downwards by the air under
about 15 lbs. pressure per square inch. The free surface of a small
body of a perfect liquid, at rest, is horizontal and perpendicular to
the action of gravity although in large bodies of liquid, as lakes and
ponds, the free surface is spherical, assuming the curvature of the
earth’s surface.


RULES RELATING TO THE VELOCITY OF FALLING BODIES.

1.—_To find the Velocity a falling Body will acquire in any given time._

Multiply the time, in seconds, by 32-1/6, and it will give the velocity
acquired in feet, per second.

_Example._ Required the velocity in seven seconds.

  32-1/6 × 7 = 225-1/6 feet. Ans.

2.—_To find the Velocity a Body will acquire by falling from any given
height._

Multiply the space, in feet, by 64-1/3, the square root of the product
will be the velocity acquired, in feet, per second.

_Example._ Required the velocity which a ball has acquired in
descending through 201 feet.

  64-1/3 × 201 = 12931; √12931 = 113·7 feet.  Ans.

3.—_To find the Space through which a Body will fall in any given time._

Multiply the square of the time, in seconds, by 16-1/12, and it will
give the space in feet.

_Example._ Required the space fallen through in seven seconds.

  16-1/12 × 7² = 788-1/12 feet. Ans.

4.—_To find the Time which a Body will occupy in falling through a
given space._

Divide the _square root_ of the space fallen through by 4, and the
quotient will be the time in which it was falling.

_Example._ Required the time a body will take in falling through 402.08
feet of space.

  √402·08 = 20·049, and 20·049 ÷ 4 = 5·012. Ans.

5.—_The Velocity being given, to find the Space fallen through._

Divide the velocity by 8, and the square of the quotient will be the
distance fallen through to acquire that velocity.

_Example._ If the velocity of a cannon ball be 660 feet per second,
from what height must a body fall to acquire the same velocity?

  660 ÷ 8 = 82·5² = 6806·25 feet. Ans.

6.—_To find the Time, the Velocity per second being given._

Divide the given velocity by 8, and one-fourth part of the quotient
will be the answer.

_Example._ How long must a bullet be falling, to acquire a velocity of
480 feet per second?

  480 ÷ 8 = 60 ÷ 4 = 15 seconds. Ans.


SPECIFIC GRAVITY.

_Specific Gravity_ is the proportion of the weight of a body to that
of an equal volume of some other substance adopted as a standard of
reference. For solids and liquids the standard is pure water, at a
temperature of 60° F., the barometer being at 30 inches.

Aëriform bodies are referred to the air as their standard. A cubic
foot of water weighs 1,000 ounces; if the same bulk of another
substance, as for instance cast iron, is found to weigh 7,200 ounces,
its proportional weight or specific gravity is 7·2. It is convenient
to know the figures representing this proportion for every substance
in common use, that the weight of any given bulk may be readily
determined. For all substances the specific gravity is used in various
tests for the purpose of distinguishing bodies from each other, the
same substance being found, under the equal conditions of temperature,
&c., to retain its peculiar proportional weight or density.

Hence tables of specific gravities of bodies are prepared for
reference, and in every scientific description of substances the
specific gravity is mentioned. _In practical use, the weight of a cubic
foot is obtained from the figures representing the density by moving
the decimal point three figures to the right, which obviously from the
example above, gives the ounces, and these divided by 16 gives the
pounds avoirdupois, in the cubic foot._

Different methods may be employed to ascertain the specific gravity of
solids. That by measuring the bulk and weighing, is rarely practicable;
as a body immersed in water must displace its own bulk of the fluid,
the specific gravity may be ascertained by introducing a body, after
weighing it, into a suitable vessel exactly filled with water, and then
weighing the fluid which overflows. The proportional weight is thus
at once obtained. Wax will cause its own weight of water to overflow;
its specific gravity is then 1. Platinum, according to the condition
it is in, will cause only from 1/21 to 1/21·5 of its weight of water
to overflow, showing its specific gravity to be from 21 to 21·5. But
a more exact method than this is commonly employed. The difference of
weight of the same substance weighed in air and when immersed in water,
is exactly that of the water it displaces, and may consequently be
taken as the weight of its own bulk of water. See Fig. 93 and rule and
example on page 95.

[Illustration: FIG. 91.]

_The specific gravity is then obtained by weighing the body first in
air, and then, suspended by a fibre of silk or a hair, in water, and
dividing the weight in air by the difference._ It is hardly necessary
to say that the substance examined must be free from mixture of foreign
matters, and especially from cavities that may contain air.

  NOTE.—_Hydrometers_ are instruments for determining the relative
  density of fluids; _distilled water_ is usually referred to as the
  standard of comparison. They consist usually of a bulb or float
  weighted at bottom so as to float upright, and having an elongated
  stem graduated to indicate the density of the liquid by the depth to
  which they sink therein.


THE HYDROSTATIC BALANCE.

Every body immersed in a liquid is submitted to the action of two
forces: gravity which tends to lower it, and the buoyancy of the liquid
which tends to raise it with a force equal to the weight of the liquid
displaced. The weight of the body is either totally or partially
overcome by its buoyancy, by which it is concluded that a body immersed
in a liquid loses a part of its weight equal to the weight of the
displaced liquid.

This principle, which is _the basis of the theory of immersed and
floating bodies_, is called the principle of Archimedes, after the
discoverer. It may be shown experimentally by means of _the hydrostatic
balance_ (Fig. 92). This is an ordinary balance, each pan of which is
provided with a hook; the beam being raised, a hollow brass cylinder is
suspended from one of the pans, and below this a solid cylinder whose
volume is exactly equal to the capacity of the first cylinder; lastly,
an equipoise is placed in the other pan. If now the hollow cylinder be
filled with water, the equilibrium is disturbed; but if at the same
time the beam is lowered so that the solid cylinder becomes immersed in
a vessel of water placed beneath it, the equilibrium will be restored.
By being immersed in water the solid cylinder loses a portion of its
weight equal to that of the water in the hollow cylinder. Now, as the
capacity of the hollow cylinder is exactly equal to the volume of the
solid cylinder the principle which has been before laid down is proved.

[Illustration: FIG. 92.]

Minerals, if suspected of containing spaces, should be coarsely
pulverized, and then the second method may be conveniently applied
to determine their density—thus prepared, a higher result will be
obtained, and even metals when pulverized were found to give a greater
specific gravity than when this is determined from samples in their
ordinary state. Very fine powders may also be examined by the method in
use for ascertaining the specific gravity of fluids, viz.: by comparing
the weight of a measured quantity with that of the same quantity of
water.

A glass vessel called a specific gravity bottle is commonly employed,
which is furnished with a slender neck, upon which is a mark indicating
the height reached by 1,000 grains of water. The substance to be
examined is introduced till it reaches the same mark, and, the weight
of the bottle being known, only one weighing is required to obtain the
result.

The specific gravity of fluids is also taken by the instrument
called a hydrometer or alcometer. Such instruments are much used for
ascertaining the specific gravity of spirituous and other liquors, as
an indication of their strength. _If the solid body to be tested is
lighter than water, it must be attached to some heavy substance to
cause it to sink._ Its specific gravity is then calculated by dividing
its weight in the air by the sum of the weights of the attached body
both in air and in water, first subtracting from this sum the weight of
the two bodies together in the water.

Bodies soluble in water may be weighed in some other fluid, as alcohol,
ether, olive oil, &c., and their proportional weight to that of this
fluid being thus ascertained, their density compared with that of water
is readily calculated or they may be enveloped in wax or other suitable
substance to protect them, and then treated by the method just given
for substances lighter than water. Gaseous bodies are weighed in a thin
glass flask or other vessel made for the purpose, and provided with a
stop-cock. The vessel is exhausted of air before the introduction of
the gas.


RULE FOR FINDING THE SPECIFIC GRAVITY OF A SOLID BODY.

_Weigh the solid in air and then in pure water._

The difference is the weight of water displaced, whose specific gravity
is 1.000.

Then, as the difference of weight is to 1·000, so is the weight in air
to the specific gravity; or divide the weight of the body in air by the
difference between the weights in air and in water.

EXAMPLE.

A lump of glass is found to weigh in air 577 grains; it is then
suspended by a horse hair from the bottom of the scale pan, and
immersed in a vessel of pure water, when it is found to weigh 399.4
grains. What is its specific gravity?

  577.0                 Then,  as 177.6 : 1 :: 577.0 : sp. gravity.
  399.4                                            1
  -----                                        -----
  177·6 the difference                   177·6)577·0(3·248, Ans.
                                               532·8
                                               -----
                                                 4420
                                                 3552
                                                 ----
                                                 8680
                                                 7104
                                                 -----
                                                 15760
                                                 14208
                                                 -----
                                                  1552

[Illustration: FIG. 93.]

  NOTE.—The above figures are introduced to show more vividly the
  comparison between _bulk and weight_, the size of the different
  substances, of course, being merely approximate. A study of the Table
  of Specific Gravities to be found in the next page is worthy of the
  time and attention.


TABLE OF SPECIFIC GRAVITIES.

  METALS.

  Iron, (cast)          7·207
    „   (wrought)       7·688
  Steel (soft)          7·780
    „   (tempered)      7·840
  Lead  (cast)         11·400
    „   (sheet)        11·407
  Brass (cast)          8·384
    „   (wire drawn)    8·544
  Copper (sheet)        8·767
    „   (cast)          8·607
  Gold  (cast)         19·238
    „   (hammered)     19·361
  Gold (22 carats)     17·481
    „  (20   „   )     15·709
  Silver (pure, cast)  10·474
    „  (hammered)      10·511
  Mercury (60°)        13·580
  Pewter                7·248
  Tin                   7·293
  Zinc (cast)           7·215
  Platinum             21·500
  Antimony              6·712
  Arsenic               5·763
  Bronze (gun metal)    8·700


  STONES AND EARTH.

  Coal (Bituminous)     1·256
    „  (Anthracite)   { 1·436
                      { 1·640
  Charcoal               ·441
  Brick                 1·900
  Clay                  1·930
  Common Soil           1·984
  Emery                 4·000
  Glass (plalte)        3·248
  Ivory                 1·822
  Grindstone            2·143
  Diamond               3·521
  Gypsum                2·168
  Lime                  2·720
  Granite               2·625
  Marble                2·708
  Mica                  2·800
  Millstone             2·484
  Nitre                 1·900
  Porcelain             2·385
  Phosphorus            1·770
  Pumice Stone           ·915
  Salt                  2·130
  Sand                  1·800
  Slate                 2·672
  Sulphur               2·033


  WOODS.

  Ash                    ·845
  Beech                  ·852
  Birch                  ·720
  Oak                   1·120
  Pine (yellow)          ·660
    „  (white)           ·554
  Cherry                 ·715
  Cork                   ·240
  Elm                    ·671
  Poplar                 ·383
  Walnut                 ·671
  Willow                 ·585


  LIQUIDS.

  Acid Sulphuric        1·851
   „   Muriatic         1·200
  Spirits of Wine        ·917
  Alcohol                ·790
  Oil (turpentine)       ·870
   „  (olive)            ·915
  Oil (linseed)          ·932
   „  (castor)           ·961
  Pure water            1·000
  Vinegar               1·080
  Milk                  1·032
  Sea water             1·029


TO FIND THE WEIGHT OF A CUBIC FOOT OF ANYTHING CONTAINED IN THESE
TABLES.

_Rule._ Multiply 62·5 lbs. (the weight of a cubic foot of pure water)
by the specific gravity of the given body.

_Example._ What is the weight of a cubic foot of sea water?

              62·5 lbs.
             1·029 sp. gravity.
             -----
              5625
             1250
            625
            -------
    Answer, 64·3125 lbs. is the actual weight: but 64
  lbs. is taken in practice as the weight of a cubic foot of sea water.

_Example._ How many cubic feet of sea water will weigh a ton?

Divide 2240 lbs. (1 ton) by 64 lbs.

     { _8)2240
  64 {    ----
     { 8)  280
          ----
     Ans.   35

_Example._ What is the weight of a cubic foot of wrought iron?

            62·5 lbs.
            7·69 sp. gravity.
           -----
            5625
           3750
          4375
          -------
  Answer, 480·625 lbs.

480 lbs. in practice is the weight of 1 cubic foot of wrought iron.

  NOTE.—35 cubic feet of sea water is accounted to be a ton, as in sea
  water ballast for steamers, and in calculating displacement of ships.

_Example._ What is the average weight of a cubic foot of Bituminous
coal?

           1·256 sp. gravity.
            62·5 lbs.
           -----
            6280
           2512
          7536
          -------
  Answer, 78·5000 lbs.

This 78·5 lbs. is the weight of a cubic foot in a _solid block_, but
loose, as used for fuel, a cubic foot weighs about 49.7 lbs. which is
the average of 13 kinds.

_Example._ What is the weight of a solid cast cylinder of copper, 4
inches diameter and 6 inches high?

           8·607 sp. gravity.
            62·5 lbs.
           -----
           43035
          17214
         51642
      --------
      537·9375 lbs. per cub. ft.
      --------
  Say 538 lbs.

            ·7854
               16 diam. squared.
            -----
            47124
             7854
            -----
          12·5664 area of base.
                6 high
          -------
          75·3984 cu. in. in volume
          -------
         Say 75·4 cubic inches.


          cub. in.   cub. in.      lbs.
  Then, as 1728    :   75·4   ::   538  : Answer.
                        538
                       ----
                       6032
                       2262
                       3770
                     ------
             { 12)40565·2
             {---------
        1728 { 12)3380·433
             {---------
             { 12) 281·702
                   -------
                    23·475 lbs.

           Answer, 23-1/2 lbs. nearly.


FRICTION AND VISCOSITY OF FLUIDS.

_Frictional Resistance._—The resistance with which bodies oppose the
movement of one surface on another is termed _friction_. It depends
on the nature, and the roughness of the surfaces in contact; at the
commencement of the sliding, it is greater than when the motion is
continued.

_Friction is in effect an equivalent force exerted in a direction
opposite to that in which the sliding occurs._ Its whole amount is the
product of two factors: the first of these, which sums up the effect of
the nature and condition of the surfaces, is called _the coefficient
of friction_; the second, which is the sum of all pressures, as weight
strain, and the adhesion due to magnetism (when employed), which act
to urge the two bodies together, _i. e._, perpendicularly to the
surface of contact, is called _the normal pressure_. But this law holds
only where, with dry surfaces, the pressure is not enough to indent
or abrade either; or, with wet surfaces, not enough to force out the
unguent. In either of these cases, the friction increases more rapidly
than the ratio of normal pressure.

_No surfaces can be made absolutely hard or smooth_; when one
surface is made to slide over another, the slight roughness of the
one interlock with those of the other, so that the surfaces must be
separated or the points abraded to allow of the motion; but if one
surface roll upon another, the prominent points are successively
raised, without the need of complete lifting of the body or wearing off
those points. _Hence, there are two kinds of friction, the sliding and
the rolling._ The former of these in amount greatly exceeds the latter;
it is a leading element in the stability of structures and fabrics of
all lands, and the most important resistance and source of waste in all
machinery, and is therefore a chief object of regard in the arts of
construction and the science of engineering.

Sliding friction increases with the roughness of the surfaces in
contact; hence, it is in practice diminished as these surfaces become
worn, also by polishing, and by the use of lubricants, which smooth the
rubbing surfaces by filling their depressions. It increases, almost
universally, in exact proportion with the entire pressure, owing to
weight or other causes, with which the two surfaces are held together;
but at very great pressures, somewhat less rapidly. Consequently, in
all ordinary cases, so long as the entire weight or pressure remains
the same, the friction is, in general, entirely independent of the
extent of the surfaces in contact.

The exceptions are, some increase when the rubbing surfaces under the
same total pressure are very greatly extended, or when either surface
is comparatively soft; and considerable lessening of friction when
the bodies are very small, as in the runners of skates upon ice. For
ordinary rates of motion, the total friction within a given space
or distance is in like manner entirely independent of the velocity
with which one surface is caused to move over the other; but in very
slow motions it is increased, and in very rapid motions perceptibly
diminished.

_Friction is also increased in proportion to the tendency of the
surfaces to adhere_; hence, it is usually found greater between bodies
of the same kind (steel on steel proving almost an exception) than
between those of different kinds; it is usually greater when the
surfaces have been long in contact, and at the beginning of motion, and
always so, unless corrected by lubricants, between metallic surfaces so
highly polished that air may be excluded from between them.

The frictional resistance retarding the flow of _water_ is subject to
three laws:

1. It is proportioned to the amount of surface in contact.

2. It is independent of the pressure.

3. It is proportional to the square of the velocity.

It should be remembered that the laws relating to friction, between
_solid bodies_ operate quite differently from what they do when applied
to liquids; hence, the large mass of data relating to the general
subject of friction must be disregarded in the consideration of
hydromechanics and allied subjects.

For all fluids, whether liquids or gaseous, the resistance is
independent of the pressure between the masses in contact. This is in
accordance with the second law as stated.

The friction for all fluids (liquid or gaseous) is in proportion to the
area of the rubbing surface; this follows from the first law and as the
sectional area of a circle is the least, _pipes_ from their circular
form present the smallest resistance to the flow of water.

From the third law, in practice we desire the making of pipes as large
as possible; experiment having proved that low speeds are preferable to
moderate and still more so, as compared to high speeds in proportioning
the piping of hydraulic apparatus.

Friction of fluids is also independent of the nature of the solid
against which the stream may flow, but dependent to some extent upon
their degree of roughness.

Friction _for all fluids is also proportional to the density of the
fluid_, and related in some way to its adhesiveness.

_Water flowing through a pipe tends to drag the pipe along with it_
on account of friction; in all actual fluids there is viscosity or
internal friction, but if the relative motion is only slow enough it
makes little difference whether the fluid is viscous or not.

_Ordinary fluids will change in shape under the action of a force_,
however small, if enough time is given for the change to take place,
and the rate of change of shape is a measure of its viscosity.

_The laws of friction, both for solids and liquids, have been
established from experiments endlessly varied._ In investigating these
principles we first proceed on the supposition that the forces in
question act without any impediments. Great simplicity is attained
by first bringing the subject to this ideal standard of perfection,
and afterwards making suitable allowances for all these causes which
operate in any given case to prevent the perfect application of the law.

Several tables and other data relating to the friction of water will be
found in the other sections of this work, reference to which is made in
the Index.

_The term viscosity_ has been described in the Glossary at
the beginning of this work; a perfect fluid is incapable of
resisting—except by its weight or inertia—a change of shape. Such a
substance does not actually exist for all fluids have _viscosity_ or
internal friction.

This is defined as a resistance to a change of shape depending on
the rate at which the change is effected, _but_, as the fluids which
engineers have to deal with are water and vapors and gases, it
simplifies nearly all the calculations to assume that they have no
internal viscosity or friction.

A slow continuous change of the shape of solids or semi-solids under
the action of gravity, or external force, is also by the extension of
the term called _viscosity_, as the viscosity of ice, as observed in
the slow movement of those rivers of ice, the glaciers.

The _viscosity_ of liquids arises from the mutual attractions of the
molecules and is diminished by the effect of the wandering molecules
(C. D.). The viscosity of gases increases while that of liquids
diminishes as the temperature is raised.

The _viscosity_ of fluids presents a certain analogy with the
malleability of solids.

_Vis Viva_ is equivalent to _active or living force_; temperature is
the _Vis Viva_ of the smallest particles of a body; in bodies of the
same temperature the atoms have the same _vis viva_, the smaller mass
of the lighter atoms being compensated by their greater velocity.

This term, which is often met with in scientific treatises, was
invented by Leibnitz. It is well known that water in rapid circulation
will absorb more heat than when stagnant or moving slowly; this is
caused by _Vis Viva_ of the atoms.


CAPILLARY ATTRACTION.

_Capillary attraction is the attraction which causes the ascent
of fluids in small tubes._ This word is derived from the Latin
_capillus_—a hair.

The tubes must be less than one-tenth of an inch in diameter in order
to produce the most satisfactory results, and tubes whose bores are
no larger than a hair present the phenomenon the most strikingly. But
though the rise of water above its natural level, is most manifest
in small tubes, it appears, in a degree, in vessels of all sizes and
shapes, by a ring of water formed around the sides with a concavity
upward.

The following are the leading _facts_ respecting capillary attraction.

(1.) _When small tubes, open at both ends, are immersed perpendicularly
in any liquid, the liquid rises in them, to a height which is inversely
as the diameter of the bore._ Though tubes of glass are usually
employed in experiments on this subject, yet tubes made of any other
material exhibit the same property. Nor does the thickness of the solid
part of the tube, or its quantity of matter, make the least difference,
the effect depending solely on the attraction of the surface, and
consequently extending only to a very small distance.

(2.) _Different fluids are raised to unequal heights by the same tube._
Thus, according to experiment, a tube which will raise water 23 inches
will raise alcohol only 9 inches.

(3.) A tube 1/100 of an inch in diameter raises water 5.3 inches; and
since the height is reciprocally as the diameter, _the product of the
diameter into the height is a constant quantity_, namely, the .053th
part of an inch square.

(4.) _Fluids rise in a similar manner between plates of glass, metal,
&c._, placed perpendicularly in the fluids, and near to one another.
If the plates are parallel, the height to which a fluid will rise, is
_inversely as the distance between the plates_; and the whole ascent is
just _half that which takes place in a tube_ of the same diameter. If
the plates be placed edge to edge, so as to form an angle, and they be
immersed in water, with the line of their intersection vertical, the
water will ascend between them in a _curve_ having its vertex at the
angle of intersection. This curve is found to have the properties and
form of the _hyperbola_.

In the adjustment of the stems of barometers and the thermometer
an allowance is made to compensate for the influence of capillary
attraction.

[Illustration: FIGS. 94-96.]

Such are the leading facts ascertained respecting capillary attraction.
Various explanations of them have been attempted but that of La Place
is most generally received. According to this high authority, the
action of the sides of the tube draws up the film of fluid nearest to
it, and that film draws along with it the film immediately below it,
and so each film drags along with it the next below, until the weight
of the volume of fluid raised exactly balances all the forces which act
upon it. The fact that the elevation of the water between the parallel
plates is exactly _half_ that in a tube of the same diameter, clearly
indicates that the force resides in the surrounding body; and the
additional fact that the thickness or quantity of that body makes no
difference, proves that the force resides in the surface, and that the
action extends only to a very small distance.

  NOTE.—Several familiar examples of capillary attraction may be
  added. A piece of sponge, or a lump of sugar, touching water at
  its lowest corner, soon becomes moistened throughout. The wick of
  a lamp lifts the oil to supply the flame, to the height of several
  inches. A capillary glass tube, bent in the form of a syphon, and
  having its shorter end inserted in a vessel of water, will fill
  itself and deliver over the water in drops. A lock of thread or of
  candle-wick, inserted in a vessel of water in a similar manner, with
  one end hanging over the vessel, will exhibit the same result. An
  immense weight or mass may be raised through a small space, by first
  stretching a dry rope between it and a support, and then wetting the
  rope.

  The several figures above need no explanation to the attentive reader.


FLOW OF WATER UNDER PRESSURE.

Under this head three general cases are to be considered: 1, that of
liquids _issuing from orifices_; 2, _their flow through tubes_, or in
streams; and, 3, _the effects of the momentum and impact of liquids_.
The principles governing the action of the two last will be introduced,
2, under that portion of the work relating to “piping,” and, 3, under
the sections pertaining to the jet pump. Throughout the different
portions of the book will the three cases be still further elucidated.

Now, as to the laws governing the escape of liquids under pressure
through an opening, it may be understood that when the liquid escapes
from a vessel, owing to the excess of the internal pressure, _the
volume which escapes depends on the section of the orifice and the
velocity with which the liquid molecules move at the moment of their
escape from it_.

This velocity depends upon the density of the liquid, the excess of
pressure at the opening, and the friction of the liquid, both at the
opening and against the walls. When the aperture is made in a very
thin wall of a large vessel, so as to remove, as much as possible, the
causes tending to modify the motion of the escaping fluid, the laws
of the escape are comprised in the following theorem, discovered by
Torricelli, in 1643, as a consequence of the law of the fall of bodies
discovered by Galileo: “Liquid molecules, flowing from an orifice,
_have the same velocity, as if they fell freely in vacuo from a height
equal to the vertical distance from the surface to the center of the
orifice_.”

Deductions from the above:—1, _the velocity depends on the depth of
the orifice from the surface, and is independent of the density of the
liquid_. Water and mercury in vacuo would fall from the same height in
the same time; and so escaping from an orifice at the same depth, below
the surface, would pass out with equal velocity; but mercury, being
13·5 times as heavy as water, the pressure exerted at the aperture of a
vessel filled with mercury, will be 13·5 times as great as the pressure
exerted at the aperture of a vessel filled with water; 2, _the velocity
of liquids is as the square roots of the depths of the orifices below
the surfaces of the liquids_.

  NOTE.—Torricelli discovered, in the early part of the 17th century,
  the remarkable fact that a fluid issues from a small orifice with the
  same velocity (friction and atmospheric resistance excluded) which it
  would have acquired in falling through the depth from its surface.
  This was one of a long series of discoveries leading toward the now
  almost exact science of hydro-mechanics.

Thus stating, the velocity of a liquid escaping from an orifice one
foot below the surface to be _one_; from a similar orifice four feet
below the surface, it will be _two_, and at nine feet _three_, at
sixteen feet _four_, and so on.

From comparative experiments made by a great number of observers,
it is learned that the actual flow is only about two-thirds of the
theoretical flow. See note.

The form and constitution of liquid veins have been studied and found
to be:

1.—That the fluid issuing vertically from an orifice made in a plane
and thin horizontal wall, is always composed of two distinct parts,
Fig. 97, the portion nearest the orifice is calm and transparent, like
a rod of glass, gradually decreasing in diameter. The lower part, on
the contrary, is always agitated, and takes an irregular form, in which
are regularly distributed elongated swellings, called _ventres_, whose
maximum diameter is greater than that of the orifice.

  NOTE.—_Theoretical and actual flow._—_The actual flow from an
  orifice_, is the volume of liquid which escapes from it in a given
  time. _The theoretical flow_, is a volume equal to that of a cylinder
  which has for its base the orifice, and for its height the velocity,
  furnished by the discovery of Torricelli. That is, the theoretical
  flow is the product of the area of the orifice multiplied by the
  theoretical velocity. It is observed that the vein escaping from an
  orifice, contracts quite rapidly, so that its diameter is soon only
  about two-thirds of the diameter of the orifice. If there was no
  contraction of the vein after leaving the orifice, and its velocity
  was the theoretical velocity, the actual flow would be the same
  as that indicated by theory. But its section is much less than at
  the orifice, and its velocity is not so great as the theoretical
  velocity, so that the actual flow is much less than the theoretical
  flow; and in order to reduce this to the first, it is necessary to
  multiply it by a fraction.

2.—In the lower part of the vein, the liquid is not continuous; for if
we employ an opaque liquid, as mercury, we can see through the vein,
Fig. 98. The apparent continuity in a vein of water is owing to the
fact that the globules which constitute it succeed each other at a
distance inappreciable to the eye.

[Illustration: FIGS. 97, 98.]

_The time it takes by a vessel to empty itself_ is to the time
required, when it is kept constantly full, to discharge the same
quantity of water, as 2 to 1, and the spaces described by the surface
in its descent in a column of equal size throughout, are as the odd
numbers, 9, 7, 5, 3, 1. Thus these spaces measure equal times. Since
liquids are not perfectly mobile, and their exit at an orifice must be
retarded by cohesion and friction, the results thus far given are much
modified in practice.

When a liquid flows through an orifice in a vessel, eddies are formed
about the sides of the orifice, preventing the escape of a jet
equivalent to its full size; and owing to these, and to acceleration
of velocity, _if the jet be downward_, it rapidly contracts in its
diameter. At a distance outside about equal to diameter of the opening,
it is contracted to 2/3 or 5/7 its original area; and this part has
been called the “contracted vein.” It has been shown, that below this
the stream still contracts, though less rapidly.

These swellings separate more widely as they descend with increased
rapidity; but falling through great heights, the whole may finally be
dissipated in a mist.

  NOTE.—The annular swellings contain air and arise from a periodical
  succession of pulsations near the orifice, which must be produced by
  very small oscillations of the entire mass of the liquid, so that the
  velocity of the flow is periodically variable. The sucking, whistling
  noise which is often heard in the descent of water through an orifice
  is caused by air drawn in by the whirling motion. See Fig. 103.

If an orifice in a vessel looks downward, and the column of liquid over
it be short, this will simply drop out by its own weight, starting
at a velocity of o. But if a considerable depth of liquid be above,
its gravity produces a corresponding pressure on its base, or on that
liquid which is near it; so that, if a plug be removed from an orifice
in or close to the base, the liquid starts at once into rapid motion.

[Illustration: FIG. 99.]

Each particle of a jet A issuing from the side of a vessel moves
horizontally with the velocity above mentioned, _but it is at once
drawn downward by the force of gravity_ in the same manner as a bullet
fired from a gun, with its axis horizontal. It is well known that the
bullet describes _a parabola with a vertical axis_, the vertex being
the muzzle of the gun. Now, since each particle of the jet moves in
the same curve, this jet C takes the parabolic form. In every parabola
there is a certain point called the focus, and the distance from the
vertex to the focus fixes the magnitude of a parabola in much the same
manner as the distance from the center to the circumference fixes the
magnitude of a circle.

Now it can be proved that the focus B is as much below as the surface
of the water is above the orifice. Accordingly, if water issues through
orifices which are small in comparison with the contents of the
vessel, the jets from orifices at different depths below the surface
take different forms, as shown at D. If these curves are traced on
paper held behind the jet, then, knowing the horizontal distance and
the vertical height, it is easy to demonstrate that the jet forms a
parabola.

_Quantity of Efflux._—If we suppose the bottom of a vessel containing
water to be thin, and the orifice to be a small circle whose area is
A (see Fig. 100) where A B represents an orifice in the bottom of a
vessel.

[Illustration: FIG. 100.]

[Illustration: FIG. 101.]

Every particle above A B tries to pass out of the vessel, at once and
in so doing exerts a pressure on those nearest. Those that issue near
A and B exert pressures in the directions M M and N N; those near the
center of the orifice in the direction R Q, those in the intermediate
parts in the directions P Q, P Q. In consequence, the water within the
space P Q P is unable to escape, and that which does escape, instead of
assuming a cylindrical form, at first contracts, and takes the form of
a truncated cone.

It is found that the escaping jet continues to contract until at a
distance from the orifice about equal to the diameter of the orifice;
this part of the jet is called the _vena contracta_ or contracted vein,
as explained on a previous page.

_Influence of tubes on the quantity of efflux._—The result before
given has reference to an aperture in a thin wall. If a cylindrical or
conical efflux tube is fitted to the aperture, the amount of the flow
is considerably increased. A short tube, whose length is from two to
three times its diameter, has been found to increase the actual efflux
per second to about 82 per cent. of the theoretical. In this case the
water on entering the tube forms a contracted vein, Fig. 101. just as
it would do on issuing freely into the air; but afterwards it expands,
and, in consequence of the adhesion of the water to the interior
surface of the tube, has, on leaving the tube, a section greater than
that of the contracted vein. The contraction of the jet within the tube
causes a partial vacuum shown in black in the figure.

Now, if an aperture is made in the tube, near the point of greatest
contraction, and is carefully fitted with a vertical tube, the lower
end of which dips into water, Fig. 101, it is found that water rises
in the vertical tube, thereby proving conclusively the formation of a
partial vacuum.

If the nozzle has the form of a conic frustum whose larger end is at
the aperture, the efflux in a second may be raised to 92 per cent.,
provided the dimensions are properly chosen. If the smaller end of a
frustum of a cone of suitable dimensions be fitted to the orifice, the
efflux may be still further increased, which will fall very little
short of the theoretical amount.

[Illustration: FIG. 102.]

_Velocities of streams._—The velocity of streams varies greatly. The
slower flow of rivers has a velocity of less than three feet per
second, and the more rapid, as much as six feet per second, which gives
respectively about two and four miles per hour. The velocities vary in
different parts of the same transverse section of a stream, for the air
upon the surface of the water, as well also as the solid bottom of the
stream, has a certain effect in retarding the current. The velocity is
found to be greatest in the middle, where the water is deepest, Fig.
102, somewhere in _m_, below the surface; then it decreases with the
depth towards the sides, being least at _a_ and _b_.

[Illustration: FIG. 103.]

_Appearance of the surface during a discharge._—A vessel containing a
liquid, discharging itself through an orifice, does not always preserve
a horizontal surface. When the vein issues from an orifice in the
bottom of a vessel, and the level of the liquid is near the orifice,
the liquid forms a whirlpool, Fig. 103. If the liquid has a rotary
movement, the funnel is formed sooner; if the orifice is at the side of
the vessel, there is a depression of the surface upon that side, above
the orifice, Fig. 104. These movements depend upon the form of the
vessel, the height of the liquid in it, and the dimensions and form of
the orifice.

[Illustration: FIG. 104.]

In order to verify many of the laws of hydraulics in an accurate
manner, it is necessary to maintain a uniform pressure on the escaping
liquid, thereby obtaining a constant velocity at the orifice. This may
be done in various ways, as by allowing the water to flow into the
vessel in a little larger quantity than can escape from the orifice,
the excess being discharged over the upper edge of the vessel; also by
means of the syphon.

_By suspending solid particles_, such as charred paper, pulverized
in the water, we render the currents that are formed visible. These
solid particles arrange themselves, in curved lines, towards and into
the orifice, as a center of attraction, Fig. 105. The particles in
immediate contact with the orifice, not moving so easily as those
within, must cause contraction; so, also, _we can see that gravity in
accelerating the velocity, must cause continual decrease in the section
of the jet_.

[Illustration: FIG. 105.]

_Upward jets of water._—As the velocity of a liquid escaping from
an orifice is the same as that which a body acquires, falling from
a height equal to the distance from the level of the liquid to the
orifice, a jet of water escaping from a horizontal opening upwards,
should theoretically reach the level of the liquid in the vessel.
But this never takes place, Fig. 106, because of—1st, the friction in
the conducting tubes destroying the velocity. 2nd, the resistance of
the air. 3rd, the returning water falling upon that which is rising.
The height of the jet is increased by having the orifices very small,
in comparison with the conducting tube; piercing them in a very thin
wall, and inclining the jet a little, thus avoiding the effect of the
returning water.

[Illustration: FIG. 106.]

_Height of the jet._—If a jet issuing from an orifice in a vertical
direction has the same velocity as a body would have which fell from
the surface of the liquid to that orifice, the jet ought to rise to
the level of the liquid. It does not, however, reach this; for the
particles which fall hinder it. But by inclining the jet at a small
angle with the vertical it reaches about 9/10 of the theoretical
height, the difference being due to friction and to the resistance of
the air.

_The quantities of water which issue from orifices of different areas
are very nearly proportional to the size of the orifice_, provided the
level remains constant, and this is true irrespective of the form of
the opening which may be round, square, or any other shape.

_Escape of liquids through short tubes._—We often place in an orifice,
to increase the flow, a short tube (called an adjutage) either
cylindrical or conical. If the vein pass through the tube without
adhering to it, the flow is not modified; if the vein adhere (the
liquid wetting the interior walls) the contracted part is dilated, and
the flow is increased.

In the last case, and with a cylindrical adjutage, its length not
being more than four times its diameter, the flow is augmented about
one-third. Conical pipes, converging towards the exterior, increase the
flow still more than the preceding, the flow and velocity of the vein
varying with the angle.

_Escape of liquids through long tubes._—When a liquid passes through
a long straight tube, the flow soon diminishes greatly in velocity,
because of the friction which takes place between the liquid particles
and the walls. If there be any bends or curves in the tube, it is still
further diminished by the same cause. The discharge is then much less
than it would be from an orifice in a thin wall, and therefore the tube
is generally inclined; the liquid then passes down this inclined plane,
or it is forced through by pressure, applied at the opposite end.

_Direction of the jet from lateral orifices._—From the principle of the
equal transmission of pressure, water issues from an orifice _in the
side of a vessel_ with the same velocity as from an aperture in the
bottom of a vessel at the same depth.


MEASUREMENT OF WATER PRESSURE.

_In reference to the table on the next page_, it may be well to say
that it has two uses; by it when the “_head_” is known the _pressure_
can be ascertained to a fraction, thus, _Ex. 1_, If the head is 140
feet, then the pressure is 60·64 pounds per square inch. Again, _Ex.
2_, If the pressure is 15·16 per square inch, then the head is 35 feet.

[Illustration: INSIDE. (_See Page 115._) OUTSIDE.]


PRESSURE OF WATER.

The pressure of water in pounds per square inch for every foot in
height to 300 feet; and then by intervals, to 1000 feet head· By this
table, from the pounds pressure per square inch, the feet head is
readily obtained; and _vice versa_.

  ------+----------
  Feet  | Pressure
  Head. |per square
        | inch.
  ------+----------
      1 |   0·43
      2 |   0·86
      3 |   1·30
      4 |   1·73
      5 |   2·16
      6 |   2·59
      7 |   3·03
      8 |   3·46
      9 |   3·89
     10 |   4·33
     11 |   4·76
     12 |   5·20
     13 |   5·63
     14 |   6·06
     15 |   6·49
     16 |   6·93
     17 |   7·36
     18 |   7·79
     19 |   8·22
     20 |   8·66
     21 |   9·09
     22 |   9·53
     23 |   9·96
     24 |  10·39
     25 |  10·82
     26 |  11·26
     27 |  11·69
     28 |  12·12
     29 |  12·55
     30 |  12·99
     31 |  13·42
     32 |  13·86
     33 |  14·29
     34 |  14·72
     35 |  15·16
     36 |  15·59
     37 |  16·02
     38 |  16·45
     39 |  16·89
     40 |  17·32
     41 |  17·75
     42 |  18·19
     43 |  18·62
     44 |  19·05
     45 |  19·49
     46 |  19·92
     47 |  20·35
     48 |  20·79
     49 |  21·22
     50 |  21·65
     51 |  22·09
     52 |  22·52
     53 |  22·95
     54 |  23·39
     55 |  23·82
     56 |  24·26
     57 |  24·69
     58 |  25·12
     59 |  25·55
     60 |  25·99
     61 |  26·42
     62 |  26·85
     63 |  27·29
     64 |  27·72
     65 |  28·15
     66 |  28·58
     67 |  29·02
     68 |  29·45
     69 |  29·88
     70 |  30·32
     71 |  30·75
     72 |  31·18
     73 |  31·62
     74 |  32·05
     75 |  32·48
     76 |  32·92
     77 |  33·35
     78 |  33·78
     79 |  34·21
     80 |  34·65
     81 |  35·08
     82 |  35·52
     83 |  35·95
     84 |  36·39
     85 |  36·82
     86 |  37·25
     87 |  37·68
     88 |  38·12
     89 |  38·55
     90 |  38·98
     91 |  39·42
     92 |  39·85
     93 |  40·28
     94 |  40·72
     95 |  41·15
     96 |  41·58
     97 |  42·01
     98 |  42·45
     99 |  42·88
    100 |  43·31
    101 |  43·75
    102 |  44·18
    103 |  44·61
    104 |  45·05
    105 |  45·48
    106 |  45·91
    107 |  46·34
    108 |  46·78
    109 |  47·21
    110 |  47·64
    111 |  48·08
    112 |  48·51
    113 |  48·94
    114 |  49·38
    115 |  49·81
    116 |  50·24
    117 |  50·68
    118 |  51·11
    119 |  51·54
    120 |  51·98
    121 |  52·41
    122 |  52·84
    123 |  53·28
    124 |  53·71
    125 |  54·15
    126 |  54·58
    127 |  55·01
    128 |  55·44
    129 |  55·88
    130 |  56·31
    131 |  56·74
    132 |  57·18
    133 |  57·61
    134 |  58·04
    135 |  58·48
    136 |  58·91
    137 |  59·34
    138 |  59·77
    139 |  60·21
    140 |  60·64
    141 |  61·07
    142 |  61·51
    143 |  61·94
    144 |  62·37
    145 |  62·81
    146 |  63·24
    147 |  63·67
    148 |  64·10
    149 |  64·54
    150 |  64·97
    151 |  65·40
    152 |  65·84
    153 |  66·27
    154 |  66·70
    155 |  67·14
    156 |  67·57
    157 |  68·00
    158 |  68·43
    159 |  68·87
    160 |  69·31
    161 |  69·74
    162 |  70·17
    163 |  70·61
    164 |  71·04
    165 |  71·47
    166 |  71·91
    167 |  72·34
    168 |  72·77
    169 |  73·20
    170 |  73·64
    171 |  74·07
    172 |  74·50
    173 |  74·94
    174 |  75·37
    175 |  75·80
    176 |  76·23
    177 |  76·67
    178 |  77·10
    179 |  77·53
    180 |  77·97
    181 |  78·40
    182 |  78·84
    183 |  79·27
    184 |  79·70
    185 |  80·14
    186 |  80·57
    187 |  81·00
    188 |  81·43
    189 |  81·87
    190 |  82·30
    191 |  82·73
    192 |  83·17
    193 |  83·60
    194 |  84·03
    195 |  84·47
    196 |  84·90
    197 |  85·33
    198 |  85·76
    199 |  86·20
    200 |  86·63
    201 |  87·07
    202 |  87·50
    203 |  87·93
    204 |  88·36
    205 |  88·80
    206 |  89·23
    207 |  89·66
    208 |  90·10
    209 |  90·53
    210 |  90·96
    211 |  91·39
    212 |  91·83
    213 |  92·26
    214 |  92·69
    215 |  93·13
    216 |  93·56
    217 |  93·99
    218 |  94·43
    219 |  94·86
    220 |  95·30
    221 |  95·73
    222 |  96·16
    223 |  96·60
    224 |  97·03
    225 |  97·46
    226 |  97·90
    227 |  98·33
    228 |  98·76
    229 |  99·20
    230 |  99·63
    231 | 100·06
    232 | 100·49
    233 | 100·93
    234 | 101·36
    235 | 101·79
    236 | 102·23
    237 | 102·66
    238 | 103·09
    239 | 103·53
    240 | 103·96
    241 | 104·39
    242 | 104·83
    243 | 105·26
    244 | 105·69
    245 | 106·13
    246 | 106·56
    247 | 106·99
    248 | 107·43
    249 | 107·86
    250 | 108·29
    251 | 108·73
    252 | 109·16
    253 | 109·59
    254 | 110·03
    255 | 110·46
    256 | 110·89
    257 | 111·32
    258 | 111·76
    259 | 112·19
    260 | 112·62
    261 | 113·06
    262 | 113·49
    263 | 113·92
    264 | 114·36
    265 | 114·79
    266 | 115·22
    267 | 115·66
    268 | 116·09
    269 | 116·52
    270 | 116·96
    271 | 117·39
    272 | 117·82
    273 | 118·26
    274 | 118·69
    275 | 119·12
    276 | 119·56
    277 | 119·99
    278 | 120·42
    279 | 120·85
    280 | 121·29
    281 | 121·72
    282 | 122·15
    283 | 122·59
    284 | 123·02
    285 | 123·45
    286 | 123·89
    287 | 124·32
    288 | 124·75
    289 | 125·18
    290 | 125·62
    291 | 126·05
    292 | 126·48
    293 | 126·92
    294 | 127·35
    295 | 127·78
    296 | 128·22
    297 | 128·65
    298 | 129·08
    299 | 129·51
    300 | 129·95
    310 | 134·28
    320 | 138·62
    330 | 142·95
    340 | 147·28
    350 | 151·61
    360 | 155·94
    370 | 160·27
    380 | 164·61
    390 | 168·94
    400 | 173·27
    500 | 216·58
    600 | 259·90
    700 | 303·22
    800 | 346·54
    900 | 389·86
   1000 | 433·18


HYDRAULIC GAUGES.

_The Piezometer, or pressure gauge, is an instrument for measuring the
pressure of water in a pipe._

[Illustration: FIG. 107.]

It may be broadly stated that all pressures and weights relating to
water, steam, gases, etc., are now recorded by gauges.

The principle of construction of the dial gauge is that the pressure
may be indicated by means of a spring and pointer upon a divided dial
similar to a clock face, but marked in divisions, indicating pounds,
hundreds, etc., _pressure_ instead of hours and minutes. The more
approved forms of gauges are now constructed upon the principle of the
_Bourdon_ spring or metallic barometer invented in 1849. (See page 113
for illus.)

[Illustration: FIG. 108.]

The essential principle—or discovery—is this: that a metal curved
tube—oval cross section, _under pressure, tends to straighten itself_
according to the force exerted by the pressure inside. Figs. 107 and
108 show the ordinary style of gauge which consists of an elliptical
tube, connected at one end to a pipe in communication with the
pressure, and at the other end with toothed arc and pinion to a pointer
spindle as shown in cuts.

  NOTE.—Hydraulic gauges are indispensable as it is often necessary to
  stop the pressure at points below that at which the safety valve has
  been set.

Within the gauges—or cases, is a small coiled tube closed at one
end, while the other end is attached to the socket through which
the water is admitted; this tube has a tendency to straighten when
under pressure, and thus its free closed end moves, and this motion
is communicated to the pointer; when the pressure is relieved the
tube assumes its original position and the pointer returns to zero.
There are many modifications and special adaptations of the Bourdon
discovery, but the principle remains, and the same useful results are
obtained with both single and double tubes, the latter being the most
resensitive.

Fig. 107 shows the dial of a hydraulic gauge which is graduated to suit
the work to which it is related. These gauges are made for pressures
from 1,000 to 20,000 pounds per square inch. The springs are formed of
heavy solid bar steel turned and bored to size and are of the Bourdon
style. They are in use in large railroad shops, sugar refineries and
cotton-seed oil mills. These gauges are also made with connections
through the back of the case.

The gauge illustrated in Fig. 108 is used in connection with hot
water heaters, denoting the height of column of water in the tank or
reservoir, one hand being painted red and the other black. As it is
necessary to have at all times in the tank or reservoir a certain
height of water, the red hand is set at the point on the dial which
denotes this height. The black hand is connected with the working parts
of the gauge and indicates on the dial the actual height of water in
the tank or reservoir.

The dial of this gauge is graduated in feet, instead of pounds.

A check valve is almost indispensable in using a hydraulic gauge, as
the pressure is often suddenly removed and the momentum of the hand
will throw the pinion out of gear with the toothed arc, and is liable
to break the hair-spring. A check valve prevents any trouble of this
kind and should always be used.



WATER PRESSURE MACHINES


WATER WHEELS.

_Hydraulic machinery_ may be broadly divided into

  1. Motor machines, and,
      2. Pumps.

_Water motors_ may be divided into

  1. Water wheels,
      2. Turbines, and,
          3. Water pressure engines.

_In hydraulic motor machines_ a quantity of water descending from
a higher to a lower level, or _from a higher to a lower pressure_,
drives a machine which receives energy from the water and applies it to
overcoming the resistances of other machines doing work.

_In the next general class_, work done on the machine by a steam engine
or other source of energy is employed in lifting water _from a lower to
a higher level_. A few machines such as the ram and jet pump _combine
the functions of both motors and pumps_.

_The subject of water wheels is but a continuation of much that has
been illustrated and defined in the historical introduction_ to which
is now added the following summary.

In every system of machinery _deriving energy from a natural water-fall
there exist the following parts_:

(1) _A supply channel_, leading the water from the highest accessible
level, _to the site of the machine_; this may be an open channel of
earth, masonry, or wood, or it may be a closed cast or wrought-iron
pipe; in some cases part of the head race is an open channel, part a
closed pipe.

(2) _Leading from the motor_ there is a tail race, culvert, or
discharge pipe delivering the water after it has done its work.

(3) _A waste channel_ placed on or at the origin of the head race by
which surplus water, in floods, escapes.

(4) _The motor itself_, which either overcomes a useful resistance
directly, as in the case of a ram acting on a lift or crane chain,
or indirectly by actuating transmissive machinery, as when a turbine
drives the shafting, belting, and gearing of a mill. With the motor
is usually combined regulating machinery for adjusting the power and
speed, to the work done.

The great convenience and simplicity of water motors has led to their
adoption in certain cases, where no natural source of water power is
available. In these cases, an artificial source of water power is
created by using a steam engine to pump water to a reservoir at a great
elevation, or to pump water into a closed reservoir in which there is
great pressure.

Water flowing from the reservoir through hydraulic engines gives back
the energy expended, less so much as has been wasted in friction.
Where a continuously acting steam engine stores up energy by pumping
the water, while the work done by the hydraulic engines is done
intermittently,—this arrangement is considered the most useful.

  NOTE.—“Wherever a stream flows from a higher to a lower level it
  is possible to erect a water motor. The amount of power obtainable
  depends on the available head and the supply of water. In choosing
  a site the engineer will select a portion of the stream where there
  is an abrupt natural fall, or at least a considerable slope of the
  bed. He will have regard to the facility of constructing the channels
  which are to convey the water, and will take advantage of any bend in
  the river which enables him to shorten them. He will have accurate
  measurements made of the quantity of water flowing in the stream,
  and he will endeavor to ascertain the average quantity available
  throughout the year, the minimum quantity in dry seasons, and the
  maximum for which bye-wash channels must be provided. In many cases
  the natural fall can be increased by a dam or weir thrown across the
  stream. The engineer will also examine to what extent the head may
  vary in different seasons, and whether it is necessary to sacrifice
  part of the fall and give a steep slope to the tail race to prevent
  the motor being flooded by backwater in freshet time.

  In designing or selecting a water motor it is sufficient to consider
  only its efficiency in normal working conditions. It is generally
  quite as important to know how it will act with a scanty water supply
  or a diminished head. The greatest difference in water motors is in
  their adaptability to varying working conditions.”—ENCYC. BRIT.

[Illustration: FIG. 110.]

_Water wheels_ are large vertical wheels driven by water falling from
a higher to a lower level: they are motors on which the water acts,
partly by weight, partly by impulse. _Turbines_ are wheels, generally
of small size compared with water wheels, driven chiefly by the impulse
of the water. Before entering the moving part of the turbine, the water
is allowed to acquire a considerable velocity; during its action on the
wheel this velocity is diminished, and the impulse due to the change
of momentum drives the turbine. Roughly speaking, the fluid acts in
a water-pressure engine directly by its pressure, _in a water wheel
chiefly by its weight causing a pressure_.

_A flutter-wheel_ is shown in Fig. 110. This is a water wheel of
moderate diameter placed at the bottom of a chute so as to receive
the impact of the head of water in the chute and penstock. Its name
is derived from its rapid motion, the effect of which is to cause a
commotion of the water like “the fluttering” of a fowl.

_Impact Wheels._—The simplest and most imperfect of the horizontal
wheels are the so-called impact wheels or impact turbines, such as
shown in Fig. 111.

[Illustration: FIG. 111.]

They consist of 16 or 20 rectangular blades fastened to the wheel at
an inclination of 50° to 70° with the horizon. The water is brought on
through a race of 40° to 20° inclination, so that it strikes at about
right angles upon the blades.

These wheels are used in falls from 10 to 20 ft., where a large
number of revolutions is necessary, as in grain mills, where the
moving millstone is hung on the vertical shaft of the wheel, hence
intermediate gearing is unnecessary. These crude machines are found in
Southern Europe, North Africa, in the Alps, Pyrenees, and in Algiers.
They are about 5 ft. in diameter, and the blades are 15 inches high and
8 to 10 inches long (measured radially).

[Illustration: FIG. 112.]

Fig. 112 shows an “_undershot water wheel_.” In this style of wheel,
the work is done by impact alone, as the running water acts only on a
few immersed buckets on the under side of the wheel.

In the _breast wheel_, Fig. 113, the water is admitted on a level or
slightly above the center of the shaft, so that the water acts by
impact and weight.

[Illustration: FIG. 113.]

  NOTE.—“_A weir_ is a dam erected across a river to stop and raise the
  water, as for the purpose of taking fish, of conveying a stream to a
  mill, of maintaining the water at a level required for navigating it,
  or for the purposes of irrigation.”

  For facilitating the computation of the quantity of water flowing
  over weirs, Weir Tables, are used, based upon approved formulas, of
  which “Francis’ Formula” is perhaps the most reliable. These tables
  are applicable to the subject of water wheels but cannot be printed
  in this work.

[Illustration: FIG. 114.]

Fig 114 represents an _over-shot water wheel_ (F G H L, with axis at O)
in which the water flows upon the top of the wheel at _h_, in the same
direction in which it revolves, therefore the impact of the water is
utilized upon the upper buckets H, a, b, after which the weight of the
water acts in the buckets c, d, e, F, e´, d´ and c´. At b´ the buckets
begin to overflow and empty themselves as shown at a´. It will be seen
that the water acts upon almost one-half the circumference of this
wheel, thus realizing the greatest mechanical effect with the smallest
quantity of water.

_The current-wheel_ is perhaps the first application of the force
of water in motion, to drive machinery. In the first century B. C.,
water-wheels for driving mills were used in Asia Minor and on the
Tiber. In the former case we suppose, but in the latter case we know,
that these were current-wheels.

[Illustration: FIG. 115.]

_The tide or current wheel_, (Fig. 115) erected in the vicinity of
the north end of London Bridge, and subsequently under its northern
arch, was erected by Peter Morice, a Dutchman, in 1582, and operated
force-pumps which supplied a part of London with water. The stand-pipe
from the pump was 120 feet high, and conducted the water to a cistern
at that height. The amount raised was about 216 gallons per minute. The
wheel worked sixteen pumps, each 7 inches in diameter, and having a
uniform stroke of 30 inches.

During the seventeenth and eighteenth centuries the works were extended
from time to time, and occupied one after another of the arches. In the
first arch of the bridge was one wheel working sixteen force-pumps. In
the third arch were three wheels, working fifty-two pumps. The united
effect was 2,052 gallons per minute, raised 120 feet high.

In 1767 Smeaton added wheels in the fifth arch. Steam-engines were
added about this time to assist at low water and at neap-tides. Thus
the matter remained till 1821. Stow, the antiquarian and historian,
describes the works in 1600; and Beighton in 1731 gives an account of
them at that date.

The water-wheels at that time were placed under several of the
arches. The axis of these wheels was 19 feet long 3 feet diameter.
The radial arms supported the rings and twenty-six floats, 14 feet
long by 18 inches wide. The axis turned on brass gudgeons supported
by counterpoised levers, which permitted the vertical adjustment of
the wheel as the tide rose and fell. On the axis of the wheel was a
cog-wheel 8 feet in diameter and having forty-four cogs; meshing into a
trundle-wheel 4-1/2 feet in diameter and having 20 rounds, or pins and
whose iron axle revolved in brasses.

The axis of the trundle was prolonged at each end, and had quadruple
cranks which connected by rods to the ends of four walking beams 24
feet long, whose other ends worked the piston-rods of the pumps. The
axis of oscillation of the lever supporting the wheel, and by which it
was adjusted to the height of the tide, was coincident with the axis
of the trundle, so that the latter engaged the 8-feet cog-wheel in all
conditions of vertical adjustment. Cranks operated one end of the beams
while pumps were attached to the other end.

[Illustration: FIG. 116.]

Fig. 116 exhibits an _overshot water wheel_ employed at Laxey, Isle
of Man, for driving the pumps which drain the mines at that village;
these have an extreme depth of 1,380 feet. The wheel is 72 feet 6
inches in diameter, 6 feet in breadth, exerts a force of about 200
horse-power and is capable of pumping 250 gallons per min. from a depth
of 1,200 feet. Its crank-stroke is 10 feet. The water for driving it is
conducted by pipes from a reservoir on a neighboring hill, and ascends
in the column of masonry shown to the left of the wheel. (Knight Vol.
III.) An extra crank appears to be shown in the foreground of this
reproduction of an old drawing.



TURBINE WATER WHEELS.


The word turbine is derived from the Latin, “_turbo_”—that which spins
or whirls around—a whirlwind.

[Illustration: FIG. 117.]

The _turbine_ is a horizontal water wheel, and is similar to the
_hydraulic tourniquet_ or reaction wheel shown in Fig. 117. This
consists of a glass vessel, M, containing water and capable of moving
about its vertical axis. At the lower part there is a tube, C, bent
horizontally in opposite direction at the two ends. If the vessel were
full of water and the tubes closed, the pressure of the sides of C
would balance each other, being equal and acting in contrary direction:
but, being open, the water runs out and the pressure is not exerted on
the open part but only on the opposite side, as shown in the figure A.

And this pressure, not being neutralized by an opposite pressure,
imparts a rotary motion in the direction of the arrow, the velocity
of which increases with the height of the liquid and the size of the
aperture. This description and the illustration gives an idea of the
crude _reaction wheel_ invented by Barker about 1740; again a turbine
is simply a centrifugal pump reversed, but the turbine is usually
furnished with curved _guide vanes_ to guide the water as it enters the
wheel.

  NOTE.—The _steam turbine_ has come into common use and competes in
  its economical performance with the simpler and less economical
  types of the steam engine; it is impelled by steam jets, the steam
  impinging upon vanes or buckets on the circumference of a rotating
  disc or cylinder.

_In those turbines which are without guide blades_—i. e., which have a
high fall—the discharged water still possesses a great velocity and the
wheel is thereby deprived of a considerable part of mechanical power.
This loss can, however, be obviated or lessened by using the energy of
this discharged water to drive a second wheel.

A construction of this sort has been carried out by Ober-Bergrath
Althaus in the tanning mill at Vallendar near Ehrenbreitstein. The
essential parts of the arrangement can be seen in Fig. 118. A E A is
an ordinary reaction wheel with four curved revolving pipes and a fall
of 124 ft., and B B is a larger wheel with floats which is set in
rotation by the water issuing from A. A. _Since the two wheels turn in
opposite directions, they must be connected together by a special form
of wheel-work._ The outer wheel affords the additional advantage of
serving at the same time as a fly-wheel, thereby giving a more uniform
rate of motion to the whole machinery.

[Illustration: FIG. 118.]

Turbines are variously constructed, but all have curved floats or
buckets against which the water acts by its impulse or reaction in
flowing either _outward_ from a 1 central chamber, 2 _inward_ from an
external casing, 3 _from above downward_, and, 4 from _below_; these
constructions are either divided into _outward, vertical or central
discharge wheels_.

Turbines may also be divided into _reaction turbines_, or those
actuated substantially by the water passing through them (their buckets
moving in a direction opposite to that of the flow); _impulse turbines_
or those principally driven by impact against their blades or buckets
(the buckets moving with the flow); and _combined reaction and impulse
wheels_ which include the best modern types of turbines. In reaction
turbines the wheel passages are designed to be always full and
therefore the water under pressure; in the impulse turbine the passages
are not usually full.

[Illustration: FIG. 119.]

Turbines in which the water flows in a direction parallel to the axis
are called _parallel flow turbines_—or _journal turbines_.

The _turbine-dynamometer_ is a device used for measurings or testing
the power delivered by turbines (whence its name).

_Fourneyron’s Turbine._ This is, in its latest form, when properly
constructed, the nearest perfect of the horizontal water-wheels. It
revolves either in the air or under water, and may be either high or
low pressure. For the low-pressure wheel, the water enters the flume
from the open reservoir, with free surface, as in Fig. 119. For high
pressure, the reservoir is boxed up and the water brought in at the
side through a pipe, as shown in Fig. 124, page 136. The first is for
low and the second for high falls.

  NOTE.—The early history of the turbine is one of considerable
  interest _especially in view of the development of the steam, from
  the water turbine_.

  “M. Fourneyron, who began his experiments in 1823, erected his
  first turbine in 1827, at Pont sur l’Ognon, in France. The result
  far exceeded his expectations, but he had much prejudice to contend
  with, and it was not until 1834 that he constructed another, in
  Franche Comté at the iron-works of M. Caron, to blow a furnace. It
  was of 7 or 8 horse-power, and worked at times with a fall of only 9
  inches. Its performance was so satisfactory that the same proprietor
  had afterwards another of 50 horse-power erected, to replace 2
  water-wheels, which together, were equal to 30 horse-power. The fall
  of water was 4 feet 3 inches, and the useful effect, varied with the
  head and the immersion of the turbine, 65 to 80 per cent. Several
  others were now erected: 2 for falls of seven feet; 1 at Inval,
  near Gisors, for a fall of 6 feet 6 inches, the power being nearly
  40-horse, on the river Epté, expending 35 cubic feet of water per
  second, the useful effect being 71 per cent. of the force employed.”

[Illustration: FIG. 120.]

_The Leffel-Samson turbine_ wheel is shown in the engraving, Fig.
120, page 129, where _N.N._ represents the bottom casting of the case
flanged to support the wheel by resting upon the bottom of the penstock.

The draft tube _I_ is of conical shape as represented at _J. J._ to
reduce the friction of discharge water which after performing its work
in the wheel escapes at the bottom of the draft tube. _This tube must
always project into the tail water at least two or three inches._ The
gates _H.H.H._ are pivoted at the center so that they are balanced and
are opened and closed with the least possible friction. These gates are
operated by rods _L. L._, connecting with a rack and pinion which are
manipulated by the operator as occasion requires, by an extension shaft
from the coupling _K_, having a hand-wheel on top.

[Illustration: FIG. 121.]

Power is transmitted from the wheel shaft _F_ to the gears and pulleys
connected with the coupling above; the manner of setting turbine wheels
in openstocks is shown a few pages further on.

From the construction of gates and guides upon turbine wheels one may
readily see the absolute necessity of carefully guarding the flume
against the admission of sticks and other solid materials that might
wreck the wheel or jam the gates so that they could not be operated;
this is best accomplished by placing a water rack in front of the head
gate at the entrance to the flume.

These water racks are best made of flat bars of wrought iron placed
edgewise in a vertical position, or what is better, let the top incline
say one foot or two (depending upon the size of flume) towards the
head gates. When placed in an inclined position it is very much easier
to clean the rack from drift wood and the like than when placed in a
vertical position as by means of a hoe or scraper these obstructions
may be hauled up over the top of the inclined rack.

The racks should be made very strong and substantial to guard against
being broken by ice in the winter, for should the rack give way at any
inopportune time the admission of sticks and other rubbish might wreck
the wheel.

The “runner” which is the revolving part, as shown in Fig. 121, is
composed of two separate and distinct types of wheels, and has two
diameters, as shown. Each wheel or set of buckets receives its separate
quantity of water from one and the same set of guides but each set acts
only once and independently upon the water used, hence the water does
not act twice upon the combined wheel as might be supposed, as in the
compound steam engine.

The upper wheel _G_ receives the water as shown by the arrows at _A_,
and has _a central and downward discharge_, while the lower wheel _C_
receives the water as shown by the arrows at _B_ and has an _inward,
downward and outward_ discharge as shown by the arrows at _D_.

These two sets of buckets need to be exceedingly strong. The lower
set _B_ are made of heavy flanged steel plate and are cast into their
places by being placed in the sand mould, and the cast iron flows
around them forming the heavy ring _C_, surrounding the outer and lower
edges. This ring is a part of the diaphragm which separates the two
wheels. The upper edge of the ring _C_ is beveled to form a neat joint
which prevents any unnecessary loss of water.

This runner is balanced and secured to a hammered iron or steel
shaft _F_. It is supported usually by a step of the best specially
selected hard wood thoroughly soaked in oil for months before use. The
lower end of the shaft is dished out at _E_, forming a true arc of a
circle—concave—while the wooden step is made spherical—convex—to fit
into the end of the shaft. The step is formed in this way so that no
sand can lodge between the bearing surfaces, and cut them out. The
resident oil in the wood combined with the water make a most durable
means of lubrication, and these steps last for many months where the
water is clear.

[Illustration: FIG. 122.]

To get at the exact quantity of water consumed by a turbine wheel,
one cannot make an accurate calculation from the openings through the
wheels but the water is measured after it has passed through the
wheel, as it flows away into the tail race. Any slight variation in
the form of buckets or admission apertures will make an appreciable
variation in the quantity of water discharged by a turbine wheel.

These wheels are made either for vertical or horizontal shafts and are
also made single or double. The engraving, Fig. 122, shows a _Hercules
turbine within the case and gate ready to set in the penstock_.

Up to the year 1876 this make of wheel tested at the flume of the
Holyoke Water Works showed the highest efficiency at all stages of
gate, namely 87 per cent. (page 97, Emerson’s tests).

The design of case will naturally lead the reader to conclude that this
wheel has, 1, an inward, 2, downward and, 3, an outward discharge which
is correct. _The gate is simply a curb_ or hollow cylinder which forms
a sleeve outside the case and is raised and lowered by the gearing and
rack shewn in the engraving. As this sleeve rises it gradually uncovers
the openings shown which admits water into the wheel.

_Horizontal Turbine_—The turbine of 10,500 horse power installed in the
Shawinigan plant, Canada, see IV Pt. 2. is of _the horizontal type_,
the water entering at, A, the lowest part of the turbine and flows
around and fills the outer special tube, passes through an annular
gate, flows radially through the wheel thence out through two draft
tubes, B, one on each side. The weight of the water wheel is 182 tons,
the shaft weighing 10 tons and the bronze runner 5 tons. It is 30 feet
from base to top and 32 feet 2-1/2 inches wide over all. The shaft, C,
is of solid forged steel, 22 inches diameter in the middle, tapering
down to 10 inches diameter on one end and 16 inches diameter on the
other, the distance between bearings being 27 feet. The intake is 10
feet in diameter and the quantity of water going through the turbine
when developing full power is 395,000 gallons a minute. The speed of
the wheel is 180 revolutions per minute with a head of water acting on
the turbine of 125 to 135 feet.

Fig 123 is designed to show _The Setting of a turbine wheel in a wooden
penstock_.

[Illustration: FIG. 123.]

The principal and most essential dimensions necessary to be considered
in setting turbines are indicated by letters, each size having its own
particular dimensions.

_In setting the wheel_ in the ordinary penstock it is necessary in the
first place, to have the floor exactly level, and it is generally more
convenient to lay down a ring of soft wood around the hole in the
floor, as it will be much easier to dress off with a plane than the
plank floor. The floor should be supported by posts under the timbers
around the hole, so that there will be no settling of the floor after
being once made level. As the flange on which the wheel rests is turned
true, the wheel will, when placed on this level floor, stand in the
exact position required, _i. e._, the shaft will be exactly vertical.

If the wheel is a large one and was taken apart for shipment, the draft
tube is first erected in position, then the wheel is placed on its
step, the other parts being put on in their order. The step and other
bearings are adjusted before leaving the shop, but it will sometimes
happen that they will in some way get shifted, and as the wheel is
being put together, they should be inspected and readjusted, if
necessary. The only change that can occur in the step is its vertical
adjustment, which is regulated by screws. When the right height is
found, the broad flange around the lower part of the wheel should stand
about one-sixteenth of an inch below the under side of the base of the
guide rim where it rests upon the draft tube. The adjustable bearing
on the top of the cover plate should be fitted up closely around the
shaft, but not screwed so tightly as to bind it.

All these wheels above fifteen inches in diameter are provided with
chains and weights to counterbalance the weight of the gate, so that it
will move easily. It is best, when it can be done without much trouble,
to carry the weights outside of the flume, but they can be used inside
where the height is sufficient, although it will require a little more
weight to be as effective. When the wheel is not likely to be started
up at once, it is a good plan, when putting it together, to smear the
step and the shaft at the bearing with tallow, as a protection against
rust while it remains idle.

It is sometimes necessary to use a draft tube longer than is ordinarily
attached to the wheel. If properly constructed and applied there will
be no sensible loss of power, but it must be air tight, and when of
considerable length it is better enlarged gradually toward the lower
end, especially in cases where it may be necessary to carry this tube
near the pit bottom.

_Iron cases for Turbines._ Fig. 124 shows the setting of a Hercules
wheel within an iron case.

[Illustration: FIG 124.]

Although the expense of iron is as a rule considerably greater than
wood, the results obtained by the use of iron cases and penstocks
are much better than could be possible with wood, on account of their
durability and freedom from leakage.

It is generally conceded that there is a great risk of the step
becoming heated and burning out when placed in a draft tube above the
tail-water, and a jet of water is required to counteract this tendency
to overheat. As all such fixtures are liable to derangement and often
fail to operate, we are in favor of setting the wheel with the step
immersed, whenever it can be done without too great expense.

This case consists of two cast iron heads with boiler iron sides and is
provided with a cover, so that the wheel may be taken out entire. This
cover is fitted with stuffing boxes for both wheel and gate shafts,
and a manhole affords easy access to the wheel. The bearing surfaces
of the heads are nicely turned, insuring tight joints, and all holes
for rivets are accurately spaced and drilled. The heads of the larger
cases are made to clamp, the two halves being planed together; the
cases are fitted with mouthpieces having cast iron flanges for feeder
connections, to secure by bolts to either iron or wooden feeders.

Where two wheels of the same or different diameters are to be used,
corresponding cases connected in the centre with one common feeder
connection, or are placed in cases provided with separate feeders. In
connection with these cases an _iron draft tube of any desired length
may be used_. The wheel is usually fitted to the case before leaving
the works, and in erecting the smaller wheels, all that remains to be
done is to set the case on the foundations provided for it and make
the necessary connections as stated in explanation previously made for
Figs. 122 and 123.

The general arrangements required for the proper erection of turbines
are well understood by competent millwrights and do not in ordinary
cases present any serious difficulties. It may be of interest to many,
and to the advantage of some who may consider the use of water power,
if a few general remarks on this subject are added.

In practice there is almost always a little loss of head due to the
velocity with which the water passes through the channels leading to
and away from the wheel, and it should be the aim in constructing
flumes to bring the loss to a minimum. When the size of the wheel and
the quantity of water to be used have been determined, 1, the size of
the conduit for carrying the water to the wheel, 2, the width and depth
of the wheel-pit and tail-race, and 3, the dimensions and location of
the flume for the wheel are to be considered and properly arranged.

All of these should be of such dimensions as to insure the flow of
water through them at a moderate velocity, and with as little change of
direction as may be practicable.

The larger the pipe or canal the better, but there must be a limit in
practice, and it may be laid down as a general rule that a velocity
of _three feet per second_ is good practice in short tubes of uniform
section of not more than fifty feet in length; but _the velocity should
be reduced as the distance increases_, until in a length of 200 feet,
it should not exceed two feet per second.

The same rule applies to the tail-race, except that the velocity should
be somewhat lower in ditches cut through rock or earth and having the
naturally resulting roughness of sides and bottom.

The width and depth of the pit below the wheel may, for a given wheel,
vary somewhat as the water discharged into it is greater or less;
therefore, the dimensions should increase with a greater head for the
same wheel. The following is an approximate rule for the dimensions
of the pit, say for a head of twenty feet: width of pit equal to four
times the diameter of wheel, depth below the level of tail-water
one and a half times the diameter of wheel. The flume for the wheel
should be about three times the diameter of the wheel in its width or
diameter, and if it is decked over at the top it should be high enough
inside to clear the coupling on the wheel shaft.

_The Watertight Turbine_ is a special machine designed to keep the case
tight by the pressure of the water against the gates at the sides, no
matter how much these gates wear.

Fig. 125 shows the plan of chutes, gate-seats, gates, and buckets of
the wheel. Part of the gates are shown open, and others are closed. The
gates make a quarter of a turn in opening, and the same in shutting,
and to open all the gates, the gate wheel makes half a revolution. The
upper half of case shows the gate-wheel and pinion for operating its
parts.

[Illustration: FIG. 125.]

[Illustration]

The small illustration is a perspective view of the gate and gate
segment used on the watertight turbine. The part cut away forms part of
the chute when the gate is open as shown in the lower left-hand side
of the figure. The sharp edge of the gate cuts off sticks and rubbish
which are liable to get in the wheel, which is an obvious advantage.
Another desirable feature claimed for this wheel is the plan of
operating the gates in opposite pairs; by this means 2, 4, 6, 8 or 10
full gates may be opened at will, according to the power required.

[Illustration: THE NIAGARA FALLS TURBINE.—FIG. 126.]

_Turbines at Niagara Falls._ A number of turbines installed at Niagara
Falls, N. Y., are here briefly described; they are about 5,000
horse-power each; a canal leads water from the river to the wheel
pit. The water is carried down the pit through steel penstocks to the
turbines, which are placed 136 feet below the water level in the canal.
After passing through the wheels the waste water is conveyed to the
river below by a tunnel 7,000 feet long. The “plan” Fig. 126 shows a
cross-section of the wheel pit, with an end view of a penstock, wheel
case and shaft. Fig. 126 exhibits part of a vertical section of the
wheel pit _and a side view_ of this penstock, with the enclosing case
and shaft of the turbine.

[Illustration: TOP VIEW OR PLAN OF FIG. 126.]

This turbine has a rock-surface wheel pit, but this surface is
protected by a brick lining having a thickness of about 15 inches.
The width of the wheel pit is 20 feet at the top and 16 feet at the
bottom, and the cylindrical penstock is 7-1/2 feet in diameter. The
shaft of the turbine is a steel tube 38 inches in diameter, built in
three sections, and connected by short solid steel shafts 11 inches
in diameter, which revolve in bearings. On the top of each shaft is a
dynamo for generating the electric power.

In Fig. 126 is shown a vertical section of the lower part of the
penstock, shaft, and twin wheels. The water fills the casing around the
shaft, passes both upward and downward to the guide passages, through
which it enters the two wheels, causes them to revolve, and then drops
down to the tail race at the entrance to the tunnel, which carries it
away to the river. The gate for regulating the supply is seen upon the
outside of these wheels, both at the top and bottom, Fig. 126.

Fig. 128 gives a larger vertical section of the lower wheel with the
guides, shaft, and connecting members. The guide passages, and the
wheel passages, are triple as shown so that the latter may be filled
not only at full gate, but also when it is one-third or two-thirds
open, thus avoiding the loss of energy due to sudden enlargement of the
flowing stream. The two horizontal partitions in the wheel are also
advantageous in strengthening it. The inner radius of the wheel is
31-1/2 inches and the outer radius is 37-1/2 inches, while the depth is
about 12 inches. In this figure the gate is represented closed and to
open, it moves downward uncovering the guide passages as shown in Fig.
126, the position it occupies loaded.

In Fig. 127 is shown a half-plan of one of the wheels, in a part of
which are seen the _guides and vanes_, there being 36 of the former and
32 of the latter. Although the water on leaving the wheel is discharged
into the air, the very small annular space between the guides and
vanes, together with the decreasing area between the vanes from the
entrance to the exit orifices, _ensures that the wheels move like
reaction turbines_ for the three positions of the gates correspond to
the three horizontal stages or openings through the guides as shown in
Fig. 128, _i. e._, three stages of gate.

  NOTE.—A test of one of these wheels, made in 1895, developed 5,498
  electrical horse-power, generated by an expenditure of 447·2 cubic
  feet of water per second under a head of 135·1 feet. The efficiency
  of the dynamo being 97 per cent., the efficiency of the wheel and
  approaches was 82-1/2 per cent.

[Illustration: FIG. 127.]

The average discharge through one of these twin turbines is about 430
cubic feet per second, and _the theoretic power_ due to this discharge
is 6,645 horse-power. Hence if 5,000 horse-power be utilized _the
efficiency_ is 75.2 per cent. Under this discharge the mean velocity
of water in the penstock is nearly 10 feet per second, but the loss of
head due to friction in the penstock will be but a small fraction of a
foot. The pressure-head in the wheel case is then practically that due
to the actual static head, or closely 141-1/2 feet upon the lower and
130 feet upon the upper wheel.

The absolute velocity of the water when entering the wheel is about 66
feet per second, so that the pressure-head in the guide passages of the
upper wheel is nearly 66 feet. The mean absolute velocity of the water
when leaving the wheels is about 19 feet per second, so that the loss
due to this is only about 4 per cent. of the total head.

  NOTE.—The above description refers to the ten turbines in wheel
  pit No. 1. The illustrations are those of the wheels called units
  1, 2, and 3 which were installed in 1894 and 1895. Units 4 to 10,
  inclusive, installed in 1898-1900, are of the same type except that
  both the penstock and wheel case have cast-iron ribs on their sides
  which rest on massive castings built into the masonry of the side
  walls. This arrangement dispenses with the supporting girders shown
  in Fig. 126 and gives much greater rigidity to both penstocks and
  wheels.

[Illustration: FIG. 128.—ENLARGED VERTICAL SECTION OF LOWER WHEEL,
SHOWING GATES.]

The weight of the dynamo, shaft, and turbine is balanced, when the
wheels are in motion, by the upward pressure of the water in the
wheel case on a piston placed above the upper wheel. The upper disc
containing the guides is, for this purpose, perforated, so that the
water pressure can be equalized.


WATER PRESSURE ENGINES.

_Water pressure engines are machines with a cylinder and piston or ram,
in principle identical with the corresponding part of a steam engine_;
the water is alternately admitted to and discharged from the cylinder,
causing a reciprocating action of the piston or ram. It is admitted at
a high pressure and after doing its work on the piston is discharged.

The water in some of these machines acquires a high velocity; _the
useful work is due to the difference in the pressure of admission and
discharge_, whether that pressure is due to the weight of a column of
water of more or less considerable height, or is artificially produced.

When an incompressible fluid such as water, is used to actuate piston
engines, two special difficulties arise. One is that the lost work in
friction is very great, if the water attains a considerable velocity;
another is that there is over-straining action on the machinery. The
violent straining action due to the more or less sudden arrest of
the motion of water in machinery is termed _hydraulic shock_. For
these reasons the maximum velocity of flow of water in reciprocating
hydraulic machines should generally not exceed 5 to 10 feet per second.

Under high pressure, where there is less object in saving and it is
very important to keep the dimensions of the machinery small, Mr.
Anderson gives 24 feet per second as the limit of velocity. In large
water-pressure engines used for pumping mines the average piston speed
does not exceed 1/2 to 2 feet per second.

The suitability of water for _the transmission of power_ has been
fully recognized in recent years; the facility with which water under
pressure is capable of being utilized, and the advantages that attend
its use in motors have resulted in many practical difficulties being
overcome, which were at first considered insurmountable.

At the outset of the employment of water pressure it was feared that
the water in the pipes and machinery might freeze. This, however,
has been found not to be a difficulty where well-known precautions
are taken. The working parts should, where possible, be placed under
ground, or should be cased in, if they are above ground. _The water
should be run out of all valves and cylinders which cannot be cased
in_, and protected as soon as the working of the machine ceases.

A very small gas jet or lamp placed near the unprotected parts will
prevent freezing.

Experiments have also shown that a mixture of glycerine and water
prevents the effects of frost at a temperature as low as 16° Fahr.,
provided the glycerine has a specific gravity of 1.125, and that it
is mixed in the proportion of one part of glycerine by weight to four
parts of water.

Where water is used over again in the machines (by returning the
exhaust water from the machines to a reservoir), such addition of
glycerine is more easily resorted to. Where moderate risks of frost
have to be dealt with, the proportion of one gallon of glycerine to 300
gallons of water proves effectual. If the water is at a high pressure,
such as 1,500 lbs. to the square inch, it is less liable to freeze than
when used at a low pressure.

Again, it was at first feared that accidents might be frequent from the
bursting of hydraulic pipes and cylinders under high pressure. Such,
however, has been proved not to be the case in practice, and even where
pipes or cylinders do burst, the pressure is at once dissipated, as the
body of water which can escape at the opening is but slight.

It is desirable to use water which is as free as possible either from
suspended matter or from chemical impurity. The former increases the
wear and tear of the packing, and is otherwise inconvenient, and the
latter acts injuriously on the seats and fittings of valves. Sea-water
can be used for hydraulic machinery, but on account of its corrosion,
fresh-water is better.

Water-pressure has sometimes been applied to operate machines which are
worked continuously and not intermittently, and to continuous working
rotary machines. This is unwise, for in applying hydraulic power to
the continuous working of shafting or shop tools, the amount of power
developed by the hydraulic engine cannot be varied to suit the work to
be done, neither can the speed be regulated with sufficient nicety.


HYDRAULIC MOTORS.

_Pressure or Hydraulic Motors_ form an interesting variety of hydraulic
devices; they consist of working cylinders with valves and pistons,
and resemble forcing pumps in their construction, but differ from
them in their operation; the pistons not being moved by any external
force applied to them through cranks, levers, etc., but by _the weight
or pressure of a column of water acting directly upon or against the
pistons_. Pressure engines or motors are applicable to locations—such
as afford a suitable supply of water for the motive column; but
where-ever refuse, impure, salt or other water can be obtained from a
sufficient elevation, such may be used to raise a quantity of fresh
water by these machines.

_The stress considered in hydro-mechanics is always a pressure_, as
liquids are in general capable of sustaining only a slight tension
without disruption: _the intensity of the pressure is measured by the
number of units of force per unit of area_. Thus we say, one thousand
pounds of pressure per square inch of piston—the pounds and the square
inches are the units used in these calculations.


[Illustration:

  FIGS. 129, 130.

For description see page 151.]

The invention of pressure engines brought to light a _new_ mode of
employing water as a motive agent: and also the means of applying
it in locations where it could not otherwise be used; with pressure
engines the motive agent may be taken to the machine itself. In valleys
or lowlands, having no natural fall of water, but where that liquid
can be conveyed in tubes from a sufficient elevation (no matter how
distant the source may be), such water, by these machines, may be
made to propel others; unlike the steam engine, a pressure engine is
inexpensive, and simple in construction—it requires neither chimneys,
furnaces nor fuel; neither firemen nor engineers, nor is there any
danger of explosions. It may be placed in the comer of a room, or be
concealed under a counter or a table. It may be set in operation in a
moment, by opening a cock, and the instant the work is done, it may be
stopped by shutting the same, and thus prevent waste of power.

Pressure engines afford an illustration of the variety of purposes to
which a _piston and cylinder_ may be applied. These were probably first
used in piston bellows; next in the syringe; subsequently in pumps
of every variety; and then in water-pressure and steam engines. _The
moving piston is the nucleus or elemental part that gives efficiency to
them all_; and the apparatus that surround it in some of them, are but
its parts.

The history of machines composed of pistons and cylinders also
illustrates the process by which some simple inventions have become
applied to purposes, foreign to those for which they were originally
designed—each application opening the way for a different one.

In another form hydraulic motors have been adopted, in favorable
locations, as first movers of machinery, and when thus used, _they
exhibit a very striking resemblance to high pressure steam engines_.
Indeed, the elemental features of steam and pressure engines are
the same, and the modes of employing the motive agents in both are
identical—it is the different properties of the agents that induces a
slight variation in the machines—_one being an elastic fluid, the other
a non-elastic liquid_.

[Illustration: FIG. 131.]

[Illustration: FIG. 132.]

In steam engines a piston is alternately pushed forward and back in
its cylinder by steam; and by means of the rod to which the piston is
secured, motion is communicated to a crank and fly-wheel, and through
these to the machinery to be driven: it is the same with pressure
engines when used to move other machines, except that instead of the
elastic vapor of water, a column of that liquid drives the pistons to
and fro.

  NOTE.—“The hydraulic engine of Huelgoat, in Brittany, is used to
  drain a mine; is single-acting, and acts directly to lift the piston
  of the pump. It makes five and a half strokes per minute, the stroke
  being a little more than eight feet in length. The piston-rod is 767
  feet long, and it weighs 16 tons. The power of the engine is derived
  from a source at a height 370 feet above its own level.”—KNIGHT.

In default of a natural head of sufficient pressure, the head is
sometimes established in _an accumulator_ of power; this is a body
of water driven into a reservoir under heavy pressure, by forcing
pumps worked by power. In cities where the water distribution is from
elevated reservoirs, and in which the water supply is sufficiently
abundant to justify the application of a portion of it to industrial
uses, the water-engine or motor is recommended.

The following description of a water engine of world-wide adaptation
will, if attentively studied, show the working of an approved type of
this machine:

Ramsbottom’s hydraulic engine (Figs. 129 and 130), is oscillating,
and employs two cylinders _b_, _l_, operating one crank-shaft, _a_,
by means of two cranks at right angles to each other. In one of the
accompanying figures the channels of induction are marked _j_ and are
cast on the cylinders; the dotted circle _c_ shows the position of
the supply and discharge pipes; in the other figure these pipes are
indicated by arrows. The two views are vertical cross-sections at right
angles to each other, one being through the axis of the cylinders and
the other through the middle post in which the inner trunnions of the
cylinders are journaled. The apertures of induction are seen at _h_
and those of eduction at _i_, and have the form of truncated circular
sectors, whose center is the center of motion.

The induction and eduction spaces are divided by a sectoral partition;
the apertures of admission and discharge on the sides of the cylinders
are of similar construction. The surfaces of contact between the
cylinders _b_, _l_ and the support _d_ are planed and polished and
are made water-tight by the adjusting screws _m_ _m_ of the pivots.
When the piston _p_ is at the end of its course in either direction
the cylinder and crank are vertical, and the valves all momentarily
closed, the openings by which the channels _j_ _j_ communicate with the
discharge and supply pipes presenting themselves exactly opposite the
solid sectors which separate _h_ from _i_.

In the next moment the flow of water will recommence, the cylinder
discharging itself from the full side of the piston, and filling anew
from the opposite side. Air chambers and relief-valves are used as a
provision against counter-pressure and hydraulic shocks.

The Brotherhood three-cylinder reciprocating engine is an appliance for
producing rotary motion by water-pressure.

The working parts of the Brotherhood three-cylinder hydraulic engine
consist only of the three pistons and connecting rods, one crank and
one rotating balanced valve and spindle which fits into the driver and
is turned direct from the crank-pin; there are no glands, stuffing
boxes, or oscillating joints.

It is shown by Figs. 131, 132. The three cylinders, A (made in one
casting) are always open at their inner ends, and are attached to a
central chamber, B. They contain three pistons, P, which transmit
motion to the crank-pin through the rods, C. The water is admitted and
exhausted by means of the circular disc valve, V, having a lignum-vitæ
seat. The valve is rotated by the eccentric pin, E. A face view of this
valve is shown above the steam chest. It has segmental ports which, in
rotating, pass over apertures in the valve seat. There being no dead
centers, the engine will start from all positions of the crank-pin, and
a uniform motion of the shaft is produced without a flywheel.

The pressure is always on the outer end of the piston, so that the
rods, C, are in compression, and take up their own wear. This engine is
well adapted for transmitting pressure to appliances which are worked
intermittently, as, owing to the great speed at which it can be run, it
will not only save the loss from friction (where gearing is employed),
but will also reduce the friction in the machine itself by enabling
the gearing for increasing speed to be dispensed with. The production
of this simple hydraulic rotary engine led to its wide application to
capstans.

Fig. 133 represents a small hydraulic engine—The Compton Hydraulic
Motor—attached to and operating a gas-compressor. It shows a style
of water motor in large use in connection with city water-mains. A
pressure of 15 to 20 lbs. per square inch is sufficient to operate it;
the motor here illustrated occupies a floor space of 9 x 23 inches; it
will supply gas burners to the extent of 6,000 candle-power.

[Illustration: FIG. 133.]

The valve motion on the motor is unique in this, the outlets and inlets
have a positive motion by which they are simultaneously opened and
closed by the motion of the piston; this valve motion is designed to
overcome the back pressure; it has a governor, incorporated in the
valve-motion for the purpose of maintaining uniform pressure on the
main pipes.


HYDRAULIC PACKINGS.

Generally speaking a packing is a contrivance or a material to close
a joint. Various greasy materials with gaskets, flax, hemp, etc., are
used in joints which are screwed down, also collars of rubber, red
lead, luting, graphite, etc.

[Illustration: “U” PACKING—FIG. 134.]

A most important part in the practical working of nearly all
water-pressure machines is the leather collar, the invention of which
by Bramah removed the difficulties which had been experienced in making
the large ram work water-tight when submitted to great pressure.

It consists of a circular piece of stout leather (see cut page 20),
in the center of which a circular hole is cut. This piece of leather
is thoroughly soaked in water and is pressed into a metallic mould
and so that a section of it represents a reversed ^U^, and is fitted
into a groove made in the neck of the cylinder. This collar being
concave downwards, then in proportion as the pressure increases, the
edge nearest the ram being trimmed down, it fits the more tightly
against the ram plunger on one side and the neck of the cylinder on the
other. It should be saturated with Neatsfoot or Castor oil so as to be
impervious to water.

[Illustration: CUP PACKING—FIG. 135.]

When the least amount of friction possible is desired in the operating
of a hydraulic plunger, there is no form of packing which can surpass
a properly prepared and applied Leather “^U^” Packing (Fig. 134), and
in practice its position is according to conditions, either in a groove
near the upper end of the cylinder, or at the lower end of the ram.

When for any reason it is not desired to use the outer lip of the
packing, the resulting form is known as a Cup Packing, (Fig. 135), and
when the inner lip is used then we have the Hat or Flange Packing. Fig.
136.

[Illustration: FLANGE PACKING. FIG. 136.]

When the water pressure is not over 2,000 lbs. to the square inch, and
a greater allowance for friction is not important, a fibrous packing
can be used, which is easier of application than these for large sized
cylinders.

The loss of power by the best of leather packings is 1 per cent. on 4
in. ram, 1/2 per cent. with 8 in. ram and 1/4 per cent. with 16 in.
ram.



  HYDRAULIC
  APPARATUS



HYDRAULIC APPARATUS.


_Apparatus is another name for machinery_ but it also carries the
particular meaning of a complete collection of instruments or devices
prepared for a particular use, hence, _hydraulic apparatus_ may be said
to include very many combinations of machines to utilize the pressure
or weight of water.

A number of these devices are illustrated in the succeeding pages. It
were vain to attempt to describe all.

Knight in his Mechanical Dictionary has grouped some six hundred
and seventy five terms and names under the heading of “Hydraulic
Engineering and Devices.” In the note are given some terms, the
definition of which the student may, perhaps, look up; thus: Gyle (the
first term given) is a large cistern or vat. The liquor gyle in a
brewery is the water-vat or _gyle-tun_.

_Hydraulic apparatus has been developed mainly from two sources._ The
“cut and try” method, which of course was the first and second from
scientific calculations, based upon both the experiments and upon the
mathematics of hydraulics.

It is difficult at this date to say to which procedure the world is
the most indebted, but it is plainly discernable that the two methods
have been necessary as a check upon each other. Untold thousands of
practical experiments and an almost equal number of tables, rules and
calculations have been made. The result has been that out of many
failures the point of economy and efficiency, aimed at, of hydraulic
apparatus is well defined.

  NOTE.—_Terms relating to hydraulics named by Edward H. Knight, Civil
  and Mechanical Engineer, as above._ Gyle; Sluice Valve; The Sough;
  Stade; Worm-safe; Weel; Water-twist; Water-lute; Water-gilding;
  Vineficatur; Tun; Tide-lock; Tail-bag; Swash-bank; Sump; Stop-plank;
  Sterhydraulic apparatus; Staith; Rip-rap; Quay; Puffer; Psychrometer;
  Levee; Leam; Leach; Land tank; Kiddle; Kimelin; Keir; Jetty;
  Invert Burette; Hydraulic Blower, etc. Some of these terms go “way
  back,” and the above are a specimen only of the 675 headings.

[Illustration: FIG. 137.

SECTION OF CLAW TYPE HYDRAULIC JACK.]


HYDRAULIC JACK.

_A Lifting-Jack_ is a contrivance for raising great weights by force
from below; also called _a jack-screw_. From its derivation from
Jack, equivalent to lad or boy, has arisen its modern use as denoting
a contrivance which is subject to rough usage. It is operated by _a
screw_, whereas—_a hydraulic jack_ is a jack or lifting apparatus
operated by some _liquid_, usually oil, acting against a piston or
plunger, the pressure on the liquid being produced by a force pump.
_The hydraulic jack_ consists of, 1, a cylinder; 2, a ram or plunger;
and 3, a pump. One of these machines is shown and described in the
Glossary, page 24, another is illustrated by Fig. 138. The Fig. 137 on
the opposite page shows the inside view of Fig. 138 but on a different
scale. _The names of the parts_ are particularly to be noted.

[Illustration: FIG. 138.]

Movable hydraulic, or screw, jacks serve on numerous occasions most
effectively for lifting or propping-up of less accessible parts.
Eye-bolts and jack-bolts are arranged for, in all parts that are likely
to be handled, to facilitate and accelerate the work in necessarily
crowded quarters.

_The base or foot_ is usually made of cast iron or cast steel and may
be either round or square to suit requirements. _The cylinder_ is bored
from a seamless steel ingot and having a thread upon its lower end is
screwed into the base.

_The ram_ is also a tube of seamless steel having a thread at the top
and is screwed into the head or cap which is made either of cast iron
or cast steel. The lower end of the ram has a thread inside to receive
the pump plug which contains the delivery valve, while upon its outside
is placed the cup leather packing and the ram packing ring. The pump
for operating the ram is from five-eighths to three-quarters of an inch
in diameter depending upon the capacity of the jack, and has a plunger
packed with a cup leather.

A suction valve is contained within the plunger. A short arm is fitted
upon a socket which enters through the side of the head or reservoir.
This arm is connected by a pin to the pump inside the ram while the
outer end of the socket has a tapered rectangular hole through it to
receive the jack-lever. A leather collar packing makes the socket tight
where it enters the side of the reservoir.

_To properly use a hydraulic jack._ Place the head under the weight to
be raised, be careful to set the jack plumb with a good solid footing;
put the lever into the socket with its projection on the bottom side;
work the lever until the weight has been raised to the desired height
_or an escape of liquid blows out of the safety vent_. Hold the lever
up or raise it to its highest position and remove it from the socket
to prevent the valve from opening. In lowering insert the lever in
the socket with the projection underneath and then cautiously press
it slowly down until it brings up against the stop; remove the lever
and turn it over with the projection on top; insert the lever in the
socket and gently but firmly press it on the end with the right hand
clasping the ram with the fore finger, and thumb of the left hand: thus
the workman has full control of the jack and can lower and stop as
frequently as may be found necessary.

If from any cause the valves stick a few sharp quick strokes of the
lever will usually release it and cause it to work, if not, it should
be thoroughly cleaned.

Before shipping the brass filling screw should always be screwed down
tight, and before using this screw should always be loosened to let the
air out and in.

  NOTE.—A prominent firm making these tools says: “In our Jacks, rams
  are cut and cylinders bored from solid high carbon steel. We have
  nearly 300 styles for pushing, pulling or lifting.” This shows the
  wide use to which hydraulic jacks are put; the style shown in the
  Glossary with its broad base is to be used when the jack stands
  upon a light board on the ground and can be placed under the work,
  or where steadiness is required. Fig. 139 shows a style to be used
  when there is not room enough to get the head of the jack under the
  work, and is the style generally used for moving engines, boilers,
  machinery, etc.

_In repairing hydraulic jacks_ the following points should be carefully
observed; before attempting to repair a hydraulic jack the trouble
should be definitely located, next:

Put the jack under a weight and attempt to raise it, carefully watching
its action. Should the liquid leak out around the lever socket, the
gland should be tightened slightly until this leak disappears. If the
packing is worn out unscrew the set screw at the back of the head about
one-quarter inch, then withdraw the socket not more than one inch,
unscrew the gland and put in a new packing of lamp wick braided and
well oiled with mineral oil, which is free from gum. Afterwards put the
socket back to its former place and tighten the set screw.

When the pump valve leaks the lever can be worked up and down without
raising the ram. This is also true when the plunger packing becomes
worn. If the trouble is found with the valve it can be ground by taking
out the pump plug and unscrewing the brass bonnet which covers the
valve.

[Illustration: FIG. 139.]

Sometimes the jack will become air bound by reason of the accumulation
of dirt around the filling plug; this must be removed before the jack
will work. Sometimes the liquid will all have been displaced before the
ram is half way up, in this emergency the reservoir must be refilled.
It often happens that when the workman stops working the lever it
will persist in rising to its highest position. This indicates the
presence of dirt under the lower or delivery valve. One or two sharp
quick strokes of the lever will generally dislodge such obstructions;
if this does not bring relief the valve is probably worn so as to need
regrinding. _When a jack has been taken apart each part should be
thoroughly washed in clean water._

While using, _if the liquid escapes over the top of the cylinder_
the ram packing is too loose, and may be set out by inserting a
strip or strips of tin or any sheet metal between the leather and
the ram packing ring; all leathers should be kept soft and pliable
by saturating with a proper leather dressing such as Frank Miller’s
Leather Preservative or Shoemakers’ Dubbing. Castor Oil is excellent as
well.

_One man can exert upon the lever_ all the pressure that the jack is
capable of raising and this pressure should not exceed 150 lbs. Beyond
this the jack will be strained.

_To repack the pump_ remove the pump plug, and unscrew the set screw in
the head, then withdraw the socket far enough to permit it to revolve
clear of the lug, on the head, which brings the piston head out of the
pump.

After the new packing is in place the piston should be worked in and
out a few strokes to see if it is right, then replace the plug.

_To fill the reservoir_ remove the filling screw in the top of the
head, and fill with a mixture of proof alcohol (95 per cent.), two
parts and water three parts for winter use, or for summer use one part
alcohol to four parts water.

_When not in use_ the ram in a hydraulic jack should be kept in its
lowest position, that is to say, all the way down, _or in_, as the case
may be.

  IMPORTANT.—Jacks should never be filled with kerosene oil, water or
  wood alcohol, for the following reasons: Kerosene oil destroys the
  leather packing, water will rust the parts and make them rough, while
  wood alcohol attacks the smooth steel surfaces, and thus destroys
  both the cylinder and ram. All liquids should be well strained before
  putting them into the reservoir and great care should be exercised to
  prevent any dirt from getting into this reservoir.

_The Pulling Jack._—The pulling jack, Fig. 139, is used in connection
with travelling cranes over wheel presses, quartering machines,
planers, drill presses and lathes. Its operation is the reverse of
lifting jacks.

This Jack has an improved force-pump on the outside, worked by a lever,
which draws the liquid from the upper end and forces it into the space
on the opposite side of the piston. The piston rod has one of the rings
attached at the end.

By this operation the rings are drawn together and with them the body
to be lifted or moved, for it will be understood that this style of
jack works either in a horizontal or vertical position. Hooks are
furnished instead of rings when desired.

The liquid is introduced into a hole in the side of cylinder, care,
being observed to push the piston into the cylinder. The proportions of
filling liquid are proof alcohol two parts and water three parts.

To use this jack extend it as far as it can be pulled apart, first
opening the valve in the side of force-pump. Now close this valve and
work the pump lever.

This jack appeals particularly to the marine engineer, to be attached
to the trolley over the engine for the purpose of raising pistons, rods
and lifting various parts of the machinery.

[Illustration: FIG. 140.]

_Horizontal Jack._—The accompanying engraving, Fig. 140, shows a
horizontal type for pulling armatures on to shafts, putting in cranks
pins, and marine work. The directions given for the care and handling
of the regular hydraulic jack apply also to this as well as other
devices of the same description.

This pump has two plungers of different diameters, the small one inside
of the large, so that by throwing a clutch, both plungers may work
together as one, or they may be separated, and the smaller one used; as
for example, in starting, the larger pump is used as far as possible,
_i.e._, until the pressure becomes too great for the large plunger,
then the clutch is thrown and the smaller one finishes the work.

The speed of this appliance may be changed to three times greater, and
its power reduced to one-third of the maximum by throwing the clutch
which brings the large plunger into operation. A rack and pinion
with handle is connected with the main ram to cause its return when
forced out to its full length. The size shown in Fig. 140 represents a
capacity of 200 tons and its approximate weight is 1,200 lbs.

[Illustration: FIG. 141.]

_The Hydraulic Bolt Extractor._—Much harm is done to coupling bolts
in driving them out with a hammer or sledge. The hydraulic bolt
extractor shown in Fig. 141 is an admirable device to do this work
without injuring the bolts or threads. This same apparatus may be used
for other purposes as well as that for which it was designed, as will
appear from time to time.

_The Hydraulic Punch._—The hydraulic punch has been found of greatest
utility in the erection of steel structures, such as buildings, bridges
and ship building. It consists of a hydraulic jack attached to a
“punching bear” instead of the usual screw to operate the punch. By
an ingenious device the punch can be shoved down close upon the work
without pumping all the way, as in the earlier styles of hydraulic
punches; this means a considerable saving of time and muscle.

[Illustration: FIG. 142.]

The construction and operation of working parts of this punch will be
easily understood by referring to the engraving, Fig. 142 where 18
represents the body or “punching bear,” 17 the ram, 19 the raising and
lowering pinion to move the ram quickly to its work; 20 shows the die
with punch in place above it, secured by its gland; 3 the punch head
cistern, the screwed cover having a hole in its center to guide the end
2 of pump plunger 9, having cup leather packing 10, at its lower end;
5 represents the lower socket which carries the arm 4 to operate the
piston 6. The suction valve 11 is supported by the spring underneath;
12 is the safety vent; 13 the release or lowering valve operated by
the stem 7 which is pushed downward by the projection of the piston 6
whenever the lever is turned and pressed downwards as described in
lowering the lifting jacks. The relief valve is kept seated by the
spring 14. 8 represents the body of the pump 16 its packing and 15 the
ram packing ring. No. 16 does not move, but the ram 17 does, having
a cup leather reversed at its upper end applied in the same way and
manner as 16, with screwed packing ring. The discharge valve is located
behind the pump plunger 9 and is, therefore, invisible.

_A hydraulic punch mounted upon three legs_ or supports is shown in
Fig. 143, and it also has a shackle at its back to suspend the punch in
mid air as occasion requires.

[Illustration: FIG. 143.]

The details of this punch are like Fig. 142. It has two guards, one
each side of the punch to pull the material operated upon off the punch
as it is raised by the lower lever. Another very convenient style of
hydraulic punch is shown in Fig. 144 where A represents the body of
punch, B the operating lever with the lowering or adjusting lever shown
broken off. The punch proper is shown at C. The center of gravity
of this punch has been so nicely located that by suspending from the
handle the ram hangs plumb.

[Illustration: FIG. 144.] [Illustration: FIG. 145.]


THE HYDRAULIC PRESS.

The hydraulic press consists of

  1. A Lever,
    2. A Pump,
      3. and a Ram working in a
        4. Cylinder.

Bramah in the year 1796 brought out a very interesting apparatus which
illustrates the law of the equality of pressure which has been widely
adopted in the practical use of the hydraulic press. The principle upon
which this press works is due to Pascal but it remained for Bramah to
put it to practical use. Enormous pressures are developed by operating
the hand lever shown at _M_ in Fig. 145, which is connected with pump
plunger P. The pump barrel A is very thick and receives its supply from
the cistern H through the suction pipe _a_.

[Illustration: FIG. 146.]

Water is delivered from the pump A through a heavy lead pipe into the
cylinder _B_ of the hydraulic press. The ram P is made tight by the
leather packing _n_ and has a table or platform attached to its upper
end as shown. The stationary part _Q_ consists of a heavy cast-iron
plate supported by four wrought-iron or machinery steel columns. By
operating the handle _M_ of the pump any substances placed between the
table on the ram P and the plate Q may be compressed to any reasonable
extent.

The pressure which can be obtained by this press depends on the
relation of the ram P to that of the plunger P. If the former has a
transverse section fifty or a hundred times as large as the latter,
the upward pressure on the ram will be fifty or a hundred times that
exerted upon the pump plunger. By means of the lever M an additional
advantage is obtained.

If the distance from the fulcrum to the point where the power is
applied is five times the distance from the fulcrum to the plunger P
the pressure on it will be five times the power. Thus, if a man acts on
M with a force of sixty pounds, the force transmitted by the plunger P
will be 300 pounds, and the force which tends to raise the ram will be
3,000, supposing the section of ram is a hundred times that of the pump
plunger.

Over-pressure, is prevented by safety-valve shown in front of the pump
A. Fig. 146 shows an enlarged section of the pump used in connection
with this press. When the plunger _P_ rises a partial vacuum is formed
below it and the suction valve _O_ rises allowing the pump barrel to
fill with water through the strainer and suction pipe in the cistern.

When the plunger descends the valve _O_ closes and the water passes
through the discharge valve _h_ into the pipe _K_, thence into the
cylinder _B_ of the press where it acts upon the ram. When the press
has done its work the ram may be lowered by opening the relief valve
_r_. The safety valve is shown at _i_. By removing the plug _h_ the
discharge valve can be reached to grind it in when necessary.

  NOTE.—_Hydraulic Pressure Transmission._ Water under high
  pressure—500 to 3000 lbs. per square inch and upwards—affords a very
  satisfactory method of transmitting power to a distance, especially
  for the movement of heavy loads at small velocities, as by cranes and
  elevators. The system consists usually of one or more pumps capable
  of developing the required pressure; 2, accumulators, described
  on the next page; 3, the distributing pipes, and 4, the presses,
  cranes, or other machinery to be operated. This property of fluids
  invests us with a power of increasing the intensity of a pressure
  exerted by a comparatively small force, without any other limit than
  that of the strength of the materials of which the engine itself is
  constructed. It also enables us with great facility to transmit the
  motion and force of one machine to another, in cases where local
  circumstances preclude the possibility of instituting any ordinary
  mechanical connection between the two machines. Thus, merely by
  means of water-pipes, the force of a machine may be transmitted to
  any distance, and over inequalities of ground, or through any other
  obstructions.


THE HYDRAULIC ACCUMULATOR.

This useful and indispensable apparatus was designed by Sir William
Armstrong. Its use was to secure _a uniform pressure of water in a
reservoir by weight_ so that however much or little of this water was
used the pressure would remain constant.

[Illustration:

ELEVATION.

FIG. 147.]

In the first accumulator which is still in use the ram was attached to
the foundation while the cylinder rose and fell as the pressure was
utilized. The weights were annular in shape and were hung upon the
outside of cylinder. In the modern types of accumulators the cylinder
is stationary and the ram supporting the weights is made to rise and
fall.

_By means of a hydraulic accumulator a uniform pressure can be
established and maintained on all parts of a hydraulic main or system._

[Illustration:

PLAN AT BOTTOM.

FIG. 148.]

The volume of water which is used intermittently for the purpose of
operating presses—draw-benches for brass and copper tubing and the
like is replaced by a pump or pumps which are started and stopped
automatically by a connection between the accumulator and the throttle
or belt shifter of the pump. The accumulator is used for a double
purpose of maintaining a constant pressure and to store up any surplus
force of the pumps. The friction loss in the transmission of power
by water through mains is very small, as for example: _It has been
found that water under a pressure of 700 lbs. per square inch may be
transmitted through well proportioned mains, one mile with a loss of
only two per cent._

The useful work stored in an accumulator may be calculated by the
following rule: _Multiply the area of ram in square inches by the
length of the stroke in inches by the pressure m pounds per square inch
divided by 33,000 lbs. the equivalent of one H. P._

This represents the work done by one full stroke of the accumulator ram
in descending from its highest position to its lowest.

Example. Required the work done by one stroke of a ram twelve inches in
diameter, and a stroke of twenty-two feet, under a pressure of 750 lbs.
to the square inch. Area of 12 ram = 113·097 square inches. No. of ins.
in 22 ft. = 264. Then

  113·097 × 264 × 750
  ------------------- = 678·582 H.P.
        33,000

Mr. Tweddel designed the accumulator shown in Figs. 147 and 148 to
furnish the varying demand for water where only one appliance of this
kind is used in connection with a hydraulic system of shop tools more
especially where these tools are numerous.

The ram or spindle _A_ is fixed top and bottom and acts as a guide for
the cylinder _B_ which slides up and down upon it.

[Illustration:

VERTICAL SECTION.

FIG. 149.]

This cylinder is loaded with weights marked to indicate the pressure
which the accumulator will balance with those weights in use. The water
is pumped into the bottom through the pipe _C_, and fills the annular
space around the spindle. The entire weight of cylinder is raised
by the pressure of water acting only on the area of the end of brass
sleeve _D D_, which is only 1/2 inch thick all around the center
spindle, and extends down through the bottom packing in cylinder, as
shown in sectional view. Fig. 149.

A compact arrangement is thus gained and any reasonable, required
cubical capacity may be reached by lengthening the stroke.

The accumulator is supplied by two pumps having plungers 1-3/8″ diam.
by 3-1/2″ stroke, speed 100 to 120 rev. per minute.

When the loaded cylinder _B_ reaches the top of its stroke, by means of
a small chain it closes the suction cock _E_, which shuts off the water
supply of the pumps.

To put in a new bottom packing, the cylinder is let down to rest on the
wooden blocks _G_, and the spindle is lifted out of its tapered seat at
the bottom by a tackle hooked into the eye-bolt at the top. To renew
the top leather the bracket holding the top end of spindle _A_, has to
be removed.

This accumulator (having only a small area) falls quickly when the
water is withdrawn, thus producing a combined blow and squeeze, which
is of great advantage in hydraulic riveting.

_The Hydraulic Intensifier_ is a cylinder having two diameters,
in principle very like the tandem compound engine. It is used for
increasing the pressure of water in hydraulic mains, pipes, or
machines, using only the energy of the pressure water to effect the
change. But for this distinction a steam pump would be an intensifier.
An intensifier worked the reverse way is a “diminisher” as a hydraulic
pump usually is, giving a reduced pressure.

_The intensifier is in some respects analogous to the electric
transformer._

The intensifier as used in connection with hydraulic apparatus was
patented in the year 1869 by Mr. Aschroft, but the principle upon which
it works is very much older. Intensifiers are made both single and
double acting.

  PERCENTAGE OF THE TOTAL AMOUNT OF WATER TAKEN FROM THE RESERVOIR.

          | Elevation of discharge above
          | delivery valve of ram in feet.
  Height  +------+------+------+------+------
  of fall |  15  |  18  |  21  |  24  |  27
  in feet.+------+------+------+------+------
          |            Percentage.
  --------+------+------+------+------+------
      2   | ·0724| ·0583| ·0402| ·0307| ·0255
      3   | ·1327| ·1020| ·0807| ·0651| ·0532
      4   | ·1960| ·1535| ·1234| ·1020| ·0854
      5   | ·2614| ·2068| ·1686| ·1404| ·1189
      6   | ·3282| ·2614| ·2146| ·1800| ·1535
      7   | ·3960| ·3170| ·2614| ·2203| ·1885
      8   | ·4647| ·3733| ·3090| ·2614| ·2248
      9   | ·5341| ·4303| ·3572| ·3030| ·2614
     10   | ·6040| ·4877| ·4058| ·3450| ·2984
     11   | ·6745| ·5459| ·4549| ·3874| ·3357
     12   | ·7453| ·6040| ·5043| ·4302| ·3733
     13   | ·8166| ·6627| ·5540| ·4732| ·4112
     14   | ·8881| ·7217| ·6040| ·5166| ·4494
     15   | ·9600| ·7809| ·6543| ·5601| ·4877
     16   |  --  | ·8404| ·7048| ·6040| ·5263
     17   |  --  | ·9001| ·7555| ·6480| ·5650
     18   |  --  | ·9600| ·8064| ·6921| ·6040
     19   |  --  |  --  | ·8574| ·7364| ·6430
     20   |  --  |  --  | ·9086| ·7800| ·6823
     21   |  --  |  --  | ·9600| ·8254| ·7217
     22   |  --  |  --  |  --  | ·8701| ·7612
     23   |  --  |  --  |  --  | ·9150| ·8007
     24   |  --  |  --  |  --  | ·9600| ·8404
  --------+------+------+------+------+------
          | Elevation of discharge above
          | delivery valve of ram in feet.
  Height  +------+------+------+------+------
  of fall |  30  |  35  |  40  |  45  |  50
  in feet.+------+------+------+------+------
          |            Percentage.
  --------+------+------+------+------+------
      2   | ·0181| ·0112| ·0063| ·0027|  --
      3   | ·0441| ·0326| ·0243| ·0181| ·0132
      4   | ·0724| ·0560| ·0441| ·0348| ·0281
      5   | ·1020| ·0807| ·0652| ·0533| ·0441
      6   | ·1327| ·1063| ·0870| ·0724| ·0608
      7   | ·1640| ·1327| ·1096| ·0920| ·0782
      8   | ·1960| ·1595| ·1327| ·1121| ·0960
      9   | ·2285| ·1868| ·1561| ·1327| ·1142
     10   | ·2614| ·2145| ·1800| ·1535| ·1327
     11   | ·2947| ·2425| ·2041| ·1746| ·1514
     12   | ·3282| ·2708| ·2285| ·1960| ·1704
     13   | ·3620| ·2994| ·2532| ·2177| ·1896
     14   | ·3960| ·3282| ·2780| ·2395| ·2090
     15   | ·4303| ·3572| ·3030| ·2614| ·2285
     16   | ·4647| ·3863| ·3282| ·2835| ·2482
     17   | ·4993| ·4157| ·3535| ·3058| ·2680
     18   | ·5341| ·4451| ·3790| ·3232| ·2380
     19   | ·5690| ·4746| ·4046| ·3507| ·3081
     20   | ·6040| ·5042| ·4303| ·3733| ·3282
     21   | ·6392| ·5340| ·4561| ·3960| ·3486
     22   | ·6745| ·5640| ·4820| ·4188| ·3688
     23   | ·7098| ·5940| ·5080| ·4417| ·3892
     24   | ·7433| ·6241| ·5341| ·4657| ·4097
  --------+------+------+------+------+------
          | Elevation of discharge above
          | delivery valve of ram in feet.
  Height  +------+------+------+------+------
  of fall |  60  |  70  |  80  |  90  |  100
  in feet.+------+------+------+------+------
          |            Percentage.
  --------+------+------+------+------+------
      2   |  --  |  --  |  --  |  --  |  --
      3   | ·0063| ·0017|  --  |  --  |  --
      4   | ·0180| ·0112| ·0063| ·0027|  --
      5   | ·0307| ·0217| ·0150| ·0099| ·0063
      6   | ·0441| ·0325| ·0243| ·0180| ·0132
      7   | ·0580| ·0441| ·0340| ·0264| ·0205
      8   | ·0724| ·0560| ·0441| ·0351| ·0281
      9   | ·0870| ·0682| ·0545| ·0441| ·0360
     10   | ·1020| ·0807| ·0651| ·0533| ·0441
     11   | ·1172| ·0934| ·0760| ·0627| ·0524
     12   | ·1327| ·1063| ·0870| ·0723| ·0608
     13   | ·1483| ·1194| ·0983| ·0821| ·0694
     14   | ·1640| ·1327| ·1096| ·0920| ·0782
     15   | ·1800| ·1460| ·1211| ·1020| ·0870
     16   | ·1960| ·1595| ·1327| ·1121| ·0960
     17   | ·2123| ·1731| ·1444| ·1223| ·1050
     18   | ·2286| ·1868| ·1561| ·1327| ·1142
     19   | ·2449| ·2006| ·1680| ·1430| ·1262
     20   | ·2614| ·2145| ·1800| ·1535| ·1327
     21   | ·2780| ·2286| ·1920| ·1640| ·1420
     22   | ·2947| ·2425| ·2041| ·1746| ·1514
     23   | ·3114| ·2567| ·2163| ·1853| ·1609
     24   | ·3282| ·2708| ·2185| ·1960| ·1704

  _For explanation of these tables see page 177._


HYDRAULIC RAM.

_A hydraulic ram or water-ram is a substitute for a pump_ for raising
water by means of the energy of the moving water, of which a portion
is to be raised. It was considered a notable discovery when it was
demonstrated by Daniel Bernovilli, in the beginning of the 18th
century, _that water flowing through a pipe, and arriving at a part in
which the pipe is suddenly contracted, would have its velocity at first
very greatly increased_.

The hydraulic ram owes its efficacy to the fact that when a flow of
water in a pipe is suddenly stopped, a considerable force is generated
by the momentum of the water, by its change from a state of motion to a
state of rest. In practice, the pipe conveying water from the reservoir
or head, connects with a chamber which has a valve opening downward,
or outlet valve, allowing the current of water to pass on or escape
when the valve is open; but on flowing the current in the pipe acquires
sufficient force to close this valve, which checks the flow in the pipe.

The current is thus suddenly stopped; this causes a reaction, which
produces pressure sufficient to open another valve (inlet valve)
between the current-pipe and an air chamber, and a portion of water
enters by means of the force of the current, but by so doing the
current has spent its force; the outlet valve at the end of the
chamber falls by its own weight, and the pressure in the pipe ceasing,
the inlet valve in the air-chamber falls and closes the opening.
The condition of things is then restored; the water then acquires a
momentum which closes the outlet valve and forces more water again into
the chamber. A very slight descending column is capable of raising
one ascending very high. In all cases the drive-pipe or inlet pipe
must be sufficiently long to prevent water being forced back into the
reservoir. The air-chamber serves to keep up a steady supply from the
reservoir, preventing spasmodic action. To prevent admixture of air
with the water in the air chamber, which is caused by pressure of water
when raised to a great height, a small hole should be made on the upper
side of the inlet pipe, immediately in front of the same. By the action
of the ram at each stroke, a partial vacuum is formed below the air
chamber, and the air rushing through the small hole in the inlet pipe,
passes into the air chamber, making good that which the water absorbs.

  NOTE.—In 1797 Matthew Boulton (manufacturer and practical engineer,
  and in later life a partner of Jas. Watt, the Father of the steam
  engine) obtained a patent for a mode of raising water by impulse. The
  apparatus had excited much attention in France, under the name of
  _Montgolfier’s hydraulic ram_, and Boulton added to it a number of
  ingenious modifications, which were the basis of his patent.

[Illustration: FIG. 150.]

Fig. 150 shows in section the construction of the ram in its simplest
form in which E is the reservoir, A the pipe in which the water falls,
B the channel, _a_ and _b_ the valves, C the air-chamber, and D the
discharge. Water first flows out in quantity through the valve _a_, and
as soon as it has acquired a certain velocity it raises that valve,
closing the aperture. The impact thus produced, acting on the sides of
the pipe and the valve _b_, raises this valve, and a quantity of water
passes into the air-chamber shutting off air and compressing it in the
space above the mouth _d_ of the discharge D. This air by its electric
force closes the valve _b_, and the water which has entered is raised
in the discharge D.

As soon as the impulsive action is over, and the water in the channel
A comes to rest, the valve _a_ again falls by its own weight, the flow
begins afresh, and when it has acquired sufficient velocity the valve
_b_ again closes, and the whole process is repeated.

_The efficiency of hydraulic rams_ has been much discussed; exhaustive
practical tests have been made and the results have been reduced to
formulas. Whittaker’s Mechanical Engineer’s Pocket Book gives the
following:

            G × H
        E = -----
            g × h

  where E = the efficiency;
        G = gallons of drive water used;
        g = gallons of water raised;
        H = height of fall, in feet;
        h = height to which the water is raised, in feet.

_The Table_ given on page 174 is from the _American Engineer_. Its use
is apparent, thus: when the height of fall in feet is, say 12 feet, and
the elevation of discharge above the delivery valve of ram, in feet, is
30 feet, _the efficiency_ or per cent., is ·3282. (_Example_) of 100
gallons 32-82/100 gallons would be delivered.

[Illustration: FIG. 151.]

_The double hydraulic ram_ is shown in Fig. 151. A sectional view of
the same device is shown in Fig. 152, the cuts represent the Rife
hydraulic engine, or ram,—a so-called double acting or double supply
type of the water ram. It is more clearly described by considering it,
first, as a single machine by disregarding its double supply feature.

First, suppose the opening at _H_, Fig. 152, to be closed, the valve
_B_ being open, the water from the source of supply from more or less
elevation above the machine flows down the drive pipe, _A_, and escapes
through the opening at _B_ until the pressure due to the increasing
velocity of the water is sufficient to close the valve, B. When the
flow through this valve ceases, the inertia of the moving column of
water produces a reaction, called the ramming stroke, which opens the
valve at _C_, and compresses the air in the air chamber, _D_, until the
pressure of the air plus the pressure due to the head of the water in
the main, is sufficient to overcome the inertia of the moving column of
water in the drive pipe. This motion may be likened to the oscillation
of water in a ^U^ shaped tube. The instant the column of water in the
drive pipe comes to rest, and the air pressure being greater than the
static head alone, the motion of the moving column is reversed, and the
valve, _C_, closes. The water in the drive pipe then moves backward,
and with the closing of valve _C_ a partial vacuum is formed at the
base of the drive pipe. This negative pressure causes the valve, _B_,
to open again, and completes the cycle of operations. At the moment
negative pressure appears the little snifting valve, _E_, admits a
small quantity of air, and at the following stroke this air rises into
the air chamber _D_, which would otherwise gradually fill with water,
or the air is gradually absorbed by the water.

In this machine the valve, _B_, is made as light as is consistent with
the necessary strength, and the negative pressure at the completion
of the stroke opens the valve. In the largest size of these machines
this valve is 18 inches in diameter, with a head of 8 feet, which is
a common head for use with hydraulic rams; the static pressure on the
under side of this valve is 883 pounds; it is seen that so great a
shock in a valve of this weight would rapidly destroy both valve and
seat.

[Illustration: FIG. 152.]

The waste in a mechanism of the Rife engine consists of a large port
with ample opening and a large rubber valve or overflow with a balance
counterweight and spring seat, which removes almost entirely the jar of
closing. The valve, _C_, in the air chamber consists of a rubber disc
with gridiron ports and convex seats fastened at the center and lips
around its circumference. The object of this arrangement is to transfer
the shock from the power of the driving water to the air cushion with
the smallest possible friction and vibration.

After the valve, _C_, closes, the pressure in the air chamber forces
the water in the air chamber out into the delivery pipes. The Rife
engine is claimed to elevate water 30 feet for each foot of fall in
the driving head; the machine is built in sizes to elevate as much as
150,000 gallons per day, the efficiency being about 82 per cent.

When a water supply pipe is attached to _H_, the engine is called
_double acting_; spring water, or that which is purer than the water
used to drive the engine, may then be supplied through the supplemental
drive pipe _I_, and by a proper adjustment of the relative flow of
the impure driving water, and that of the pure supply, the engine may
be made to deliver only the pure water into the mains. This method is
employed where the supply of pure water is limited.

The most important detail in which the Rife engine differs from the
ordinary hydraulic ram is _the waste valve_. It will be seen in the
engraving that the counterweight on the projecting arm of this valve
permits the adjustment of this valve to suit varying heads and lengths
of drive pipe. By adjusting the counterweight so that the valve is
nearly balanced, the valve comes to its seat very quickly after the
flow past it begins. The result is that the ram makes a great number
of short, quick strokes, which are much easier on the valves and seats
than slower and heavier strokes. The stroke must be sufficiently
powerful to act efficiently in overcoming the head in the delivery
pipe. The adjustable weight permits this to be effected with great
nicety.

  NOTE.—The engine illustrated weighs approximately 2,800 pounds; the
  capacity of the air chamber is 20-3/4 cubic feet; diameter of drive
  pipe, 8 inches; diameter of the waste valve, 18 inches; weight of
  waste valve, 50 pounds; diameter of delivery pipe, 4 inches; height
  to top of air chamber, 7-1/2 feet.

_Lifts and Cranes._ These, as hydraulic machines, are adapted to very
many places where other power apparatus is too slow; they operate on
the same principle as the hydraulic press; having a cylinder and a ram:
they have chain wheels attached to the outer end of the ram, as shown
in the illustration.

[Illustration: Crane]

As the ram advances the chain is shortened and when it recedes the
chain is lengthened, thus, the weight attached to the end of the chain
is raised and lowered. The hydraulic “lift” in passenger elevators
operates upon the same principle and this gives an idea of the rapid
motion capable of being imparted to the load. It is by the adaptation
of hydraulic lifts and cranes in steel mills that such economical
results have been attained.


PUMPS AS HYDRAULIC APPARATUS.

In Figs. 153 and 154 are shown representations of certain apparatus,
long used in schools, to explain the rather obscure operation, of even
the simplest of pumps; these models are made of glass so that all the
movements of the valves, etc., may be clearly noted. Credit is due to
Monsieur Ganot, author of Elements of Physics, for the following.

_Fig. 153 represents a model of a suction-pump_ such as is used in
lectures, but which has essentially the same arrangement as the
pumps in common use. It consists, 1st, of a _glass cylinder_, B,
at the bottom of which is a valve, S, opening upwards; 2nd, of a
_suction-tube_, A, which dips into the reservoir from which water is
to be raised; 3rd, of a _piston_, which is moved up and down by a rod
worked by a handle, P. The piston has a hole in its center; this upper
aperture is closed by a valve, O opening upwards.

[Illustration: FIG. 153.]

When the piston rises from the bottom of the cylinder B, a vacuum is
produced below, and the valve O is kept closed by the atmospheric
pressure, while the air in the pipe A, in consequence of its
elasticity, raises the valve S, and part of it passes into the
cylinder. The air being thus rarefied, water rises in the pipe until
the pressure of the liquid column, together with the pressure of the
rarefied air which remains in the tube, counterbalances the pressure of
the atmosphere on the water in the reservoir.

When the piston descends, the valve S closes by its own weight, and
prevents the return of the air from the cylinder into the tube A. The
air compressed by the piston opens the valve O, and escapes into the
atmosphere by the pipe C. With a second stroke, the same series of
phenomena is produced, until after a few strokes the water reaches the
cylinder. The effect is now somewhat modified; during the descent of
the piston the valve S closes, and the water raises the valve O, and
passes above the piston by which it is lifted into the upper reservoir
D. There is now no more air in the pump, and the water forced by the
atmospheric pressure rises with the piston, provided that when it is at
the summit of its course it is not more than 34 feet above the level of
the water into which the tube A dips.

[Illustration: FIG. 154.]

_In practice the height of the tube A does not exceed 26 to 28 feet_;
for although the atmospheric pressure can support a higher column,
the vacuum produced in the barrel is not perfect, owing to the fact
that the piston does not fit exactly on the bottom of the barrel. But
when the water has passed the piston, it is the ascending force of
the latter which raises it, and the height to which it can be brought
depends on the power which works the piston.

The action of this pump, a model of which is represented in Fig. 154,
_depends both on exhaustion and on pressure_. At the base of the
barrel, where it is connected with the tube A, there is a valve, S,
which opens upwards. Another valve, O, opening in the same direction,
closes the aperture of a conduit, which discharges from a hole, _o_,
near the valve S, into a vessel, M, which is called the _air-chamber_.
From this chamber there is another tube, D, up which the water is
forced.

At each ascent of the piston B, which is solid, the water rises through
the tube A into the barrel. When the piston sinks the valve S closes,
the water is forced through the valve O into the reservoir M, and
thence into the tube D. The height to which it can be elevated in this
tube depends solely on the motive power which works the pump.

If the tube D were a prolongation of the tube J_ao_, the flow would
be intermittent; it would take place when the piston descended, and
would cease as soon as it ascended. But between these motions there is
an interval, which, by means of the air in the reservoir M, ensures
a continuous flow. The water forced into the reservoir M separates
into two parts, one of which, rising in D, presses on the water in
the reservoir by its weight; while the other, by virtue of this
pressure, rises in the reservoir above the lower orifice of the tube
D, compressing the air above. Consequently, when the piston ascends,
it no longer forces the water into M, the air of the reservoir, by the
pressure it has received, reacts on the liquid, and raises it in the
tube D, until the piston again descends, so that the jet is continuous.

_Hydraulic Machine Tools._ Probably in no department of engineering
has the use of hydraulic power met with more success than in its
application to certain machine tools. This success is owing to the
peculiar suitability of pressure—water as the motive agent for the
performance of a certain class of operations requiring the exertion of
a great force with comparative slow motion, as in punching, riveting,
forging and the like.

The wide spread and successful use of hydraulic machines—of which a few
only have been described and illustrated upon the pages of this book—is
due to the necessity for such tools and the inventive ability of our
tool designers.

_A large fixed hydraulic riveter_ is shown in Fig. below; it is capable
of exerting on the rivet a pressure of 40 tons or more; the machine has
a _working pressure_ of 1,500 pounds per square inch. Working pressures
of 5,000 to 10,000 pounds per square inch are used in _hydraulic
forging presses_, but in the riveter much less pressure is required.

[Illustration: Large fixed hydraulic riveter.]

  NOTE.—_The proportions_ of this machine are immense. The platform
  weighs 22,500 lbs. and is operated by a single lever shown in the
  side view. The “_gap_” is 8 feet across. The machine has a large
  steel “_stake_” carrying the stationary die; this is held in tension
  strain by the two steel bolts shown, one upon each side of the
  machine. The other part of the jaw is cast iron.



  CLASSIFICATION
  OF PUMPS
[Illustration: FIG. 155.—THE BELLOWS PUMP.]



CLASSIFICATION OF PUMPS AND PUMPING ENGINES.


The simplest division of the subject matter relating to this branch of
practical mechanics is that which goes back to the very earliest of
times; it is thus:

  1. Hand Pumps.
  2. Power Pumps.

The names indicate the dividing line between the two. The following are
more modern divisions, indicating the method of action distinguishing
each:

  1. Suction or Lift Pumps.
  2. Force Pumps.
  3. Suction and Force Pumps.

These again may be reciprocating or rotary. The powers actuating pumps
are, in the main, as follows:

  1. Manual.
  2. Animal.
  3. Belts.
  4. Water.
  5. Wind.
  6. Steam.
  7. Gas.
  8. Electricity.

These various motors give distinct names to general classes, thus,
electric pumps, belt pumps, elevator pumps, etc. A sub-division of
titles indicating differences in construction are these:

  1. Vertical Pumps.
  2. Horizontal Pumps, or again
  1. Single Acting Pumps.
  2. Double Acting Pumps.

The list is still further extended, as pumps vary in design to suit
their several uses, and are defined as rope, chain, diaphragm, jet,
centrifugal, rotary, oscillating, cylinder. It is with the last named
with which this volume has principally to deal; cylinder pumps cause
the last given classification, as they are either single or double
acting.

A single acting pump does its work through one end of the cylinder or
barrel of the pump.

In double acting pumps the motion of the piston in one direction causes
an inflow of water, and a discharge at the same time, in the other;
and on the return stroke this action is renewed as the discharge end
alternately becomes the suction end; the pump is thus double acting.

Finally pumps may be classified with reference to particular uses to
which they are specifically adapted by their form and the materials
they are required to handle.

Pumps now raise, convey and deliver beer, molasses, acids, oils, and
melted asphalt. They also handle such gases as air, ammonia, lighting
gas and even oxygen.

In the orderly progress of the contents of the volume, it will be seen
that the main subject, occupying many pages with illustrations, is that
relating to “Steam pumps;” those having a _steam-end_ and a _water-end_
and which consist of pump and steam-motor combined. An interesting
class under Vacuum-pumps will be found, 1, the combined vacuum and
feed; 2, the combined vacuum and circulating and, 3, the combined
vacuum and refrigerating pumps.

Under Pumping Engines and the Steam Fire Engine will be found a
description of the most brilliant and fascinating of modern scientific
and mechanical achievements; these two sections relate to hydraulic
engineering in its highest development.


HAND PUMPS.

The _theoretical action of_ a pump has already been described and
illustrated;—the _practical operation_ is described in the note below.
The subject is important enough to justify the space it takes to
present these two descriptions of the action of a pump.

[Illustration: FIG. 156.]

The parts of which a pump is composed are: 1, _the barrel or cylinder_;
2, _the plunger or piston_; 3, _the valves_; 4, _the pipes_.

The barrel of a modern pump is a tube of metal having a water tight
plunger or piston which moves freely up and down at the pleasure of the
operator. This plunger is in its simplest form made of cast iron in two
parts. The upper part consists of an arched part having a hole in its
center to receive a bolt which passes through it and a jaw on the lower
end of the pitman or connecting rod. The upper end of this pitman is
attached to the pump handle by means of a bolt. The inside of the upper
part of the plunger is threaded to receive the lower part with a cup
leather packing and contains a valve of metal having a conical seat.
Fig. 156 shows a design of a pump in common use in the 14th century.

  NOTE.—The action of a pump is as follows: The piston or plunger by
  moving to one end, or out of the pump cylinder, leaves the space it
  occupied, or passed through, to be filled by something. As there is
  little or no air therein a partial vacuum is formed unless the supply
  to the pump is of sufficient force to follow the piston or plunger
  of its own accord. If this is not the case, however, as it is when
  the water level from which the pump obtains its supply is below the
  pump itself, there being a partial vacuum produced, the atmospheric
  pressure forces the water into the space displaced by the plunger or
  piston, continuing its flow until the end of stroke is reached.

  The water then ceases to flow in, and the suction valve of the pump
  closes, forbidding the water flowing back the route it came. The
  piston or plunger then begins to return into the space it has just
  vacated, and which has become filled with water, and immediately
  meets with a resistance which would be insurmountable were the water
  not allowed to go somewhere. (See next page.)

Its only egress is by raising the discharge valve by its own pressure,
and passing out through it. This discharge valve is in a pipe leading
to the boiler, and in going out of the cylinder by that route the water
must overcome boiler pressure and its own friction along the passages.
Water is inert and cannot act of itself; so it must derive this power
to flow into the feed pipe and boiler from the steam acting upon the
steam piston of the pump. The steam piston and pump piston are at the
two ends of the same rod. Therefore the steam pressure exerted upon the
steam piston will be exerted upon the pump piston direct.

Between the upper and lower parts of the plunger a cup leather is
introduced before these parts are screwed together. This cup leather,
while it allows the plunger to move freely, also makes a water-tight
joint.

The lower valve consists of a piece of cast-iron flat on the bottom
and circular in shape about three-eighths inch thick with a curved toe
at one side. This iron disc is secured to the flat leather valve by a
screw that passes through the valve and is threaded in the disc.

[Illustration: FIG. 157.]

The object of this toe upon the disc is to open the lower valve by
means of raising the pump handle as far as it will go which lowers the
plunger upon the toe and tips the lower valve upon its seat. This same
operation also lifts the valve in the plunger off its seat, so that all
the water in the barrel drains back into the well so the pump is kept
from freezing up in winter.

[Illustration: FIG. 158.]

The leather which forms the lower valve is held in place by clamping
the pump barrel upon it, so that it is held between the barrel and the
base plate.

Hand pumps are primarily divided into: 1, suction or lift pumps; 2,
force pumps, and 3, suction and forcing pumps; 4, also pumps for
exhausting air from vessels.

Of the first class, the common single-acting house-pumps shown in Figs.
157 and 158 are examples; the pumps are simply modifications of the
suction-pump; a common form of lift-pump has a pitman-rod which pushes
the water up instead of lifting it through a spout at or near the top
of the cylinder.

The details of the suction-pump are as follows—at the bottom of the
cylinder is a pipe communicating with the liquid to be raised, and a
valve which opens from beneath. A similar valve is placed in the piston.

A force-pump is shown in Fig. 159; from the two figures the difference
between the lift and the force-pump may be understood; while the
former raises the liquid above its piston from which it flows under
no pressure, the latter forces it out of the barrel under a varying
pressure which depends upon circumstances. When the piston rises
the suction valve opens, and the valve in the piston closes by the
air-pressure. The liquid then enters the barrel beneath the piston. On
the descending stroke the suction valve closes, and the liquid flows
upward into the discharge pipe.

[Illustration: FIG. 159.]

_In Fig. 160 is shown an air-chamber_ attached to a force-pump for the
purpose of preventing shocks in the discharge, and for producing a
steady flow; air-chambers are also frequently attached to suction pipes
for a similar purpose.

According to the underlying principles of action thus far explained
hundreds of thousands of pumps have been constructed and operated. It
is beyond the limits of this volume—or any single book to give the
names and details of these so-called “hand-pumps,” however, three
approved styles are shown in Figs. 161, 162, 163.

Fig. 161 represents a _double acting force pump_ used extensively on
ship-board, wharves, around factories, mills, etc., and in residences,
for tank pumping. On ships these pumps perform the three-fold purpose
of filling boilers when cold, washing down decks and to satisfy
government inspection as to fire protection; in service in mines
they are unaffected by mine water, the working parts being made
non-corrosive. It is claimed that a three-inch diameter cylinder with
a stroke of four and a half inches with a 1-1/4-inch suction pipe and
1-inch discharge pipe will lift and force water 150 ft. high and has a
capacity of ·28 gallons for each stroke, with the water not more than
twenty-five feet below the pump.

[Illustration: FIG. 160.]

Fig. 162 represents _a two cylinder force pump_; this has vertical
single acting pistons actuated by one lever, producing the same
results as a double-acting pump. It is claimed that the total lift
and force, from supply to point of delivery, with the pump not more
than twenty-five feet above water will attain one hundred feet; that a
3-inch × 4 inch cylinder, 1-1/2-inch suction and 1-1/4-inch discharge
will deliver ·24 gallons of water for each stroke.

Fig. 163 represents a widely used type of suction pump, it is
designed for vessels of not more than fifteen to twenty feet deep;
for contractors who wish to pump large quantities of water from
excavations, etc.; for irrigation or any other purpose where a compact
and capacious pump is desired.

The lever may be worked from three different points as shown by lugs on
the illustration. The lever socket is made at such an angle that the
bent wrought iron lever when put in one side up, is right for ordinary
pumping and by simply changing it the other side up, it becomes a
vertical lever. The valves are accessible and removable by hand from
above. It is claimed that with 8-1/2-in. diameter cylinder and 6-in.
stroke that the capacity is 1-47/100 gallons for each stroke, with 20
feet lift—the suction pipe being 3-in. in diameter.

[Illustration: FIG. 161.]

In the illustrations (Figs. 161 and 162) it will be noticed that the
discharge is conveniently arranged to receive either fire hose, or iron
pipe connections for other uses, as in mines and on ship-board.

_Being made in large factories_, there are immense numbers in
world-wide use; every detail of these pumps is carefully considered;
the sizes manufactured range from 2 inches to 6 inches diameter of
cylinders, with strokes 4, 4-1/2 and 5 inches.

_The capacity_ of each pump is also given in the published lists by the
makers; this is given under the heading “Capacity per Revolution” with
the added information as to the best sizes to be used for the suction
and discharge pipes.

[Illustration: FIG. 162.]

  NOTE.—It were well for the student to know that in case of breakage
  or worn out parts of an otherwise serviceable apparatus that the
  makers _have provided for their repairs_ as will be indicated by the
  following taken from the catalogue of a well known manufacturer. “In
  the following lists will be found descriptions of pieces for all
  the staple pumps, which will prove of decided convenience. In this
  connection we desire to impress most emphatically on the minds of
  dealers that the threads are cut to exact and accurate gauges; all
  holes in flanges, etc., drilled to templets; all castings made from
  exact metal patterns, similar parts being always the same. Therefore,
  repairs will invariably take the place of the broken parts.”

_Fig. 163 represents a Pitcher Spout Pump_, of large size for
contractors, and Fig. 164 the parts of a common house pump. The two
figures show pumps substantially the same.

[Illustration: FIG. 163.]

The smallest size “listed” of this pump has a cylinder diameter of
2-1/2 inches, fitted with 1-1/4 in. pipe and it has a capacity of ·09
gal. per stroke and it takes more than eleven strokes to pump a single
gallon. With a cylinder 4-1/2 inches, with pipe 1-1/2 in. diam., the
pump has a capacity of ·34 gal. per stroke.

[Illustration: FIG. 164.]

The engraving 164 shows a pitcher pump dissected, in which A represents
the lever or handle, B the plunger which contains the discharge valve
and is made tight by a cup leather packing, C is the fulcrum for the
lever, D the barrel or cylinder, E the lower or suction valve, F the
base which supports the pump. The leather which forms the valve E also
makes the joint between the cylinder and the base.

Fig. 165 represents a _Two-Cylinder Suction and Force Pump_ arranged
with extension levers. When these levers are put in place, they afford
room for a large force of men to work, renders this pump a most
powerful engine for throwing water on fires, or supplying it for many
uses about factories, warehouses, wharves, etc.

The discharge hose can be fitted both ends for wrought-iron pipe or
either end for hose. The Table below gives the makers’ numbers, the
diameter of the cylinders, etc., and also distance to which the water
can be lifted or forced.

[Illustration: FIG. 165.]

  TABLE OF SIZES, CAPACITIES, ETC.

  ---+--------+---------+---------+------ -------+--------------+---------
  No.|Diameter| Stroke  |Capacity |  Discharge   |    Suction   |*Lift and
     |Cylinder|         | per Rev.|              |              |  Force
  ---+--------+---------+---------+--------------+--------------+---------
   4 |3    in.|6-1/2 in.| ·40 gal.|1-1/4 in. hose|1-1/2 in. pipe|100 ft.
   4 |3     „ |6-1/2  „ | ·40 gal.|1-1/4     „   |1-1/2     „   |100 ft.
   6 |3-1/2 „ |6-1/2  „ | ·54  „  |1-1/2     „   |2         „   | 75  „
   8 |4     „ |8      „ | ·87  „  |2         „   |2-1/2     „   | 75  „
  10 |4-1/2 „ |8      „ |1·10  „  |2         „   |2-1/2     „   | 75  „
  12 |5     „ |8      „ |1·36  „  |2         „   |2-1/2     „   | 75  „
  16 |6     „ |7      „ |1·96  „  |2-1/2     „   |4         „   | 50  „
  ---+--------+---------+---------+--------------+--------------+---------

* _Total lift and force from supply to point of delivery, Pump not more
than 25 feet above water._

Fig. 166 represents _a hand, rotary force pump_ provided with a balance
wheel. A sectional view of this pump is given in Fig. 167; these pumps
are adapted for almost any place or purpose where lift or force pumps
can be used, they can be moved to any place where water is within
suction distance and immediately operated.

[Illustration: FIG. 166.]

The provision of a foot valve at the end of the suction pipe will keep
it always filled.

_In the rotary pump there are no pistons._ As will be seen in the Fig.
167, there are two pinions of extremely coarse pitch meshing into
one another with neat fit in the case; the joints become practically
air-tight by the water which surrounds them and passes through the case.

[Illustration: FIG. 167.]

Both pinions are supported by a journal at each end, the shaft of one
being extended to receive a pulley or hand wheel as shown in Fig. 166,
hence, one pinion causes the other to revolve. The teeth on the bottom
side of the pinions move away from each other and form a partial vacuum
which the water fills and is carried around between the teeth of the
pinions on opposite sides and is discharged through a central opening
in the case at the top, thence through the discharge pipe into the tank
or reservoir.

In the small sizes of the rotary pump there is no trouble from leakage,
until the parts become much worn.

[Illustration: FIG. 168.]

_Bag Pump._ This is a form of bellows-pump in which the valve disc A,
which takes the place of the bucket, is connected with the base of the
barrel by an elastic bag distended at intervals by rings. This bag
may be made of leather or of double canvas. The upper end of the bag
should be firmly tied with a cord in a groove gouged out of the rim of
the board at A. Into this board is fixed the fork of the piston rod,
and the bag is kept distended by a number of wooden hoops or rings of
wire, fixed to it at a few inches distance from one another, and kept
at equal distances by three or four cords binding them together and
stretching from the top to the bottom of the bag. Now let this trunk be
immersed in the water: it is evident that if the bag be stretched from
the compressed form which its own weight will give it by drawing up the
piston rod, its capacity will be enlarged, the valve A will be shut by
its own weight, the air in the bag will be rarefied, and the atmosphere
will press the water into the bag. When the rod is thrust down again,
the water will come out at the valve A, and fill part of the trunk. A
repetition of the operation will have a similar effect; the trunk will
be filled, and the water will at last be discharged at the spout.

[Illustration: FIG. 169.]

_Bellows-pump_ (Page 186). This is an atmospheric pump in which the
part of the piston is played by the top leaf of the bellows. A very
simple method of describing an invention, from which great good in
drainage of waste lands in Europe, was realized. “There was of course a
valve covering the interior orifice of the nozzle and opening outwards,
to prevent the air from entering when the upper board was raised. This
valve is not shown because the art of representing the interior of
machines by section, was not then understood, or not practiced. The
lower board is fastened to the ground by a platform while the suction
pipe dips into the water. A weight is placed on the upper board to
assist in expelling the water.”

Fig. 169 represents a _Double Lantern Bellows-Pump_ as used in the 16th
century. This engraving is plain and requires no description. Fig. 170
shows a diaphragm pump in which a sheet of rubber or its equivalent is
used as a substitute for a piston in a cylinder.

[Illustration: FIG. 170.]

  NOTE.—When an ox or a horse plunges his mouth into a stream, he
  dilates his chest and the atmosphere forces the liquid up into his
  stomach precisely as up the pipe of a pump. It is indeed in imitation
  of these natural pumps that water is raised in artificial ones. The
  thorax is the pump; the muscular energy of the animal, the power that
  works it; the throat is the pipe, the lower orifice of which is the
  mouth, and which he must necessarily insert into the liquid he thus
  pumps into his stomach. The capacious chest of the tall camel, or of
  the still taller cameleopard or giraffe, whose head sometimes moves
  twenty feet from the ground, is a large bellows-pump which raises
  water through the long channel or pipe in his neck. The elephant
  by a similar pneumatic apparatus, elevates the liquid through that
  flexible “suction pipe,” his proboscis; and those nimble engineers,
  the common house-flies, raise it through their minikin trunks in the
  manner of the gigantic animals which in remote ages roamed over this
  planet, and which quenched their thirst as the ox does. There could
  have been none which stood so high as to have their stomachs thirty
  feet above the water they thus raised into them.

_Rope Pump._ This machine consists of one or more endless ropes, all
stretched on two pulleys as shown in Figs. 171 and 172. These pulleys
have grooves formed in their surfaces for the reception of the ropes.
A rapid rotary motion is communicated to the upper pulley, by a
multiplying wheel, and the ascending side of each rope carries up the
water absorbed by it, and which is separated from it while passing over
the upper pulley, partly by centrifugal force, and partly by being
squeezed in the deep groove.

[Illustration: FIG. 171.]

[Illustration: FIG. 172.]

In the beginning of the motion, the column of water adhering to the
rope, is always less than when it has been worked for some time, and
continues to increase till the surrounding air partakes of its motion.
By the utmost efforts of a man, nine gallons of water were raised
by one of these machines from a well, ninety-five feet deep, in one
minute. (_Adam’s Philos._)

_The hydraulic belt_ is a similar contrivance. It is an endless double
band of woolen cloth, passing over two rollers, not here shown. It is
driven with a velocity of not less than a thousand feet per minute;
when the water contained between the two surfaces is carried up and
discharged as it passes over the upper roller, by the pressure of the
band. Some machines of this kind are stated to have produced an effect
equal to seventy-five per cent. of the power expended, while that of
ordinary pumps seldom exceeds sixty per cent. (_Lon. Mechan. Mag._)

_Spray Pump._ Fig. 173 exhibits a carefully designed pump made to spray
trees, plants, etc. All the working parts are of brass, the valves
are metal; the air chamber is made of galvanized iron or copper and
has large capacity. It will hold sufficient compressed air to keep
the spray going from six to ten minutes after the pumping stops. The
“agitators” are placed so that they keep the liquid thoroughly stirred.
The plungers can be easily removed and packed without the necessity of
taking the pump to a shop.

[Illustration: FIG. 173.]

The pump is fastened to the bottom of the barrel by a bolt passing
through the barrel and secured by a nut underneath, with packing to
prevent leakage, and by an iron plate at the top covering the opening
through which the pump is placed in the barrel. This pump is arranged
with one, or two levers, and for one or two lines of discharge hose.
The cylinders are 2-1/2 inches diameter with stroke 3 inches; its
capacity per stroke is 0·13 gal.

_Combined Pump and Horse Power._ The “horse power” (apparatus) with its
“pole” for one horse and two poles for two horses and its wrought iron
“tumbling shaft” has been so modified that a horse operates the pump,
by means of a “sweep,” direct connected to the pump crank shaft.

The animal will make three to four circuits per minute, giving the pump
crank shaft a speed of 40 to 50 revolutions per minute. The capacity
of a 4 in. plunger and 8 in. stroke is given as 3·120 gallons per
hour; the suction pipe is given as 3-1/2 in. diam. and the discharge as
3 in. pipe.


DRIVEN OR TUBE WELLS.

[Illustration: FIG. 175.]

[Illustration: FIG. 175-A.]

Aside from the wells described on page 45 and those following it, there
are wells made by forcing iron tubing down into the earth until a water
supply is reached. Within reasonable distances and in a remarkably
large proportion, these pipe wells are directly connected with the
suction part of hand pumps.

  NOTE.—“When a well fails to yield a fair amount of oil or water,
  an increase in the flow is often effected by means of the Roberts
  torpedo. This is a thin water-tight cylinder of metal or paper,
  4 to 6 ft. long and 2 or 3 in. in diameter, charged with powder,
  gun-cotton or nitro-glycerine. It is lowered to the bottom of the
  well, or to a depth that will bring it opposite the desired stratum,
  and the well is then flooded. The charge is exploded by a cap or
  electric spark, and the explosion often clears away the obstruction
  from the oil or water vein. This applies particularly to deep wells.”

To this class also belong the famous oil and artesian wells which
penetrate through earth and rock thousands of feet, many of them
operated by power pumping machines.

[Illustration: FIG. 176.]

[Illustration: FIG. 177.]

The process of driving tube-wells resembles pile-driving, but with
this distinction, that while piles receive the blows of the “monkey”
on their heads, the tubes are not struck at all, the blow being
communicated by the clamp, which receives the blow near the ground.
The tube-well, as in ordinary use, is not intended for piercing rock
or solid formations, but is quite capable of penetrating very hard
and compact soils, and can be also successfully driven through chalk,
breaking through the flints which may obstruct its passage downward.
When solid masses of rock or stone are reached, special means of
drilling have to be provided for it. When coming upon rock or stone,
the best plan is to pull up the tube and try in another spot. This
applies also when deep beds of clay are driven into; for, by going a
little distance off, and testing again, in many cases water will be
found.

[Illustration: FIG. 178.]

The operation is as follows: The first or pioneer tube, shown in Fig.
175 is furnished with a steel point of bulbous form, and perforated
with holes varying from one-eighth to an inch, extending from 15 in.
to 3 ft. from the point, Fig. 178. The enlargement of the point serves
to clear a passage for the couplings by which the tubes are screwed
together. On this tube the clamp Fig. 176 is held about 3 ft. from the
point by two bolts; the clamp is of wrought iron with steel bushing
screwed internally so as to form teeth to grip the tube. Next, the
cast-iron driving-weight or monkey is slipped on to the tube above the
clamp. The monkey is operated with ropes.

_Sucker-Rod Couplings._ These couplings are usually made of iron
galvanized and are used to connect the ends of wooden sucker rods for
deep well pumps. Each half of coupling is secured to the end of wooden
rods by three bolts; the ends of the couplings are joined by male and
female threads in the usual way.

Either bolts or rivets may be used to attach the rods to the couplings.
(See Fig. 179.)

[Illustration: FIG. 179.]

POINTS FOR ERECTING AND OPERATING HAND PUMPS.

_Foundation_—For the smaller sizes a foundation is not necessary,
other than a good floor. With the large sizes it is advisable to have
a substantial foundation. Concrete, well rammed into place, surmounted
by a capstone, is as good as any. The foundation allows the pump to be
run at a higher speed; a plan showing location of bolt-holes, position
of flanges, and general dimensions, so that there may be no delay in
setting the pump upon arrival at its destination.

[Illustration: FIG. 180.]

_Suction Pipe_—The suction pipe should be as short and direct as
possible, avoiding all turns not necessary. Place a strainer and
foot-valve, Fig. 180, on the suction pipe. It is better for the pump to
have a slight suction except when hot water is pumped, than to supply
the water to the pump under a slight head.

_Discharge Pipe_—Make the discharge piping as straight as possible,
using long bends.

_Packing_—The stuffing boxes should be carefully packed and the gland
brought up firmly against the packing; screwing up the gland by hand
should be sufficient.

Large sizes of suction and discharge pipe are desirable, because the
friction of the water in the pipes thus reduced makes the pump work
easier.



POWER PUMPS


POWER DRIVEN PUMPS.

By _a power-driven pump_ is meant one actuated by Belt,
Rope-transmission, Gear, Shafting, Electric-motor, Water-wheel,
Friction, or by direct connection to a power shaft. It thus becomes
very frequently a question which apparatus is most desirable.

These are classified, thus—

  1. Single power pumps,
    2. Duplex power pumps,
      3. Triplex (triple) power pumps,
        4. Quadruplex, etc. Where the sizes still

further increase they are named from the number of barrels or water
cylinders, but when of much larger size than the Triplex they come
under the classification of pumping engines.

Where power can be had from a shaft in motion there is no pump so
economical as the power or belt driven pump. This fact is shown by the
rapid increase in the number of applications of this type of pump: the
reduced cost of manufacture in making the teeth of the gear wheels, the
use of automatic machinery, the production of interchangeable parts
have tended to produce a high grade of machine at an attractive price.

The energy expended in operating the power driven pump is obtained
at the same economy as that required by the machinery in the mill
or factory, and as a modern automatic cutoff engine will develop
a horse power with considerable less steam than the direct acting
steam pump the cost of the power required by the power driven pump
is correspondingly less; it participates in the economy of the steam
engine using from one and a half pounds of coal to five or six pounds
per H. P. per hour.

For this reason the power driven pump is oftentimes the more
economical, and especially where shafting is adjacent to the location
of the pump, or can be conveniently arranged by simply adding another
length of shafting with the necessary pulleys, or even by cutting
suitable openings through the walls for the belts.

_Single, duplex and triplex power pumps_ are described and illustrated
upon the succeeding pages; power pumps are built with one, two, three,
four or five cylinders and for either high or low pressure or general
service, and their sizes, capacities, and the materials they handle are
no more numerous than their combinations in erection.

The portion of this work devoted to power pumps should be especially
interesting and instructive to the attendants operating steam,
compressed air and power driven pumps. Particular attention has been
given to _single-cylinder steam pumps_ because of the great variety of
steam-actuated valves to be found in practice, each differing from the
other in one or more essential features.

It is due very largely to the numerous designs of steam valves,
that difficulty has been encountered in managing single-cylinder
pumps as successfully as those of the duplex type, the similarity of
construction in the latter type, even in minor details, being much more
marked.

The successful operation of a pump depends to a great extent upon
the intelligence displayed in its management, and an engineer can
scarcely hope to obtain quiet and smooth running pumps and freedom from
breakdowns and perplexing delays except by a thorough knowledge of the
details of construction and operation.

It must be remembered that _power pumps_ are to be illustrated and
explained in a class entirely excluding _steam pumps_; the latter are
pumps in which the moving force is steam.

_Electric Pumps_ are properly power pumps in which the moving force is
_electricity which is conducted to the pumps by wires_.


PUMP PARTS.

[Illustration: FIG. 181.]

_Water Ends._ There are properly speaking four kinds of water ends to
steam and power pumps:

1, A solid plunger, with a stuffing box used for heavy pressings in
hydraulic apparatus, or as shown in Fig. 182, for larger plungers.

2, A piston packed with fibrous material within the cylinder. See Fig.
181. The letter P in Fig. 182 and the following cuts indicates the
plunger.

3, A plunger packed with a metal ring around the outside, as
illustrated in Fig. 183.

4, Two plungers, Fig. 184, connected outside of the cylinder with a
stuffing box in two cylinder heads, through which the plungers work.
These are more fully explained and illustrated as they occur in many
examples as they are referred to in the oncoming chapters of this work.

The construction of the water ends of single cylinder and duplex pumps
is practically the same; any slight differences which may be found are
confined to minor details, which in no way affect the general design or
operation of the pump.

_The steam or power ends_ of numerous and varied makes of pumps
are also as shown in the following pages of this work; all pumps
actuated by power—steam, electric, etc.—are possessed of these two
distinguishing features—1, a steam or power end, and 2, the water end.

  NOTE.—This statement has exception in the cases of large pumping
  engines having a fly wheel or supplemental cylinders attached to
  an accumulator, in which case the steam is worked expansively.

[Illustration: FIG. 182.]

[Illustration: FIG. 183.]

_The steam end of the ordinary single steam pump, and also of the
duplex pump, differs from the steam cylinder of the steam engine in
that the former has four ports to each cylinder, i. e., two steam ports
and two cushioning ports as shown hereafter in figures._

Under the division of the work allotted to the “Steam Pump” will be
found all necessary further notice of the steam ends of Pumps.

_Pump Valves._ The valve apparatus is perhaps the most important part
of any form of pump and its design has a material bearing upon its
efficiency.

[Illustration: FIG. 184.]

[Illustration: FIG. 185.]

The valves shown in Fig. 181 are carried by two plates or decks, the
suction valves being attached to the lower plate and the delivery
valves to the upper one. The upper deck, and sometimes both decks,
are removable. The valves are secured to the plates by means of bolts
or long machine screws, which, in turn, are screwed into the bridge
across the board in the plate, as shown in Figs. 185 and 186 or capped
as in Fig. 187. The valves in all pumps except the large sizes, which
may properly be classed with pumping engines, are of _the flat rubber
disc type_, with a hole in the center to enable the valve to rise
easily on the bolt, the latter serving as a guide. _A conical spring_
is employed to hold the valve firmly to its seat, the spring being held
in position by the head of the bolt, or cap, as shown.

Certain improvements in pump-valves have been made which tend to
increase the durability and to prevent the liability of sticking, which
is not an uncommon occurrence after the valves have become badly worn.
The improved forms of pump valves are shown in Figs. 186 and 187.

[Illustration: FIG. 186.]

[Illustration: FIG. 187.]

When these valves leak through wear the disc may be reversed, using
the upper side of the disc next to the valve seat. This can be done
with ordinary valves also, provided the spring has not injured the
upper surface of the disc. Valve seats are generally pressed into the
plates, although instances may be found where they are screwed. When
pressed in they may be withdrawn by substituting a bolt having longer
screw threads than the regular bolt, and provided with a nut, as shown
in Fig. 188. The bolt is slipped through a yoke and screwed into the
bridge. By turning the nut the seat can generally be started without
difficulty.

[Illustration: FIG. 188.]

Fig. 189 represents the customary _gland and stuffing-box_ in which
the gland is adjusted by the nuts C and D upon two studs. After the
adjustment has been properly made lock-nuts are tightened which leaves
the gland free yet preserves the alignment.

It has been proven by practice—after long and costly experiments—that
a number of small valves instead of one large one are far the most
durable; _durability_ being the question. Corliss, Leavitt, Holly and
other leading pump builders had occasion to find the truth of this
statement early in their careers. The “slamming” of large valves under
moderate speeds proved itself an almost insurmountable difficulty until
the principle of keeping the valve area as low as possible within
reasonable limits had been fully demonstrated.

[Illustration: FIG. 189.]

To illustrate the advantage of having a number of comparatively small
valves instead of one large one, suppose a pump to be fitted with four
3-1/2-inch delivery valves at each end, the valves covering ports 2-1/2
inches in diameter. The area of each port is 4·9 square inches. In
order to provide an equal area between the valve and the seat the valve
must rise a distance equal to one-fourth the diameter of the port.

The combined area of the four ports is 19·6 square inches, which
corresponds to the area of a circular opening 5 inches in diameter,
one-fourth of which is 1-1/4 inches. It will be understood that the
smaller valves can seat much more quickly and with less jar than the
larger one, hence a larger number of small valves is not only better
because of the great reduction in slippage, but they are also more
economical, being subjected to less wear and tear.

_The lift of valves_ for moderate or low speed pumps is seen in Fig.
190 and those for higher speeds in Fig. 191. These engravings clearly
show the relative position of the suction and discharge valves during
the movements of the piston.

[Illustration: FIG. 190.]

[Illustration: FIG. 191.]

_Pump slip_ or slippage is a term used to denote the difference between
the calculated and the actual discharge of a pump, and is generally
expressed as a percentage of the calculated discharge. Thus, when the
slippage is given as 15 per cent. it indicates that the loss due to
slip amounts to 15 per cent. of the calculated discharge. Slippage
is due to two causes, the time required for the suction and discharge
valves to seat.

When pumps run very fast the piston speed is so high that the water
cannot enter the pump fast enough to completely fill the cylinder and
consequently a partial cylinder full of water is delivered at each
stroke. _High speeds also increase slippage_, due to the _seating of
the valves_. Fig. 191 represents a sectional view of the water end of a
pump, showing the position of the valves during a quick reversal in the
direction of the arrows, which illustrates the position of the valves
corresponding to high speed. The valves in a pump, like almost every
other detail in the operation of machinery, do not act instantaneously,
but require time to reach the seats.

When pumps run at high speed the piston will move a considerable
distance, while the valves are descending to their seats, and water
flows back into the pump cylinder until the valves are tightly closed.
The valves will remain in the raised position shown in Fig. 191 until
the piston stops at the end of the stroke, and under high speed the
piston will reach the position on the return stroke indicated by the
dotted line _L_ by the time the valves are closed. The cylinder will be
filled up to this point with water from the delivery chamber so that no
vacuum can be formed until after the piston reaches this position. The
volume of water that can be drawn into the cylinder must necessarily
be represented by the cubic inches cf space, minus the quantity which
flows back during the time the valves are closing. It will thus be seen
that the actual volume of water discharged is considerably less than
a cylinderful, and the difference, whatever it may prove to be, is
called, and is due to slippage.

[Illustration: FIG. 192.]

Fig. 190 represents the same pump running at a comparatively low speed.
It will be noticed that the valves have not been raised as high as in
Fig. 191, because a longer time being allowed for the discharge of the
water, a smaller orifice is sufficient. It will be seen also that the
piston, moving at a lower velocity, cannot travel as far in Fig. 190
before the valves seat, and consequently a vacuum can be created in
the cylinder earlier in the stroke, and a larger volume of water can
therefore be drawn in during the return stroke. In the latter case it
is evident that the volume of water drawn into the cylinder will be
nearly equal to a cylinderful and consequently the loss by slippage
must be correspondingly less.

In order to reduce the loss by slippage several valves are used instead
of a single valve of equal area. A flat disc valve will rise a distance
equal to one-fourth the diameter of the port or of the opening in the
seat to discharge the same volume of water that can flow through the
port in the same time. In practice the rise exceeds this proportion of
one-fourth a trifle, owing to the friction of the water, and this is
especially true at high speeds.

[Illustration: FIG. 193.]

_Reinforced pump valves._ Where pure gum has been used for pump valves
it has always proved too soft and when it has been compounded with
other substances it has been found too hard to withstand the severe
duty to which it is subjected as a material for pump valves.

In the accompanying Fig. 192 is shown the Braden pump valve, which is
made of _composition of rubber having wire rings embedded in the center
of the disc_. The composition has been removed from a section to show
these rings. A ferrule of composition metal forms a hub around the
center through which the bolt or stud passes to guide the valve and to
prevent excessive wear of the hole.

Its wire coil frame work clothed with rubber maintains a due amount
of stiffness, with a degree of flexibility which prevents its bulging
into the holes in the seats, or sticking therein, and thus impairing
the suction and discharge. Both sides, the upper as well as the lower,
are made available for service. These qualities of stiffness and
flexibility combined, permit this valve to adjust itself to form a
water-tight seat.

[Illustration: FIGS. 194, 195, 198.]

[Illustration: FIGS. 196, 197.]

_Armored pump valves._ As represented in Fig. 193 this is a valve
made by stamping a metal disc out of steel which is then plated with
copper to protect the surface and secure the adhesion of the rubber.
Marginal notches are left on the inside and outside edges of the plate
and rubber is moulded around these, and vulcanized to the required
hardness; a brass or copper plate may be used instead of steel and the
plates may be corrugated radially to increase their stiffness when the
area of the valve is large.

Experience proves that the water valve adopted together with its
location, has a material bearing upon the efficiency of any pump;
easy seating valves are subject to more or less slippage, owing to
tardy seating; the location of water valves should be above the pump
cylinder, inasmuch as in operation the pump is always primed, while if
suction valves are placed below, any wear on the valves or valve seats,
or obstruction under the valves, will cause the water to leak entirely
out of the water cylinder, making it necessary to prime the pump before
it can be started.

  NOTE.—The screwed seat is shown in Fig. 194, Stud Fig. 195, Metal
  Valve Fig. 196, Spring Fig. 197, and all put together in Fig. 198.

[Illustration: FIG. 199.]

_Valve seats, bolts and springs_ should be of the best composition
or gun-metal; and valves of composition, or hard or soft rubber, to
suit the duty such pump is required to perform. These valve seats
are screwed into the valve plate, and valves may be changed from
composition to rubber by merely removing bolt, and substituting one for
the other without removing the seat. This is of great advantage where
a pump is to be used for hot water after being used for cold water.
[Illustration: FIG. 200.]

[Illustration: FIG. 201.]

_Air chambers_ are placed upon the top of a pump, see Figs. 199 and
200, and contain air for the purpose of introducing an _air cushion_
to counteract the solidity of the water, thus preventing shocks as the
water flows through the valves; and also for the purpose of securing a
steady discharge of water.

The water being under pressure in the discharge chamber, compresses the
air in the air chamber during each stroke of the water piston and, when
the piston stops momentarily at the end of the stroke, the air expands
to a certain extent and tends to produce a gradual stopping of the flow
of water, thus permitting the valves _to seat easily and without shock
or jar_.

_The capacity of the air chamber_ varies in different makes of pumps
from 2 to 3-1/2 times the volume of the water cylinder in single
cylinder pumps, and from 1 to 2-1/2 times the volume of the water
cylinder in the duplex type. _The volume of the water cylinder is
represented by the area of the water piston multiplied by the length of
stroke._

For single-cylinder, boiler-feed pumps and those employed for elevator
and similar service the volume of the air chamber should be 3 times the
volume of the water cylinder, and for duplex pumps, not less than twice
the volume of the water cylinder. High speed pumps, such as fire pumps,
should be provided with air chambers containing from 5 to 6 times the
volume of the water cylinder.

The diameter of the neck should not exceed one-third the diameter of
the chamber. When the pumps work under pressure exceeding 85 or 90
pounds per square inch, it is frequently found that the air gradually
disappears from the air chamber, the air passing off with the water
by absorption. In this case air should be supplied to the air chamber
unless the pump runs at very low speeds, say, from 10 to 20 strokes
for the smaller sizes and from 3 to 5 strokes per minute for pumping
engines. At higher speed and with no air in the air chamber the valves
are apt to seat heavily and cause more or less jar and noise, and the
flow of water will not be uniform. The water level in the air chamber
should be kept down to from one-fourth to one-third the height of the
air chamber for smooth running at medium and high speeds.

  NOTE.—In large pumping plants small air pumps are employed for
  keeping the air chambers properly charged. In smaller plants an
  ordinary bicycle pump and a piece of rubber tubing are used to good
  advantage.

_Vacuum chambers_ are shown in Figs. 199, 200 and 201. These devices
are attached to the suction pipe. When the column of water in the
suction pipe of a pump is once set in motion, it is quite important,
especially under high speeds, to keep the water in full motion,
and when it is stopped, to stop it gradually and easily. This is
accomplished by placing a vacuum chamber on the suction pipe, as shown
in the figures.

The location of the vacuum chamber may be varied to suit the
convenience of the engine room arrangements. Fig. 199 represents the
vacuum chamber at the side of the pump, Fig. 200 shows it opposite the
suction and Fig. 201 represents its position at the end of the pump.

[Illustration: FIG. 202.]

[Illustration: FIG. 203.]

_Vacuum chambers_ are practically of two designs, as shown in Figs. 202
and 203. The one shown in Fig. 203 should be placed in such position as
to receive the impact of the column of water in the suction pipe. In
order to do this effectively it should be placed in the position shown
in Figs. 199, 200 or 201. The chamber illustrated in Fig. 202 is placed
in the suction pipe below, but close to the pump.

_The action of the vacuum chamber is practically the reverse of that
of the air chamber._ The object of the vacuum chamber is to facilitate
changing continuous into intermittent motion. The moving column of
water compresses the air in the vacuum chamber at the ends of the
stroke of the piston, and when the piston starts the air expands (thus
creating a partial vacuum above the water) and aids the piston in
setting the column of water in motion again.

Thus the flow of water into the suction chamber of the pump is much
more uniform during each stroke of the piston than without the vacuum
chamber, and consequently the pump can be run at higher speeds without
increasing the loss due to slippage and without “slamming” of the
valves. Vacuum chambers should be slightly larger than the suction pipe
and of considerable length rather than of large diameter and short. The
size of the neck is substantially the same as in the air chamber.

[Illustration: FIG. 204.]


PIPING A PUMP.

Fig. 204 on the opposite page represents the pipe connections, etc.,
of a pump with the delivery opening on the opposite side. D represents
the _foot valve and strainer_ placed on the lower end of the suction,
which should be not less than a foot from the bottom of the well;
the distance named provides for the gradual filling of the well. C
is the _suction pipe_ proper, screwed into _the elbow_, E, which
changes its direction into the suction chamber, which contains _the
strainer_, A. This strainer can be removed for cleaning by lifting _the
bonnet_ secured by stud bolts on top. In connecting large pumps it is
customary to attach a vacuum chamber, F, which in the absence of any
regular pattern, may be made of a piece of pipe of the same diameter
as the suction and screwed into a ^T^, instead of the elbow, E, with a
regulation screwed cap on top as shown in the dotted lines.

A _priming pipe_ is shown by the letter J, often used to fill the pump
on starting. The _discharge pipe_ connection is shown at G with the
_air chamber attached_.

This figure is introduced for the purpose of showing an approved method
of piping a pump. It may be observed that the flange joints in this
design are so arranged that they may be disconnected without unscrewing
any part of the suction pipe; this feature is almost essential in view
of needed repairs.

The foregoing description of the parts of a pump relate to the water
end solely; there remain the more complex and widely differing parts
of the steam-end which constitute the distinguishing characteristics
of the pumps built by the different makers. There remain also the
particular parts belonging to the large pumping engines, air-pumps, etc.

These will be described under their respective chapters with much
added and essential matter. Particular details as to the conditions of
service under which it is proposed to operate pumps are to be found on
the next page.


CONDITIONS OF SERVICE REQUIRED OF A PUMP.

It is especially important that the makers and also the sellers of
pumps and pumping machinery should be informed regarding the proper
type, size, pattern and _proportion of parts_ for any peculiar service,
as well as to the plan of their connections and the kind of material to
be used in their construction.

This information regarding the conditions of the service under which
the pump is to be worked is quite pertinent to the foregoing pages
regarding the parts of pumps. The following questions are extracted
from the catalogue of an extensive manufacturer.

_First_—To what service is it to be applied?

_Second_—The quality of the liquid to be pumped, whether salt, fresh,
acid, clear or gritty, and whether cold or hot?

_Third_—To what _height_ is the water to be lifted by _suction_, and
what are the length and diameter of the suction and discharge pipes?

_Fourth_—Of what material is the suction pipe, and what is its general
arrangement as regards other pipes leading into it, etc.?

_Fifth_—Will the supply be taken from a driven well? If not, from what
source?

_Sixth_—To what height, or against what pressure, is the water to be
pumped?

_Seventh_—What is the greatest quantity of water to be delivered per
hour?

_Eighth_—What boiler pressure of steam is carried?

_Ninth_—Will the pump exhaust into the atmosphere, into a condenser, or
against a back pressure? If the latter, how much?


BELTED PUMPS.

[Illustration: FIG. 205.]

Fig. 205 represents an approved form of steam boiler feed pump, single
acting. It has a crank shaft and a tight and loose pulley. It may be
driven direct from any line shaft, a countershaft being unnecessary.

This is a compact form of a boiler feed pump; formerly the pump crank
shaft was attached to floor beams or timbers above and connected by a
long pitman to the pump which stood upon the floor; the objections to
the older system of apparatus were found to be the vibration of the
long pitman and the springing of the floors.

To obviate these two difficulties the pump and countershaft were
attached to a post bringing them nearer together but finally resulting
in the design of pump here shown. The broad base insures great
stability in the operation of the pump especially when fixed to a rigid
floor or timber foundation.

In the Table below are given some details furnished by the makers
relating to six sizes of this style of pump, to which may be added that
_the speed_ ordinarily used varies from 100 revolutions per minute for
the small sizes, to 20 revolutions for the larger sizes.

  TABLE.

  ===+=========+===============+================+=======+========
  No.| Size    |Suction fitted |Discharge fitted|Stroke.|Size
     |piston.  |     for.      |      for.      |       |pulleys,
     |         |               |                |       |in.
  ---+---------+---------------+----------------+-------+--------
   1 |2     in.| 1     in. pipe| 1     in. pipe | 3 in. |16 × 4
   2 |2-1/2  „ | 1      „   „  | 1      „   „   | 3  „  |16 × 4
   3 |3      „ | 1-1/4  „   „  | 1-1/4  „   „   | 3  „  |16 × 4
   4 |2      „ | 1-1/4  „   „  | 1-1/4  „   „   | 6  „  |18 × 4
   5 |2-1/2  „ | 1-1/4  „   „  | 1-1/4  „   „   | 6  „  |18 × 4
   6 |3      „ | 1-1/2  „   „  | 1-1/2  „   „   | 6  „  |18 × 4
  ---+---------+---------------+----------------+-------+--------

[Illustration: FIG. 206.]

Fig. 206 exhibits two independent pumps. The description of the pump
shown in Fig. 205 will apply to the left-hand pump which is _a boiler
feed pump_. The improvement consists in the addition of another pump at
the right-hand side; this is a _suction force pump with an air chamber_
and is used to draw water from a well and discharge it into a tank from
which it is taken by the other pump and forced into the boiler, as
occasion requires.

These two pumps work simultaneously, being driven from the same shaft
with cranks set opposite each other. Like the pump previously described
this has a tight and loose pulley. The larger sizes are geared, having
a pinion on the pulley shaft and a spur wheel on the crank shaft.

These two pumps represent a high service and a low service, the
left-hand pump working under high pressure, against that in the boiler
and the right one against the head of water in the tank. Each pump
has its own separate connections—one or more—to suit the required
conditions.

The right-hand pump is double acting; the plunger-rod is guided by a
steadiment which holds it in line and preserves this alignment and the
power is transmitted through a forked connecting rod. The Table below
refers to both these pumps.


  TABLE.

  ===============================+=============================
            BOILER PUMP.         |   DBLE.-ACTING FORCE PUMP.
  ---------+-----------+---------+-------+-----------+---------
   Diam.   | Suc. and  | Gal. per| Diam. | Suc. and  | Gal. per
    cyl.   |   dis.    |  stroke |  cyl. |    dis.   |  rev.
  ---------+-----------+---------+-------+-----------+---------
  2-1/2 in.| 1-1/4 in. |   1—8   |  3 in.|  1-1/2 in.|  2—5
  2-1/2  „ | 1-1/4  „  |   1—8   |  4  „ |  2      „ |  4—5
  ---------+-----------+---------+-------+-----------+---------


In Fig. 207 is shown a double acting power pump used principally for
feeding boilers but may be employed for any purpose in forcing water
or other liquids against pressure. This pump is double acting, is made
with four _check valves_, as shown in engraving, and will draw water
through 25 feet of suction pipe. On a high lift like the foregoing a
foot valve (as shown at D in Fig. 204) should be used.

[Illustration: FIG. 207.]

The form of valves used in this type of pump are the regular commercial
check valves, made of steam-metal, extra heavy; the valve proper is of
the _wing_ pattern as shown in the small cuts. There are four of these
wings on each valve, at right angles to one another forming a cross
with arms of equal lengths.

[Illustration: STRAIGHT WINGS.]

[Illustration: SPIRAL WINGS.]

The seat of the valve has an angle of 45° to which the valve is
adjusted. A part of this valve projects above the top and has a slot,
shown by the dotted line in it to receive the edge of a screw-driver,
held in a bit stock to grind the valve seat in refitting. The lift of
the valve is regulated by the distance between the top of the stem and
the bottom of the covering nut or cap.

In hydraulic pumps it is found to be good practice to give the wings of
these valves a twist, or pitch, so that the water in passing through
will cause the valve to rotate and fall in a new position every time it
comes in contact with the seat.

Fig. 208 represents a very compact design of _double acting low service
belt driven pump_. The water cylinder is bored and has a piston fitted
to it; both ends of this cylinder are covered with “heads,” one of
which has a stuffing box through which the piston operates; the outer
end of this piston rod is fitted to a slotted yoke which slides upon a
guide at the bottom.

This mechanism, just described, takes the place of a pitman connection
and occupies very much less space. The crank shaft is supported at each
end in pillow blocks and is driven by a belt having a tight and loose
pulley; larger sizes are geared. Access to the two sets of valves can
be had by slacking up four nuts upon the long belts, two of which are
shown in the engraving. The broad base secures great stability for this
size pump.

[Illustration: FIG. 208.]

[Illustration: FIG. 209.]

[Illustration: FIG. 210.]

Fig. 209 exhibits two _single acting plunger pumps_ actuated by one
shaft having a crank upon each end with crank pins opposite to one
another. This shaft is supported on the top of two pillars which form
a part of the solid cast iron frame. The boxes are babbited. The crank
shaft has a cast iron spur gear keyed to it and meshes into a pinion
upon the pulley shaft. The teeth are cut to insure smooth and quiet
running. The power is transmitted through a belt upon a tight and loose
pulley. Each pump is secured to the frame by four bolts. The lower
end of the pitman has an arrangement to take up the wear by means of
two set screws with lock-nuts as shown in the figure on the top of
each plunger. This pump is largely used as a boiler feed pump. These
pumps can be used separately or together and with single or compound
connections.

_Duplex Power Pump._ This engraving, Fig. 210, shows a special
boiler feed pump having ball valves, as shown in section, and which
is also intended for use in pulp mills and in other places where it
is necessary to pump sandy or muddy water, or chemicals, soap and
other heavy bodied liquids. These pumps have composition ball valves,
composition plungers and composition lined cylinders and glands.

The two barrels or cylinders of this pump are brought together so as to
occupy as little space as possible. Instead of cranks eccentrics are
used having very large wearing surfaces. Each pitman has a ball at its
lower extremity forming a “ball and socket” joint, which is adjustable
to compensate for wear. All the bearings are Babbitted and like the
last pump described the gears have cut teeth. It is belt driven.

_If there are two cranks as in the duplex power pump_ they are placed
opposite to one another or 180° apart, the circle described by the
crank-pin containing 360 degrees. _In the triplex pump_ this circle is
divided into three equal parts of 120° each which is represented by the
position of the cranks; _a quadruplex_ or two duplex pumps attached to
the same shaft the cranks will be 90° apart. This arrangement effects a
uniform distribution of load on the crank shaft and one of the pumps is
continuously discharging at its maximum capacity.

This duplex _power_ pump should not be confounded with the “Duplex
Pump” so called. The latter has two steam cylinders and two water
cylinders and is double acting while the former is single acting.

The successful operation and durability of these, as of all power
pumps, depends largely upon the judicious selection and application
of a proper _packing to the stuffing boxes_. As for example, plaited
flax dipped in a mixture of warm graphite and tallow, braided rawhide,
Selden’s packing, etc., have proved by long service to have a _low
co-efficient of friction_ and are not liable to cut the plungers.

_The triplex power gang pump_ is shown in Fig. 211. The engraving
represents two triplex pumps bolted to one bed, and having an extended
pulley shaft with pinions near each end to drive all of the pumps.

[Illustration: FIG. 211.]

  TABLE.

  ===========+========+========+========+========+========
     No.     |    1   |    2   |    3   |    4   |   5
  -----------+--------+--------+--------+--------+--------
   Size of   |        |        |        |        |
   Plunger   |  2-1/4 |  3     |  4-1/2 |  6     |  8
  in inches  |        |        |        |        |
  -----------+--------+--------+--------+--------+--------
  Length of  |        |        |        |        |
   Stroke    |  2-3/4 |  3-1/4 |  4-3/4 |  6-1/2 |  8-1/2
  in Inches  |        |        |        |        |
  -----------+--------+--------+--------+--------+--------
  Gallons    |        |        |        |        |
  per Stroke |   .28  |   .58  |   1.96 |   4·76 |  11.08
  or 1 Rev.  |        |        |        |        |
  -----------+--------+--------+--------+--------+--------
  Revolutions|        |        |        |        |
     per     |20 to 50|10 to 40|10 to 40|10 to 30|10 to 25
   Minute    |        |        |        |        |
  -----------+--------+--------+--------+--------+--------
  Size of    |        |        |        |        |
  Suction    |  1-1/4 |  1-1/2 |  2-1/2 |   4    |   5
  in Inches  |        |        |        |        |
  -----------+--------+--------+--------+--------+--------
  Size of    |        |        |        |        |
  Discharge  |  1-1/4 |  1-1/2 |   2    |  3-1/2 |   4
  in Inches  |        |        |        |        |
  -----------+--------+--------+--------+--------+--------
  Size of    |         ACCORDING TO DUTY REQUIRED
  Pulleys    |
  -----------+--------+--------+--------+--------+--------
  Geared     | { *16 }| { *16 }| { *13 }| { *20 }| { *20 }
             | { 72# }| { 80# }| { 71# }| { 89# }| { 80# }
  -----------+--------+--------+--------+--------+--------
  Pressure   |   175  |   175  |   170  |   165  |   160
  Pounds     |        |        |        |        |
  -----------+--------+--------+--------+--------+--------

  * Teeth in Pinion.      # Teeth in Spur Gear.

The description of the duplex power pump just given, applies to this
type also. The exception is that _the triplex has three plungers and
barrels_ instead of two. There are two spur wheels and two pinions
on each pump to equalize the power to better advantage, as by this
arrangement one eccentric is placed between each pair of spur wheels
and two eccentrics outside. The pinion shaft is in one piece having
tight and loose pulleys.

[Illustration: FIG. 212.]

_The eccentrics_—six in number—are set at 60°, and an even strain on
the belt at all points of the stroke is thus obtained, and connecting
both discharges together insures a steady flow without shock. Where
light duty only is required, these pumps are made without gears to run
with the belt over pulleys.

Fig. 212 represents _a single acting triplex plunger pump_ actuated by
a belt over a tight and loose pulley.

The principal characteristic of this pump is the long connecting rods.
These have at their upper ends regular connecting rod straps with
brasses fitted to them and adjusted by wedges and set screws. At the
plunger or lower ends of these rods bronze bushings and steel pins are
used.

These pumps are largely employed for pumping semi-liquids such as tar,
soap, mud, tan-liquor, oils, chemicals, sewage, etc.

The teeth of the pinion and the meshing part of the two gears are
protected by _a shield_ to prevent clothing being caught or parts of
the body from being injured.

For these various materials different valves are necessary to be used
each suited to the substance to be elevated or conveyed.

The removal of one cover, in this pump, exposes all the discharge
valves and a plate uncovers each of the three groups of suction valves,
as shown. The suction pipe may be attached at either end of the suction
chamber while the discharge pipe may be connected with one or both ends
of the discharge chamber.

The pump here represented has barrels 8-inch in diameter by 10-inch
stroke. The air chamber is very large in proportion to the pump.

  TABLE.

  ===============+=============+==================+======+==========
     PLUNGERS    |Capacity one |  SIZES OF PIPE   |      |  Tight
  ---------------+Revolution of+--------+---------+Geared|and Loose
  Diameter Stroke| Crank Shaft |Suction |Discharge|      |  Pulleys
  ---------------+-------------+--------+---------+------+----------
    4 in.   4 in.|  0·65 gals. | 3 in.  |   3 in. |5 to 1|20 × 3 in.
    4 „     6 „  |  1·     „   | 3 „    |   3 „   |5 to 1|20 × 3 „
    5 „     6 „  |  1·5    „   | 4 „    |   4 „   |4 to 1|20 × 4 „
    5 „     8 „  |  2·     „   | 4 „    |   4 „   |4 to 1|20 × 4 „
    7 „     8 „  |  4·     „   | 5 „    |   5 „   |4 to 1|30 × 5 „
    8 „    10 „  |  6·5    „   | 6 „    |   6 „   |5 to 1|36 × 6 „
    8 „    12 „  |  7·8    „   | 6 „    |   6 „   |5 to 1|36 × 6 „
  ---------------+-------------+--------+---------+------+----------


_The Deane single acting triplex power pump_ is shown in Fig. 213.
Pumps of this type are used for general service in places where a large
quantity of water is to be obtained in a short time and delivered under
high pressure; they are adapted for tank service, water works, boiler
feed, etc.

[Illustration: FIG. 213.]

The pillar, or column design of frame is employed in this pump which
secures great strength with the least weight of material, and at
the same time is accessible for adjustment or repairs. The bearings
for both the steel shafts are unusually long, which reduces the
pressure per square inch below the factor of safety and increases the
durability. The crankpins are set 120 degrees with one another so that
the strokes successively overlap, which promotes an easy flow of water
through the delivery pipe. The crank shaft is of the composite design,
the center crank pin is of equal diameter and forming a part of the
shaft, with discs and crank pins attached to each end by shrinking fits
and keys. Either disc, crank, or their crank pins, can be duplicated
without sacrificing any other part, which in itself is a great
advantage.

The connecting rods have solid ends with adjustable boxes, with
adjustment by means of wedge and screws. The brasses are lined with a
special anti-friction metal bored to exact size.

The crossheads are of the box design with adjustable shoes having large
wearing surfaces in bored guides. These guides are secured to the frame
by studs and nuts.

The plungers are outside packed, the cylinders are submerged, thus
keeping the pump primed at all times. The plungers are bolted to the
crossheads and are readily removed when necessary. The cylinders are
single acting and are cast separate from the base and other parts
of the machine, so that repairs can be made at small cost, and,
furthermore, should it be desirable to use the pump for moving liquids
which would be injurious to cast iron, cylinders of other metals are
substituted. The water chest is cast separate from the cylinders and is
provided with large handholes, affording easy access to the interior
and to the valves for inspection and cleaning. The handholes are
located so that one valve may be removed independent of the others.

Improved grease cups are placed on all the bearings. This pump is very
popular with the users of power driven pumps and is generally selected
for high pressures and for hot or gritty water. Its simplicity of
design and construction, together with the convenient arrangement of
working parts, renders it desirable in isolated places where little
attention is given to any kind of pumps.

[Illustration: FIG. 214.]

Fig. 214 represents the Gould triplex single acting power pump and is
one of many designs of this class of power pumps. The frame consists of
two standards, which contain the two end cylinders, and the seats to
which the outside crosshead guides are bolted. These are held together
by two castings, one containing the center crosshead guide, and the
other the center cylinder. The crankshaft is a solid steel forging,
while the bearings are of phosphor bronze, and the pinion shaft
bearings Babbitted.

The gear wheels are machine cut, the pinion and the adjacent teeth of
the large gear are covered by suitable guards.

The crossheads are provided with adjustable shoes or gibs, which work
in bored guides. The connecting rods are fitted with straps and bronze
boxes, which are adjustable for wear by means of wedge and set screws,
the wristpin brasses being of the marine type. The cylinders are
provided with bronze liners, which are readily removable when necessary
for repairs, the plungers being ground to size, present a smooth
polished surface to resist the wear.

The valve boxes are separate castings, and each contains a set of
suction and discharge valves. These valves are rubber discs, held
firmly against the bronze seats by cylindrically wound springs. All
of these pumps are furnished with air chambers, and vacuum chambers
are provided when the nature of the service demands it. All valves and
other working parts of the pump are accessible for inspection, cleaning
and repairs, all internal parts being arranged within easy reach
through the large handholes.

The pumps here shown are intended for moderately light pressures as for
example not to exceed 150 lbs. per square inch, but they are also made
in heavier proportions for very high pressures (5,000 lbs. to 15,000
lbs.) such as is necessary to operate hydraulic presses, draw benches
for brass and copper tubing and that class of work.

A very simple automatic regulator and by-pass connection (shown in the
chapter on accessories) can be attached to these pumps in situations
where a constant pressure is to be maintained and allow the pump to run
continuously at its maximum speed. This regulator is adjusted to open
the by-pass valve whenever the pressure in the compression tank or pipe
system exceeds the limit pressure, and so fills the office of a safety
valve by allowing the surplus water to return to the tank.

_The Riedler belt driven pump_ is shown in Fig. 215.

The principal feature of this pump is its valve; there is but one valve
for the suction and one for the discharge, which greatly simplifies
the pump end. When working against high pressures, the ordinary rubber
or leather faced valves are oftentimes pounded to pieces, but in this
pump, on account of the mechanical control, the valves work well under
all pressures.

[Illustration: FIG. 215.]

This valve and valve seat are circular in form, and made of bronze, as
shown in Fig. 216. The valve has a lift of from 1 to 2 inches, and an
area sufficiently large to reduce the velocity of the water flowing
through it to a few feet per second.

At the beginning of the stroke the valve opens automatically,
controlled, however, by a very simple and effective mechanical device,
and it remains open practically during the entire stroke. When near the
end, it is positively closed at the proper moment by the controller.

This valve, see Fig. 216, may be briefly described as follows. The
seat, A, is turned to slip into its place in the pump and is made tight
by a round rubber hydraulic packing, B, in a groove near the bottom.
A spindle or stud, C, in the center of this seat supports and guides
the valve, D, which is made tight by a leather seal, E. The rubber
collar or buffer spring holds the valve above its seat, and this valve
unlike ordinary pump valves, always remains open except when pressure
is brought to bear to close it. The valve bonnet, G, also forms the
bearing for the valve stem with fork, which spans the spindle, C, at
one end and having the valve lever and pin, H, for operating at the
other end. The valve stem is made tight by a stuffing-box and gland as
shown. The operation of this valve is substantially as follows.

[Illustration: FIG. 216.]

At the beginning of the suction stroke the valve is opened by the
rubber spring, F, the pressure upon the collar being relieved by
lifting of the valve fork arms through motion of the eccentric.

It will be observed from an inspection of Fig. 215 that both
the suction valve and the discharge valve are controlled by an
eccentric—rock arm—and valve levers similar to the motion of _Corliss_
valves.

As the plunger nears the end of its stroke and before it starts on the
return stroke, the valve fork closes the valve, and thus prevents slip
and avoids pounding, so common in pumps having valves that close by
their own weight. In case of any obstruction between the valve and its
seat the rubber buffer spring will be compressed thus preventing all
injury to mechanism.

The lost work expended in closing the valves is hardly worth any
consideration as it is practically the friction only of the eccentric
and the members of the valve gearing, the bearings of which are all
small.

The motion for these valve gears is usually taken from an eccentric on
the main shaft.

The standard speed of the Riedler pumps is about 150 revolutions per
minute. Smaller pumps run even faster than this.

It may be desired to connect a pump directly to a high speed electric
motor or water wheel already installed. To meet these conditions, a
special design known as the Riedler Express pump, is built.

The chief feature of this pump, is its suction valve. This valve is
concentric with, and outside of the plunger, and lifts in the opposite
direction to that of the plunger when on its suction stroke. At the end
of the suction stroke, the plunger presses the valve to its seat, thus
making it certain that the valve is seated when the plunger starts on
its delivery stroke, allowing practically no slip. A high air suction
chamber containing a column of water is placed immediately before the
suction valve, so it is certain that the pump will fill as the plunger
moves. Ordinarily the pump would not completely fill, owing to the high
speed of the plunger.

These pumps are also built with steam cylinders both of the plain slide
valve and Corliss designs.



  THE ELECTRIC
  PUMP

[Illustration: COMPASS NEEDLE—See PAGE 266.]



ELECTRICITY AND ELECTRICAL MACHINERY.


Each kind of power requires its own special machinery so constructed
and adapted as to utilize it; hence, to be serviceable to mankind,
electricity demands machinery suited to its nature; what that is, will
be indicated in the following few paragraphs.

Electricity is a name derived from the Greek word _electron_—amber. It
was discovered more than 2,000 years ago that amber when rubbed with a
Fox’s tail possessed the curious property of attracting light bodies.
It was discovered afterwards that this property could be produced in
a dry steam jet by friction, and in A. D. 1600 or thereabouts, that
glass, sealing-wax, etc., were also affected by rubbing, producing
electricity.

Whatever electricity is, it is impossible to say, but for the present
it is convenient to consider it as a kind of invisible something which
pervades all bodies. While the nature and source of electricity are a
mystery, and a constant challenge to the inquirer, many things about
it have become known—thus, it is positively assured that electricity
never manifests itself except when there is some mechanical disturbance
in ordinary matter, and every exhibition of electricity in any of its
multitudinous ways may always be traced back to a mass of matter.

  NOTE.—The great forces of the world are invisible and impalpable; we
  cannot grasp or handle them; and though they are real enough, they
  have the appearance of being very unreal. Electricity and gravity are
  as subtle as they are mighty; they elude the eye and hand of the most
  skillful philosopher. In view of this, it is well for the average man
  not to try to fathom, too deeply, the science of either. To take the
  machines and appliances as they are “on the market,” and to acquire
  the skill to operate them, is the longest step toward the reason for
  doing it, and why the desired results follow.

Electricity, it is also conceded, is without weight, and, while
electricity is, without doubt, one and the same, it is for convenience
sometimes classified according to its motion, as—

  1. _Static electricity_, or electricity _at rest_.

  2. _Current electricity_, or electricity _in motion_.

  3. _Magnetism_, or electricity _in rotation_.

  4. _Electricity in vibration._

Other useful divisions are into—

  1. _Frictional_ and

  2. _Dynamical_,

And into—

  1. _Static_, as the opposite of

  2. _Dynamic electricity._

There are still other definitions or divisions which are in every-day
use, such as “vitreous” electricity, “atmospheric” electricity,
“resinous” electricity, etc.

_Static Electricity._—This is a term employed to define electricity
produced by friction. It is properly employed in the sense of a static
charge which shows itself by the attraction or repulsion between
charged bodies. When static electricity is discharged, it causes more
or less of a current, which shows itself by the passage of sparks or a
brush discharge; by a peculiar prickling sensation; by an unusual smell
due to its chemical effects; by heating the air or other substances in
its path; and sometimes in other ways.

_Current Electricity._—This may be defined as the quantity of
electricity which passes through a conductor in a given time—or,
electricity in the act of being discharged, or electricity in motion.

An electric current manifests itself by heating the wire or conductor,
by causing a magnetic field around the conductor and by causing
chemical changes in a liquid through which it may pass.

  NOTE.—_Statics_ is that branch of mechanics which treats of the
  forces which keep bodies at rest or in equilibrium. _Dynamics_ treats
  of bodies in motion. Hence static electricity is electricity at rest.
  The earth’s great store of electricity is at rest or in equilibrium.

_Radiated electricity_ is electricity in vibration. Where the current
oscillates or vibrates back and forth with extreme rapidity, it takes
the form of waves which are similar to waves of light.

_Positive Electricity._—This term expresses the condition of the point
of an electrified body having the higher energy from which it flows to
a lower level. The sign which denotes this phase of electric excitement
is +; all electricity is either positive or,-, negative.

_Negative Electricity._—This is the reverse condition to the above and
is expressed by the sign or symbol-. These two terms are used in the
same sense as _hot_ and _cold_.

_Atmospheric electricity_ is the free electricity of the air which is
almost always present in the atmosphere. Its exact cause is unknown.
The phenomena of atmospheric electricity are of two kinds; there are
the well-known manifestations of thunderstorms; and there are the
phenomena of continual slight electrification in the air, best observed
when the weather is fine; the aurora constitutes a third branch of the
subject.

_Dynamic Electricity._—This term is used to define current electricity
to distinguish it from static electricity. This is the electricity
produced by the dynamo.

_Frictional electricity_ is that produced by the friction of one
substance against another.

_Resinous Electricity._—This is a term formerly used, in place of
negative electricity. The phrase originated in the well known fact that
a certain (negative) kind of electricity was produced by rubbing rosin.

_Vitreous electricity_ is a term, formerly used, to describe that kind
of electricity (positive) produced by rubbing glass.

_Magneto-electricity_ is electricity in the form of currents flowing
along wires; it is electricity derived from the motion of magnets—hence
the name.

_Voltaic Electricity._—This is electricity produced by the action of
the voltaic cell or battery.

_Electricity itself is the same thing, or phase of energy, by whatever
source it is produced_, and the foregoing definitions are given only as
a matter of convenience.


ELECTRO-MOTIVE FORCE.

The term is employed to denote that which moves or tends to move
electricity from one place to another. For brevity it is written E. M.
F.; it is the result of the difference of potential, and proportional
to it. Just as in water pipes, a difference of level produces a
pressure, and the pressure produces a flow so soon as the tap is
turned on, so difference of potential produces electro-motive force,
_and electro-motive force sets up a current so soon as a circuit is
completed for the electricity to flow through_. Electro-motive force,
therefore, may often be conveniently expressed as a difference of
potential, and _vice versa_; but the reader must not forget this
distinction.

In ordinary acceptance among engineers and practical working
electricians, electro-motive force is considered as pressure and it
is measured in units called volts. The usual standard for testing and
comparison is a special form voltaic cell, called the Clark cell. This
is made with great care and composed of pure chemicals.

The term _positive_ expresses the condition of the point having the
higher electric energy or pressure, and, _negative_, the lower relative
condition of the other point, and the current is forced through the
circuit by the (E. M. F.) electric pressure at the generator, just as a
current of steam is impelled through pipes by the generating pressure
at the steam-boiler.

Care must be taken not to confuse electro-motive force with electric
force or electric energy, when matter is moved by a magnet, we speak
rightly of magnetic force; when electricity moves matter, we may speak
of electric force. But, E. M. F. is quite a different thing, not
“force” at all, for it acts not on matter but on electricity, and tends
to move it.


THE DYNAMO, OR GENERATOR.

The word dynamo, meaning power, is one transferred from the Greek to
the English language, hence the primary meaning of the term signifying
the electric generator is, the electric power machine.

The word generator is derived from a word meaning birth giving,
hence also the dynamo is the machine generating or giving birth to
electricity.

[Illustration: FIG. 217.—See page 251.]

Again, the dynamo is a machine driven by power, generally steam or
water power, and _converting the mechanical energy expended in driving
it, into electrical energy of the current form_.

To summarize, the dynamo-electric generator or the dynamo-electric
machine, proper, consists of five principal parts, viz:

1. _The armature or revolving portion._

2. _The field magnets_, which produce the magnetic field in which the
armature turns.

3. _The pole-pieces._

4. _The commutator or collector._

5. _The collecting-brushes_ that rest on the commutator cylinder and
take off the current of electricity generated by the machine.

Fig. 218 shows a dynamo of the early Edison type—the names of the
principal parts are given in the note below, as well as those of the
other parts of the machine.

[Illustration: FIG. 218.]

_This is a two-pole machine_, direct current; the figure is introduced
to show the “parts” only—as this dynamo has been largely superseded by
others of the four pole type.

  NOTE.—A, Magnet yoke; B, Magnet and field piece; C, Pole piece;
  D, Zinc field piece; E, Armature; F, Commutator; I, Quadrant; JJ,
  Brushes; K, Adjusting handle for the brushes; L, Switch pivot; M,
  Pilot lamp receptacle; N, Negative lug; O, Switch lever; P, Positive
  lug; Q, Positive terminal; R, Negative terminal; S, Negative rod; T,
  Pole piece; UU, Bearings; X, Slides for belt tightener; VVV, Driving
  pulley; Y, Connecting blocks, one on each side of machine.

_An electric motor_ is a machine for converting electrical energy into
mechanical energy; in other words it produces mechanical power when
supplied with an electric current; a certain amount of energy must be
expended in driving it; the _intake_ of the machine is the term used
in defining the energy expended in driving it; the amount of power it
delivers to the machinery is denominated _its out-put_.

The difference between the out-put to the intake is the real
_efficiency_ of the machine; it is well known that the total efficiency
of _an electric distribution system_, which may include several
machines, usually ranges from 75 to 80 per cent., at full load, and
should not under ordinary circumstances fall off more than say 5 per
cent. at one-third to half load; the efficiency of motors varies
with their size, while a one horse-power motor will, perhaps, have
an efficiency of 60 per cent., a 100 horse-power may easily have an
efficiency of 90 per cent. and the larger sizes even more.

The general and growing application of electric power to the driving
of all kinds of machinery including pumps makes _the question of
motor driving one of the most important in the power field_. For
many purposes, a single speed is sufficient, but for others, it is
imperative that the speed should be variable; and for still others,
though not absolutely necessary, a speed adjustment is very desirable.

While the _direct-current motor_ has been in this field so long that
its properties are well known and its possibilities fully developed, in
the operation of motors located in the immediate neighborhood of the
generator the _alternating-current motor_ has marked advantages where a
large area of territory has to be covered and the conditions are nearly
uniform, that is to say—

Where the current has to be transmitted a long distance and the load is
approximately constant, the alternating system is preferred, as it can
be operated with small main lines or conductors. This effects a saving
in copper, over the direct system which requires larger conductors.
[Illustration: FIG. 219.]

[Illustration: FIG. 220.]

Fig. 217, on page 247, shows _a four-pole generator_ designed to run by
a belt or directly connected to an engine. The five parts named, as the
principal parts of a dynamo, are all shown in the figure. The machine
is arranged ready to be bolted to the floor.

Fig. 219 on the opposite page is the _armature_ which is made up of
coils of insulated wire, the free ends of which, see Fig. 220, are
united to the arms of the _commutator bars_. When the armature is
finished, as shown, the wire forms an unbroken circuit.

[Illustration: FIG. 221.]

Fig. 221 is intended to represent another form of armature, but the
principle upon which it operates, is the same, as the other shown. A
A, represents the wire coils of the armature, B, is the shaft with its
journals, C, is the commutator. All commutators both for generators and
for motor armatures are insulated by mica between the bars.

[Illustration: FIG. 222.]

Fig. 222 shows _a woven wire brush_. The brushes on the dynamo, page
247, are made of carbon.

[Illustration: FIG. 223.]

Fig. 223 shows an alternating _induction_ motor. Induction is a
property by virtue of which an electric current is transferred from one
conducting line to another _without any metallic connection_; it is
that influence by which a _strong current_ flowing through a conductor
controls or affects _a weaker current_ flowing through another
conductor in its immediate neighborhood,—the strong current remaining
unaffected.

[Illustration: FIG. 224.]

Fig. 224 exhibits the armature for the above alternator; it is
familiarly called a “squirrel cage armature” on account of its
resemblance to the wheel in a squirrel’s cage.

Its peculiar construction enables it to run without producing any
sparks; this feature renders it safe to run where there are explosive
gases which might be ignited by an electric spark. In the machine the
bearings are cast solid with the end shields, thus assuring perfect
alignment when properly turned. Another feature is the automatic self
adjusting bearings which are lubricated mechanically by rings resting
upon the shaft. These rings were formerly a failure, but by the use of
mineral oils are now a success.

This machine is one of the simplest designs of alternating motors, the
example, Fig. 223, is one developing one hundred horse-power.

[Illustration: FIG. 225.]

Fig. 225 shows a revolving _field_ with “spider.” In this construction
of generators or motors the field revolves in place of the armatures,
the first object of this design is to reduce the high rotative speed;
it is also claimed to have a better electrical efficiency.

The field spider consists of an extra heavy cast iron pulley which
is keyed to the shaft; the low speed at which it runs permits the
employment of bolts to secure the field coils and laminated pole
pieces to the rim of the spider, as shown in the engraving. With this
construction each individual pole piece can be removed and replaced
independent of the others.

_The laminated pole piece_, one of which is shown in detail in Figs.
226-229, takes its name from the fact that it is built up of a large
number of layers of soft sheet iron, which it has been demonstrated
give a better electrical efficiency than a solid iron. Soft iron is the
most magnetic of all metals and is better suited for pole pieces than
steel.

It should be understood that each individual pole piece is insulated
from the others as well as from the spider. The pieces of sheet iron
are stamped out—like washers and are cut apart and the ends united so
as to form a continuous coil, like a coil of wire and each coil is
isolated; mica is used between the layers.

[Illustration: FIGS. 226-229.]

Fig. 230 is designed to illustrate the front of a continuous current
two wire switchboard with circuit breakers; these are made up
usually of marble or slate so that they will not burn; the Insurance
Underwriters require a non-combustible material at this place, as well
as hangers, and insulators used for conductors.

_The Switches_ shown in the middle of the board, are enlarged in Fig.
232, and are used for closing the connections with the generators and
lines running to various parts of the field to be lighted or furnished
with power.

The switch handles are made usually of wood or hard rubber; the blades
are of copper. The connections are soldered into the sockets shown
upon the ends of the screws which project beyond the back of the
switch-board.

The upper row of figures as shown in Fig. 230 and enlarged in the
engraving, 231, are _circuit-breakers_. The use of these is analogous
to that of the safety-valve upon a steam boiler, so that when the
pressure in the circuit exceeds that at which it is set the “breaker”
opens the circuit and thus prevents damage.

[Illustration: FIG. 230.]

In this case, the main contact is formed by means of a laminated
brush while the final stroke is made on carbon, the motion of this
breaker is by means of a toggle-joint which so multiplies the power
applied that it does not require much of an effort to close it; this
device maintains the same speed in operating the breakers when the
circuit-breaker is tripped.

_A Rheostat_ is a device for controlling the amount of electricity in
a conductor—by the insertion of coils of wire in a box—which may be
successively switched in or out of the main circuit by means of a lever
and button-switch. The best place to install a rheostat is on a wall
or post, as the resistance transforms a portion of the electric energy
into heat, which heat must be dispersed into the atmosphere.

_A transformer_ is an induction coil employed usually for lowering
electric pressure, but it may also be used for raising the same, in
which case it is sometimes called a _booster_. _A compensator_ is a
transformer which works automatically.

[Illustration: FIG. 231.]

[Illustration: FIG. 232.]

_Ammeters_ record _the quantity of current flowing through the circuit,
in amperes_. _Voltmeters_ record _the pressure_ or strength of the
current in _volts_.

An _Ampere_ is an electric current which would pass through a circuit
whose resistance is one ohm under an electro-motive force of one volt.
A _Volt_ is an electro-motive force of sufficient strength to cause _a
current of one ampere to flow against a resistance of one ohm_.

The _ampere_ is the unit for calculations relating to _the quantity_
or volume of a current; the _volt_ is the unit for calculating the
_pressure_ or strength of the current.

_The action of the electric current_ in producing rotation in an
electric motor is really quite simple. While many electrical problems
are comparatively complicated, the principal elements in the operation
of electric motors may be readily understood. The fundamental fact
in this connection is the relation between an electric current and a
magnet.

If a piece of round bar iron be surrounded by a coil through which
an electric current passes, it becomes a magnet. In Fig. 233 the
passage of a current through the coil of wire around the iron bar in
either direction, _renders the iron a magnet_, with all its well-known
properties. It will attract iron, and the space surrounding it becomes
magnetic. Iron filings will arrange themselves in the direction shown
by the dotted lines in the figure. One end of the magnet is the North
or positive + pole and the other the South or negative - pole.

If a wire, such as _CD_, be moved past either pole of the magnet, there
will be a tendency for current to flow in the wire either from _C_ to
_D_ or _D_ to _C_, according to the character of the pole past which it
is moved, and to the direction of the movement. If the ends of the wire
_CD_ are joined by a conductor, so that there is a complete circuit, a
current of electricity will flow through this circuit.

This circuit may be a simple wire, as shown by the line _CEFD_, or
it may be the wire coils on machines enabling the current to produce
mechanical work, or it may be electric lamps producing light. The
indispensable feature is that there shall be a complete unbroken
circuit from _C_ to _D_ for the current to flow, no matter how
complicated or how long this circuit may be.

This description of a dynamo and motor carries with it all of the
elementary theory of electric generators and motors that is necessary
for an attendant to know in order to take reasonably intelligent care
of electric machines. Further useful knowledge must be acquired by
studying the different types of electric motors and dynamos. All these
other types of _direct current_ machines have the same elementary
theory, although their construction may be quite different.

By suitable illustrations the operation of the electric motor as
applied to pumps will be easily understood; its application to other
machines is the same in theory and practice.

“_Why an electric motor revolves_” is a question well worth careful,
and, if necessary, long study.

[Illustration: FIG. 233.]

The reason why there is a tendency for an electric current to flow
in the wire _CD_ when it is moved in the vicinity of a magnet is not
fully known. There are several theories, all more or less complicated,
and depending upon pure assumptions as to the nature of an electric
current. For practical purposes it matters little what the reason is,
_the fact that current flows when there ts an electric pressure in
a closed circuit_, is the important thing, and it serves all useful
purposes to know that current does flow, and that its direction and
amount are always the same under similar circumstances. There are many
facts in mechanics that are accepted and used practically, about which
little is known as to their fundamental and primary causes, and this
fact about motors and dynamos is, therefore, only one of many which all
must accept without a full and complete explanation.

_The intensity of the electric pressure_, or electro-motive force,
depends upon the velocity of revolution of the wire sections in the
armature and upon the strength of the magnets, and the quantity of
current depends upon the electro-motive force and upon the amount of
the resistance in the circuit. Other things being equal, the current,
flowing through a long small wire, or greater resistance, will be less
than through a short, thick wire, or a less resistance.

Having seen that when a wire is moved in the vicinity of a magnet an
electric pressure is produced which will cause a current to flow in
a closed circuit, one can easily conceive of many ways in which, by
combining magnets and wires so that there will be a relative motion
between them, a current of electricity may be generated. In order to
cause a continuous flow the relative motion must be continuous; and if
the current is to be uniform the motion must be uniform.

[Illustration: FIG. 234.]

Two electro-magnets are shown in Fig. 234, in which the North pole
of one magnet is near the South pole of the other, and the magnetic
field between the two lies in the approximately straight lines between
the two magnets, as indicated by the dotted lines. If the wire _CD_
be moved across this field and its ends be joined, as by the metallic
circuit _CEFD_, a current will flow in this circuit. The wire _CD_ may
be made to revolve around the wire _EF_, passing in front of one pole
and then in front of the other pole, as in Fig. 235. The current in
the circuit will pass in one direction when the wire is passing one
pole, and in the other direction when it is passing the other pole.
The connection between this elementary arrangement and the dynamo
is easily recognized. In the dynamo a magnetic field is produced by
electric magnets, called “pole pieces,” and a considerable number of
wires similar to the wire _CD_ are placed upon an armature so that they
revolve in front of these poles. Each individual wire produces current
first in one direction and then in another direction, as explained
above; but if there be many wires there will always be the same number
in front of the North, or positive pole, and the same number in front
of the South, or negative pole, so that the total or resultant action
is practically uniform, and may be made to produce a continuous
current. Such a machine is the common direct current dynamo, or motor.

[Illustration: FIG. 235.]

A dynamo transforms mechanical into electrical energy, and a motor
transforms electrical into mechanical energy. The two operations are
reversible, and may be effected in the same machine; a dynamo may be
used as a motor, or a motor may become a dynamo.

_A dynamo is a motor when it is driven by a current of electricity, and
it is a dynamo when it is driven by mechanical power and produces an
electric current._ If a motor be driven by an engine, it can deliver
a current of electricity which is able to operate other motors or
electrical apparatus or lights. A simple form of electric machine is
shown in Fig. 236, which is a general form of the electric motor. In
this there are two projections of steel, _H_ and _G_, which are made
electro-magnets by the current flowing through the wires wound around
them from any source of electricity, such as a battery at _I_ and _J_.
These magnets have poles facing toward an armature, _K_, on a shaft.
The poles _G_ and _H_ are called the “salient” poles; the poles _M_ and
_P_ are called the “consequent” poles. The magnetic flow or field is
shown by the dotted lines. On the periphery of the armature are wires
in the slots shown. As this armature revolves, there will be a tendency
for electricity to flow through the wires.

[Illustration: FIG. 236.]

In order to distribute a current of electricity through these wires it
is necessary to make a complete circuit. As each of the wires in the
slots passes in front of a pole, a pressure or electro-motive force
will be generated, and its direction will depend upon whether the pole
is a North or a South pole, _i. e._, + or -.

  NOTE.—In the above illustrations I and J represent the ordinary
  electric battery; in electrical literature such marks always indicate
  a battery.

The pressure or electro-motive force generated in the wires moving in
front of the North, or positive field poles, will be in one direction,
while that of those in front of the South, or negative field poles,
will be in the opposite direction. Therefore, if two such wires be
connected together at one end of the armature, the free terminals
of the wires at the other end of the armature will have the sum of
the electro-motive forces generated in the two wires. The wires so
connected can be considered as a turn of a single wire instead of two
separate wires, and this turn may be connected in series with other
turns, so that the resulting electro-motive force is the sum of that
in all the turns and all the wires so connected. It is customary to
connect the coils of an armature so that the electro motive force
given is that obtained from half the coils in series. The other half
of the coils is connected in parallel with the first half, so that the
currents flowing in the two halves will unite to give a current in
the external circuit equal to twice the current in the two armature
circuits or paths.

It is evident that, as the armature revolves, wires which were in front
of the positive pole will pass in front of the negative, and that
in order to maintain the electro-motive force it will be necessary
to change the connections from the armature winding to the external
circuit in such a way that all the wires between the two points
of connection will have their electro-motive forces in the proper
direction. The connection to the armature must therefore be made not
at a definite point in the armature itself, but at a definite point
with reference to the field magnets, so that all the wires between two
points or contacts shall always sustain the same relation to the field
magnets.

For this purpose a device known as a “commutator” is provided. The
commutator is made up of a number of segments, as shown at _A_, in Fig.
237, which are connected to the armature winding. On the commutator,
rest sliding contacts, or brushes, which bear on the segments and are
joined to an external circuit, making a continuous path through which
current may flow. As the commutator revolves, the different segments
come under the brushes, so that the relative position of the armature
wires between the brushes is dependent on the position of the brushes.
The armature wires which connect the brushes are those sustaining the
desired definite position to the field magnets, so that the currents
from the armature at all times flow properly into the external circuit,
although individual armature wires carry currents first in one
direction and then in the other direction, depending on the character
of the pole in front of which they may be moving.

[Illustration: FIG. 237.]

On two-pole machines there are two brush-holders, each containing one
or more brushes. On the four-pole machine there may be either two or
four brush-holders, and on a six-pole machine, either two, four, or six
brush-holders.

A single path of the current through the commutator and armature
winding is shown by the arrows on Fig. 237. The brushes _B_ and
_C_ are placed on the top side of the commutator to make them more
accessible, and this shows a peculiar but simple armature winding.

For the sake of simplicity, the batteries _I_ and _J_, of Fig. 236, are
not used on common forms of generators or motors, but the current that
flows from the armature through the commutator is made to flow through
the electro-magnets either in whole or in part. If all of the armature
current flows around the electro-magnets or fields of the machine, it
is a “series” machine; if only a part of the current is used in this
way, it is a “shunt” machine; that is, some of the current is “shunted”
through the fields. Sometimes both the shunt and series windings
are used, and in that case the machine is called a “compound wound”
machine. Such a machine has a large wire through which the main current
passes, and a fine wire through which the shunted current flows. Fig.
237 shows how the commutator and the fields are connected, and how the
current flows from the wires in the armature through the commutator in
a series machine.

If the current delivered by a dynamo does not flow in the desired
direction, it can be reversed by shifting the wires in the binding
posts or by throwing a switch. If the motor does not revolve in the
desired direction, it can be made to do so by reversing the connections
to the armature or field-coils; so that, without knowing which way a
current of electricity is to be generated, any practical man can make a
motor revolve in a proper direction by simply changing its connections.

It is natural that a machine which gives out electric energy when
driven by an external power, should, when electric energy is delivered
to it, reverse its action and give out mechanical power and do work.

Perhaps the simplest way to explain the cause of the movement of
an electric motor, when supplied with a current, is to compare its
action to the well-known attraction of unlike poles or magnets and
the repulsion of like poles. Unlike poles are North and South; like
poles are two North or two South. In all motors a current through the
field causes a North or South pole to be maintained, and a current
through the armature and brushes causes an opposite polarity. These
constantly-maintained unlike poles attract each other and pull the
armature around on its axis.

It has been explained that if a motor be driven by a belt an
electro-motive force is produced and the machine acts as a dynamo.
It is also a fact that an electro-motive force is produced whether
the power for driving the machine is received from a belt or from
the electric current,—that is, whether the machine be driven as a
dynamo or as a motor. In a dynamo, however, the current follows the
direction in which the electro-motive force is acting. In a motor, the
electro-motive force produced has a direction opposed to that of the
flow of current. This may be illustrated by the following experiment.

Two similar machines are driven independently at 600 revolutions and
give an electro-motive force of 100 volts. Similar terminals of the two
machines are connected together; no current flows between the machines,
because the two pressures are the same and are in opposite directions.
If now the belt be thrown off from one machine, its speed will begin to
fall; this will lower its electro-motive force below that of the other
machine or dynamo, but will not change the direction of the force.
There will now be a difference of pressure in favor of the machine
which is driven, and it will deliver a current through the other
machine and run it as a motor. The speed of the motor will continue to
fall until the difference in pressure or electro-motive force between
the two machines is only sufficient to cause the flow of enough current
to keep the motor running against whatever frictional resistance, and
other resistance there may be. The electro-motive force generated in
the motor, which is against, or counter to that of the current in the
circuit, is called the “counter electro-motive force.”

In order to determine how fast a motor will run without doing work
under any given pressure, it is not necessary to know anything
about the dynamo that furnishes the pressure. The pressure alone
is sufficient to determine the speed of the motor. For instance, if
a motor will give a pressure of 500 volts when running free at 100
revolutions, it will always run at about 100 revolutions when not doing
work on an electric circuit where the pressure is 500 volts.


MAGNETIC NEEDLE.

The figure on page 242 shows a magnetic compass needle. This is used
to test the direction of an electric current flowing through a wire or
cable conductor. The plus sign, +, is the positive and the minus, -,
sign is the negative end or pole. _A continuous current always flows
from the positive to the negative end or pole_, hence the north end or
pole, N, is the positive end of the needle and the south pole, S, is
the south pole of the needle.

When one of these devices is held in close proximity to a conductor
of electricity _it immediately assumes a parallel position to the
conductor_ and indicates the direction in which the current is flowing.
The long, upper arrow, as shown in the figure, tells the direction of
the flow. A small pocket compass may be used in place of this device
and is often carried in the pocket of electricians for the purpose of
indicating the direction of the current.


PRESSURE IS NECESSARY TO PRODUCE AN ELECTRIC CURRENT.

It should be understood that an electric dynamo or battery does not
generate electricity, for if it were only the quantity of electricity
that is desired, there would be no use for machines, as the earth may
be regarded as a vast reservoir of electricity, of infinite quantity.
But electricity in quantity without pressure is useless, as in the
case of air or water, we can get no power without pressure, a flow of
current.

As much air or water must flow into the pump or blower at one end, as
flows out at the other. So it is with the dynamo; for proof that the
current is not generated in the machine, we can measure the current
flowing out through one wire, and in through the other—it will be found
to be precisely the same. As in mechanics a pressure is necessary to
produce a current of air, so in electrical phenomena an electro-motive
force is necessary to produce a current of electricity. A current in
either case can not exist without a pressure to produce it.


ELECTRIC PUMPING MACHINERY.

Since the conditions surrounding pumping plants are so widely
different, it is impossible to treat every practical application in
detail, hence, the space allotted to this subject has been used in the
preceding succinct and plain discussion of the principles upon which
electric power is applied to the operation of pumps.

The following are some of the advantages claimed for electric pumping
machinery:

“Economy in operation and maintenance is the first and most vital
consideration that demands the attention in the installation of
pumping machinery. In respect to economy, the electric system has many
important advantages. It is saving in the transmission of power, and
thus enables a pumping installation to be situated at a considerable
distance from the source of power where the first cost and maintenance
expense of other systems would be almost prohibitive.

“The economy in space required is also worthy of consideration. The
driving mechanism of a modern electric pumping outfit occupies a small
amount of room and the space required for wiring is negligible. In
case of accident, any mechanical injury to wires can be quickly and
easily repaired--thus the economy in time and expenditure for repairs.
There is no large loss by condensation. The only loss sustained with
the electric system in the transmission of power is a small loss due
to line resistance, increasing directly with the amount of water being
pumped and ceasing entirely when the pump is not in operation.”

A well designed electric pump will give an efficiency of from 75 to 80
per cent.; and, as the transmission loss depends upon the weight of
copper in the transmission line it can be made as low as the cost of
power, and, 2, the investment in copper will warrant.


DIRECTIONS FOR INSTALLATION.

1. It is important to locate the electric pump where it will be dry and
clean and where it will be thoroughly accessible for proper care.

2. No pipes should be allowed to pass above the electric motor where
liquids are likely to drip upon it.

3. The suction or supply pipe must be as short and straight as possible
and must be air tight, as air entering the pump through the suction
reduces its capacity or prevents it from working altogether.

4. A tight foot valve and a strainer should invariably be used on the
bottom end of the suction pipe when the water is to be lifted from 8
ft. to 10 ft. below the pump. Where the lift is excessive or for any
reason the supply be limited, an air chamber placed on the suction
pipe near the pump will prove beneficial in preventing slamming of the
valves.

5. Provision should be made for draining both pumps and pipes in cold
weather by a proper application of frost cocks.

6. If the electric pump is kept _dry, clean and well oiled_, it will
prove the most desirable and least expensive apparatus to be had for
the service.

7. Ascertain the nature of electric current to be used. Direct or
alternating? Voltage? (If alternating, note phase and number of
alternations.)

8. Also record any unusual or peculiar circumstances connected with
the installation or operation of the apparatus; and if so, what?


DOMESTIC ELECTRIC PUMPS.

[Illustration: FIG. 238.]

[Illustration: FIG. 239.]

In many places the pressure on the mains is insufficient to raise the
water to the upper floors or through improperly designed systems of
piping the pressure may be so diminished as to make the flow extremely
weak or the difficulty in securing proper water supply may be due to
inconvenient location with reference to water mains. _The automatic
electric house tank pumping plant_ has been designed and perfected to
meet these conditions; the electric plant is connected to some power or
lighting circuit and provided with an automatic attachment requiring
no more care than can be given by any casual attendant. Such an
installation avoids the smoke, ashes, dust and objectionable odors that
accompany steam or gas plants.

The accompanying diagram shows the general arrangement of the automatic
electric house system used with a tank in the upper part of the
building and the pump in the basement or cellar. The operation is as
follows:

When water is being delivered to the tank, the float rises until the
upper knob makes forcible contact with the switch lever, opening the
switch and stopping the pump. When water is withdrawn from the tank,
the float falls until the lower knob makes contact with the switch
lever, which again closes the switch and starts the pump. The supply
of water is thus maintained within the tank without the aid of an
attendant. The accompanying illustration, Fig. 238, shows a Worthington
house tank pump of 500 gallons per hour capacity belted to a General
Electric direct current motor, the pump and motor being mounted on the
same base.

  TABLE OF CAPACITY.

  ================+========+========+========+=========
  Diameter        |        |        |        |
  of Plungers     |   2    | 2-3/4  |   3    | 3-3/4
  ----------------+--------+--------+--------+---------
  Length          |        |        |        |
  of Stroke       |   4    |   4    |   4    |   4
  ----------------+--------+--------+--------+---------
  Revolutions     |        |        |        |
  per Minute      |   45   |   45   |   45   |   45
  ----------------+--------+--------+--------+---------
  Gallons         |        |        |        |
  per Minute      |  9.8   |  18.5  |  21.8  |  34.4
  ----------------+--------+--------+--------+---------
  Maximum Water   |        |        |        |
  Pressure in Lbs.|  150   |   75   |   60   |   40
  ----------------+--------+--------+--------+---------
  Gallons per Hour|  500   | 1,000  | 1,200  | 1,800
  ----------------+--------+--------+--------+---------
  Feet 1 H.P. Will|        |        |        |
  Pump Against    |  175   |   80   |   70   |   50
  ----------------+--------+--------+--------+---------
  Feet 2 H.P. Will|        |        |        |
  Pump Against    |  300   |  175   |  140   |  100
  ----------------+--------+--------+--------+---------

The above useful table is inserted to show the capacities, revolutions,
size of plungers, etc., in these electrically driven pumps, the
automatic feature of which is truly admirable.

It must be remembered that the number of combinations between small
electric motors and proportionate pumps for water, gas, air, etc.,
afford an endless field for the exercise of engineering skill.


ELECTRIC MOTOR AND AIR PUMP.

Fig. 240 is intended to show the application of the electric motor
to a triplex pump of small size, the plungers being 3-1/8 inches in
diameter. The Stroke is 4-7/8 inches which gives a capacity of 108
cubic inches per revolution, with a pressure of 50 lbs. to the square
inch. The pumps require about one-half horse power applied at the motor.

[Illustration: FIG. 240.]

The high speed of the motor is reduced by two belt pulleys and two
chain wheels. These pumps may be worked independently to produce
pressure or vacuum as desired by a separate pipe for each pump.


MOTOR AND CENTRIFUGAL PUMP.

Fig. 241 is intended to show the application of the electric motor
to a centrifugal pump; these two machines are mounted on one bed
plate, directly connected by a flange coupling between them. The motor
shown, is almost identical with the machine illustrated, Fig. 217,
and described on page 251. The pump is so arranged that the discharge
can be turned in any direction desired. Wherever electric power is
available and the centrifugal pump is the form best adapted to the
work, this combination presents advantages over a steam engine operated
by a plain slide valve such as is generally used.

[Illustration: FIG. 241.]


DIRECT DRIVEN MOTOR PUMP.

Fig. 242 shows a double pump driven directly, without gears or belt,
from the shaft of an electric motor. The pump crossheads are connected
directly to cranks at each end of the motor shaft. The cranks are set
at right angles and each pump is double acting, or has two plungers
connected by outside rods and with outside packed stuffing-boxes, so
that this portion of the pump is always accessible.

The plungers are 3-1/2 inches diameter and 5-1/2 inches stroke. The
pump and motor are mounted upon a rigid box girder frame: this unit is
self-contained and occupies a relatively small floor space.

_Electric Drive for Fire Pumps._ The importance of instantly operating
fire extinguishing apparatus can scarcely be exaggerated. The largest
conflagrations are but little flames at the beginning, and if caught
at the critical moment they make no record of destruction; for such
service the electric current is the ideal agent. A notable installation
of electric-driven pumps for fire service is in the Marshall Field
store, Chicago, a building occupying an entire city block. The outfit
consists of a Laidlaw-Dunn-Gordon _duplex Underwriter pump connected by
single reduction gearing to a waterproof electric motor_.

[Illustration: FIG. 242.]

The pump cylinders, 8 × 12 inches, have a computed capacity of 700
gallons per minute at 140 pounds water pressure. The pump, besides its
other special features, is claimed to be rust proof throughout so that
it will not get out of ready running condition.

[Illustration: FIG. 243.]


ELECTRIC-MINING PUMPS.

The electric system has especial conveniences for mine pumping because
of its adaptability to long transmissions of power; electric power can
be transmitted to almost any distance, and the pumps can be supplied
with either direct or alternating current motors. A mining outfit can
be easily divided into a number of parts, to facilitate lowering into a
mine, after which the assembling of the parts is a simple operation.

Stationary pumps for mine use are made in two classes: first, vertical
pumps having cylinders in a vertical position in which the over all
height is comparatively great and the horizontal dimensions as small
as possible; second, horizontal pumps with cylinders in a horizontal
position and having for cross dimensions the over all length. The class
of pump to be selected, of course, depends upon the limitations of
the location. In either case, the motor used for driving the pump is
mounted on an extension of the pump base, making a self-contained and
compact outfit.

Engraving, Fig. 243, represents a Quintuplex pump used principally in
mining operations, or wherever large quantities of water are to be
delivered under high pressure in the shortest possible space of time.
The pump here shown was designed to deliver 225 gallons of water per
minute under a head of 1,200 feet. It has five plungers 4 inches in
diameter each and having a uniform stroke of 12 inches.

These pumps driven by electric motors it is said represent the most
economical method of transmitting power, as compared with the best
designs of steam pumps. An efficiency of 80 per cent. is claimed for
these pumps.

  NOTE.—It is interesting to know that in one of the largest electric
  pumping installations which has ever been made for mining work, the
  power is carried 2,500 feet underground at a potential of 3,500
  volts and then transformed into 220 volts at the motors. No trouble
  has thus far resulted from the high voltage or any other cause; in
  regard to danger from underground electric pumps, it can be stated
  that accidents due to the use of electricity in such installations
  are almost unknown. _Induction motors are arranged to operate without
  moving contacts._ They are therefore free from sparks and can be used
  in mines where the presence of gases compels the use of safety lamps.

Fig. 244 exhibits an electric induction motor operating a 5-1/2 × 8
portable track pump.

Portability is an important feature in all pumps for mine use; and,
as track pumps may be put into service immediately at any point on a
system of tracks, they meet this requirement better than pumps of any
other form.

Such an outfit can be hauled to any point in the mine and there
operated from some convenient circuit such, for instance, as the
circuit supplying power to mine locomotives.

[Illustration: FIG. 244.]

The pump and motor shown in Fig. 244 are mounted on an iron truck, no
wood whatever being used in construction, so that adjustment cannot be
affected by moisture and an easy running and durable pump is assured.
The pumps are made as compact and strong as possible for mine service,
which is usually exceptionally rough and continuous. They are of the
horizontal type which is best adapted for low passageways and are
designed so as to afford easy access to all parts. The pumps are single
acting and the plungers are provided with outside stuffing-boxes, which
can be packed, and being in sight, any leakage can be quickly detected.
Access to all valves is made easy by the removal of one large hand-hole
cover on the valve chest.



  THE STEAM
  PUMP

[Illustration: FIG. 245.

  G. KIRKHAM]


THE STEAM PUMP.

The illustration, Fig. 245, on the opposite page represents _the first
practical steam pump ever made_; on pages 67-69 will be found an
interesting account of it. The water end is _single acting_; the steam
end is, of necessity, _double acting_ to produce the reciprocating
motion. From this original design has been evolved the piston valve as
well as many other designs of valve motion for pumps.

Having already taken up in some detail the construction of “the parts
of the pump” and the necessary appliances connected with its use, it
now remains to consider the means by which the steam power generated is
made available and the mechanism by which the energy is _transformed
from pressure into pumping power_.

It may be well to consider at some length the “Steam end” of the pump.
This consists primarily of cylinders, together with their connections;
_these constitute the muscular system of the pump_. The muscular or
operating end is separate and distinct from the water end so far as
construction is concerned but in operation the two are closely allied.
It is therefore necessary as well as convenient to unite them in
one equipment and thus enable the propelling mechanism to furnish a
constant source of power.

So far as the elastic force of steam itself is concerned its history
dates back to a period two hundred years B. C., when, as described by
Hero, the force generated by steam was utilized for actuating certain
devices constructed rather for curiosity than for any benefit which
might be derived from their use. Very little advance was made in
the construction of practical devices until the latter part of the
eighteenth century when James Watt by his improvements placed the
stationary engine on an operative basis and gave to the world what has
proved to be the greatest invention of all time.

_The first stationary steam engines were used for pumping water and
were of the single acting type_, in which the steam was admitted at one
end of the cylinder, the opposite end being open to the atmosphere.
The steam acting on the piston forced it to the limit of its stroke
when the supply was cut off. The steam then condensed in the cylinder,
forming a partial vacuum, and the force of the atmosphere upon the
opposite side of the piston forced it back, causing it to complete its
stroke before another supply of steam was admitted. This was a slow
process, wasteful of steam and attended with many other inconveniences.

An improvement on this device was made in an engine built by Watt in
1774. This was a single acting engine but _the condenser was separated
from the cylinder_. The valves were so arranged as to admit live steam
into the upper end of the cylinder on the top of the piston and at the
same time open the lower end of the cylinder to the condenser. The
steam followed the piston in its downward stroke in which action it was
aided by the partial vacuum formed in the condenser. At the completion
of the downward stroke the valves were changed so as to close the
ports to the steam supply and the condenser, and at the same time open
a communication between the two ends of the cylinder equalizing the
pressure above and below the piston. The weight of the pump rod on the
beam or lever connection overbalanced the weight of the piston and
caused it to complete the return stroke.

In 1782 _the double acting steam engine_ was patented by Watt. This
was a device in which the live steam acted on each side of the piston
alternately, the opposite side of the cylinder being in communication
with the condenser. The same patent covered the method of applying _the
principle of expansion of steam in the cylinder_; a non-condensing
engine was also described.

  NOTE.—This invention was of great historical importance as it covered
  all the essential detail of modern practice in steam engine building
  and constituted the fundamental principle of all steam engines.

  Improvements have been made in form and construction, necessitated
  by new adaptations which have been constantly developed. The
  requirements for higher speed, increased pressure which implies
  greater power, and the constant desire for greater economy in fuel
  have produced a variety of changes in detail but have not altered the
  fundamental idea.

When the steam after being utilized in the cylinder makes its exit
directly to the open air, the engine is called _single expansion_ for
the reason that the action of the steam takes place in one cylinder
during a single stroke, and what expansion takes place must be during
one half of a revolution. When the steam from one cylinder instead
of exhausting into the open air, is passed to a second cylinder, of
larger area, and by expanding exerts a pressure on a second piston to
aid in the completion of the revolution, the engine is called _double
expansion or compound_, because the steam instead of completing its
work in a single operation is afforded a double opportunity for
expansion and an increased range of action. _In the single cylinder the
temperature of the walls is reduced in each revolution to correspond
with that of the steam at the exhaust pressure._

This temperature must be restored by incoming steam at the beginning of
a new stroke which means a reduction of power. With a double cylinder
owing to the greater range of expansion, a higher temperature can
be maintained in the first cylinder and a large amount of initial
condensation is prevented. _A still greater use of expansion may be
obtained by the introduction of a condenser_ which allows the final
exhaust to be carried below the atmospheric pressure to the extent
of the vacuum formed. In stationary and marine practice triple and
quadruple expansion engines are common. These are used in large units
to give the greatest possible economy in fuel.

_Properties of Steam._—Before taking up in detail the valve and other
mechanism of the steam pump it may not be out of place to consider
briefly the action of steam and its expansive properties. _Heat is
identical with mechanical force and the one can be converted into the
other._ Aside from the means used in converting or developing the
action _a certain quantity of heat always produces a certain quantity
of work_.

[Illustration: FIG. 246.

Relative Volume of Steam at 200 pounds Pressure from One Cubic Inch of
Water

Relative Volume of Steam at Atmospheric Pressure from One Cubic Inch of
Water]

The temperature of steam at atmospheric pressure (14.7 lbs. absolute)
is 212° Fahr. As the pressure increases the temperature rises, but is
always the same for a given pressure. The sensible heat required to
raise the temperature of water from 32° to 212° is 180° and the heat
absorbed by the water or latent heat at 212° is 996° making the total
amount of heat expended 1176°. As the temperature rises the latent heat
decreases in nearly the same proportion as the sensible heat increases.
This number may therefore be taken as a constant to express the unit
of heat in one pound of steam from 32° up to the temperature at which
evaporation takes place. Then 1176 × 772 = 907,872 pounds raised one
foot which represents the mechanical equivalent or maximum theoretical
duty of the quantity of heat contained in one pound of steam.

One cubic inch of water if converted into steam at the pressure of the
atmosphere (14.7 pounds) will occupy the space of 1642 cubic inches
or nearly one cubic foot. As the pressure increases the volume is
relatively diminished and if the same quantity of water is converted
into steam say at 200 pounds pressure it will occupy a space of only
133 cubic inches. Assuming that no loss occurred by condensation, if
released at this pressure it would expand and again occupy its relative
volume at atmospheric pressure.

This is illustrated by the accompanying diagram, Fig. 246, showing a
cylinder with an internal capacity of 1642 cubic inches provided with
a movable piston. A quantity of steam representing that formed from
one cubic inch of water is forced into it, supposing the weight on the
piston to be 200 lbs. per square inch, this weight will be raised until
the space under the piston occupied by the steam will be 133 cubic
inches. If the supply is now cut off (assuming that no condensation
takes place) the piston will remain at this place supporting its load.
If the load on the piston is diminished the volume of steam will expand
and the piston will be correspondingly raised in the cylinder. This
action will be continued until all the load is removed and only the
weight of the atmosphere remains. The volume of steam under the piston
will then be 1642 cubic inches. It will therefore be seen that the same
quantity of steam has exerted a lifting pressure upon the piston due
to its relative volume commencing at 200 pounds per square inch and
gradually decreasing until the pressure of the atmosphere is reached.

The English unit of heat is that which is required to raise the
temperature of one pound of water one degree Fahrenheit and is known
as the British Thermal Unit, or B. T. U. Dr. Joule demonstrated by an
ingenious device, Fig. 247, in which a weight operated a paddle wheel
agitating water in a closed vessel, that it required 772 foot pounds
to raise the temperature of one cubic foot of water one degree, or, on
the other hand, it was deduced that one unit of heat was capable of
raising 772 pounds one foot high. The mechanical equivalent of heat is
therefore accepted as 772 foot pounds for one B. T. U. based on Joule’s
experiment.[A]

[Illustration: FIG. 247.]

The theoretical efficiency of the use of steam by expansion can never
be realized, owing to losses occasioned by condensation, caused by
contact with the cooler walls of the cylinder, the unavoidable friction
of the working parts, and from the fact that a certain portion of
the pressure must be utilized to create a draft for the fire. All
these losses must be taken into consideration in calculating the work
actually done.

From the foregoing it will be readily understood that if the steam is
allowed to exhaust from the cylinders at or near the pressure at which
it is admitted the work which it might have accomplished by expansion
will be lost. This means not only a loss of the steam but of a part of
the fuel used to generate it.

It is therefore advisable to get all the work out of the steam that
is possible and the nearer to atmospheric pressure the exhaust can be
brought the greater will be the economy.

[Footnote A: NOTE.—This unit has been recently changed to 778.]


USEFUL DEFINITIONS RELATING TO STEAM.

_Steam_ is water in a gaseous state; the gas or vapor of water; it
liquifies under a pressure of 14·7 and temperature of 212° F.

_Steam_ is a joint production of the intermingling of water and heat.
Water is composed of two gases which have neither color nor taste, and
steam is made up of the same two gases with the addition only of that
mysterious property called heat by which the water becomes greatly
expanded and is rendered invisible. The French have a term for steam
which seems appropriate when they call it water-dust.

This is what takes place in the formation of steam in a vessel
containing water in free communication with the atmosphere. At first,
a vapor is seen to rise that seems to come from the surface of the
liquid, getting more and more dense as the water becomes hotter. Then
a tremor of the surface is produced, accompanied by a peculiar noise
which has been called _the singing_ of the liquid; and, finally,
bubbles, similar to air bubbles, form in that part of the vessel which
is nearest to the fire, then rise to the surface where they burst,
giving forth fresh vapor.

The curious fact must be here noted that if water be introduced
into a space entirely void of air, like a vacuum, it vaporizes
instantaneously, no matter how hot or cold, so that of an apparent and
fluid body there only remains an invisible gas like air.

That steam is _dry_ at high pressure is proved by an experiment which
is very interesting. If a common match head is held in the invisible
portion of the steam jet close to the nozzle, it at once lights, and
the fact seems convincing as to complete dryness, as the faintest
moisture would prevent ignition even at the highest temperature. This
experiment proves dryness of the steam at the point of contact, but if
throttling exists behind the jet, the steam supplied by the boiler may
be in itself wet and dried by wire drawing.

_Dead steam_ is the same as exhaust steam.

_Live steam_ is steam which has done no work.

_Dry steam_ is saturated steam without any admixture of mechanically
suspended water.

_High-pressure steam_ is commonly understood to be steam used in high
pressure engines.

_Low-pressure steam_ is that used at low pressure in condensing
engines, heating apparatus, etc., at 15 lbs. to the inch or under.

_Saturated steam_ is that in contact with water at the same
temperature; saturated steam is always at its condensing point, which
is always the boiling point of the water, with which it is in contact;
in this it differs from superheated steam.

_Superheated steam_, also called steam-gas, is steam dried with heat
applied after it has left the boiler.

_Total heat of steam_ is the same as steam heat.

_Wet steam_, steam holding water mechanically suspended, the water
being in the form of spray.

Specific gravity of steam is ·625 as compared to air under the same
pressure.

The properties which make it so valuable are:

1. The ease with which we can condense it.

2. Its great expansive power.

3. The small space in which it shrinks when it is condensed either in a
vacuum chamber or the air.

A cubic inch of water turned into steam at the pressure of the
atmosphere will expand into 1,669 cubic inches.


THE DAVIDSON.

The Davidson pump is shown complete in Fig. 248; the valve motion
consists principally of _a valve, valve pistons, valve pin and cam_.
The main valve is operated by a positive mechanical connection between
it and the main piston rod, also by the action of steam on the valve
pistons. The engraving, Fig. 249, shows the details of valve gear and
steam cylinder. The steam end consists of the cylinder, M, valve, A,
and valve pistons, B and B. These pistons are connected with sufficient
space between them for the valve, A, covering the steam ports, F and
F_{1}, Fig. 250.

[Illustration: FIG. 248.]

The valve is operated by the steel cam, C, acting on a steel pin, D,
which passes through the valve into the exhaust port, N, in which
the cam is located. In addition to this positive motion steam is
alternately admitted to and exhausted from the ends of the valve piston
through the ports, E and E_{1}, which moves the pistons, B and B_{1}.

[Illustration: FIG. 249.]

Assumed that this pump is at rest with the valve, A, covering the
main steam ports, F and F_{1}, in which position the cam C, holds
the main valve by means of the valve pin, D, so that ports, E and
E_{1}, admit steam to one end of the valve piston at the same time
connects the other end with the exhaust port. The steam, acting on
the valve pistons, moves both, opening the main ports, F and F_{1},
admitting steam to one end of the steam cylinder and opening the other
end to the exhaust. If the valve occupies any other position than the
one described, the main ports, F and F_{1}, will be opened for the
admission and exhaust of steam; consequently it is evident that this
pump will start from all points of the stroke.

[Illustration: FIG. 250.]

On the admission of steam to the cylinder the main port, F, the main
piston, cam and valve will move in the direction indicated by the
arrows. The first movement of the cam oscillates the valve, preparatory
to bringing it into a proper position for the opening of the auxiliary
steam ports, E, to live steam, and E, to exhaust also to close the
valve mechanically just before the main piston reaches the end of
its stroke. This causes a slight cut-off and compression, and fully
opens the auxiliary ports, E, to steam, and E_{1}, to exhaust. By the
admission of steam to one end, the other being open to the exhaust,
the valve pistons move the valve to allow the admission and exhaust of
steam from the cylinder for the return stroke.

This main valve is as much under the control of the piston rod as is
the valve of an ordinary steam engine worked by an eccentric which
insures a positive action, the pump being capable of starting from all
positions and maintaining a uniform and full stroke.

_To set the valve piston_, push the main pistons to the end of the
stroke until the inner edge of the port and the piston coincide, then
loosen the side lever, turn the cam, C, until the valve piston uncovers
the auxiliary steam port, E, leading to the same end of the steam chest
occupied by the main piston.

[Illustration: FIG. 251.]

After setting, secure the cam and then connect the side lever to
the connecting rod. The side lever and cam occupy correct relative
positions, therefore, the lever should be secured to the cam shaft
while in this position. The stroke may be regulated by raising or
lowering the end of the connecting rod in the slotted end of the slide
lever. Raising the connecting rod shortens the stroke and lowering it
lengthens the stroke. When making the foregoing adjustments it is well
to have the connecting rod at or near the bottom of the slot as shown
in the engravings.


LAIDLAW-DUNN-GORDON.

The single cylinder pumps of this make are equipped with the gear
illustrated in Fig. 252, in sizes varying from 4 inches in diameter by
5 inches stroke to 28 inches in diameter by 24 inches stroke.

The arrangement of valves and ports is shown in the engravings, Figs.
253 and 254.

The admission of live steam to the cylinder and of exhaust steam to the
atmosphere is controlled by a valve piston, A, shown in Fig. 252.

[Illustration: FIG. 252.]

Assume that the piston is in position shown, Fig. 253, and that both
the main and auxiliary valves cover their respective steam ports. By
means of a starting bar, operating through a stuffing-box in the valve
chest, the piston valve, A, is moved toward the head of the steam
chest, D, thus opening the ports, E and L, and admitting live steam
through L, from the cavities, S, of the valve piston to the housing end
of the main steam cylinder, through the port, F, Fig. 255, forcing the
main piston, P, toward the opposite end of the stroke, or toward the
left in the figure. The port, E, Fig. 253, being open, the exhaust
steam escapes from front of the main piston through the port, F, Fig.
255, into the main exhaust port, G, through the port, E. The piston, P,
travels to its extreme left position and the auxiliary slide valve has
been drawn to such a position in the direction indicated by the arrow
in the smaller drawing in Fig. 252, as to bring valve piston, A, toward
the opposite end; the exhaust steam from the steam chest escapes from
before it, through the exhaust port, K, the opening of which into the
chest is at such a distance from the head as will permit sufficient
exhaust steam to remain to afford a cushion to the valve piston.

[Illustration: FIG. 253.]

[Illustration: FIG. 254.]

[Illustration: FIG. 255.]

[Illustration: FIG. 256.]

With the auxiliary slide valve in position to bring the hole, H, over
the port, J, Fig. 256, it is plain that the exhaust through the port,
K, will pass into the main exhaust through the port, L. With the main
piston at its extreme travel toward the right, the ports, E and L,
which correspond to F and F, respectively, in Fig. 255, are opened in
such a manner as to exhaust steam to the atmosphere from the housing
end of the steam cylinder through the port, F, and live steam from the
chest to the head end of the main cylinder, through the port, F, thus
driving the main piston, P, toward the housing end of the cylinder, or
toward the right. The piston and reciprocating parts traveling in this
direction move the auxiliary slide valve to its maximum point of travel
in the opposite direction, thus opening the opposite auxiliary steam
and exhaust ports and again driving the valve piston toward the head,
D, of the steam chest, whence a new stroke begins.

Lost motion in the valve gear is taken up by adjustable links, on all
sizes above 7 inches diameter by 10 inches stroke and on some smaller
sizes.

Cushioning of the steam pistons in the larger sizes and upwards is
accomplished by means of suitable valves called cushion valves. In the
smaller sizes sufficient cushioning is done by exhaust steam passing
from the clearance space next the head through a small hole drilled
into the main steam port.

_To set the valve_ of this pump it is only necessary to place the
piston in its central position and adjust the lever so that the valve
will occupy its central position. By this proceeding the travel of the
valve is equalized.


THE FOSTER.

[Illustration: FIG. 257.]

The Foster single cylinder pump valve motion is a compound valve piston
and slide valve in one piece and performs the office of both a main
and auxiliary valve. It seats over the main steam cylinder on the web
or casting connecting together the valve pistons, and is provided at
the bottom with vents or openings, _A_ and _B_, Fig. 257, for opening
and closing the main steam ports to the main steam cylinder. The sides
of this valve are cut to form the recesses, _C_ and _D_, which are for
the purpose of opening and closing the small steam ports, which admit
steam to the valve pistons; it is also provided with L shape slots for
the purpose of alternately exhausting steam from the valve pistons
through the steam ports.

[Illustration: FIG. 258.]

[Illustration: FIG. 259.]

[Illustration: FIG. 260.]

In operation the main piston rod commences its forward stroke, motion
is communicated to the vertical arm, which moves forward on the rod
until it engages with one of the cams, _E_, Fig. 259, adjusted on the
valve stem. The arm coming in contact with the inclined faces of the
cam imparts a rolling or oscillating movement to the stem and valve,
opens one of the recesses, _C_ or _D_, cut in the side of the valve
and admits steam through a port to one of the valve pistons. At the
same time this oscillating movement of the valve opens the slot, _F_,
Fig. 260, opposite the first, and exhausts steam through the alternate
port from the other piston. Steam thus admitted to one of the pistons
(while exhausts from the other piston), carries the valve over its
seat, and by means of the vents, _A_ and _B_, steam is admitted through
one of the main ports and exhausts through the other. When the main
piston has completed one stroke, it moves backward on its return; the
arm strikes against the other cam on the valve stem and communicates a
reverse motion to the valve which closes and opens the alternate ports
to admit and exhaust steam to and from the pistons. It also cushions
the piston at the end of each stroke which prevents the piston from
striking the heads.

_To set the valves._ This can best be done by starting the pump slowly
and adjusting the cams, _E_, so as to open the valve at the proper time
to compel the piston to make a full stroke. A little experimenting
combined with good judgment is all that is necessary, unless the piston
valve be badly worn, in which case _a new valve must be substituted_
and fitted to the valve chest.


THE CAMERON.

The plunger in the Cameron pump is reversed by means of two plain
tappet valves, shown in the accompanying engraving, Fig. 261, and the
entire valve mechanism consists of four pieces, all of which work in
a direct line with the main piston. This pump is simple and has no
delicate parts.

[Illustration: FIG. 261.]

As here represented—_A_ is the steam cylinder; _C_, the main piston;
_L_, the steam chest; _F_, the valve piston, the right-hand end of
which is shown in section; _G_, the slide valve; _H_, a lever, by means
of which the valve piston, _F_, may be moved by hand when expedient;
_I_, _I_ are reversing valves; _K_, _K_ are the reversing valve chamber
bonnets, and _E_, _E_ are exhaust ports leading from the ends of steam
chest direct to the main exhaust. The passages, _M_, _M_, lead directly
into the exhaust (although the connection is not shown, being cut away
in the sectional view), and closed by the reversing valves, _I_, _I_.

The piston, _C_, is driven by steam admitted under the ^B^ slide valve,
_G_, which, as it travels backward and forward, alternately supplies
steam to opposite ends of the cylinder, _A_. The slide valve, _G_, is
operated by the valve piston, _F_; _F_ hollow at the ends, which are
filled with steam, which, issuing through a hole in each end, fills the
spaces between it and the heads of the steam chest in which it works.

The pressure being equal at each end, the valve piston, _F_, under
ordinary conditions, is balanced and motionless; but when the main
piston, _C_, has traveled far enough to the left to strike and open the
reverse valve, _I_, the steam exhausts from behind the valve piston
through the port, _E_. The pressure being now unequal behind the two
ends, the valve piston immediately shifts accordingly and carries with
it the slide valve, _G_, reversing the piston. No matter how fast the
piston may be traveling, it must instantly reverse when it touches the
valve, _I_.

In its movement the valve piston, _F_, acts as a slide valve to close
the port, _E_, and is cushioned on the confined steam between the
ports and steam chest cover. The reverse valves, _I_, _I_, as soon as
the piston, _C_, leaves them, close by the constant pressure of steam
behind supplied direct from the steam chest through the ports, _N_,
_N_, shown by dotted lines.

_To set the valve_, it is only necessary to keep valves tight by
occasional grinding. The piston as it nears the end of each stroke
strikes the stem and lifts the valve off its seat; this allows the
exhaust steam behind the piston valve to escape. The live steam pushes
the piston towards the exhausted end carrying the main slide valve
along with it.


THE MASON.

The Mason pump has a valve piston, a main valve, a preliminary valve
and a yoke connected directly to the valve stem, as shown in Fig. 262.
The valve piston is contained in a cylinder above the steam chest, and
moves the main valve by means of a pin, which projects into a pocket in
the top.

[Illustration: FIG. 262.]

The main valve and preliminary valve travel on the same seat, and
receive their motion from the yoke, _E_, Fig. 263, which surrounds
them. This yoke fits the preliminary valve neatly, allowing an
independent movement of the main valve and valve piston.

The preliminary valve is the ordinary ^D^ type and controls three
ports, as shown in Fig. 263, the two steam ports are connected with
either end of the auxiliary cylinder and the exhaust, with the small
port, _A_, in the main valve seat. The duty of the preliminary valve
is to alternately connect each end of the auxiliary cylinder with this
port. The main valve controls four ports, and is also of the ^D^ type,
having an extended cavity connecting the exhaust from the preliminary
valve with the main exhaust. The main valve also controls the main
steam and exhaust ports of the pump cylinder.

Steam enters the chest through the steam pipe, passes around the
central portion of the valve piston and through the passages in the
piston to both ends of the valve cylinder, thus balancing the valve
piston.

Suppose that the yoke and preliminary valve have been carried to the
back end of the chest, and have moved the main valve to bring its
auxiliary cavity over the auxiliary port, _A_, Fig. 263, in the main
valve seat, which connects the back end of the auxiliary cylinder
with the main exhaust. The steam from the end of the chest passes up
through port, _B_, down through port, _C_, and up through port, _A_,
into the exhaust port, _D_, in the main valve. This unbalances the
auxiliary piston, which is driven back by pressure on the opposite
end, and carries the main valve independently of the yoke. The travel
of the main valve causes it to cut off the exhaust from the auxiliary
cylinder, and the remaining steam cushions the valve piston.

[Illustration: FIG. 263.]

The travel of the main valve also opens the main steam port to the
forward end of the pump cylinder, and connects the back end of the
cylinder with the main exhaust, thus reversing the motion of the piston.

This action is repeated at the end of each stroke. Whatever position of
the piston, the pump will start when steam is turned on, as there is
always a connection either directly from the steam inlet to one of the
steam ports, or, if the main valve has covered both steam ports, it is
in a position to connect the auxiliary cavity in the main valve seat
with the main exhaust, which at once releases the steam from one end of
the valve piston, and the pressure on the other end drives the piston,
thus moving the main valve and giving direct communication between the
steam inlet and one of the main steam ports.

Thus it is seen that the piston cannot get into a position where it is
impossible for it to respond to the steam pressure.

_To set the valve_ place the piston in the mid-stroke position and set
the auxiliary valve with rocker arm plumb, and the preliminary valve
covering all its ports equally. These positions may be secured by
adjusting the position of the clamp on the valve stem and move the main
piston sufficiently so that the auxiliary valve will open one of its
ports.


THE BLAKESLEE.

[Illustration: FIG. 264.]

The accompanying engraving, Fig. 264, shows a section of the slide
valve chamber, which is fitted to the top of cylinder. The slide valve,
B, is fitted in the valve chamber, A, the cut-off valve, C, works on
top of the slide valve and is operated by the valve stem, D. The lever,
F, which moves the valve, is attached to the crosshead on the piston
rod. While the crosshead moves the length of the stroke, the cut-off
valve, C, moves twice the width of the steam ports in the cylinder.
The opening in the cut-off valve, C, is equal to the length of the dog,
E, plus the throw of the slide valve, B, plus one-sixteenth inch. The
length of the valve chamber on the inside is equal to the length of the
cut-off valve minus the throw of the cut-off valve. The valve stem,
D, is connected to the cut-off valve, C, so that it moves the latter
valve a distance proportional to the movement of the steam piston. The
opening through the cut-off valve is equal in width to the distance
from inside to inside of the ports on top of the slide valve. As the
piston moves to the right, as shown in the drawing, the cut-off valve
moves to the left, so as to open the right-hand end of the valve box
and admits steam, which acts upon the slide valve and moves it to the
left-hand end of the valve box. This opens the port wide in the slide
valve, which corresponds with the port leading to the cylinder while
in the upper side of the slide valve the port is nearly closed by
the cut-off valve, so that little steam is admitted to the cylinder;
consequently, the piston is gradually started on its return stroke. On
the return stroke the cut-off valve begins to move and opens one of the
ports on top of slide valve, which stands still until the piston has
made a half stroke.

By this time the valve is wide open “full port” to the cylinder. The
cut-off valve, C, coming in contact with the dog, E, both the slide
valve and cut-off valve move together to the end of the stroke. Notice
that as soon as the cut-off valve, C, engages the slide valve and it
begins to move, the port to the cylinder closes so that at the end of
the stroke but little steam can get to the piston. The cut-off valve
opens the valve box, A, to admit steam to complete the stroke of slide
valve, and should the steam fail to throw the slide valve, the piston,
by means of the cut-off valve, C, coming in contact with the dog, E,
moves the slide valve, thereby opening the opposite port and preventing
the piston from striking the cylinder head.

The lower corner of the slide valve, B, is removed and a slot cut to
the exhaust port, the slot being of sufficient size to release the
steam from the ends of the valve box and exhaust pressure of it into
the pocket of the slide valve.

The movement of this valve very much resembles that produced by means
of an eccentric. The movements of the valves are so timed that as the
main piston nears the end of the stroke its movement is sufficiently
retarded to permit the water valves to seat quietly and without jar,
also on the return stroke, the steam is so gradually admitted that
the piston starts with ease and gradually increases its speed to the
middle of the stroke, from which point it gradually decreases toward
the opposite end. A proper adjustment of the cut-off valve allows
the piston to stop momentarily at the ends of the stroke without any
possibility of striking the cylinder heads.

_To Set the Valve._ Adjust all joints so that there will be no lost
motion in the valve gear. Then move the crosshead to the end of
its stroke, and see that the cut-off valve opens the valve chamber
one-sixteenth of an inch, and that the steam valve closes the port
leading to the cylinder to within one-sixteenth of an inch. Next move
the crosshead to the other end of its stroke and note that the valves
are in the same relative position. If, from any cause the cut-off valve
does not open correctly to admit steam to the valve chamber at the ends
of the stroke of the piston, the valve can be shortened by filing off
the ends. This should not be done, however, until all lost motion has
been taken up in the valve gear.


THE HOOKER, WITH OUTSIDE VALVE GEAR.

In this pump (see Figs. 266, 267) the steam is admitted to the center
of the valve chamber which contains the main valve, A, and the
supplemental slide valve, B. The recess in the center of the valve
piston, C, receives the main valve and moves it when steam is supplied
to or exhausted from either end of the valve piston.

In operation live steam passes through the left-hand ports, D and E,
drives the main piston to the right and the exhaust passes out of
the right-hand port, F, into the cavity in the main valve, A, thence
through the exhaust port, G, into the atmosphere.

[Illustration: FIG. 265.]

As the main piston nears the right-hand port, the valve lever H,
attached to and moving with piston rod brings the dog, I, on plate, J,
in contact with the valve arm, K. This moves the supplemental valve, B,
to the right and supplies live steam to the right of the valve piston,
C, and exhausts the steam from the left-hand end through the ports, L.
The main valve, being enclosed by the valve piston, moves with it to
the left. As the steam enters the right hand main port and exhausts
from the left hand port, the main piston commences its return stroke
and the operation just described becomes practically continuous. As
the main piston closes the main port, F, to the right, it cushions on
compressed exhaust steam, because the main valve, A, has then closed
the auxiliary port, M, leading to that end of the main cylinder. The
steam in this case is supplied through the main and auxiliary ports,
but exhausts through the main port only.

[Illustration: FIG. 266.]

[Illustration: FIG. 267.]

_The slow movement of the main piston near the ends of the stroke_
allows the pump valves to seat quietly, and gives the pump cylinder
time to fill with water, thus effectually preventing shock and noise.
The valve piston, C, is cushioned by cushion valves, which are simply
loose valves inserted near the ends in the valve piston. By removing
the steam valve chamber, the main and supplemental valves may be
readily examined or repaired. These valves are the ordinary plain flat
slide with which all engineers are familiar.

_To set the valve of this pump._ Place the piston in the center of its
travel with the valve lever, H, plumb and also valve arm, K, plumb;
adjust the supplemental valve so as to cover equally all the posts,
which is done by lengthening or shortening its valve stem.


THE NATIONAL.

[Illustration: FIG. 268.]

[Illustration: FIG. 269.]

The main valve in this pump is moved by steam acting upon a valve
piston. The steam admitted to and released from the auxiliary cylinder
is controlled by a small slide valve operated by the valve gear. This
small slide valve is in every essential feature identical with the
slide valve of a steam engine, admitting and releasing the steam in
precisely the same manner. In this pump the usual collars and tappets
on the valve stem are dispensed with, the stem receiving motion by
means of a roller carried by a slide block to which the valve stem is
attached.

The roller is given a lateral motion by set screws in the forked ends
of the rocker arm, as shown in the engraving, Fig. 269. By adjusting
these set screws the travel of the small slide valve is made to suit
the speed of the pump, thus preventing the main piston from striking
the cylinder heads.

A sectional elevation of the cylinder and main valve is also shown; the
connection of the valve piston to the main valve, also the construction
of the small slide valve. The valve gear is provided with roller
bearings to reduce the friction.

_To set the valve._ The main piston must be moved to the end of the
stroke, so that the face of the piston and the edge of the steam port
are flush, as a preliminary step to set the small slide valve, then the
set screw in the rocker arm nearest the roller on the valve stem should
be adjusted so that when the roller is in contact with the set screw
the small slide valve will have opened the steam port corresponding to
the position of the main piston.

Now push the main piston to a corresponding position at the opposite
end of the stroke and adjust the other set screw nearest the roller on
the valve stem in the same manner as the first one.

Mark the striking points of piston on the piston rod close to the
stuffing-boxes. Start the pump slowly, and if the parts work smoothly,
gradually increase the speed, keeping close watch of the striking
points to see that the piston has ample clearance.

If the stroke is too short, the set screws should be backed out until
the stroke is found to be right. Screwing the set screws in shortens
the stroke and increases the clearance at the ends of the stroke. A
full stroke should always be required of every pump.


THE HILL.

[Illustration: FIG. 270.]

This pump is for deep wells; it has a valve piston and two slide valves
operated by valve stem, also supplemental port valves to regulate
and control the up and down strokes of the main piston. The main and
auxiliary valves are both flat slides, each covering five ports, as
shown in Fig. 271. The main valve is actuated by means of a valve
piston, the steam being admitted to and exhausted from the ends of the
valve piston in precisely the same manner that the main valve controls
the admission and release of steam in the main pump cylinder.

[Illustration: FIG. 271.]

One of the auxiliary ports enters the end of the main steam chest, and
the other enters at a point nearer the middle of the chest. The end
ports are admission only and the inner ones exhaust. When the auxiliary
valve reaches the upper end of its travel, as shown in the engraving,
the admission port opens at the bottom of the steam chest, while the
one at the top closes.

At the same time, the upper end of the main cylinder is open to the
exhaust. The admission of steam drives the valve piston upward, but
before reaching the end of its stroke it closes the exhaust port, thus
entrapping a portion of the exhaust steam, which cushions the valve
piston at the ends of the stroke.

The auxiliary slide valve is operated by means of a double-cone tappet
on the piston rod, which strikes a rocker bar pivoted to the frame of
the pump. The rocker bar carries an arm or lever at right angles to it
and to this arm the valve rod is connected.

A short shaft runs across and through the upper part of the steam chest
and is provided with a toe, as shown, by means of which the valve
piston may be moved by hand when necessary and without disconnecting
any part of the pump or valve gear.

[Illustration: FIG. 272.]

The port valves provide a simple means of contracting these passages
and regulating the velocity of the up and down strokes to meet the
requirements of the water ends of the pump so that uniform strokes are
obtained regardless of the resistance against the main piston.

When adjusting the auxiliary valve, place the rocker bar parallel to
the piston rod and so that the arm to which the valve rod is connected
will stand at right angles to the piston rod. The auxiliary valve must
then cover all the ports equally. The upper or outer end of the arm on
the rocker bar is slotted, hence moving the valve rod pin toward the
end of the arm lengthens the stroke and moving it toward the piston rod
shortens it.

_To set the valve_ of this pump it is necessary only to square the
levers and equalize the travel.


THE GUILD AND GARRISON.

[Illustration: FIG. 273.]

[Illustration: FIG. 274.]

The steam chest of this pump differs somewhat from other pumps in
which valve pistons are employed to operate the main valve. See
accompanying engraving, Fig. 272. This pump has a steam chest with a
cover for inspection and repairs. This chest is bored at each end to
form suitable cylinders to receive the valve piston, E. By the side of
the valve piston, E, in the steam chest is an auxiliary slide valve, G,
Figs. 273 and 274, which admits and releases the steam from the ends of
the valve piston. The valve piston, E, has two slots at the center, the
lower one receiving the lug on the back of the main valve and the upper
one the toe on the rocker shaft, D. The rocker shaft has two toes, the
larger one, F, engaging with the valve piston, and the smaller one with
the auxiliary slide valve, G, as shown in Fig. 274. The auxiliary, as
well as the main, valves are plain slides designed to take up the wear
automatically. The pendulum lever, J, Fig. 273, is connected with the
piston rod as shown and rotates the shaft, D, and by means of the toes
the valves move together.

The auxiliary slide valve, G, admits and exhausts the steam to and from
the ends of the valve piston. Steam being admitted, the piston moves
toward one end. The two valves also move in the same direction by means
of the rocker shaft and the toes. This movement continues until the
piston has nearly completed its stroke, when the auxiliary valve opens
one of the small ports leading to the end of the valve piston, thus
admitting steam at one end and exhausting it from the other. The valve
piston moving from one end of the steam chest to the other, shifts the
position of the main valve and reverses the motion of the main piston.
The valve piston is moved the greater part of its travel by the toe
on the rocker shaft, thus reversing the steam distribution, by steam
pressure, which brings the opposite end of the slot in the driver to
a second engagement by the toe on the rocker shaft which begins the
return stroke.

The steam acts to throw the main valve only near the ends of the valve
travel, and being already in motion the valve requires but very slight
help to complete its stroke quickly without shock.

The motion of the auxiliary valve is synonymous with the main piston
so there can be no practical dead center. The valves are very durable
under such easy motion.

_With this arrangement of valves no setting is necessary_ because when
assembling the parts the centers of the pendulum lever and the toes on
the rocker shaft are adjusted parallel with one another.


THE McGOWAN.

The McGowan single cylinder steam pump and section is shown in Fig.
275. Its main valve is of the ^B^ form and is driven by a valve piston.
Steam enters the central port in valve seat and into the cylinder
through one of the cavities in the valve and exhausts through the
opposite. The two tappet valves cover the auxiliary ports, shown by
dotted lines, leading to the ends of the steam chest and connect with
the main exhaust ports. These tappet valves are raised by means of
levers, the ends of which project downward and into the cylinder so
that when the piston nears the end of a stroke it comes in contact with
the lever and raises it sufficiently to lift the tappet valves.

Each tappet valve lever is pivoted on a pin which fits into a recess
near the main ports, as indicated by the dotted lines.

[Illustration: FIG. 275.]

When the piston reaches the end of its stroke it lifts one of the
tappet levers and with it the corresponding valve is raised from its
seat, opening the port leading from the end of the steam chest to
the main exhaust port. The pressure is thus relieved on one end of
the valve piston and the steam pressing on the opposite end forces
the valve piston to the opposite end of its stroke, thus reversing
the distribution of steam to the cylinder and starting the piston on
its return stroke. The valve piston thus moves back and forth, the
ends of the steam chest being filled with steam at initial pressure.
Steam escaping from one end of the steam chest causes a difference of
pressure on the two ends of the valve piston, from which we realize the
power to move the main valve. The tappet valves, having a very slight
lift, operate without shock or noise. The main valve is connected with
the valve piston so that all lost motion is taken up automatically.

A rocker shaft, extending through the steam chest carries a toe moving
in a slot in the top of the valve piston, so that the valve can be
moved by hand.

_To set the valves of this pump._ Simply keep the valves in order. The
motion of the piston as it nears the end of the stroke opens and closes
the valves.


THE KNOWLES.

In the Knowles pump a valve piston, G, Fig. 277, in the steam chest
moves the main valve. This valve piston is driven alternately backward
and forward by the pressure of steam, carrying with it the main valve,
which admits steam to the main steam piston that operates the pump. The
main valve is a plain slide whose section is of ^B^ form, working on a
flat seat.

[Illustration: FIG. 276.]

[Illustration: FIG. 277.]

The valve piston is slightly rotated back and forth by the rocker bar,
H; this rotative movement places the small steam ports, D E F, Fig.
276, which are located in the under side of the valve piston in proper
position with reference to the corresponding ports, A B, cut in the
steam chest. Steam enters through the port at one end and fills the
space between the valve piston and the head, drives the valve piston
to the end of its stroke and carries the main slide valve with it.
When the valve piston has traveled a certain distance, a corresponding
port in the opposite end is uncovered and steam enters, stopping its
progress by giving it the necessary cushion. In other words, when the
reciprocating rotative motion is given to the valve piston through the
outside mechanism, it opens the port to steam admission on one end, and
at the same time opens the port on the other end to the exhaust. There
is no point in the stroke at which either the valve piston or the main
piston is not open to direct steam pressure, hence the immunity from
any dead position or dead center.

The operation of the pump is as follows: The piston rod with its tappet
arm, J, Fig. 277, moves backward and forward with the piston. At the
lower part of this tappet arm is attached a stud or bolt, K, on which
is a friction roller, I. This friction roller, lowered or raised,
adjusts the pump for a longer or shorter stroke. This roller coming in
contact with the rocker bar at the end of each stroke, and this motion
is transmitted to the valve stem, causing the valve to roll slightly.
This action opens the ports, admits steam and moves the valve piston,
which carries with it the main slide valve which admits steam to the
main piston. The upper end of the tappet arm does not come in contact
with the tappets, L M, on the valve rod, unless the steam pressure
from any cause should fail to move the valve piston, in which case the
tappet arm moves it mechanically.

_To set the valve_, loosen the set screws in the tappets on the valve
stem. Then place the piston at mid-stroke, and have the rocker bar, H,
in a horizontal position, as shown in the engraving. The valve piston
should then occupy the position shown at C, Fig. 276. The valve piston
may be rotated slightly in order to obtain this position by adjusting
the length of connection between the rocker bar, H, and the valve stem.
Then turn the valve piston, G, one way or the other to its extreme
position, put on the chest cover, and start the pump slowly.

If the pump should make a longer stroke on one end than on the other,
simply lengthen or shorten the rocker connection so that the rocker
bar, H, will touch the rocker roller, I, equally distant from the
center pin, J.

In case the pump hesitates in making its return stroke, it is because
the rocker roller, I, is too low and does not come in contact with the
rocker bar, H, soon enough. To raise it, take out the rocker roller
stud, K, give the set screw in this stud a sufficient downward turn,
and the stud with its roller may at once be raised to its proper height.

[Illustration: FIG. 278.]

When the valve rod has a tendency to tremble, slightly tighten the
valve rod stuffing-box nut. When the valve motion is properly adjusted,
the vertical arm should not quite touch the collar, L, and the clamp,
M. Rocker roller, I, coming in contact with the rocker bar, H, reverses
the stroke.

The water piston is packed by means of segments that will be seen by
taking off the follower. The packing may be quickly set out to insure
a good vacuum and at the same time not to be so tight as to bind. All
wearing parts are made adjustable.


THE MOORE.

The valve for admitting steam to and exhausting it from the cylinder
of this pump is contained within the cylinder and moves simultaneously
with the steam piston, having no outside mechanism. See Fig. 278.

The piston, and also the valve, are of the form of spools, each
representing a hollow sleeve with a ring packed piston head at
either end. The piston is secured to the piston rod and the sleeve
connecting the two heads serves as the valve seat for the cylindrical
valve. The sleeve of the piston contains two longitudinal ports, one
port communicating with one end of the cylinder, and the other port
communicating with the opposite end. Suitable holes drilled through the
walls of the sleeve and communicating with the longitudinal ports, act
as admission and exhaust ports, with which the holes and cavities in
the sleeve coincide at proper positions in the stroke.

Referring to the accompanying engraving, Fig. 279, which represents
the valve and piston in the position occupied when ready to commence a
stroke from left to right, the reader will easily understand the action
of these parts. When the piston reaches the end of the stroke steam
enters through the steam pipe at A, between the pistons, and forces
the valve to the left as shown. This movement opens the port, B, and
also brings the cavity, C, in communication with port, D, steam being
admitted through ports, B and D, into the longitudinal port, F, thence
into the clearance, G, of the cylinder. This causes the piston to move
toward the right. When the piston has moved a short distance to the
right steam is admitted into the space, H, surrounding the valve, and
passing into the cavity, C, and through the port, D, furnishes steam to
complete the stroke.

Should the piston stop at mid-stroke it will start again as soon as
steam is turned on, because the port, D, remains open until the valve
is reversed at the opposite end of the stroke.

When the piston reaches the latter position, Fig. 280, the valve is
reversed, due to steam entering at A, and again forcing the pistons
apart, as shown. The steam, which drove the piston from left to right,
now escapes through the port, I, into the cavity, J, and around the
sleeve to the holes, K, Fig. 279, where it enters the hollow piston,
and finally escapes through the hollow rod, L, and the port, M. The
live steam for the next stroke from right to left, now enters through
ports, N and O, Fig. 280, and flows through the longitudinal port, P,
into the end, Q, of the cylinder.

[Illustration: FIG. 279.]

[Illustration: FIG. 280.]

The exhaust steam may be allowed to flow into the atmosphere or into
the suction chamber as desired. A valve is located in the base of
the pump, which changes the course of the steam from the atmospheric
discharge to the suction chamber. The valve is operated by a lever
shown by dotted lines. When the lever is turned down toward the steam
end, the steam is directed into the atmospheric exhaust, and when
turned in the opposite direction the steam will enter the pump suction
and be condensed.

_There is no valve setting to be done on this pump._ Should the pump
fail to work properly, due to the failure of the steam end, all that is
necessary is to take out the valve and piston and clean them thoroughly
and after replacing them and starting the pump to see that these parts
are properly lubricated. The remainder of the pump requires the same
care and attention that is, or should be, given all pumps.


THE SNOW.

The auxiliary valve of this pump is a plain flat slide operated by a
valve stem, the latter being moved back and forth by means of a rocker
shaft, as shown in the engraving, the upper end of which alternately
comes in contact with the collars on the stem.

The outer end of the valve stem passes through a sleeve attached to
a pin in the upper end of the rocker arm, as shown. A knuckle joint
near the stuffing-box permits the rod to vibrate without causing any
derangement in the alignment of valve stem through the stuffing-boxes.

On the valve stem at either end of the auxiliary valve is a spring,
which tends to keep the valve in a central position, so that when the
rocker arm engages one of the collars, the valve is drawn against the
spring toward that end of the stroke. The result is that the stem and
valve follow the rocker arm on the return stroke to its mid-position,
and are started on the latter half of the stroke by the stem, but
without shock or lost motion. This arrangement is particularly valuable
in the case of condensers, and in pumps where the first part of the
stroke is made quickly, and the piston is then suddenly stopped by
coming in contact with a solid body of water, the latter part of the
stroke being made much more slowly. The springs on either side of the
auxiliary valve take up lost motion and keep the parts in absolute
contact, thus preventing shocks and unnecessary wear.

[Illustration: FIG. 281.]

[Illustration: FIG. 282.]

The auxiliary valve controls the admission and exhaust of steam for the
steam chest and valve piston in the manner common to all slide valve
engines. The valve piston is connected to the main valve, which allows
the valve to find its own bearings on the seat and not only takes up
the wear automatically, but produces even wear.

_To set the auxiliary valve_, see that the valve is in its central
position when the rocker arm is plumb, and that the collars on the
valve stem are located at equal distances from each end of the sleeve.
When the piston moves to one end of the stroke, the auxiliary valve
will open the small port at the opposite end, provided the collars on
the valve stem have been properly placed. Setting the collars closer
together shortens the stroke of the piston, and moving them farther
apart lengthens the stroke. The piston should always make a full stroke
without danger of striking the cylinder heads.


THE DEANE.

The details of the valve gear used on the Deane single cylinder steam
pumps are shown in the accompanying engraving. The main valve is
operated by a small piston called the valve piston, shown in Fig. 286.
The ears on the main valve fit freely but without lost motion into a
slot cut in the valve piston, so that when the valve piston moves in
either direction it carries the main valve with it.

The valve piston is fitted to the valve chest and is operated by steam
admitted alternately to the opposite ends of the chest. The movements
of this valve piston are controlled by a secondary valve, which admits
and exhausts the steam to the valve piston through the small ports at
the sides of the steam chest. The secondary valve derives its motion
from the valve stem, tappets, links and the piston rod as shown.

The valve piston is steam jacketed which insures equal expansion of the
parts in starting the pump and prevents the seats from pinching the
valve piston before these parts have acquired a uniform temperature.

The action of this pump is as follows: Suppose the piston moving in the
direction of the arrow nears the end of the stroke; the tappet block
comes in contact with the left-hand tappet and throws the secondary
valve to the left until it’s edge, A, Fig. 284, uncovers the small
port, S, Fig. 283, admitting steam to the valve piston.

The port, E, and chamber, F, in the secondary valve provide for
the exhaust of steam from the left-hand end of valve piston in the
same manner and at the same time that steam is admitted behind the
right-hand end. The exhaust ports in the chest allow for properly
cushioning the valve piston. The small ports on the other side of the
steam cylinder, Fig. 283, control the motion of the valve in the other
direction and act in exactly the same manner as those just described.
In case the steam pressure should for any reason fail to start the
valve piston in time there is a lug, B, Fig. 286, which forms a part
of the valve stem and comes in contact with the valve piston and the
entire power of the steam cylinder starts it. The correct timing of the
valve movements is controlled by the position of the tappets. If they
are too near together, the valve will be thrown too soon and thus the
stroke of the pump will be shortened, while on the other hand if too
far apart, the pump will complete its stroke without moving the valves.
The tappets are set and keyed securely before leaving the factory.

[Illustration: FIGS. 283-285.]

[Illustration: FIG. 286.]

The exhaust from the cylinder is cut off when the piston covers the
inner port, and forms a steam cushion for the piston to prevent it
striking the heads.

_To set the valve._ Place the steam piston at the end of stroke nearest
stuffing-box and the secondary valve so that it will uncover the steam
port, S, Fig. 283. Set the tappet next to the steam cylinder on the
valve stem against the tappet block and secure it in this position.

Slide the secondary valve forward until the opposite steam port is
uncovered and place the steam piston in its extreme outward position,
then set the other tappet against the tappet block. Now set the valve
so that the inside main steam port is open and the valve piston in
position to engage the main steam valve, put the valve chest on the
cylinder and secure it in place. The pump will then be ready to start
on the admission of steam to the steam chest.

If when steam is turned on the pump refuses to start, simply move the
valve rod by hand to the end of its stroke and the pump will move
without trouble.

In renewing the packing between the steam chest and cylinder extreme
caution should be observed to cut out openings for the small ports.


THE BUFFALO SINGLE CYLINDER PUMP.

The engravings, Figs. 287, 288, show the valve gear, also section of
steam cylinder and steam chest. The piston and valves are in their
central position, which condition never occurs in the operation of this
pump; if it did the pump would stop. The valves and pistons being at
one end or the other of the stroke uncovers the ports, and the moment
steam is admitted the pump will start. Referring to the engravings, A,
is the main steam pipe, and B, the auxiliary steam pipe. These pipes
are one, inside the casting, so that one pipe supplies both. Assume the
valve, C, moved to the left so that the port, D, is uncovered.


[Illustration: FIG. 287.]

[Illustration: FIG. 288.]

Live steam then flows through the port, D, and pushes the balanced
piston valve, E, to the left, carrying the slide valve, F, with it to
the left, so that the port, G, is opened to the steam cylinder. The
steam enters through the port, G, pushes the main piston, H, to the
left, completing one stroke of the piston. As the piston travels to
the left the lever, J, pushes the crosshead, I, to the right, which
opens corresponding ports in the left-hand end of the cylinder, and
the piston valve, E, is pushed to the right, which admits steam on the
left-hand side of the main piston through the port, K, pushing the
piston to the right, completing the second stroke of the piston. The
auxiliary slide valve, C, is operated by the crosshead, I, coming in
contact with the tappets, L L.

The auxiliary tappets and stem, M M, theoretically could be dispensed
with, but they are put in place for the reason that occasionally the
valve, E, might stick, due to the pump standing for some time unused
or from some other cause. In such a contingency the crosshead, I, is
pushed to the right by the action of the main piston and comes in
contact with the tappets, M M, which causes the piston valve to start,
after which steam will complete the work. When the pump is running, the
crosshead, I, never quite touches the tappets, M M, because it engages
the tappets, L L, admitting steam to the piston valve and shifts it
before the tappets, M M, are touched.

The reason of the double ports in the auxiliary steam chest is to
have one port, D, for steam, and one port, N, for the exhaust. Steam
being imprisoned between these two ports forms a cushion, preventing
the piston valve from striking the heads of the chest. The tappets,
L L, set closer together or farther apart control the stroke of the
main piston, H. When the pump is running very fast the momentum of
the moving parts increases and the tappets will have to be set closer
together for high speed than for slow. The tappets, M M, are adjustable
to their right relation with the tappets, L L. The general design and
easy means of adjustment make a reliable single cylinder valve motion.

_To set the valves._ There are no complicated internal parts requiring
adjustment, and almost all parts requiring manipulation can be handled
while the pump is running.


THE WEINMAN.

The accompanying engraving, Fig. 289, represents the Weinman pump and
the sectional engraving, Fig. 291, the valve motion.

[Illustration: FIG. 289.]

The motion of the main piston is controlled by steam valve, A, which
is a hollow cylinder combining a valve piston and slide valve in one
and the same casting and sliding horizontally in steam chest, D. This
valve is prevented from revolving by a cap screw, B. Small drilled
openings, C, C, permit the steam to pass from the steam valve to each
end of the steam chest, D. This valve, A, is moved horizontally in
either direction by steam pressure, and the movement is controlled
by an auxiliary valve, E. The openings, F, F (Fig. 290), conduct the
steam from the ends of the steam chest to the auxiliary valve, which is
connected to the piston rod by a tappet rod and the side arm, X.

Steam being admitted to steam chest, it passes through steam valve,
A, to ports, H, H. As the construction permits but one of the ports,
H, H, to be in communication at a time with one of the passages, I,
I, leading to the opposite ends of the steam cylinder a dead center
becomes an impossibility. While one of the ports, H, H, is in
communication with one of the passages, I, I, the opposite passage, I,
is in communication with the exhaust, J.

[Illustration: FIG. 290.]

Suppose that the steam piston has moved to the end of its stroke, the
auxiliary valve, which, as stated above, is connected to the piston
rod, is shifted. This releases the steam from one end of the steam
chest, D, through port, K, to exhaust, L. The steam pressure at the
opposite end of the steam chest causes the steam valve to slide to
opposite end of the steam chest, thus reversing the motion of the main
steam piston.

To set the auxiliary valve, remove the pendulum or tappet lever, X,
and the cap or bonnet, O, and take out the auxiliary valve, E. With a
straight edge and scriber indicate the working edges on the end of the
valve, and mark the edge of the port on the valve seat so that it can
be seen when the auxiliary valve is in its proper place. Replace the
valve, and the pendulum lever, omitting the bonnet.

[Illustration: FIG. 291.]

Push the steam piston to one end of the stroke, then swing the pendulum
lever toward the end of the cylinder corresponding to the piston, and
until the auxiliary valve uncovers the port leading to the end of the
valve chest farthest from the piston. Connect the horizontal rod to the
bottom of the pendulum lever. Then remove the lever from the auxiliary
valve stem and replace the bonnet and pendulum lever, shown by dotted
lines. The length of the stroke may be regulated by raising or lowering
the end of the horizontal rod in the slotted lower end of the pendulum
lever. Lowering the rod produces a longer stroke, and raising it
shortens the stroke.


THE BURNHAM.

[Illustration: FIG. 292.]

The accompanying engravings illustrate the cylinder valves and valve
motion of the Burnham single cylinder pump. Fig. 294 is a plan of the
main cylinder valve face, having the same arrangement of ports as the
cylinder shown in Fig. 293.

A longitudinal section of the steam cylinder is shown in Fig. 292.
Motion is imparted to the slotted arm and cam, A, by means of a
crosshead and a roller on the piston rod.

The cam works between and in contact with two blocks on the valve
stem, and by adjusting these two blocks the stroke may be shortened or
lengthened, as the case may require. The valve stem of the auxiliary
valve, H, Fig. 293, always moves in a direction opposite to that of the
piston.

The action of this valve alternately admits steam through the double
ports, J J, and K K, to each end of the valve cylinder, causing the
valve piston, I, to move the main slide valve, D, which, in turn,
admits steam to the main cylinder through the double ports, E E, and
L L. As the travel of the cam is only one-fifth that of the piston
travel, the valve moves slowly, and without jar or noise which is often
caused by long travel and rapid motion.

[Illustration: FIG. 293.]

[Illustration: FIG. 294.]

Steam enters the steam chest at B, and fills the space, F, between the
valve piston heads and the auxiliary valve chest, G, shown in Fig. 292.
With the auxiliary valve, H, in the position shown, Fig. 293, steam
passes into both ports, J and K, but as the port, J_{1}, is closed by
the valve piston, I, no steam can enter the valve cylinder through
it, but the other port, K (extending to the extreme end of the valve
cylinder), never being covered by the piston, is open, and admits steam
into the space, M.

As this port is quite small the space fills slowly and the piston moves
gradually until it uncovers the last port, J_{1}, when the full volume
of steam is admitted, which quickly moves the piston to the opposite
end of the valve cylinder. During this movement of the valve piston,
the large port, J, remains open to the exhaust until it is covered
by the valve piston. When the port, J, is covered by the valve as at
J_{1}, it has no connection with the exhaust, consequently, there being
no outlet for the exhaust vapor, it is compressed and forms a cushion
for the valve piston, I. The valve piston carries with it the main
valve, D, which admits steam to the main steam cylinder through the
double ports, E, E_{1}, and L, L_{1}, Fig. 294. The same cushioning
and slow starting of the piston occurs in the main as in the valve
cylinder, each having double ports.

This arrangement insures a uniform travel of piston under varying
degrees of load. A momentary pause of the piston at each end of the
stroke permits the water valves to seat quietly, without shock or jar,
and the slow initial movement of the piston (whereby the water columns
are started gradually) relieves the pump and piping of excessive
strains.

_To set the valve._ Set the lever, A, plumb and the valve to cover all
the ports equally.


THE DEAN BROS. PUMP.

The Dean Bros. pump is shown in Figs. 295, 296 and 297.

[Illustration: FIG. 295.]

The auxiliary valve, A, Fig. 297, has in its face two diagonal exhaust
cavities, B B_{1}. The ports, C C_{1}, and the exhaust port, D, are
placed in a triangular position with one another, the diagonal cavities
diverging so that the cavity B, when the valve is in place, connects
the ports, C_{1} and D. Cavity B_{1} connects the ports C and D, when
the valve, A, is at the end of the stroke. The three small cuts show
relation of auxiliary valve to ports.

[Illustration: FIG. 296.]

The piston starts from left to right when the valve, A, moves in an
opposite direction, opens the port, C, admitting steam to the auxiliary
cylinder at the moment the main piston has reached the end of its
stroke. The auxiliary piston, E, is forced to the left, opening the
main port and admitting steam to the main cylinder, reversing the
movement of the main piston the return stroke of the main piston
reverses the movement of the auxiliary valve, whereby the port, C, is
closed, at the moment the main piston reaches the end of its outer
stroke. The port, C_{1}, is opened by the valve, A, and reverses the
valve piston, E, opens the main port and reverses the motion of the
main piston.

[Illustration: FIG. 297.]

This port arrangement admits of a short valve with a long travel. The
stroke of the pump can be regulated by moving the stud up or down in
the segmental slot, Fig. 296, which varies the travel of the auxiliary
valve and reverses the stroke of the main piston as desired. By raising
the stud the pump will make shorter strokes, and by lowering it will
make longer strokes.

The motion of the auxiliary steam slide valve is like that derived
from an eccentric. The ports leading to the valve piston, E, Fig. 297,
remain closed, except at the moment the main piston is reversed; hence,
there can be no waste of steam from leaks when the valve piston becomes
worn.

Having a long stroke and a rapid motion, the auxiliary valve insures a
certain reversal of the piston at the proper time.

_To set the valve_, turn the steam chest upside down. Put valve stem
through the stuffing-box and secure in place the clamp for small
slide valve. The diameter of valve stem is smaller where the clamp is
attached.

Now screw up the stuffing-box nut (having previously removed the
packing), then move the valve and stem so that the small port at right
of valve will be open 1/16 inch and make a scratch upon the stem close
to stuffing-box nut. The valve should then be moved in the opposite
direction to open the other small port 1/16 inch and make a second
scratch upon the valve stem next to stuffing-box nut. Prepare joint
and replace steam chest on cylinder. To square the valve, slacken the
screw in crosshead and move the latter to the end of stroke with edge
of crosshead flush with the end of guide, then set the valve stem so
that the first scratch is flush with the face of nut, same as when the
scratch was made. Tighten screw in set screw under valve rod dog and
move the crosshead to the opposite end of stroke, and note the position
of second scratch. If it does not come to the position in which it was
made, _split the difference by slackening the set screw under valve rod
dog and move the valve rod to equalize the travel of valve_.

In replacing steam chest on cylinder, cover the opening with a thin
board, or piece of sheet iron, before turning it over to prevent the
valve from dropping out of place.

This slide valve has a fixed travel and _the process of setting is
precisely the same as for that upon a steam engine with a plain slide
valve_.


SMITH-VAILE SINGLE PUMP.

[Illustration: FIGS. 298, 299.]

The accompanying sectional view of steam end of the “Smith-Vaile”
exhibits some very novel features. So far as the piston and cylinder
in this pump are concerned they are not unlike the average first class
pump, but with this difference. It has only one set of cored ports, B,
B. The supplemental ports, C, C, are drilled.

The main valve, A, is a slide and is moved by a valve piston, D. Almost
all the valve pistons as now made are simply plugs turned accurately
to fit the holes in the chest and without any means of adjustment to
compensate for wear. After these valve pistons become worn they have to
be replaced with new ones, but there is a period between the time when
the valve piston becomes so leaky as to render the action of the pump
uncertain and the time when the worn valve is replaced by a new one
that the pump is very wasteful of steam.

The valve piston in this pump is provided with packing rings, E, E,
which compensate for wear of these parts so that this valve is expected
to do efficient service long after a slow valve. The supplemental
valve, F, has a reciprocating rotary motion which is communicated to
it by the rock arm, G, and pitman, H, connecting with the crosshead,
I, secured to the piston rod. It will be observed that the piston
rod, J, and the rod, K, of the water end are separated so that should
either one give out through wear or accident it can be replaced without
sacrificing both, as would be the case if they were solid in one
piece. This supplemental valve, F, in general appearance very closely
resembles the “Corliss” valve, and its action is somewhat similar, in
controlling the action of the valve piston, which will be understood
from the engraving without further description. These pumps all have
removable water ends and can be rebored or otherwise manipulated
without disturbing the steam end of pump. The cylinder can be separated
from the foot by removing the bolt, M.

The duplex pump is also shown in the accompanying engraving, where, A,
A, represents the steam cylinders, secured to the foot, B, by bolts, as
previously described.

The usual slide valves have been replaced by piston valves, C, in this
instance and are provided with removable seats, D, D.

These piston valves have packing rings, E, E, also to compensate for
wear and the valves are cast hollow to reduce their weight as much as
possible consistent with good workmanship, also to serve as ports for
steam admission. When these valve seats become worn they may be easily
removed and rebored or replaced by new ones, as desired. It will be
observed that these ports are very short to reduce the clearance as
much as possible, and to secure a more satisfactory cushion. Each valve
is operated by the rock arm connected with the opposite engine in the
usual way.



  THE DUPLEX
  PUMP

[Illustration: FIG. 300.]


THE DUPLEX STEAM PUMP.

[Illustration: FIG. 301.]

_The word duplex_ means two fold, or double, and has a wide
application, as the duplex lathe, the duplex watch, etc., hence, the
well-known duplex-pump is one in which _two direct acting pumps are
placed side by side_ and so connected that the steam piston of one
operates the valve of the other. See Fig. 300.

Fig. 301 shows one of the smallest manufactured patterns of this type
of pumps. Its dimensions are as follows: 2-inch diam. steam cylinder;
1-1/8-inch water cylinder; 2-2/3-inch stroke. Its capacity is .044
gallons per revolution; rev. per minute, 80; gallons per minute, 3.5.
Steam pipe, 3/8-inch; exhaust pipe, 1/2-inch; suction pipe, 1-inch;
discharge, 3/4-inch. Floor space occupied, 1´ 9″ × 7″ wide; requires
1/2 H.P.

The valve motion (see Figs. 302, 303) of one cylinder is communicated
or produced by the piston of the other through the medium of rocker
arms and links. By means of the small lost motion of the levers the
pistons have a slight pause at the end of each stroke, which allows the
water valves to seat quietly, thus preventing any slam or jar.

With this arrangement, as one of the steam valves must always be open,
there can be no dead point, thus removing the liability of the pump to
stick. The simplicity of the duplex movement is at once evident, each
valve is dependent upon its counter part, and both directly control
the action of the steam, which is supplied through one simple throttle
valve.

  NOTE.—Of the effect produced by the steam-moved direct-acting pump of
  much greater capacity it may be said there are now in use pumps of
  this class, exerting over 250 horse-power, delivering five million
  gallons of water in twenty-four hours through main pipes, say thirty
  inches diameter and fourteen miles long, without the use of an air
  chamber, and which do their work so quietly, steadily, and gently,
  that a nickel coin set on edge on the extreme end of the pump would
  not be overthrown by any jar or motion of the pump while it was doing
  this work.

[Illustration: FIG. 302.]

[Illustration: FIG. 303.]

_The adoption of the Worthington design of duplex pumps_, has been
well nigh universal, especially so since the expiration of the earlier
patents. Nearly all leading manufacturers now make “duplex pumps.”
Single, compound and triple expansion.

Compounding consists of adding a second steam cylinder on the end of
the high pressure in use, both using the same piston rod, the steam
from the boiler being first used in the smaller cylinder, and at the
end of the stroke of the piston being exhausted behind the piston of
the larger cylinder on its return stroke. In this way the measure of
the expansion of the steam used, was the relation of one cylinder to
the other.

By this arrangement a much smaller steam cylinder, for using the high
pressure steam, could be adapted to do the same work, for in addition
to the pressure of steam working full stroke in the small cylinder,
was to be added the pressure of the steam being expanded in the large
cylinder.

In addition to this, for large compound and triple expansion engines
was added the further economy realized by attaching a condenser to form
a vacuum in the large steam cylinders.

Adapting these newer improvements in the marine engine coupled with
what had previously been accomplished in the direct-acting steam pump,
they were at once brought up in size, capacity, and economy alongside
the previously constructed rotative pumping engines.

The history of the invention of this pump is given on pages 69 and 70;
to these pages a careful attention is advised, as they briefly describe
also the fundamental principles of its operation. This form of steam
pump has been so long and generally in use that the valve mechanism is
already familiar to most engineers.

The simplicity of both its theory and its practical application
obviates the necessity of devoting very much space to its
consideration. The final improvement made by Worthington in connection
with the steam duplex pump was in the adaptation of triple expansion in
its steam ends.


THE WORTHINGTON DUPLEX PUMP.

The illustrations, Figs. 302 and 303, are sectional views of one side,
or half, of the Worthington steam pump, showing two different designs.
They illustrate the interior arrangement of the pump. The valve, as may
be seen at, E, is an ordinary slide valve; the motion of this valve is
controlled by a vibrating arm, F, which swings through the whole length
of the stroke. The moving parts are always in contact, which ensures
smooth and even motion.

_This valve motion is the prominent and distinguishing characteristic
of the Worthington duplex pump._ Two steam pumps are placed side by
side and so combined that one piston acts to give steam to the other,
after which it finishes its own stroke and waits for its valve to be
acted upon by the other pump before it can renew its motion. This pause
allows the water valves to seat quietly, and removes any harshness of
motion. As one or the other of the steam valves is always open, there
is no dead point, and therefore the pump is always ready to start when
the steam is admitted.

[Illustration: FIG. 304.]

_In the plunger and ring pattern_, Fig. 302, there is a double-acting
plunger, B, working through a deep metallic ring bored to fit the
plunger. The plunger is located some inches above the suction valves,
leaving a _settling chamber_, into which any foreign substance may
fall out of the way of the wearing surfaces. Both the plunger and ring
can be taken out and either refitted or, when necessary, renewed. The
valves consist of small discs of rubber, or other suitable material,
and are easily accessible through convenient handholes. This pattern is
recommended where the liquid to be pumped contains small quantities of
grit or foreign material, or where there is an unusually long or high
suction lift.

_In the piston-pattern pump_, Fig. 303, there is a packed water piston,
G, working in a brass-lined cylinder, H. Both the suction and the
discharge valves are located above the water pistons, so that the
pistons may be at all times submerged. This pattern is recommended
where the liquid to be pumped _contains no grit or foreign material_.

Fig. 304 _shows the Worthington Admiralty pattern boiler feed pump_
which is designed to meet the requirements of the United States Bureau
of Steam Engineering for steam boiler pressure up to 250 lbs. to the
square inch. The ordinary slide valves are replaced by piston valves
with outside, adjustable, lost-motion links, making it possible to
readily adjust the stroke. The water end is made of composition, gun
metal, or cast-iron, as desired. When made of cast iron the water end
is brass-fitted throughout.

  TABLE OF SIZES, CAPACITIES, ETC.

  ===========+===========+========+=================
             |           |        |  Horse-power
             |           |        | of Boiler based
             |           |        | on 45 pounds of
             |           |        | water per hour,
             |           |        |   which this
  Diameter of|Diameter of| Length |   pump will
    Steam    |   Water   |   of   |   supply at
  Cylinders  |  Pistons  | Stroke |  slow speed.
  -----------+-----------+--------+-----------------
     4-1/2   |   2-3/4   |    4   |      170
     5-1/4   |   3-1/2   |    5   |      280
     6       |   4       |    6   |      470
             |           |        |
     6       |   4-1/2   |    6   |      590
     7-1/2   |   5       |    6   |      670
     9       |   6       |    6   |      960
             |           |        |
     7-1/2   |   4-1/2   |   10   |      800
     9       |   6       |   10   |     1400
    10       |   7       |   10   |     2200
             |           |        |
    12       |   8-1/2   |   10   |     3200
    12       |   9-1/4   |   10   |     3800
    14       |  10       |   15   |     4800
  -----------+-----------+--------+-----------------

  ===========+===========+========+======================================
             |           |        |          Sizes of Pipes for
             |           |        |            Short Lengths
             |           |        |          To be enlarged as
             |           |        |          length increases.
             |           |        +-------+---------+---------+----------
  Diameter of|Diameter of| Length |       |         |         |
    Steam    |   Water   |   of   | Steam | Exhaust | Suction | Delivery
  Cylinders  |  Pistons  | Stroke | Pipe  |   Pipe  |   Pipe  |   Pipe
  -----------+-----------+--------+-------+---------+---------+----------
     4-1/2   |   2-3/4   |    4   |   3/4 |  1-1/4  |  2      |   2
     5-1/4   |   3-1/2   |    5   | 1     |  1-1/2  |  2-1/2  |   2-1/2
     6       |   4       |    6   | 1-1/2 |  2      |  4      |   3
             |           |        |       |         |         |
     6       |   4-1/2   |    6   | 1-1/2 |  2      |  4      |   3
     7-1/2   |   5       |    6   | 1-1/2 |  2      |  5      |   4
     9       |   6       |    6   | 2     |  2-1/2  |  5      |   4
             |           |        |       |         |         |
     7-1/2   |   4-1/2   |   10   | 1-1/2 |  2      |  4      |   3
     9       |   6       |   10   | 2     |  2-1/2  |  5      |   4
    10       |   7       |   10   | 2     |  2-1/2  |  6      |   5
             |           |        |       |         |         |
    12       |   8-1/2   |   10   | 2-1/2 |  3      |  6      |   5
    12       |   9-1/4   |   10   | 2-1/2 |  3      |  6      |   6
    14       |  10       |   15   | 2-1/2 |  3      |  8      |   6
  -----------+-----------+--------+-------+---------+---------+----------


  ===========+===========+========+=========================
             |           |        |
             |           |        |   Approximate Space
             |           |        |       Occupied
             |           |        |         Inches
             |           |        +--------+-------+--------
  Diameter of|Diameter of| Length |        |       |
    Steam    |   Water   |   of   | Height | Depth | Width
  Cylinders  |  Pistons  | Stroke |        |       |
  -----------+-----------+--------+--------+-------+--------
     4-1/2   |    2-3/4  |    4   |   38   |  18   |  23
     5-1/4   |    3-1/2  |    5   |   46   |  22   |  29
     6       |    4      |    6   |   50   |  23   |  32
             |           |        |        |       |
     6       |    4-1/2  |    6   |   50   |  23   |  32
     7-1/2   |    5      |    6   |   54   |  28   |  33
     9       |    6      |    6   |   57   |  27   |  36
             |           |        |        |       |
     7-1/2   |    4-1/2  |   10   |   66   |  28   |  33
     9       |    6      |   10   |   68   |  27   |  36
    10       |    7      |   10   |   77   |  34   |  40
             |           |        |        |       |
    12       |    8-1/2  |   10   |   86   |  39   |  44
    12       |    9-1/4  |   10   |   86   |  39   |  44
    14       |   10      |   15   |  110   |  36   |  50
  -----------+-----------+--------+--------+-------+--------

A notable feature in this pump is the location of the exhaust passage;
_this opening is underneath the cradle_—or the part that the pump rests
upon—just forward of the steam cylinders. The flanges of the steam end
and cylinders and the steam chest cover have been made heavier than the
regular and strengthened to withstand the higher pressures.

Fig. 305 is a sectional view of a larger size duplex pump than the one
shown in Fig. 302. The plunger, B, packing is identical, but the number
of water valves is double; access for cleaning the suction chamber, C,
is had by removing the hand hold plate at the side and in the center.
The discharge valves are reached through the hand hold at D.

[Illustration: FIG. 305.]


SETTING THE VALVES OF THE DUPLEX PUMP.

_The following rule applies to nearly all duplex pumps of the
Worthington type._ The valves are usually of the common “^D^” valve
type, working on the cylinder iron, or bronze seats, and suitably
“set.” Sufficient cushion at the end of each stroke is provided by
separate valves in the ports.

RULE.—1, _Locate the steam piston in the center of the cylinder_, Fig.
305. This is accomplished by pushing the piston to one end of its
stroke against the cylinder head and marking the rod with a scriber at
the face of the stuffing-box, and then bringing the piston in contact
with the opposite head; 2, _divide exactly the length of this contact
stroke_. Shove the piston back to this half mark, which brings the
piston directly in the center of the steam cylinder, F; 3, _perform
the same operation with the other side_; 4, _place the slide valves_,
which have no lap, _to cover all the ports_, E; 5, _pass the valve
stem through the stuffing-box and gland_. The operation of placing the
pistons in the center of their cylinders will bring the levers and rock
shafts in a vertical position; 6, _screw the valve stem through the
nuts_ until the hole in the eye of the valve stem head comes in a line
with the hole in the links, connecting the rocker shaft; then put the
pins in their places; 7, _adjust the nuts on both sides of the lugs_ of
the valves to leave about 1/4″ or 1/8″ loss motion on each side.

This process of adjustment being performed with both cylinders, the
steam valves are set. In short the travel of the two valves is simply
equalized.


DUPLEX OIL PUMPS.

The pattern of pump shown in Fig. 306, is especially designed for use
in connection with hydraulic lifts and cranes, cotton presses, testing
machines, hydraulic riveting and punching machines, and hydraulic
presses of all kinds. Also for _oil pipe lines_ (see Table, page 341),
mining purposes, and such services as require the delivery of liquids
under heavy pressures.

There are four single acting outside packed plungers, which work into
the ends of the water cylinders, the latter having central partitions;
each individual valve has its own cover or bonnet. The arrangement
of compound steam cylinders is shown. The water valves are easily
accessible, and are contained in small chambers, capable of resisting
very heavy pressures. The general arrangement shown in the engraving
is subject to numerous alterations, according to various requirements,
_but the general characteristic of four outside packed plungers is in
all cases preserved_.

[Illustration: FIG. 306.]


SPECIAL DUPLEX PUMP.

(_Outside packed Plunger Pattern for High Pressure._)

  TABLE.

  ==========+==========+========+====================+============
            |          |        |                    |
    Steam   |  Water   |        |Capacity in Gallons,| Strokes per
  Cylinders.| Plungers.| Stroke.|     per Stroke     |   Minute,
            |          |        |    each Plunger.   |    each
  ----------+----------+--------+                    |  Plunger.
     Ins.   |   Ins.   |  Ins.  |                    |
  ----------+----------+--------+--------------------+------------
            |          |        |                    |
     16     |    5     |   12   |       1.02         | 50 to 100
     16     |    6     |   12   |       1.47         | 50  „ 100
     16     |    7     |   10   |       1.66         | 50  „ 100
     16     |    7     |   18   |       3.00         | 40  „  80
     16     |    8     |   12   |       2.61         | 50  „ 100
     16     |    8     |   18   |       3.91         | 40  „  80
     16     |    9     |   12   |       3.30         | 50  „ 100
   18-1/2   |    7     |   12   |       2.00         | 50  „ 100
   18-1/2   |    7-1/2 |   12   |       2.30         | 50  „ 100
   18-1/2   |    8     |   18   |       3.91         | 40  „  80
   18-1/2   |    9     |   18   |       4.95         | 40  „  80
   18-1/2   |   10     |   12   |       4.08         | 50  „ 100
   18-1/2   |   10     |   18   |       6.12         | 40  „  80
     20     |    8     |   12   |       2.61         | 50  „ 100
     20     |    8     |   18   |       3.91         | 40  „  80
     20     |    9     |   12   |       3.30         | 50  „ 100
     20     |    9     |   18   |       4.95         | 40  „  80
     20     |   10     |   12   |       4.08         | 50  „ 100
     20     |   10     |   18   |       6.12         | 40  „  80
  ----------+----------+--------+--------------------+------------

  ==========+==========+========+=============+============
            |          |        | Capacity of |
    Steam   |  Water   |        |    Both     |
  Cylinders.| Plungers.| Stroke.|Cylinders, in| Steam Pipe.
            |          |        |  Gallons,   |
  ----------+----------+--------+ per Minute. +------------
     Ins.   |   Ins.   |  Ins.  |             |   Ins.
  ----------+----------+--------+-------------+------------
            |          |        |             |
     16     |    5     |   12   | 102 to 204  |   2-1/2
     16     |    6     |   12   | 147  „ 294  |   2-1/2
     16     |    7     |   10   | 166  „ 332  |   2-1/2
     16     |    7     |   18   | 240  „ 480  |   2-1/2
     16     |    8     |   12   | 261  „ 522  |   2-1/2
     16     |    8     |   18   | 312  „ 625  |   2-1/2
     16     |    9     |   12   | 330  „ 660  |   2-1/2
   18-1/2   |    7     |   12   | 200  „ 400  |     3
   18-1/2   |    7-1/2 |   12   | 230  „ 460  |     3
   18-1/2   |    8     |   18   | 312  „ 625  |     3
   18-1/2   |    9     |   18   | 396  „ 702  |     3
   18-1/2   |   10     |   12   | 408  „ 816  |     3
   18-1/2   |   10     |   18   | 490  „ 980  |     3
     20     |    8     |   12   | 261  „ 522  |     4
     20     |    8     |   18   | 312  „ 625  |     4
     20     |    9     |   12   | 330  „ 660  |     4
     20     |    9     |   18   | 396  „ 792  |     4
     20     |   10     |   12   | 408  „ 816  |     4
     20     |   10     |   18   | 490  „ 980  |     4
  ----------+----------+--------+-------------+------------


  ==========+==========+========+==============+==============
            |          |        |              |
    Steam   |  Water   |        |              |
  Cylinders.| Plungers.| Stroke.| Exhaust Pipe.| Suction Pipe.
            |          |        |              |
  ----------+----------+--------+--------------+--------------
     Ins.   |   Ins.   |  Ins.  |     Ins.     |     Ins.
  ----------+----------+--------+--------------+--------------
            |          |        |              |
     16     |    5     |   12   |      3       |      4
     16     |    6     |   12   |      3       |      5
     16     |    7     |   10   |      3       |      6
     16     |    7     |   18   |      3       |      7
     16     |    8     |   12   |      3       |      7
     16     |    8     |   18   |      3       |      8
     16     |    9     |   12   |      3       |      8
   18-1/2   |    7     |   12   |    3-1/2     |      6
   18-1/2   |    7-1/2 |   12   |    3-1/2     |      6
   18-1/2   |    8     |   18   |    3-1/2     |      8
   18-1/2   |    9     |   18   |    3-1/2     |      8
   18-1/2   |   10     |   12   |    3-1/2     |     10
   18-1/2   |   10     |   18   |    3-1/2     |     10
     20     |    8     |   12   |      5       |      7
     20     |    8     |   18   |      5       |      8
     20     |    9     |   12   |      5       |      8
     20     |    9     |   18   |      5       |      8
     20     |   10     |   12   |      5       |     10
     20     |   10     |   18   |      5       |     10
  ----------+----------+--------+--------------+--------------


  ==========+==========+========+==========+====================
            |          |        |          |
    Steam   |  Water   |        | Discharge|    Water Press.
  Cylinders.| Plungers.| Stroke.|   Pipe.  |   Pump End will
            |          |        |          | stand, in lbs., per
  ----------+----------+--------+----------+    square inch.
     Ins.   |   Ins.   |  Ins.  |   Ins.   |
  ----------+----------+--------+----------+--------------------
            |          |        |          |
     16     |    5     |   12   |    3     |       450
     16     |    6     |   12   |    4     |       450
     16     |    7     |   10   |    5     |       300
     16     |    7     |   18   |    6     |       450
     16     |    8     |   12   |    6     |       300
     16     |    8     |   18   |    7     |       450
     16     |    9     |   12   |    7     |       250
   18-1/2   |    7     |   12   |    5     |       250
   18-1/2   |    7-1/2 |   12   |    5     |       300
   18-1/2   |    8     |   18   |    7     |       450
   18-1/2   |    9     |   18   |    7     |       250
   18-1/2   |   10     |   12   |    8     |       250
   18-1/2   |   10     |   18   |    8     |       250
     20     |    8     |   12   |    6     |       450
     20     |    8     |   18   |    7     |       450
     20     |    9     |   12   |    7     |       250
     20     |    9     |   18   |    7     |       250
     20     |   10     |   12   |    8     |       250
     20     |   10     |   18   |    8     |       250
  ----------+----------+--------+----------+--------------------

A test of the superiority of this method of moving, and controlling
long columns of fluids under extreme heavy pressures was made at the
time of the introduction of long pipe lines _for conveying oil from the
wells to the seaboard_.

  NOTE.—After trying various kinds of pumps for forcing the oil through
  these long pipes, and after having a succession of disasters in the
  way of burst pipes, and leaking joints, it was decided to test the
  efficiency of the direct-acting duplex steam pump. These pumps were
  placed in the various stations along the pipe lines, and after a
  continued service of many years, have shown their perfect adaptation
  to that exceptionally hard service. These pumps convey the oil over
  mountains where at times the coupled lines have been over one hundred
  miles long between the pumps, and where the pressure on the plunger
  of the pump sometimes rises to 1,500 lbs. per square inch.

  J. F. HOLLOWAY.

[Illustration: FIG. 307.]


COMPOUND DUPLEX PUMPS.

(_With The Deane Switch Valve._)

The application of this valve is shown in Fig. 307, on the opposite
page. It can be attached to any regular Compound or Triple Expansion
Pump, and if not in use does not in any way impede the regular running
of the machine.

The Deane switch valve is a device by which compound low service pumps
may be converted into powerful fire pumps. This appliance consists of
a valve of such construction that steam may be allowed to enter the
cylinders as usual for compounding, or may be diverted by simply moving
a lever, when all four cylinders receive steam at boiler pressure, each
exhausting independently to the atmosphere. The change makes each steam
cylinder available for its maximum power, all four cylinders develop
their full power, and its effect can be utilized in powerful fire
streams.

It should be borne in mind in justice to the manufacturers that
the Deane switch valve is not to be classed with the ordinary two
or four-valve arrangement, which, while admitting initial steam to
the second cylinders, develops no power in the first, or, as it
is sometimes arranged, uses initial steam in all four cylinders
and develops less power than if the second cylinders were used
independently.

This valve is recommended by the Insurance companies, and compound
duplex pumps fitted with the Deane switch valve will be accepted in
place of the Underwriter pump of similar capacity. This valve is also
frequently used where two widely differing water pressures are required
for other purposes than for fire protection.

Every machine is subject to rigorous tests before leaving the factory,
including a 300-pound test of the water cylinders. Every pump is
guaranteed to be in full accordance with the specifications.


UNDERWRITER FIRE PUMPS.

The Insurance Companies have issued detailed specifications for the
construction of fire pumps to be known as Underwriter Fire Pumps.
They have agreed that such pumps with their specified attachments be
recognized as the approved type, and that pumps built and fitted up
less perfectly be not approved in future installments.

_The wide experience and systematic methods_ of the Insurance Companies
place them in position to give valuable suggestions as a result of
their observation and experiment, and these are embodied in carefully
drawn regulations issued by their Engineering Department.

The specifications are very exacting in every particular, entering into
_the design, material, and workmanship in minute detail_. They call
for a number of fittings and attachments not usually furnished, and a
most rigid test at the factory before shipping, and by the Inspecting
Engineers of the Insurance Companies after the pump is installed, which
secures for the purchaser the certainty of having a machine which
beyond any reasonable doubt can be relied upon to do its full duty when
emergency arises calling for its use.

There are a few quite important features not found in pumps of usual
construction. The pumps are composition fitted throughout, the water
cylinder bushings and plungers and linings to stuffing-boxes are of
composition, the piston and valve rods, made unusually heavy, are of
Tobin bronze. The mixture of the copper and tin composing the plungers
and bushings varies for the two so as to prevent their cutting. Owing
to the very high speed at which these pumps are liable to be run
during a fire, all the working parts are made excessively strong, and
the valve area and water passages are larger than usual. The interior
of each Underwriter pump is treated with a rust-proof coating, and
every precaution taken so that the pump will start instantly after an
indefinite period of disuse.

Figs. 307 and 308 exhibit two somewhat varying but acceptable forms of
the duplex steam pump.

_Among the attachments included in an outfit_ for the underwriter pump
may be mentioned: an elbow or tee for the suction connection with a
large suction air chamber, a set of brass priming pipes with special
gate and check valves for the same, an automatic water pressure relief
valve fitted to a cone and overflow pipe, a steam gauge and a special
water gauge with duplex spring, each of which in the Underwriter Pump
is mounted on an ornamental plate rigidly attached to the machine.

[Illustration: FIG. 308.]

Straightway hose valves for the proper number of streams are placed
in the neck to a very large discharge chamber, and there is also a
large discharge opening for connection to the system of hydrants and
sprinklers.

A stroke pointer is attached which travels between graduations marked
on the yoke, indicating the length of stroke which pump travels,
a one-point sight feed cylinder lubricator, a capacity plate with
enamelled face giving instructions for operating, etc., is attached to
each machine.



  SPECIFICATIONS
  OF THE
  National Board of Fire Underwriters
  FOR THE MANUFACTURE OF
  STEAM FIRE PUMPS
  AS RECOMMENDED BY THE
  National Fire Protection Association.


  EDITION OF 1904


THE NATIONAL STANDARD PUMP.

This pump is merely a pump of the well-known “duplex” type, built in a
very substantial manner, and with certain improvements suggested by the
experience of inspectors with Fire Pumps.

The principal points of difference between the National Standard Pump
and the ordinary commercial pump are:

  _1st. Its steam ports and water passages and air_ chamber are made
  much larger than in common trade pumps, so that a larger volume of
  water can be delivered in an emergency without water hammer.

  _2nd. It is “rust proofed” that it may start instantly_ after disuse,
  by making its piston rods and valve rods of Tobin Bronze, instead of
  steel; its water pistons, stuffing boxes and rock-shaft bearings of
  brass, instead of cast iron. Its valve levers are made of steel or
  wrought-iron forgings, or of steel castings.

  _3d. The following necessary attachments_ are all included in the
  price of the “National Standard Pump,” viz.:—a vacuum chamber, two
  pressure gauges, a relief valve, a set of brass priming pipes, 2 to 6
  hose valves, a stroke gauge, a capacity plate, an oil pump, a sight
  feed lubricator and a cast-iron relief-valve discharge-cone.

  _By reason of the larger ports, passageways and pipes_, its larger
  number of valves, and the added attachments, and general superior
  construction a “National Standard” pump costs more than a common
  trade fire pump, but the cost per gallon which these pumps can
  _deliver in an emergency_ by reason of their large passageways, etc.,
  is no greater than for the old style of fire pump and is well worth
  this extra cost.

  _Finally it should be remembered that these specifications_ cover
  only the outlines of the design, and that all pumps built under them
  are not of equal merit, for certain of the pump factories possess
  a broader experience and better shop facilities than others, and
  that the responsibility for first-class workmanship and strength of
  materials rests on the pump manufacturers, and not on the insurance
  companies.

  _We advise that all contracts call for strict conformity to the
  National Standard Steam Fire Pump specifications of the National
  Board of Fire Underwriters._


UNIFORM REQUIREMENTS.

The following specifications for the manufacture of Steam Fire Pumps,
developed from those originally drawn by Mr. John R. Freeman, are now
used throughout the whole country, having been agreed upon in joint
conference by representatives of the different organizations interested
in this class of work. They will be known as “The National Standard,”
and have been up to this time adopted by the following associations:
Associated Factory Mutual Fire Insurance Companies, National Board of
Fire Underwriters, National Fire Protection Association.


NATIONAL STANDARD SPECIFICATIONS FOR THE MANUFACTURE OF STEAM FIRE PUMPS

1. WORKMANSHIP.

_a._ The general character and accuracy of foundry and machine work
must throughout equal that of the best steam-engine practice of the
times, as illustrated in commercial engines of similar horse-power.

  This refers to strength of details, accuracy of foundry work,
  accuracy of alignment, accuracy of fits, quality of steam joints and
  flanges, construction of steam pistons and slide-valves, etc., and
  does not apply particularly to exterior finish.

2. DUPLEX ONLY.

_a._ Only “Standard Duplex pumps” are acceptable.

  So-called “Duplex” pumps consisting of a pair of pumps with
  “steam-thrown valves” actuated by supplemental pistons are not
  acceptable.

  Experience shows that duplex pumps are more certain of starting after
  long disuse. The whole power of the main cylinder is available for
  moving a corroded valve or valve rod, whereas on a single pump with a
  “_steam-thrown_” valve no such surplus of power is available.

  Further, the direct acting duplex has the great advantage over a
  fly-wheel pump of not suffering breakage if water gets into steam
  cylinder.

3. SIZES OF PUMPS.

_a._ Only the four different sizes given on the next page will be
recognized for “National Standard” pumps.

  The multiplicity of odd sizes of “Trade Pumps” is confusing, and
  different makers have, in the past, estimated the capacity in gallons
  according to different arbitrary standards.

  NATIONAL STANDARD PUMP SIZES.

  ======================+=======+===============================
                        | Ratio |           Capacity
       Pump Sizes.      |  of   |          At 100 lbs.
                        | Piston|           at Pump.
  ------+-------+-------+ Areas.+----------+--------+-----------
  Steam.| Water.|Stroke.|       | Number of| Nominal|   Actual
        |       |       |       | 1-1/8 in.|  Gals. | Gals. Per
        |       |       |       | Streams. |  Per   |Min. as per
        |       |       | About |          | Minute.|   Art. 4.
  ------+-------+-------+-------+----------+--------+-----------
    14  ×   7   ×   12  |4 to 1 |  =Two=   |  =500= |    4830
    14  × 7-1/4 ×   12  |       |          |        |     520
  ----------------------+-------+----------+--------+-----------
    16  ×   9   ×   12  |3 to 1 | =Three=  |  =750= |    8060
  ----------------------+-------+----------+--------+-----------
    18  ×  20   ×   12  |3 to 1 |  =Four=  | =1000= |    9990
  18-1/2 × 10-1/4 × 12  |       |          |        |    1050
  ----------------------+-------+----------+--------+-----------
    20  ×  12   ×   16  | 2-3/4 |  =Six=   | =1500= |    1655
                        |  to 1 |          |        |
  ----------------------+-------+----------+--------+-----------

  NATIONAL STANDARD PUMP SIZES.(continuation)

  ======================+===============+================
                        |  [B] Boiler   |
       Pump Sizes.      |    Power      |  Full Speed.
                        |   Required    |
  ------+-------+-------+------+--------+-------+--------
  Steam.| Water.|Stroke.|Horse | Steam  | Rev.  |Piston
        |       |       |Power.| Pres.  | Per   |Travel
        |       |       |      |at Pump,|Minute.|Feet Per
        |       |       |      |  lbs.  |       |Minute.
  ------+-------+-------+------+--------+-------+--------
    14  ×   7   ×   12  | 100  |  40    |   70  |  140
    14  × 7-1/4 ×   12  |      |        |       |
  ----------------------+------+--------+-------+--------
    16  ×   9   ×   12  | 115  |  45    |   70  |  140
  ----------------------+------+--------+-------+--------
    18  ×  20   ×   12  | 150  |  45    |   70  |  140
  18-1/2 × 10-1/4 × 12  |      |        |       |
  ----------------------+------+--------+-------+--------
    20  ×  12   ×   16  | 200  |  50    |   60  |  160
                        |      |        |       |
  ----------------------+------+--------+-------+--------


[Footnote B:

  This boiler power is required for continuous running at full speed
  and pressure. It is, however, often best to put in a larger pump than
  the existing boilers could drive at full capacity, as a _small boiler
  will drive a 750-gallon pump at the 500-gallon speed with very nearly
  as good economy as it can drive a 500-gallon pump at full speed_. The
  pump then does not have to be changed when the plant is enlarged and
  the boiler power increased.

  A steam piston relatively larger than necessary is a source of
  weakness. It takes more volume of steam, and gives more power with
  which to burst the pipes if the throttle is opened wide suddenly
  during excitement.

  It has been common to make all fire-pumps with water plunger of
  only one-fourth the area of steam piston, with the idea that pump
  could thereby be more readily run at night, when steam was low. The
  capacity in gallons is thus reduced 25 per cent. as compared with a 3
  to 1 plunger on the same steam cylinders.]

_b._ The above sizes of steam and water cylinders and length of stroke
have given general satisfaction and will now be considered as standard.

  Often, especially with large pumps, “4 to 1” construction is a
  mistake, and gives no additional security, although the pump might
  start and give a few puffs with 30 lbs. of steam on banked fires;
  because, if any pump of whatever cylinder ratio draws 50 or 100
  horse-power of steam from boilers with dead fires, it can run
  effectively only a very short time (ordinarily, perhaps, 3 to 5
  minutes), unless fires are first aroused to make fresh steam to
  replace that withdrawn.

  Steam pressures stated above must be maintained _at the pump_, to
  give full speed and 100 lbs. water pressure. Pressure at boilers must
  be a little more, to allow for loss of steam pressure between boiler
  and pump. Pumps in poor order, or too tightly packed, will require
  more steam.

  The boiler horse-powers above are reckoned on the A. S. M. E. basis
  of 34-1/2 lbs. of water evaporated from and at 212 degrees Fahrenheit
  as the unit of boiler horse-power. From 12 to 15 square feet of
  water-heating surface in the boiler is commonly assumed necessary for
  the generation of one horse-power.

  Smaller boilers than called for above, if favorably set, and having
  excellent chimney draft, can sometimes be forced to nearly double
  their nominal capacity for a short run, as for fire service.

_c._ _250 gallons per minute is the standard allowance for a good
1-1/8-inch (smooth nozzle) fire stream._

  A so-called “Ring Nozzle” discharges only three-fourths as much water
  as a smooth nozzle of the same bore, and is not recommended.

  From fifteen to twenty automatic sprinklers may be reckoned as
  discharging about the same quantity as a 1-1/8-inch hose stream under
  the ordinary practical conditions as to pipes supplying sprinkler and
  hose systems respectively.

4. CAPACITY.

_a._ Plunger diameter alone will not tell how many gallons per minute
a pump can deliver, and it is not reasonable to continue the old time
notion of estimating capacity on the basis of 100 feet per minute
piston travel.

_b._ The capacity of a pump depends on the speed at which it can be
run, and the speed depends largely on the arrangement of valves and
passageways for water and steam.

_c._ _It is all right to run fire-pumps at the highest speed that
is possible without causing violent jar, or hammering within the_
_cylinders. Considerations of wear do not affect the brief periods
of fire services or test, hence these speeds are greater than those
allowable for constant daily duty._

_d._ Careful experiments on a large number of pumps of various makes at
full speed, show that in a new pump with clean valves, and an air-tight
suction pipe, and less than 15 feet lift, the actual delivery is only
from 1-1/2 to 5 per cent. less than plunger displacement. This slip
will increase with wear, and for a good average pump in practical use,
probably 10 per cent. is a fair allowance to cover slip, valve leakage,
slight short-stroke, etc.

_e._ Largely from tests, but partly from “average judgment,” and
recognizing that a long stroke pump can run at a higher rate of piston
travel in lineal feet per minute than a short stroke pump, and that a
small pump can make more strokes per minute than a very large one, the
speeds given in the preceding table have been adopted as standards in
fire service for direct acting (non-fly-wheel) steam pumps, which have
the large steam and water passages herein specified.

_f._ Rated capacity is to be based on the speed in the preceding table,
correcting the plunger displacement for one-half the rod area and
deducting 10 per cent. for slip, short-stroke, etc.

  Men sometimes ask why, (if they can run a pump smoothly so as to get
  a delivery of 1,000 gals. per minute,) we should not accept as “a
  thousand gallon pump,” irrespective of its suction valve area or its
  exhaust port area or the size of its cylinders.

  To this we reply that _when new and favorably set_ almost any pump
  built according to these specifications can run at a much greater
  delivery than here rated, but when lift is unusually high or suction
  pipe long, or when the pump takes its suction under a head, no pump
  can be run so fast as on, for instance, a 5-foot lift. A solid
  foundation is also a great and indispensable aid in running a pump
  fast.

  Standard 500-gallon pumps have often delivered 800 gallons, and
  1,500-gallon pumps have delivered 2,000 gallons; but some margin must
  be allowed for unfavorable conditions and for deterioration as a pump
  grows old, or for the absence of an expert to get its utmost duty.

5. CAPACITY PLATE.

_a._ Every steam fire-pump must bear a conspicuous statement of its
capacity securely attached to the inboard side of air chamber, thus:—

  NATIONAL STANDARD FIRE PUMP

  16 × 9 × 12

  CAPACITY
  750 GALLONS PER MINUTE, OR
  3 GOOD 1-1/8-IN. SMOOTH NOZZLE
  FIRE STREAMS

  FULL SPEED
  70 REVOLUTIONS PER MINUTE

  NEVER LET STEAM GET BELOW
  50 POUNDS, NIGHTS, SUNDAYS
  OR AT ANY OTHER TIME

  The name “Underwriter” has been largely used for a considerable time
  to designate the type of pump covered by the principal features of
  these specifications. While our preferences are against the use of
  this word as designating any piece of apparatus objections will not
  be raised at the present time to its being continued on name plates
  in place of the words “National Standard,” if manufacturers so desire.

_b._ This plate must have an area of not less than one square foot, and
must be made of an alloy at least two-thirds aluminum and the remainder
zinc. The letters must be at least one-half inch in height, plain and
distinct, with their surfaces raised on a black background and buffed
off to a dead smooth finish.

  The name of pump manufacturer may also be placed on this plate, if
  desired.

_c._ A smaller plate of composition must be attached to steam chest
bearing the size of pump, the shop number, and the name of shop in
which the pump was built.

6. STRENGTH OF PARTS.

_a._ The maker must warrant each pump built under these specifications
to be at time of delivery, in all its parts, strong enough to admit
of closing all valves on water outlet pipes while steam valve is wide
open and steam pressure eighty pounds, and agree to so test it before
shipment from his works.

_b._ The pump must be warranted so designed and with such arrangement
of thickness of metal that it shall be safe to instantly turn a full
head of steam on to a cold pump without cracking or breaking the same
by unequal expansion.

7. SHOP INSPECTION.

A systematic shop inspection must be given to each pump to ensure
completed workmanship, and to prevent the use of defective parts,
improper materials, or the careless leaving of foreign matter in any
part of the cylinders or chests.

  Several instances have occurred in which chisels, bolts, or core
  irons have been found in steam chests or steam cylinders. This
  has resulted in a serious crippling of the pump and in some cases
  requiring repairs to be made before the pump could be used for fire
  purposes.


THE STEAM END.

8. STEAM CYLINDERS.

_a._ These must be of hard close iron with metal so distributed as to
ensure sound castings and freedom of shrink cracks. The following are
the minimum thicknesses acceptable:

  14″ Diam. 7/8″  thick
  16″  „    15/16″  „
  18″  „    1″      „
  20″  „    1-1/8″  „

_b._ The inside face of the steam cylinder heads and the two faces of
the piston must be smooth surfaces, fair and true so that if the piston
should hit the heads it will strike uniformly all around, thus reducing
to a minimum the chances of cramping the piston rod or injuring the
pump.

_c._ All flanged joints for steam must be fair and true and must be
steam tight under 80 lbs. pressure if only a packing of oiled paper
1/100 inch thick covered with graphite were used. Jenkins, “Rainbow”
or equivalent packing of not exceeding 1/32 inch original thickness is
acceptable. Oiled paper is not acceptable as a final packing, as it
burns out.

For size of steam and exhaust pipes, standard flanges and bolting, see
Art. 39.

  The specifications originally required machine facing for all these
  surfaces. The art of machine molding from metal patterns with draw
  plates, etc., has, however, attained such excellence in certain
  shops, that in regular practice “foundry faced” cylinder heads and
  piston faces can be made true and fair, and steam joints can be made,
  tight under 80 lbs. pressure with a packing of oiled paper only 1/100
  inch thick.

  Under proper assurance that this precision can be obtained in regular
  practice at the shop in question, foundry finish may be accepted on
  cylinder heads and piston faces, steam chests and steam-chest covers.

  In the case of _built-up pistons_, of separable form, it must be
  conclusively shown that the boring and finishing are carried on by
  such methods as will ensure the faces of pistons being exactly square
  to the piston rod and exactly parallel to the cylinder head.

  In the case of _solid pistons_ the two faces must be machine faced,
  as proper parallelism cannot well be obtained by foundry methods.

  Ordinary foundry finish secured by the old methods and wooden
  patterns is not acceptable and acceptance of any foundry-finish can
  only be secured after a special investigation of shop practices.

_d._ Heads at both ends of cylinder must be beveled off very slightly
over a ring about one inch wide, or equivalent means provided to give
steam a quick push at piston, should it stand at contact stroke.

9. BOLTS AND STUDS.

_a._ The stress on bolts or studs in connection with steam cylinders
must not exceed 7,500 lbs. per square inch under a test pressure of 80
lbs. steam, disregarding such initial strain as may be due to setting
up. (Compute pressure area out to center line of bolts.)

No stud or bolt smaller than 3/4 inch should be used to assemble parts
subject to the strain of steam pressure as smaller bolts are likely to
be twisted off.

10. YOKE.

_a._ The steam cylinders and water cylinders must be connected by such
a form of yoke as requires no packing, a metal to metal joint at this
connection being considered necessary. The piston-rod stuffing box
heads should concentrically fit the counter-bore of the yoke.

  If packing is put into these joints, there is a chance of the steam
  and water ends getting out of alignment and leaking at the joint
  between cylinders and yoke.

11. STEAM PORTS.

_a._ The area of each exhaust steam passage, at its smallest section,
must not be less than 4 per cent. of the area of the piston from which
it leads.

  This is a large increase over the size heretofore common, but
  indicator cards which we have taken from pumps of several different
  makes indicate this to be one of the points in which improvement
  is most needed to accommodate the high speeds at which fire pumps
  are always supposed to run, and this unrestricted exhaust aids very
  materially in giving steadiness to the jet of water.

_b._ Each admission port must be not less than 2-1/2 per cent. of
area of its piston, and to avoid wasteful excess of clearance, these
passages should not be bored out larger in interior of casting than at
ends or passage.

_c._ The edges of the steam-valve ports must be accurately milled, or
chipped and exactly filed to templets, true to line, and the valve seat
must be accurately fitted to a plane surface, all in a most thorough
and workmanlike manner and equal to high-grade steam-engine work.

_d._ To guard against a piston ring catching in the large exhaust
ports, these ports must have a center rib cast with cylinder at
cylinder wall. See also Art. 13 _d._

12. STEAM-CLEARANCE SPACE.

_a._ Clearance (including nut-recess, counter-bore, and valve passages)
must not exceed 5 per cent. for contact stroke or about 8 per cent. for
nominal stroke (_i. e._, contact stroke should overrun nominal stroke
not more than one-half inch or not less than one-fourth inch, at each
end).

_b._ The clearance space between face of piston and cylinder head must
be reduced to smallest possible amount, and these contacting surfaces
be flat, without projections or recesses other than the piston rod nut
and its recess.

  Some makers, with the idea that a fire pump need not be economical,
  have not taken pains to keep these waste spaces small.

  Securing small clearance costs almost nothing but care in design, and
  is often of value, since at many factories boiler capacity is scant
  for the large quantity of steam taken by a fire pump of proper size.

13. STEAM PISTONS.

_a._ May be either built up or solid, as maker thinks best.

  It is believed that “solid” (cored) pistons with rings “sprung
  in,” are for fire-pumps much preferable to built-up pistons, since
  follower bolts _do_ sometimes get loose.

_b._ Piston must not be less than four inches thick between faces. If
solid, walls should be not less than 1/2 inch thick, and special care
should be given to shop inspection to determine uniformity of thickness.

_c._ If built up pistons are used, involving follower bolts, such bolts
must be of best machinery steel, with screw thread cut for about twice
the diameter of the bolt and fitting tightly its whole length.

_d._ The width of each piston ring must exceed the length of the large
exhaust port by at least 1/4 inch.

  This is to avoid the possibility of piston ring catching in the port.

See also Art. 11 _d._

14. STEAM SLIDE VALVES.

_a._ Slide valves must be machine fitted on all four of the outer
edges, the exhaust port edges, and the surfaces in contact with rod
connections.

_b._ The slide valve itself must have its steam and exhaust edges
fitted up “line and line” with their respective steam and exhaust ports.

  The adding of lap to these edges in lieu of lost motion is not
  acceptable further than a possible 1/32 of an inch to cover
  inaccuracies of edges.

_c._ The valves must be guided laterally by guide strips cast in steam
chest, and these strips must be machine fitted. The lateral play at
these surfaces should not exceed 1/16 inch. The height of these guide
strips should not be less than 1/2 inch, measuring from valve seat.

The construction must be such as to absolutely preclude the possibility
of the valve riding up on top of this guide strip.

_d._ The valves must be guided vertically by the valve-rod itself, the
inside end of which must be kept in alignment by the usual form of
tail-rod guide.

The vertical play at these parts should not exceed 1/8 of an inch.

_e._ The surface of valves must be machine faced and accurately fitted
to a plane surface, and be steam tight when in contact with the seat of
steam valve.

15. STEAM SLIDE VALVE ADJUSTMENT.

_a._ The lost motion at the valves and the setting of them must be
determined by a solid hub on the rod, finished in the pump shop to
standard dimensions, so that no adjustment is possible after the pump
is once set up.

  This hub may be forged on the rod and then lathe-finished to standard
  dimensions, or it may be made by turning down a rod of the size of
  the hub. It is believed that Tobin bronze can be safely forged after
  a little experience, if care is taken to maintain the proper heat.

  It is recognized that the practice of making adjustable valve tappets
  located outside of the steam chest is a good thing in a large pump
  in constant service and operated by a skilled engineer, but for
  the infrequently used ordinary fire-pump, the utmost simplicity is
  desirable, and it is best not to tempt the ordinary man to readjust
  the valve gear.

  The common form of lost motion adjustment consisting of nut and
  check nut at each end of the slide valve is not acceptable, as these
  nuts are liable to become loose and may be incorrectly reset by
  incompetent persons. A long rectangular nut in the center of the
  valve is also not acceptable, as it can be moved out of adjustment.
  A solid hub made as a part of the rod is required, as it absolutely
  avoids the possibility of the hub becoming loose, an accident
  possible with a separate hub attached to the rod.

  The amount of lost motion should generally be such that admission
  takes place at about 5/8 of the stroke of the piston, _i. e._, for
  12-inch stroke R. H. valve will be about to open when L. H. piston
  has moved 7-1/2 inches to 8 inches from the beginning of stroke. When
  piston is at end of stroke the ports should be full open.

16. ROCK SHAFTS, CRANKS, LINKS, ETC.

_a._ Rock shafts must be either forged iron, forged steel, or cold
rolled steel. Cast iron is not acceptable. The following are the
minimum diameters acceptable:

   500 gallon pump    1-1/2 in.
   750 gallon pump    1-3/4 in.
  1000 gallon pump    2 in.
  1500 gallon pump    2 to 2-1/4 in.

_b._ The rock shaft bearings must be bushed with bronze and the
bushings pinned firmly in place. The length of each of these
non-corrosive bearings must be not less than 4 inches.

_c._ Rock shaft cranks, valve rod heads, valve rod links, and piston
rod spools or crossheads may be wrought iron or steel forgings, or
steel castings. If of a heavy, strong pattern, these parts, with the
exception of valve rod links, may be of semi-steel or cast iron.

_d._ The sectional area of all connections between rock shaft cranks
and valve rod must be such as to give a tensile or compressive strength
substantially equal to that of the valve rod.

17. VALVE MOTION LEVERS.

_a._ The valve motion levers must be steel, wrought iron, or steel
castings. Cast iron is not acceptable. Steel castings, if used, must
be deeply stamped with the name of the makers, with letters one-eighth
inch high, near the upper end of each lever, where it can easily be
seen,—thus “....._Steel Castings_.”

  Cast-iron arms, if bulky enough to be safe against external blows,
  are awkward in shape. The sectional area necessary for any arm
  depends upon the means provided for preventing a sidewise strain on
  the lever, due to rotation of piston or friction of its connection
  to piston rod. The spool or crosshead on the piston rod should be so
  designed that no sidewise strain can be thus produced on the lever.

_b._ The levers must have a double or bifurcated end at crosshead.

  The double end is less likely than a single end to put an undue
  strain on the lever as the rod turns, and is also likely to give
  trouble from lack of lubrication or from a loosening of any small
  parts, and has proved to be the most satisfactory arrangement.

18. VALVE MOTION STAND.

_a._ The valve motion stand must be securely dowel-pinned to the yoke
castings, to prevent any movement after being once adjusted.

19. CUSHION VALVES.

_a._ Cushion-release valves regulating the amount of cushion steam
retained at ends of stroke must be provided.

_b._ The cushion release must be through an independent port as shown
in Figs. 2 and 3, so located as to positively retain a certain amount
of cushion steam.

  The old form of cushion release through bridge between ports is
  not acceptable. This form while leading into the exhaust passage
  as formerly, differs by starting from a small independent port
  (about 1/2-inch wide × 2-1/2 inches long) through the cylinder wall,
  located about 3/8 or 1/2 inch back from the cylinder head. (The
  exact position for affording the best action has to be determined by
  experiment with each different make of pump, as it depends somewhat
  on the extent of clearance space and on the point of closure
  of exhaust by piston and somewhat on the weight of reciprocating
  parts.)

[Illustration: FIG. 2.]

[Illustration: FIG. 3.]

This style of cushion port makes the pump safer in case cushion valves
are unskillfully left open too wide and tends to prevent a pump from
pounding itself to pieces in case of a sudden release of load, as by a
break in suction or delivery mains, or by a temporary admission of air
to suction pipe.

[Illustration: FIG. 4.]

Pumps made with this form of cushion release, have given very
satisfactory results, and if the ports are properly located, there will
be no re-bound of piston.

_c._ Cushion valves must be always provided with hand-wheels marked as
per sketch, for the reason that very few men in charge of fire-pumps
are found to clearly understand or to remember their use.

The lettering must be very open, clear and distinct, not liable to be
obscured by grease and dirt, and of a permanent character.

  It is desirable that spindle or wheel be so formed that a monkey
  wrench can get a grip to open a jammed valve. Fig. 5 shows the stem
  flattened for this purpose.

[Illustration: FIG. 5.]

_d._ The valve and stem of cushion valve must be in one piece without
any swivel joint.

  Swivel joints are apt to come apart and make it impossible to operate
  the valve.

20. PISTON RODS.

_a._ Piston rods for their entire length must be of solid Tobin Bronze,
and the distinguishing brand of the manufacturers of this metal must be
visible on at least one end of each rod.

_b._ The sizes must be not less than in table below.

  =========+==========+===========+============+============
  =Size of=|          |           |            |
  =Pump.=  |=500 gal.=|=750 gal.= |=1,000 gal.=|=1,500 gal.=
  ---------+----------+-----------+------------+------------
  Diameter |          |           |            |
  of rod   | 2 inch.  |2-1/4 inch.|2-3/8 inch. | 2-1/2 inch.
  ---------+----------+-----------+------------+------------

_c._ The size and form of connection of rod to piston plunger and
cross-head must be such that the stress in pounds per square inch at
bottom of screw thread, or at such other point of reduced area as
receives the highest tensile strain, shall not exceed 8,000 lbs. per
square inch, when the steam pressure acting on the piston is 80 lbs.
per square inch.

_d._ Piston rod nuts, in both steam and water ends, must be tightly
fitted, and preferably of a finer thread than the United States
Standard. This is to avoid as much as possible the unnecessary
weakening of the rod at the bottom of the thread, and to reduce the
tendency of the nut to work loose.

  In practice 8 threads per inch has been found to give good
  satisfaction.

_e._ In addition to a tightly fitting nut, some reliable device must be
provided, in both steam and water ends, for absolutely preventing these
nuts from working off.

[Illustration: FIG. 6.]

  Fig. 6 shows one form of such a locking device and illustrates the
  kind of security desired.

  This device combines the advantage of a taper key and a split pin,
  and the elongated key-slot gives sufficient leeway to always insure
  that the key can be driven up tight against the nut and thus prevent
  it from even starting to work off. Other methods will be approved in
  writing, if found satisfactory.

21. VALVE RODS.

_a._ Valve Rods for their entire length must be of solid Tobin Bronze,
with sizes not less than in table below.

  =========+==========+===========+============+============
  =Size of=|          |           |            |
   =Pump.= |=500 gal.=|=750 gal.= |=1,000 gal.=|=1,500 gal.=
  ---------+----------+-----------+------------+------------
  Diameter |          |           |            |
  of rod   |  1 inch. |1-1/8 inch.| 1-1/8 inch.| 1-1/4 inch.
  ---------+----------+-----------+------------+------------

_b._ The net area of valve-rod at its smallest section subject to
tensile stress, must not be smaller than at bottom of U. S. standard
screw thread on rod of diameter given above.

  The construction of this rod as affecting lost motion at slide valve
  is specified under Article 15.

22. STUFFING BOXES.

[Illustration: FIG. 7.]

_a._ All six stuffing boxes must be bushed at the bottom with a brass
ring with suitable neck and flange, and the follower or gland must be
either of solid brass, or be lined with a brass shell 3/16-inch thick,
having a flange next the packing, as shown in the sketch.

The bottom of stuffing boxes and the end of glands should taper
slightly towards the center as per sketch.

_b._ These glands should be strong enough to withstand considerable
abuse, so as not to break from the unfair treatment of unskilled men.

23. PRESSURE GAUGE.

_a._ A pressure gauge of the Lane double tube spring pattern with 5
inch case must be provided and attached to the steam chest inside the
throttle valve.

The dial of gauge should be scaled to indicate pressures up to 120 lbs.
and be marked “STEAM.”

  This kind of gauge is used on locomotives and is the best for
  withstanding the vibration which causes fire-pump gauges to be often
  unreliable. Moreover, this double spring is safer against freezing.

24. DRAIN COCKS.

_a._ Four brass drain cocks, each with lever handle and of one-half
inch bore, are to be provided, and located one on each end of each
steam cylinder.

  Care should be taken to select a pattern of cock whose passageway is
  the full equivalent of a 1/2-inch hole. Some patterns of 1/2-inch
  commercial cocks although threaded for 1/2-inch pipe thread have but
  a 1/4-inch hole through them. Such are not acceptable.

25. OILING DEVICES.

_a._ A one-pint hand oil pump, to be connected below the throttle, and
a one-pint sight feed lubricator, to be connected above the throttle,
must be furnished with each pump.

_b._ Oiling holes must be provided for all valve motion pins, and for
each end of both rock shafts.

26. STROKE GAUGE.

_a._ A length-of-stroke-index must be provided for each side of pump.
These must be of simple form for at all times rendering obvious the
exact length of stroke which each piston is making, and thus calling
attention to improper adjustments of cushion valves or stuffing boxes.

_b._ The gauge piece over which the index slides must have deep,
conspicuous marks at ends of nominal stroke, and also light marks at
extreme positions; it need contain no other graduations.

_c._ This stroke index must be rigidly secured to cross-head in such a
way that it cannot get loose or out of adjustment.


THE WATER END.

27. WATER CYLINDERS.

_a._ These must be of hard close iron with metal so distributed as to
ensure sound castings, and freedom from shrink cracks.

_b._ The design should be along lines best calculated to resist
internal pressure so as to avoid as much as possible the need of ribs
for stiffening.

_c._ They must be capable of withstanding, without showing signs of
weakness, the pressures and shocks due to running under the conditions
mentioned in Chapter “Tests for Acceptance,” Art. 48-54.

The suction chamber should be able to withstand a water pressure of 100
lbs.

  Although suction chambers are not regularly subject to a pressure, it
  is sometimes desired to connect them to public water supplies, and
  where foot valves are used there is a chance of getting pressure on
  the suction, so that ample strength is necessary.

  Foundry finish may be permitted on the joints at water cylinder heads
  and at hand-hole plates, provided surfaces are so true that a rubber
  packing not over 1/16 of an inch in thickness is sufficient to secure
  perfect tightness.

_d._ Conveniently placed hand-holes of liberal size must be provided
for the ready examination and renewal of valve parts at the yoke end of
water cylinders and in the delivery chamber.

  This will necessitate holes not less than 6 × 8 inches, or its
  equivalent, for the two largest-size pumps, and holes proportionately
  as large for the 500 and 750-gallon pumps. The easy access to
  the valve parts is of vital importance, and must receive careful
  attention.

_e._ The thickness of metal for cylinder shell, valve decks,
partitions, ribs, etc., will depend largely upon the form of
construction, but, in a general way, to establish safe minimums for
the average water cylinder, of nearly cylindrical form, whose flat
surfaces are stiffly ribbed, we submit the table below:

  =========================+==========+==========+============+============
      =Size of Pump.=      |=500 gal.=|=750 gal.=|=1,000 gal.=|=1,500 gal.=
  -------------------------+----------+----------+------------+------------
  Thickness of cylinder    | Inches.  | Inches.  |   Inches.  |  Inches.
    shell when of nearly   |          |          |            |
    cylindrical form       |   7/8    |   1      |    1-1/8   |   1-1/4
                           |          |          |            |
  Thickness of valve decks |          |          |            |
    when well ribbed       | 1-1/4    |   1-1/4  |    1-1/4   |   1-1/4
                           |          |          |            |
                           |          |          |            |
  Thickness of transverse  | 1-1/4    |   1-1/4  |    1-1/2   |   1-1/2
    partition, depending   |   to     |    to    |     to     |    to
    on ribbing             | 1-1/2    |   1-1/2  |     2      |    2
                           |          |          |            |
  Thickness of longitudinal|  1-1/4   |   1-1/4  |    1-1/4   |   1-1/2
    partition, depending on|   to     |    to    |     to     |    to
    ribbing                |  1-1/2   |   1-1/2  |     2      |    2
                           |          |          |            |
  Thickness of ribs        |   3/4    |    7/8   |     1      |    1
                           |          |          |            |
  Thickness of suction     |          |          |            |
    chamber                |   5/8    |    3/4   |     3/4    |    7/8
                           |          |          |            |
  Thickness of delivery    |          |          |            |
    chamber                |   7/8    |     1    |    1-1/8   |   1-1/4
                           |          |          |            |
  -------------------------+----------+----------+------------+-----------

Lighter construction than herein specified will not be regarded as
satisfactory, and any construction will be finally passed upon on
examination of drawings.

_f._ The bolting of all parts of the water end is to be of such
strength that the maximum stress at bottom of screw thread will not
exceed 10,000 lbs. per square inch (disregarding for the moment the
initial stress due setting up nuts) for a water pressure of 200 lbs.
per square inch, computed on an area out to centre line of bolts.

No stud or bolt smaller than 3/4-inch should be used to assemble parts
subject to the strain of water pressure, as smaller bolts are likely to
be twisted off.

  Although these pumps are not expected to be designed for a regular
  working water-pressure of 240 or 320 lbs., it is expected that bolts,
  shells, rods, etc., will be figured to stand this comparatively
  quiet, temporary, high pressure, exclusive of further allowance for
  initial strain due setting up of bolts, with a factor of safety of at
  least four.

  This high test pressure is analogous to the custom of proving all
  common cast-iron water pipes to 300 lbs. and all common lap-welded
  steam pipes to 500 lbs. per square inch, and common water-works gate
  valves to 400 lbs., even though these are to be regularly used at
  much less pressure.

We are assured that castings no heavier than at present used by the
best makers will stand this test, _if properly shaped and liberally
bolted_.

_g._ For requirements for stuffing boxes, see Art. 22.

28. WATER PLUNGERS AND BUSHINGS.

_a._ The “inside plunger and bushing” is preferred for all situations
where the water is free from grit or mud.

_b._ Water-plungers must be of solid brass or bronze, and the bushing
in which they slide must also be of brass or bronze. The composition of
the plunger and its bushing should be of very hard, though dissimilar
alloys, to ensure good wearing qualities.

For material and size of piston rods and lock for nuts, see Art. 20.

  With poor alignment or bad workmanship or lack of skill in mixing the
  alloys, brass plungers are liable to score and give trouble; but with
  proper selection of alloys and true cylinders accurately aligned,
  they can be made to run all right wherever iron ones can. It is quite
  a fine point to get these wearing surfaces just right; and _this
  is wherein the experience, skill and shop practice of one maker is
  likely to be much superior to that of another working under the same
  specification_.

_c._ The length of machined cylindrical bearing within the partition
must be not less then 2 inches. The plunger bushing must have a faced
seat transverse to its axis against partition, forming a water-tight
ground joint not less than one-half inch wide.

Any rubber gasket or other compressible packing for making this joint
water-tight is not acceptable.

_d._ The construction of bushing and hole in partition must be
such that a cylindrical shell for use with a packed piston can be
interchangeably inserted in its place and secured by the same bolts.

  This can readily be arranged and enables a packed piston to be
  inserted in place of a plunger subsequent to the installation of the
  pump with a minimum of expense, should this become desirable from
  change of conditions at any future time.

_e._ Small transverse grooves cut within the sliding surface of the
plunger bushing, with a view to lessen the leakage, are not acceptable.

  Although a slight advantage in this respect for clean water, they are
  a disadvantage on the whole, as dirt catches in them in the ordinary
  situation and cuts the plungers.

29. STANDARD DIMENSIONS OF PLUNGERS AND PLUNGER BUSHINGS.

_a._ To bring all these expensive parts to the same standard of weight
and bearing surface, the following dimensions are specified as the
least that will be acceptable. These are based on a length of plunger
which uncovers the bushings one inch at end of nominal stroke.

SOLID BRONZE PLUNGERS AND BUSHINGS.

  ===============+==============+==========+================+===========
  =Size of Pump.=|  =500 gal.=  |=750 gal.=|  =1000 gal.=   |=1500 gal.=
  ---------------+--------------+----------+----------------+-----------
  =Plunger.=     |              |          |                |
    Diameter     |7 or 7-1/4-in.|   9-in.  |10 or 10-1/4-in.|   12-in.

    Length       |     17-in.   |   17 „   |      18-in.    |   24  „
    Thickness of |              |          |                |
      transverse |              |          |                |
      partition  |     5/8 „    |   5/8 „  |      3/4 „     |   3/4 „
    Thickness    |              |          |                |
      next to    |              |          |                |
      partition  |     1/2 „    |   1/2 „  |      5/8 „     |   3/4 „
    Thickness    |              |          |                |
      next to end|    5/16 „    |   3/8 „  |      3/8 „     |   1/2 „
    Number       |              |          |                |
      of ribs    |      4       |    4     |        6       |    6
    Thickness    |              |          |                |
      of ribs    |    5/16 „    |  5/16 „  |      3/8 „     |   3/8 „
                 |              |          |                |
  =Bushing.=     |              |          |                |
    Length       |      7 „     |    7  „  |        8 „     |    10 „
    Thickness    |              |          |                |
      at end     |   5/16 „     |  3/8  „  |      3/8 „     |   1/2 „
    Thence       |              |          |                |
      tapered    |              |          |                |
      evenly to  |              |          |                |
      a thickness|              |          |                |
      next to    |              |          |                |
      bearing of |              |          |                |
      not less   |              |          |                |
      than       |    1/2 „     |  5/8  „  |      5/8 „     |   3/4 „
    Thickness at |              |          |                |
       the center|              |          |                |
       bearing   |              |          |                |
       not less  |              |          |                |
       than      |    3/4 „     |  3/4  „  |      3/4 „     | 13/16 „
  ---------------+--------------+----------+----------------+-----------

30. WATER PISTONS AND BUSHINGS.

_a._ The “water piston with fibrous packing” is preferred for many
situations in the West or South, or for water containing grit or mud,
like that of the Ohio River; and, for the comparatively few cases where
pump pressure governors are used, the packed piston will give better
service and longer wear.

_b._ The removable bushing or cylinder in which this piston works must
be of solid bronze.

_c._ As stated in Art. 28 _d_, this bushing should be so constructed as
to be readily interchangeable with the bushing of the inside plunger
type.

_d._ The length of bushing must be such that the ends of piston will
barely come short of the edges of cylinder at contact stroke and not
uncover.

_e._ The thickness of the cylindrical bushings must be not less than is
given in the following table:

BUSHINGS FOR PACKED WATER PISTONS.

  ====================+========+=======+=======+========
    =Size of Pump.=   | =500=  | =750= |=1000= | =1500=
                      | =gal.= | =gal.=|=gal.= | =gal.=
  --------------------+--------+-------+-------+--------
  =Solid Bronze.=     |        |       |       |
                      |        |       |       |
  Thickness at        |7/16-in.|1/2-in.|1/2-in.|9/16-in.
  extreme end         |        |       |       |
                      |        |       |       |
  Tapered evenly from |9/16  „ |5/8 „  |11/16 „|3/4   „
  end to a thickness  |        |       |       |
  next to bearing     |        |       |       |
  of not less than    |        |       |       |
                      |        |       |       |
  Thickness at center |3/4   „ |3/4 „  | 3/4  „|13/16 „
  bearing at least    |        |       |       |
  --------------------+--------+-------+-------+--------

_f._ In other respects, the specifications for plunger bushings,
already given in Art. 28, will apply to the above.

_g._ The water piston used in the shell described above must expose not
less than 2 inches in width of fibrous packing, and must be of bronze,
with disc and follower accurately turned to a sliding fit, so that the
leakage past it will be a minimum, even when no fibrous packing is in
place. There must be at least 2 inches in length of metallic bearing on
both disc and follower.

The follower must be accurately centered and fitted to hub of piston,
so that alignment will not be disturbed if taken apart.

_h._ The water piston must be of simple and strong construction, with
follower bolts tightly fitted, and with fibrous packing so cut as to
prevent by-passing.

_i._ All materials used in construction of piston, except packing, must
be brass, bronze, or other non-corrosive metal.

_j._ Bushing studs must be of Tobin Bronze, and of such size and
number, that the maximum stress at the bottom of the screw thread
shall not exceed 10,000 lbs. per square inch, in the event of plunger
becoming fast in the bushing with 80 lbs. of steam in the steam
cylinders.

_k._ For each bushing stud there must be provided a composition nut and
check nut.

_l._ All minor parts exposed to the action of water in water cylinder,
that are not herein specified, must be of brass, bronze, or other
non-corrosive material.

31. PUMP VALVES.

_a._ All the suction and discharge valves in any one pump must be of
the same size and interchangeable.

_b._ There must be a clear space around each rubber valve, between it
and the nearest valve, equal to at least one-fourth of the diameter
of the valve, or between it and the wall of the chamber of at least
one-eighth of the diameter of the valve.

_c._ These valves must be of the very best quality of rubber, of medium
temper, with a face as soft as good wearing quality will permit.

They must be double-faced, so they can be reversed when one face is
worn.

  The quality of rubber is almost impossible of determination by brief
  inspection or by chemical analysis. The relative amount of pure gum
  and of cheaper composition may vary, or good material may be injured
  by defective vulcanization. The only safe way to secure excellence
  and uniformity is for the pump manufacturer to test samples of each
  new lot under severe duty (as by a week’s run in a small special
  pump, with say 150 pounds pressure and heavy water hammer, or by some
  equivalent means) and to furthermore require the rubber manufacturer
  to mould a date mark as “(Name of pump manufacturer, lot 201—April 3,
  1904.)” on the edge of every valve, by which the pump manufacturer
  can keep track of those which prove defective.

32. SIZE AND NUMBER OF PUMP VALVES.

_a._ The diameter of the disc of rubber forming the valve must not be
greater than 4 inches or less than 3 inches. Three and a half inches
diameter is probably the most favorable size, but is not insisted upon.

  There is some confusion between different shops about designating
  size of valves. The practice is here adopted, which is much the most
  widely used, of naming the diameter of the disc of rubber which
  covers the ports, and it is hereby specified that this shall be about
  1/2-inch greater than the diameter of the valve-port circle which
  it covers, thus affording about 1/4-inch overlap or bearing for the
  rubber disc all around its edge.

  If valves are larger than 4-inch there is an increased tendency to
  valve-slam at the very high speed at which the pump is designed to
  run, and if valves are smaller than 3 inches diameter the greater
  number tends to unnecessary multiplication of parts, and the ports
  being so small are a little more liable to become obstructed by
  rubbish.

_b._ The thickness of the rubber valve must in no cases be less than
5/8-inch.

33. SUCTION VALVE AREA.

_a._ The total lift of suction valves must not exceed 1/2-inch.

_b._ The net suction valve port area and the total suction valve outlet
area under valves lifted 1/2 inch high must not be smaller than the
figures given in the table below.

  ====================================+=====+========
  (1) Length of Stroke                |=12= | 16
      (in inches)                     |     |
  ------------------------------------+-----+--------
  (2) Greatest No. revolutions per    |=70= | 60
      minute.                         |     |
  ------------------------------------+-----+--------
  (3) Corresponding Piston travel     |=140=| 160 ft.
      per minute.                     |     |
  ------------------+-----------------+-----+--------
  Approx.           |(4) Feet         | 308 | 352
  actual max. Piston|    per minute.  |     |
  velocity at full  +-----------------+-----+--------
  speed, per row    |(5) Feet         | 5.1 | 5.9
  (3) × 2.2.        |    per second.  |     |
  ------------------+-----------------+-----+--------
  (6) Net Suction Valve-port area     |=56%=| 64%
      speed regarded necessary for    |     |
      this per cent. of Plunger area. |     |
  ------------------------------------+-----+--------
  (7) Total Suction Valve Outlet      |=56%=| 64%
      Area under Valves lifted        |     |
      1/2 in. high.                   |     |
  ------------------------------------+-----+--------
  (8) Discharge Valve Area.           |2/3 of Suction
                                      |Valve Area.
  ------------------------------------+--------------

  By “valve-outlet area,” we mean the vertical cylindrical surface over
  the outer edge of the valve ports, _i. e._, the distance L multiplied
  by the circumference at the outer edge of the valve ports _C_, Fig.
  8. Thus for a 4-inch valve, with ports inscribed in a 3-1/2-inch
  circle, whose circumference is 3·5 × 3·1416 = 11 inches; the valve
  “outlet area” for 1/2-inch lift would be 5-1/2 inches.

  [Illustration: FIG. 8.]

  The actual velocity of piston during the middle portion of stroke is
  from 2.0 to 2.4 (average 2.2) times as great as the piston travel per
  minute (as determined in experiments by Mr. J. R. Freeman on several
  duplex pumps of different manufacture). This is because each piston
  stands still nearly half the time, or while its mate is working,
  and, moreover, moves more slowly near start and finish of stroke.
  The words “piston speed” are commonly incorrectly used and refer to
  “piston travel.” A clear understanding that the actual piston speed
  is _more than twice as great_ leads to more generous valve design.

  Large aggregate valve areas are necessary for pumps designed to run
  as fast as these, and experience has shown that to prevent valve slam
  at high speed and to accommodate high suction lifts, it is just as
  important to have a large “valve outlet area” as to have a large area
  of valve port.

  It is valve slam or water hammer which commonly limits the highest
  speed at which a pump can be run. This water hammer may originate
  from the pulsations in a long or small suction pipe. The vacuum
  chamber lessens it, but there is commonly some point of high water in
  the vacuum chamber that will give much smoother action than any other.

  Valve slam in this style of pump is caused chiefly by the short
  rebound of the steam piston against the elastic steam cushion at the
  end of the stroke. This in turn snaps the valves down with a jump
  when the speed is high. Dividing this impact or slam on numerous
  valves of low lift, tends to break up and lessen the shock, therefore
  with valves of the size and style used in fire-pumps, other things
  being equal, the less they have to rise and drop to let the water
  through them, the less will be the valve slam. This height of rise
  and drop is governed by the circumference rather than the port area.
  Experience and practice has shown that a 1/2-inch limit of lift is
  reasonable and does ensure a smooth working pump under all ordinary
  conditions.

_c._ The following table gives minimums for aggregate valve port area
and aggregate valve outlet area, for the different size plungers,
figured on a basis of 56% of plunger area for a 12-inch stroke, and 64%
for a 16-inch stroke.

  ===+=======================+=========+========+=======+========
     |    =Size of Pump.=    | =500=   | =750=  |=1000= |=1500=
     |                       | =Gal.=  | =Gal.= | =Gal.=| =Gal.=
     +-----------------------+---------+--------+-------+--------
  =1=| Diameter of plunger.  |         |        |       |
     | Inches                |  7-1/4″ |   9″   |   10″ |  12″
     +-----------------------+---------+--------+-------+--------
  =2=| Area of plunger in    |         |        |       |
     | sq. inches            | 41·28   | 63·62  |  8·54 | 113·10
     +-----------------------+---------+--------+-------+--------
     | 56% of plunger area,  |         |        |       |
     | or Minimum aggregate  |         |        |       |
  =3=| valve port area       |         |        |       |
     | allowed per section.  |         |        |       |  64% =
     | Square inches         | 23·11   | 35·63  | 43·98 |  72·38
     +-----------------------+---------+--------+-------+--------
     | Minimum aggregate     |         |        |       |
  =4=| valve port            |         |        |       |
     | circumference, allowed|         |        |       |
     | per section. Inches   | 46·22   | 71·26  | 87·96 | 144·76
     +-----------------------+---------+--------+-------+--------
     | Minimum aggregate     |         |        |       |
     | valve outlet area     |         |        |       |
  =5=| allowed per section   |         |        |       |
     | for valves lifted     |         |        |       |
     | 1/2 inch high.        |         |        |       |
     | Square inches         | 23·11   | 35·63  | 43·98 |  72·38
  ---+-----------------------+---------+--------+-------+--------

_d._ If we consider using any one of the three sizes of valves below,
whose port areas may be assumed approximately as

  =========+================+===========+================
   Diam.   | Diam. of Valve |  Circ. of |  Valve Port
   Valve.  |  Port. Circ.   |   V. C.   |  Area (Net).
           |                |  Circle.  |  Square inches.
  ---------+----------------+-----------+----------------
    3″     |    2-1/2″      |  7·85″    |     3·5
    3-1/2″ |    3″          |  9·42″    |     4·7
    4″     |    3-1/2″      | 10·99″    |     6·3
  ---------+----------------+-----------+----------------

given, then the necessary number of valves per section will be as in
the table following:

  =================+============+============+============+=============
   =Size of Pump.= |   =500=    |    =750=   |   =1000=   |   =1500=
                   |   =gal.=   |    =gal.=  |   =gal.=   |   =gal.=
  -----------------+--+------+--+--+------+--+--+------+--+--+------+---
  =Size of Valves.=|3″|3-1/2″|4″|3″|3-1/2″|4″|3″|3-1/2″|4″|3″|3-1/2″|4″
  -----------------+--+------+--+--+------+--+--+------+--+--+------+---
  Necessary number |  |      |  |  |      |  |  |      |  |  |      |
  of  valves       |  |      |  |  |      |  |  |      |  |  |      |
  to satisfy       |  |      |  |  |      |  |  |      |  |  |      |
  (4) under _c_    | 6|   5  | 5| 9|   8  | 7|11|  10  | 8|19|  16  |14
  -----------------+--+------+--+--+------+--+--+------+--+--+------+---
  Necessary number |  |      |  |  |      |  |  |      |  |  |      |
  of valves        |  |      |  |  |      |  |  |      |  |  |      |
  to satisfy       |  |      |  |  |      |  |  |      |  |  |      |
  (3) under _c_    | 7|   5  | 4|10|   8  | 6|13|  10  | 7|21|  16  |12
  -----------------+--+------+--+--+------+--+--+------+--+--+------+---

The exact number and size of valves will, however, not be insisted upon
provided the aggregate valve area and the aggregate valve outlet area
for each section is not less than that given in the table under _c_ for
the limiting lift of 1/2 inch.

  Manufacturers will note that with the established lift of 1/2
  inch, the 3-1/2-inch valve will permit a valve outlet area more
  nearly equal to its port area than will either the 3-inch or 4-inch
  valves, and a _relatively_ less number of valves will satisfy the
  specifications.

34. DELIVERY VALVES.

_a._ The total lift of delivery valves must not exceed one-half inch.

This is to avoid valve slam, as explained in Art. 33.

_b._ The aggregate valve-port area should be restricted to about
two-thirds the suction-valve area.

  A small restriction of water-way through the delivery valves steadies
  the action of the pump and tends to prevent undue pulsations of
  pressure in the delivery pipe or fire hose. Fewer delivery valves
  than suction valves are, therefore, preferred, and if extra holes
  in the delivery deck are cast for shop purposes these had better be
  plugged than fitted with valves.

  The suction valves require more generous port-circumference and
  port-area than delivery valves because when a pump has to suck its
  supply through a considerable height or through a long pipe there
  should be the least practicable waste of the atmospheric pressure in
  getting the water into the plunger chamber, or in retarding it from
  following the plunger in full contact. With the water once into the
  plunger chamber there is plenty of steam pressure available to force
  it out through the delivery valves.

35. VALVE SPRINGS, GUARDS AND COVERS.

_a._ All valve springs must be of the best spring brass wire, and must
be coiled on a cylindrical arbor.

  Conical valve springs are not approved because the strain is not
  uniform throughout spring, thereby increasing the liability to
  breakage and the chance of their getting out of center and becoming
  “hooked up.”

_b._ The valve spring must be held centrally at its top by resting in a
groove in valve guard, substantially as shown in Fig. 9.

_c._ A light, rustless metallic plate must be interposed between the
bottom of the spring and the rubber valve, and must be the full area of
the valve. This plate must also be formed with a raised bead to guide
the spring at the bottom.

  The weight of this plate should be small, for the inertia of the
  lifting parts of the valves should be the least possible, to permit
  quick action and to avoid pounding.

_d._ For the average condition of a 10 or 15-foot lift, the stiffness
of suction valve springs should be such that a force of about one pound
per square inch of net port area will lift valve 1/4 inch off its seat.

The springs on the delivery valves should ordinarily be from two to
three times as stiff as just specified, but any other reasonable degree
of stiffness which is proved to work well in practice will not be
objected to.

  For suction under a head, the greater snap with which water enters
  the plunger chamber when thus pushed in by say twice the atmospheric
  pressure renders it difficult to avoid water hammer at high speed.
  Extra stiff suction valve springs will commonly aid in controlling
  this and should be used wherever pumps are to work under a head.

  An approved type of indicator water gate on the suction pipe near the
  pump, which can be partly closed, will enable the pump to run quietly
  at high speed. Such a gate is an extra not included in price of the
  pump.

36. STICKING OF VALVES.

_a._ Steam fire-pumps should be started, to limber them up, _at least_
once a week.

  Although vulcanized India-rubber is much the best material yet used
  for fire-pump valves, unfortunately the brass is sometimes corroded
  by the free sulphur contained in the rubber, so that if the pump is
  left standing for several weeks the rubber valve discs may become
  stuck to their brass seats, and, if suction has a high lift, there
  may not be vacuum enough to tear all the suction valves open when
  pump is started.

37. VALVE SEATS.

_a._ All water valve seats must be of bronze composition. They may be
either screwed into the deck on a taper or forced in on a smooth taper
fit. With either arrangement, the seat must be either flanged out on
the under side all the way round or be provided with a substantial lug
opposite each rib, these lugs being expanded out after the valve is
inserted.

  If the valve seats are not expanded after being put in place, there
  is a possibility that now and then a valve seat will work loose and
  come out, thus crippling the pump.

_b._ The under side of the valve deck must be rounded over to give good
bearing for the expanded part of the seat.

_c._ Three-inch valves must have four or five ribs, three and a half
inch valves five or six ribs, and four inch-valves six ribs.

  Enough ribs must be provided to give proper support to the rubber
  valve, but too many are objectionable, as small ports would be liable
  to obstruction by refuse.

_d._ The edges of the valve-seat ports must be moderately rounded over,
to remove such sharp edges and points, as would be liable to cut, or
damage the rubber valve when under pressure.

38. VALVE STEMS.

_a._ All valve stems must be of 3/4-inch Tobin bronze and of the fixed
type, and must have the guard fastened on by one of the methods shown
in Figs. 9 and 10.

[Illustration: FIG. 9.]

[Illustration: FIG. 10.]

  Other methods may be approved, in writing, if found by test and
  experience to have especial merit.

_b._ These stems must be screwed into the seats on a straight, tightly
fitting thread, and the lower end then well headed over into a
countersink. The valve guard and nut must be of composition.

  In Fig. 9 the upper part of the stem is slabbed off on two opposite
  sides and fits a corresponding hole in the guard.

  The guard, therefore, cannot turn. The outside of the special nut is
  fitted on a taper to the inside of the guard, and the nut tapped out
  to fit the 5/8 U. S. thread on the stem.

  The action of the valve, whether with the spring or without, tends to
  drive these taper fits together, producing a frictional lock similar
  to that of a friction clutch; and although the nut may be loose on
  the thread, it cannot possibly work off.

  It will be apparent that the taper fit on the nut must be so made as
  to always bear on the taper fit in the guard, and not bottom in the
  guard.

  It is believed that with the present screw machine practice in shops
  of to-day these small parts can readily be turned out accurately and
  cheaply in large quantities. The nuts and guards made in any one
  shop must be exactly of standard dimensions, so that the product of
  different periods will be interchangeable.

  The taper should be about one inch to one foot. With this taper the
  nut can be readily turned in or out, but there is friction enough to
  hold the guard and nut together even if the spring is off.

  In Fig. 10, the top of the guard is recessed in the form of a hollow
  inverted pyramid of six sides, to correspond to a hexagonal nut. The
  angle of two opposite sides of this recess, which should be about 75
  degrees, will both surely lock the nut and still permit of its being
  turned with a wrench.

  The guard is kept from turning by slabbing off the stem, in the same
  manner as described and shown in Fig. 9.

  To facilitate the removal of the nut, the edges should be slightly
  chamfered. An unfinished nut simply drilled and tapped is all that is
  desired. Any hexagonal or square nut within the size of the tapered
  recess will be locked.

With this construction, the nut cannot turn in either direction without
compressing the spring and is therefore locked, and, in the event of
the spring breaking or being left off, the nut is well protected in
its recess from the possible turning effects of water currents, and
experiments have shown that it will still stay in place.

With machine molding it will be possible to make these guards complete
in foundry, requiring no machine work further than a possible broaching
out of hole to fit the stem, as a fairly good fit is necessary.

While both of these devices are effective even though not tightened
down to a shoulder, they should be so tightened for greater safety and
to fix the lift at the half-inch limit.

39. PIPE SIZES.

_a._ Water and steam pipe connections must have standard flanges to
connect with pipes of the sizes given below.

  =============+==============+===============+========+========
  Size of Pump.|  Diameter of |   Diameter    | Steam  | Exhaust
  Gal. Per Min.| Suction Pipe.|Discharge Pipe.| Pipe.  |  Pipe.
               |    Inches.   |   Inches.     |        |
  -------------+--------------+---------------+--------+--------
      500      |       8      |      6        |  3     |    4
      750      |      10      |   7 or 8[C]   |  3-1/2 |    4
    1,000      |      12      |      8        |  4     |    5
    1,500      |      14      |     10        |  5     |    6
  -------------+--------------+---------------+--------+--------

[Footnote C: Eight-inch preferred, this being the more common size for
valves, fittings, and pipes.

These suction pipe sizes, although larger than common for trade pumps
of the same size, are believed to be amply justified by experience, and
exert a powerful influence toward enabling the pump to run smoothly at
high speed with water cylinders filling perfectly at each stroke. No
defect is more common than restricted suction pipes.]

_b._ A single suction entrance at the end of the pump is to be provided
unless otherwise specified by the purchaser.

  Some situations render desirable side suction entrances, for
  permitting drafting water from two different sources of supply. These
  additional openings are to be considered as extras. Ordinarily, the
  purchaser can provide for such situations by proper piping at the
  single end suction entrance.

  If there is to be but one suction opening on casting, this had best
  be at center, for the reason that, if suction pipe ever gets to
  leaking air, this air stands a better chance of being distributed
  equally to the two plungers, and has less tendency to make the pump
  run unevenly.


_c._ Standard flanges and standard bolt layouts as adopted by the
Master Steam Fitters, July 18, 1894, must be used on all the above pipe
connections, as per table given below.

  SCHEDULE OF STANDARD FLANGES.

  ==============+==============+========+==============+=========
  Size of Pipe ×|   Diameter   | Number |   Size       | Flange
      Diam.     |      of      |   of   |    of        |Thickness
    of Flange.  | Bolt Circle. | Bolts. |   Bolts.     | at Edge.
                |              |        |              |
    Inches.     |    Inches.   |        |  Inches.     | Inches.
  --------------+--------------+--------+--------------+---------
   3 × 7-1/2    |      6       |    4   |  5/8 × 2-1/2 |  13/16
   3-1/2 × 8-1/2|      7       |    4   |  5/8 × 2-1/2 |   7/8
   4 × 9        |      7-1/2   |    4   |  3/4 × 2-3/4 |  15/16
   4-1/2 × 9-1/4|      7-3/4   |    8   |  3/4 × 3     |  15/16
   5 × 10       |      8-1/2   |    8   |  3/4 × 3     |  15/16
   6 × 11       |      9-1/2   |    8   |  3/4 × 3     |  1
   7 × 12-1/2   |     10-3/4   |    8   |  3/4 × 3-1/4 |  1-1/16
   8 × 13-1/2   |     11-3/4   |    8   |  3/4 × 3-1/2 |  1-1/8
   9 × 15       |     13-1/4   |   12   |  3/4 × 3-1/2 |  1-1/8
  10 × 16       |     14-1/4   |   12   |  7/8 × 3-5/8 |  1-3/16
  12 × 19       |     17       |   12   |  7/8 × 3-3/4 |  1-1/4
  14 × 21       |     18-3/4   |   12   | 1    × 4-1/4 |  1-3/8
  --------------+--------------+--------+--------------+---------

Do not drill bolt holes on center line, but symmetrically each side of
it.

On steam and exhaust openings loose flanges threaded for wrought-iron
pipe must be provided.

  Where the situation will not permit of a standard flange on exhaust
  opening for lack of room, a special flange threaded to fit the proper
  size wrought-iron pipe may be used.

40. AIR AND VACUUM CHAMBERS.

_a._ Air and vacuum chambers in accordance with the sizes given in the
following table must be provided with all pumps. If the air chamber
is cast iron, the pump manufacturers must warrant that it has been
subjected to a hydraulic test of 400 lbs. per square inch before it is
connected to pump.

It is to be thoroughly painted inside and out to diminish its porosity.

  SIZE OF VACUUM AND AIR CHAMBERS.

  ====================+===================+================
                      | Vacuum Chamber is | Air Chamber is
                      |   to contain:—    |  to contain:—
  --------------------+-------------------+----------------
     500-gallon pump. |    13 gallons.    |   17 gallons.
     750    „    „    |    18    „        |   25    „
   1,000    „    „    |    24    „        |   30    „
   1,500    „    „    |    30    „        |   40    „
  --------------------+-------------------+----------------

  The air chamber, combined with connections for discharge pipe, relief
  valve, and hose valves, should be carefully designed to make the
  whole weight as small as possible. Keeping this weight down makes
  the pump run steadier and brings less strain on the flanges at high
  speeds.

  An air chamber of hammered copper and warranted tested under a
  hydraulic pressure not less than 300 lbs. per square inch is a little
  better than cast iron as it holds air better, and being lighter it
  wrenches and strains the pump less when running fast and shaking, but
  because it costs from $25 to $50 more than cast iron, it is not often
  adopted.

_b._ The vacuum chamber must be attached to the pump in the most direct
way practicable, but provision must be made for attaching it in such
manner as not to prevent readily taking off the cylinder heads.

_c._ Every vacuum chamber should be provided on one side near the top
with a 1/4-inch pipe hole plugged. This to be used for attaching a
vacuum gauge if desired.

41. PRESSURE GAUGE.

_a._ A pressure gauge of the Lane double tube spring pattern with
5-inch case, must be provided with the pump, and connected near to
inboard side of air chamber, as shown in Fig. 12, by a 1/4-inch cock,
with lever handle.

The dial of this gauge should be scaled to indicate pressures up to 240
lbs. and be marked “WATER.”

  This kind of gauge is used on locomotives and is the best for
  withstanding the vibration which causes fire-pump gauges to be often
  unreliable. Moreover, this double spring form is safer against
  freezing.

42. HOSE VALVES.

_a._ Hose valves must be attached to the pump (and included in its
price) as follows:—

  For the 2 stream or   500-gal. pump, 2 hose valves.
  For the 3 stream or   750-gal. pump, 3 hose valves.
  For the 4 stream or 1,000-gal. pump, 4 hose valves.
  For the 6 stream or 1,500-gal. pump, 6 hose valves.

  These are to be 2-1/2-inch straightway brass valves, without cap,
  and similar and equal in quality to those made by the Chapman Valve
  Company, the Ludlow Valve Company, or the Lunkenheimer Company.

  The hose-screw at end of these valves is to be fitted to a hose
  coupling furnished by the customer, or where this cannot be procured
  may be left with the thread uncut.

  To accommodate locations where all the lines of hose must lead off
  from one side of the pump—makers can furnish a spool piece or special
  casting to which the hose valves can be attached—but this is an extra
  not included in the regular price.

43. SAFETY VALVE.

[Illustration: FIG. 11.]

_a._ A safety or relief valve of the Ashton, Crosby, American, or
other make agreed upon in writing with this office, is to be regularly
included in the price, and is to be attached to each pump; preferably
extending horizontally inboard from base of air chamber, as shown in
Fig. 12, so that its hand-wheel for regulating pressure is within easy
reach. This hand-wheel must be marked very conspicuously as shown in
Fig. 11.

_b._ This valve is to be set ordinarily at a working pressure of 100
pounds to the square inch, and is to be of such capacity, that when set
at 100 pounds it can pass all the water discharged by the pump at full
speed, at a pump pressure not exceeding 125 pounds per square inch.

  For   500-gallon pump a 3 inch valve.
  For   750-gallon pump   3-1/2 inch valve.
  For 1,000-gallon pump   4 inch valve.
  For 1,500-gallon pump   5 inch valve.

The relief valve must discharge in a vertical downward direction into a
cone or funnel secured to the outlet of the valve. (See Art. 44.)

[Illustration: FIG. 12.]

The valve must be so attached to the delivery elbow and discharge cone
by flange connections as to permit of its ready removal for repairs
without disturbing the waste piping.

44. DISCHARGE CONE.

_a._ This cone should be so constructed that the pump operator can
easily see any water wasting through the relief valve, and its passages
should be of such design and size as to avoid splashing water over into
the pump room.

_b._ The cone must also have a one-inch tapped connection for the
air-vent pipe required by Art. 45, and the arrangement must be such
that the pump operator can easily tell whether water is coming from the
air pipe or is wasting through the relief valve.

_c._ The cone should be piped to some point outside of the pump house
where water can be wasted freely, the waste pipes being as below.

  ===============+====================
     SIZE OF     |   DIAMETER OF WASTE
     PUMP.       |    PIPE FROM CONE.
  ---------------+--------------------
     500-gallon. |     5 inches.
     750   „     |     6   „
   1,000   „     |     7   „
   1,500   „     |     8   „
  ---------------+--------------------

  The waste pipe can pass down to floor between the yokes at middle
  of pump. It should be piped in such a way that steam and gases from
  other drains or waste pipes will not work back through it, and, by
  being troublesome in the pump room, suggest the covering of the cone
  in any way, as it is desirable that the pump operator should always
  be able to see instantly any waste from the relief valve or air vent.

This cast-iron cone, connected to the safety valve and air vent, is
included in price of pump, but the waste pipe beyond it is not.

45. AIR VALVE.

[Illustration: FIG. 13.]

_a._ An air vent with a brass gate valve and brass pipe for connecting
up, must be provided and connected with delivery elbow and discharge
cone.

_b._ The size of this air vent should be one inch for 500-gallon and
750-gallon pumps, and one and one-fourth inches for the 1000-gallon and
1500-gallon sizes.

_c._ The hand wheel of this valve must be marked as per Fig. 13. The
lettering must be very open, clear and distinct, not liable to be
obstructed by grease and dirt, and of a permanent character.

  The object of this valve is to reduce the pressure above force valves
  and secure a prompt riddance of all air that may come through the
  water cylinders when first starting up.

  This valve, of course, should be closed when once pump is under way,
  to prevent waste of water.

46. PRIMING.

_a._ Each pump must be fitted with a set of brass priming pipes and
valves, according to either one or the other of the following methods:

_b._ For 1,000 and 1,500 gallon pumps, the priming pipes must be 1-1/4
inches. For the 500 and 750 gallon pumps, the pipes must be 1 inch.
Pump-makers are to furnish these pipes and the fittings called for
below, and are to connect them up providing a 2-inch outlet, looking
upwards, ready for the supply from the priming tank.

  The pipe from the priming tank to this outlet should be at least
  2-inch, and may be of iron, and is to be furnished by the purchaser.
  All parts furnished by the pump-maker are to be of brass, and are to
  be included in the price of the pump.

CONTROLLABLE VALVE ARRANGEMENT.

_c._ Four 2-seat controllable valves, one for each pulsation chamber,
and of the general type illustrated in Fig. 14, must be provided. In
these the inlet of water and outlet of air are simultaneously opened
and closed by the pump operator.

[Illustration: FIG. 14.]

  Objection has been raised to this double-seated valve from the
  possible difficulty of keeping both seats tight. If desired, the
  valve may be fitted with a flange instead of a screw connection, and
  the stem between the two seats somewhat enlarged and provided with a
  suitable spring, thus giving flexibility between the two seats and
  preventing all trouble from uneven wear.

_d._ The hand-wheel of each of these valves must be marked as per Fig.
15, so that the pump operator I may clearly understand their use. The
lettering must be very open, clear and distinct, not liable to be
obscured by grease and dirt, and of a permanent character.

[Illustration: FIG. 15.]

[Illustration: FIG. 16.]

_e._ There must be provided and fitted to each combined valve a check
and umbrella-top air vent, as shown in Fig. 16. This fitting must have
a clear passageway through it, the full equivalent of a 1/2-inch bore.

  The check-valve is to permit the outflow of air, but to prevent the
  influx when the plunger is sucking.

  This method is preferred to the one using rubber priming checks, as
  now and then a rubber valve will stick on its seat and thus prevent
  priming of one of the chambers. In this arrangement the pump operator
  has absolute control over the priming water into each chamber.

  Another advantage is that the connection of the air-vent with the
  priming valve ensures that the air-vents will be opened; and further,
  by the vigorous spurting out of water as soon as the pump is primed,
  the pump operator is reminded that the priming valve should be closed.

  Should the pump operator, however, through a mistaken idea of
  the proper method of operation, think that the priming should be
  continued until all air was exhausted from the suction pipe and the
  pump running in normal condition, there would be some by-passing
  between chambers, but as there is a free vent for the air, the main
  result would be simply to limit the amount of air exhausted per
  stroke, from the main suction, by the amount of water which entered
  a chamber in this way. The amount of water thus entering, however,
  would not be appreciably greater than that which would enter from the
  priming-tank with the check-valve arrangement.

  If, even in spite of the warning given by the spurting air-vents,
  the pump operator should neglect to close the priming-valves when
  the pump was running normally, the priming-tank would eventually
  be overflowed; but this would not be as serious as the drawing in
  of air from an exhausted priming-tank, which would result with the
  check-valve method, were the main 2-inch valve similarly neglected.

RUBBER CHECK VALVES.

_f._ Four rubber check valves, one for each pulsation chamber, and
similar to ordinary pump valves, must be provided. The chambers for
these should preferably be made as a part of the pump cylinder, thus
securing a compact arrangement.

Figure 12 shows this arrangement in outline.

_g._ The valve seat should have three ribs to the central hub,
supporting the rubber valve. The net port area through the valve should
be not less than 1-1/2 square inches.

  This valve seat should rest in an inverted position, and can be so
  fitted up as to be readily removed. The valve stems can be of the
  removable type screwing into the seat, but must be made long enough
  to receive a check nut on the opposite side of seat. This will
  effectually lock the stem in place.

_h._ Care must be taken to arrange the water passages through and about
these priming checks, so as to avoid all air pockets and so as to
reduce to a minimum the possibility of the valves becoming choked up by
refuse.

_i._ The valve seats, stems and all parts must be of composition and of
strong rugged design, so fitted up that there is the least chance for
the rubber valves to stick, and with all parts securely put together
the valves must be readily accessible.

_j._ The valve springs must have only sufficient strength to keep the
valves on their seats, so that they will freely open even with the low
head of priming water often existing.

[Illustration: FIG. 17.]

_k._ There must be provided, and attached to the top of each plunger
chamber, a brass check valve and air cock with umbrella top, as shown
in Fig. 17. This cock and valve must have a clear passageway through
them—the full equivalent of a 1/2-inch bore.

  The check valve is to permit the outflow of air, but to prevent the
  influx when the plunger is sucking. Cocks with lever handles are
  used, as these show clearly whether they are open or shut.

_l._ There must also be provided a 2-inch brass gate valve for the
general control of the water to the four-check valves. The hand wheel
of this valve must be marked as per Fig. 15. The lettering must be very
clear, open, and distinct, not liable to be obscured by grease, and of
a permanent character.

  It is essential for a properly working pump that the main 2-inch
  priming-valve should be closed as soon as the pump is primed.
  Otherwise, water will be drawn from the priming tank, lessening the
  lifting power of the pump through the main suction, and if this is
  continued the priming tank will often be exhausted and air drawn into
  the pump, interfering with its proper action. It is for this reason
  that the marking on the priming valve is required.

  For all average situations, either method of priming permits of
  getting the pump under way in a very few minutes, but, for cases
  where the suction pipe is over 300 or 400 feet in length, or
  sometimes where the lift is over 18 feet, or where there is a
  combination of long length and lift within these limits, so much
  time is consumed in exhausting the air from the suction pipe that it
  becomes desirable to supplement this method.

  For such situations, a steam ejector connected to the suction pipe
  near the pump is advised, and may be required in addition to the
  regular priming pipes and tank. The size of the ejector should be
  sufficient to exhaust the suction pipe within about three minutes.
  Such ejectors will be considered as extras not included in the
  ordinary pump fittings.

  For cases where pump can only take its suction under a head, if
  absolutely certain that the level of the suction water will never
  fall below level of center of pump, these priming pipes may be
  omitted, but openings for them into the pump shell must be provided
  and capped or plugged.

  _A foot valve on a fire-pump suction is not advised_ except in very
  rare cases, as with a lift of 18 feet or a suction pipe 500 feet or
  more long. A foot valve is not needed when there is a good efficient
  set of priming arrangements as described above and it is commonly
  found this gives a false sense of security, and that with a fire-pump
  left standing several days the water will often be found to have
  leaked back, so that it is no better than if no foot valve had been
  used.

  A foot valve must of necessity generally be located where it is
  inaccessible for quick repairs, and as they grow old, foot valves
  are often a source of trouble. Where a suction pipe is exposed even
  slightly to frost, a foot valve is specially objectionable.

  _A priming tank is provided for the purchaser_ in all cases where
  there is ever to be any lift on the suction. It is generally advised
  that this tank have a capacity of one-half of what the pump can throw
  at full speed in a minute. This means 250 gallons for a 500-gallon
  pump and 500 gallons for a 1,000-gallon pump, etc. It is the
  intention to make the pump a truly “independent source” of supply,
  therefore the need of a special priming tank.

OLDER PRIMING ARRANGEMENTS.

The form of priming arrangement heretofore used, with metal check
valves, one main 2-inch priming valve, and 1-inch priming pipes,
separate controllable air cocks, may be retained on all pumps at
present in service, and will be considered satisfactory, if kept in
good order.

If in any case such checks give trouble the priming arrangement may
be changed and valves like Fig. 14 or rubber checks as described
in sections _f-j_, made up in detachable form,[D] may be put on if
desired, where the connections on the pump permit them.

Where neither method is desired or where neither is feasible the faulty
checks may be replaced by a special type such as are now made for
this use, by the Locke Regulator Company, of Salem, Mass. These are
1-inch check valves, adapted to use a small disc of medium hard rubber,
similar to a pump valve.

These fittings are very near the dimensions of the commercial check
valve, so that with slight shortening of piping connections they will
fit into the present arrangements, and give satisfaction.

47. DRAIN COCKS.

_a._ Five brass drain cocks, each with a lever handle and of 1/2-inch
bore, are to be provided, and located one on each end of each water
cylinder, and one above the upper valve deck.

  Care should be taken to select a pattern of cock whose passageway
  is the practical equivalent of a 1/2-inch hole. Some patterns of
  1/2-inch commercial cocks although threaded for 1/2-inch pipe thread
  have but a 1/4-inch hole through them. Such are not acceptable.


[Footnote D: Such detachable rubber check valves are now made up in
regular form by the George F. Blake Mfg. Co., East Cambridge, Mass.]


TESTS FOR ACCEPTANCE.

48. TEST FOR SMOOTHNESS OF ACTION.

_a._ Provide outlets for the water; start the pump slowly, gradually
open steam-throttle to bring the pump to full speed.

The pump should run smoothly at the rated full speed of 70 revolutions
per minute (or 60 revolutions if a 1,500-gallon pump) with full length
of stroke, and meanwhile maintain a water pressure of 100 lbs. per
square inch.

If the hose lines are short, or discharge is too free, partly close the
water outlet valves, thus throwing an extra back pressure on the pump
equivalent to that which would be produced through a greater length of
hose.

  During this trial it is preferable to discharge the water through
  lines of 2-1/2-inch cotton rubber-lined hose, preferably each 150
  feet long, each connected directly to the hose outlets on the pump,
  and each line having a 1-1/8-inch smooth nozzle at its outer end. Two
  lines should be connected for a 500-gallon pump, three for a 750, and
  so on, having as many lines as rating of pump requires.

  A hose line 150 feet long, with an inside surface of average
  smoothness, and with a 1-1/8-inch nozzle attached, will require about
  80 pounds pressure at the pump to discharge 250 gallons per minute,
  and the nozzle pressure will be about 45 pounds. Therefore, with
  lines attached as above, a pressure at the pump of about 80 pounds
  should represent a discharge about equal to the rated capacity of
  the pump, and would ordinarily correspond with the rated full speed
  revolutions.

  If the pump runs smoothly under these conditions, it is well to open
  the throttle somewhat further, and bring the pressure at the pump
  up to 100 pounds. This will give a discharge of about 280 gallons
  per stream, or about 12 per cent. in excess of the rated capacity.
  The revolutions will, of course, correspondingly increase, and
  under all ordinary conditions a pump should run smoothly at this
  higher capacity though a little more vibration and pounding would be
  expected than when running simply at its rated speed.

  After cushion valves are adjusted there should be no noteworthy water
  hammer or valve-slam. Sometimes valve-slam is not the fault of the
  pump, but arises from an obstructed suction pipe. It is objectionable
  to doctor water hammer in a pump by “snifting” air into the suction,
  as this cuts down the efficiency and is a poor expedient.

  The quietness of that part of the hose near the pump, or its freedom
  from rubbing back and forth crosswise an inch or more with each
  pulsation of the pump, is a good index of the pump maker’s skill
  in securing uniform delivery. Bad pulsation quickly wears holes in
  the hose, and to reveal this is the object of testing _with hose
  connected directly to the pump_.

49. TEST OF THE INTERNAL FRICTION.

_a._ This is shown by the reading of steam gauge compared with water
pressure gauge at air chamber.

Tests have generally run about as follows, for pumps running at full
rated speed:

  ===============+=========+=========+=========+=============
  Size Gallons   |  500    |   750   |  1,000  |    1,500
  Per Minute     |         |         |         |
  Capacity.      |         |         |         |
  ---------------+---------+---------+---------+-------------
  Ratio of Steam |=4= Times|=3= Times|=3= Times|=2-3/4= Times
  Piston Area to |         |         |         |
  Water Piston   |         |         |         |
  Area.          |         |         |         |
  ---------------+---------+---------+---------+-------------
  Water          |   100   |   100   |   100   |   100
  Pressure       |         |         |         |
  lbs. Per       |         |         |         |
  Sq. in.        |         |         |         |
  ---------------+---------+---------+---------+-------------
  Steam Pressure |    25   |    33   |    33   |   36·5
  Theoretically  |         |         |         |
  Necessary,     |         |         |         |
  Disregarding   |         |         |         |
  Friction.      |         |         |         |
  ---------------+---------+---------+---------+-------------
  Excess of Steam|    15   |    12   |    12   |   13·5
  Pressure Needed|         |         |         |
  to Overcome    |         |         |         |
  Friction, Back |         |         |         |
  Pressure, Etc. |         |         |         |
  ---------------+---------+---------+---------+-------------
  Actual Steam   |    40   |    45   |    45   |   50
  Pressure Found |         |         |         |
  Necessary at   |         |         |         |
  the Pump.      |         |         |         |
  ---------------+---------+---------+---------+-------------

_b._ The steam pressure needed will vary slightly with the freedom of
the exhaust pipe and with the tightness of the packings, etc., but a
steam pressure of 45 pounds at the steam chest should suffice for 100
pounds water pressure on pump in proper adjustment.

50. TEST OF STRENGTH AND TIGHTNESS.

_a._ First, shut the main valve between the pump and the fire system
lest a sprinkler head be burst, then shut all water outlets nearly, but
not quite tight, so pump will move very slowly. Screw safety valve down
hard. Slowly and carefully admit steam pressure sufficient to give 240
pounds per square inch water pressure.

_b._ With this extreme pressure all joints should remain substantially
tight, and the slow motion of the pump should be tolerably smooth
and uniform. (The leakage of a few drops here and there and a little
unsteadiness of motion are to be expected.)

_c._ If boiler pressure is above 85 pounds, the safety valve on pump
should be attached and screwed down only enough to hold the required
pressure. For with 100 pounds or more of steam the water pressure might
be carried too high.

After completing the above test slack off on safety valve, setting it
so that it will begin to open at about 100 pounds pressure.

51. TEST OF CAPACITY OF SAFETY VALVE.

_a._ The relief valve may next be tested by first adjusting it to
“pop” at 100 pounds, then shut the main outlet to pump, and then shut
the hose gates one by one, and thus force all the discharge through
the relief valve, meanwhile opening steam throttle, so as to run pump
_first at two-thirds speed or about 50 revolutions per minute_, and
finally at full speed (70 revolutions). The safety valve (relief valve)
should carry all this and not let the pressure rise above 125 pounds.

  The pressure in a quick-moving fire-pump necessarily fluctuates 5
  to 15 pounds at different points in stroke, and an air chamber of
  reasonable size cannot wholly remove this. Therefore the safety valve
  must be set at about 15 pounds higher than the intended average
  working pressure; otherwise it will get to jumping with almost every
  stroke.

52. TEST OF INTERNAL LEAKAGE OR SLIP.

_a._ Set safety-valves at 115 lbs., shut all water outlets, admit steam
enough to give 100 pounds water pressure, then pump will move very
slowly under the influence of the leakage past plungers. About one
revolution of pump per minute shows a proper accuracy of fit. Anywhere
from 1/3 to 2 revolutions per minute is satisfactory.

  _Too tight a fit is bad_, as if not exceedingly uniform it induces
  scoring or cutting of the metals. Moreover, should the pump happen
  to be run dry for a few minutes before catching its suction a slight
  warming and expansion of the plunger may cause it to stick and cut.

53. TEST WITH MAXIMUM WORKING PRESSURE.

_a._ For this, alternately shut down the main outlet gate and adjust
the hand-wheel of the safety valve, and open up on the throttle as may
be required, running pump at say one-half speed (or, in experienced
hands, at full rated speed), and note the greatest water pressure which
the full boiler pressure (unless boiler pressure is above 85 lbs.) will
yield with pump at full speed.

  Sometimes it may be necessary to force water through very long lines
  of hose, or to an unusual height.

  Steam fire engines are not infrequently called on to give 200 pounds
  per square inch water pressure.

  To test short hose lines with anywhere near so high a pump-pressure
  is dangerous, lest nozzle kick and pull itself away from the man
  holding it and thrash around; but the ability of the pump may be
  tested by putting this high pressure-delivery mainly through the
  safety valve, or in part through the partially closed main outlet
  gate.

  _It is not advisable to carry this water pressure above 200 pounds
  in this test_ at the factory, (although in the shop test the water
  pressure is carried to 240 pounds) and engine driver should stand
  with his hand on the throttle.

54. TEST FOR MAXIMUM DELIVERY.

_a._ This can best be tried by adding one or, in some cases, two more
streams than the pump is rated to deliver by attaching the extra lines
of hose to some hydrant near, and then speed up the pump gradually,
to see how fast it may be run before violent pounding or slamming of
valves begins.

  Sometimes the increased delivery can be drawn off through an open
  hydrant-butt meanwhile holding sufficient back pressure to show 100
  pounds on the water gauge by partly closing the discharge valve.

  The engine driver should stand with his hand on or near the throttle
  when thus speeding the pump.

  It is all right to run a fire-pump up to the utmost speed possible
  before water hammer begins, and very often a pump, while new and if
  favorably set up, can deliver 25 to 50 per cent. more than rated
  capacity; nevertheless, although expert treatment can force 1,000
  gallons from a 16 × 9 × 12 pump we can rate it as only a 750-gallon
  pump. _There must be some margin to allow for wear and for the
  possible absence of the expert at time of fire._

THE MAIN POINTS OF DIFFERENCE BETWEEN THE “NATIONAL STANDARD” AND THE
“TRADE PUMP” ARE:

  Brass Plungers instead of cast-iron plungers.
  Wrought iron side levers instead of cast iron.
  Bronze piston rods and valve rods instead of iron or steel.
  Pump has brass-lined stuffing boxes instead of cast iron.
  Rock shafts are brass bushed.
  Area of water valves is 25 to 50 per cent. greater.
  Steam and exhaust passages 20 to 50 per cent. greater.
  Suction pipe connections two to four inches greater diameter.
  Cushion valves better arranged.
  Air chamber is made much larger.
  Shells and bolting are warranted especially strong.

The following necessary fittings are included in the price, and
regularly furnished as a part of this pump, viz.:

  A capacity plate.
  A stroke gauge.
  A vacuum chamber.
  Two best quality pressure gauges.
  A water relief valve of large capacity.
  A cast iron relief valve discharge cone.
  A set of brass priming pipes and special priming valves.
  From two to six hose valves.
  A sight feed cylinder lubricator connected above throttle.
  A one-pint hand oil pump connected below throttle.

Information regarding tests made under these specifications can be
obtained by addressing Underwriters’ Laboratories, Chicago, Ill.



INDEX TO PUMP SPECIFICATIONS.


        Article No.
        and section.

  Acceptance, tests for, 48 to 54

  Air chamber, 40

  Air valve, 45

  Automatic sprinklers, discharge of, 3 _c_


  Boiler power required for driving pumps, 3 _a_

  Bolts, allowable stress and size, 9, 27 _f_

  Bolting standards required, 39 _c_

  Bushings for packed water pistons, 30

  Bushings for plungers, 28, 29


  Capacity of pumps, method of computing, 4

  Capacity plate, 5

  Chambers, air and vacuum, 40

  Clearance in steam cylinders, 12

  Cone, discharge, 44

  Cover plates for water valves, 35

  Cranks, 16

  Crossheads, 16 _c_

  Cushion valves, 19

  Cylinders, steam, 8

  Cylinders, water, 27


  Delivery, test of maximum, 54

  Discharge cone, 44

  Drain cocks, 24, 47

  Duplex pumps required, 2


  Fire stream, standard, 3 _c_

  Flanges, standards required, 39 _c_

  Friction, internal, tests for, 49


  Guards for valves, 35

  Gauges, pressure, 23, 41

  Gauges, stroke, 26


  Hose valves, 42


  Inspection at shop, 7


  Leakage, test of internal, 52

  Levers, valve motion, 17

  Links, 16


  Name plates, 5


  Oiling devices, 25


  Pipe, sizes, steam and water, 39

  Piston areas, ratio, 3 _a_

  Pistons, packed water, 30

  Piston rods and nuts, 20

  Pistons, steam, 13

  Plunger bushings, 28, 29

  Plunger, water, 28, 29

  Pressure, maximum, working tests for, 53

  Priming, methods required, 46


  Rock shafts, 16

  Rods, piston, 20

  Rods, valve, 21


  Safety valves, 43

  Safety valve, test of capacity, 51

  Shop inspection, 7

  Single pumps not acceptable, 2

  Sizes of pumps, standards, 3 _a_

  Slip, 4 _f_

  Slip, test of internal, 52

  Smoothness of action, test for, 48

  Speed of pumps, 3 _a_, 33 _b_

  Speed of pumps, revolutions per minute, 3 and 4

  Springs, valve, 35

  Steam cylinders, 8

  Steam, clearance space, 12

  Steam joints, 8 _c_

  Steam pistons, 13

  Steam ports, 11

  Steam slide valves, 14, 15

  Strength of parts, 6

  Strength, tests for, 50

  Stuffing box, 22


  Tests for acceptance, 48 to 54

  Tightness, tests for, 50


  Vacuum chamber, 40

  Valves, water valve areas, 33-34

  Valve, air, 45

  Valve, cover plates, 35

  Valves, delivery, 34

  Valve guards, 35

  Valves, hose, 42

  Valve motion stand, 18

  Valves, pump, general requirements, 31

  Valves, pump, size and number, 32

  Valve rods, 21

  Valve rod heads, 16 _c_

  Valves, safety, 43

  Valve seats, water, construction of, 37

  Valve springs, 35

  Valve, steam slide, 14

  Valves, steam slide adjustment, 15

  Valve stems, types required, 38

  Valves, sticking of water valves, 36

  Valve, suction valve area, 33


  Water cylinders, 27

  Workmanship, character of, 1


  Yoke, 10



  INDEX
  TO PART ONE



  _Any one, and more especially the attentive student, can with the
  least trouble avail himself of the subject matter contained in this
  work by doing as indicated in the following old English couplet
  quoted by Chas. Reade._

  “_=For index-reading turns no student pale,
  Yet takes the eel of science by the tail.=_”



THE INDEX

TO PART ONE OF ROGERS PUMPS AND HYDRAULICS.


        PAGE

  =Accumulator=, an, des., 151
    hydraulic, ills. and des., 171-173
    rule for calculating capacity of, 172

  =Acid, muriatic=, specific gravity of, 96
    sulphuric, specific gravity of, 96

  =Adjustment of the slide valves= of the underwriter steam fire pumps,
    360

  =Advantages of a duplex pump= as a fire pump, 351

  =Aëriform fluids=, des., 15

  =Air=, des., composition of, 15, 16
    and vacuum chambers for the underwriter pump, 381
    Practically the reverse of each other, 221

  =Air-bound=, def., 17

  =Air chamber of pump=, ills., 223
    chambers, ills. and des., 220

  =Air-cock=, def., 17

  =Air=, gravity and elasticity of, 16

  =Air pump=, 13
    and electric motor, ills. and des., 271
    valve, marking of, for the underwriter pump, 385

  =Alcohol=, specific gravity of, 96

  =Alcometer=, def., 94

  =Allen, Frank=, annotations, IV, VIII

  =Alternating motor=, des. and ills., 252

  =Ammeters=, des. and ills., 256

  =Ampere=, def., 256

  =Angle for crank positions of duplex, triplex and quadruplex pumps=,
    230
    of check valve, ills. and des., 227

  =Animal power=, 187

  =Animals=, when drinking are natural bellows pumps, Note, 199

  =Annular valve=, def., 17

  =Antimony=, specific gravity of, 96

  =Apparatus, hydraulic=, def., 157

  =Archimedes and the hydrostatic balance=, 93

  =Area=, def., 17

  =Armature=, des. and ills., 247, 251

  =Armored pump valves=, ills. and des., 217

  =Armstrong, Sir William=, designer of the hydraulic accumulator, 171

  =Arsenic=, specific gravity of, 96

  =Asphalt, melted=, raised by pumps, 188

  =Assembling=, def., 17

  =Atmospheric electricity=, 245
    pressure, def., 17

  =Attraction=, capillary, def., 103
    of gravitation, 85

  =Auxiliary=, def., 17


  =Bag pump=, ills. and des., 198

  =Balanced valve=, def., 18

  =Ball check-valve=, def., 18

  =Barrel= or cylinder of a pump, des., 189
    ills., 195

  =Base= of hand pump, ills., 195

  =Basket=, def., 18

  =Battery=, how indicated by the signs + and -, 261

  =Bellows-pump=, illustrated and des., 186, 198, 199

  =Belted pumps=, des. and ills., 225

  =Belt-pumps=, hydraulic, 200
    pumps, why so called, 187

  =Bends=, def., 18

  =Bethesda, pool of=, historical def., 49

  =Bibb-cock=, def., 18

  =Blakeslee steam pump=, ills. and des., 299-301

  =Bodies soluble in water=, how weighed, 94

  =Boiler feed pump duplex power=, ills. and des., 230-231
    pumps, ills. and des., 225-234
    table of capacity of, 226

  =Boiling point of water=, 76

  =Bolt-extractor=, des. and ills., 164

  =Bolts and stubs= to be used in the underwriter steam fire pump, 356

  =Bonnets=, def., 18
    ills., 223

  =Boss=, def., 19

  =Boulton, Matthew=, inventor of hydraulic ram note, 175

  =Bourdon spring=, of metallic barometer des., 115-116

  =Bounarbashi fountains of=, historical def., 50

  =Braden pump valve=, ills. and des., 215-216

  =Bramah=, time of his invention of the hydraulic press, 169

  =Brass=, specific gravity of, 96

  =Breast=, water wheel des. and ills., 122

  =Brick=, specific gravity of, 96

  =Bronze=, specific gravity of, 96

  =Brotherhood three cylinder hydraulic engine=, 150-152

  =Brushes=, dynamo, des. and ills., 251, 262

  =Buckets, gaining and losing=, historical, des. and ills., 59, 60
    part of water wheel, 130

  =Buffalo single cylinder pump=, ills. and des., 319-321

  =Burnham steam pump=, ills. and des., 324-326

  =Bushing=, def., 19


  =Caffee, Alberto H.=, dedication of work to, V

  =Calabash=, des., 38

  =Cameron steam pump=, ills. and des., 295, 296

  =Capacity of a pump=, depends upon speed, etc., 353-354

  =Capacity plate= of the underwriter steam fire pump, 355

  =Capillary attraction=, def., 103
    facts and ills., 103, 104
    note, containing examples of, 104

  =Care and management of electric pumps=, 268

  =Carlyle=, quotation, IV

  =Cases= for turbines, des. and ills., 136

  =Castor oil=, specific gravity of, 96

  =Cauldron=, ills., 35

  =Centrifugal pump and electric motor=, ills. and des., 272
    pumps, why so called, 188

  =Chain of pots=, des. and ills., 63
    pumps, why so called, 187

  =Chambers=, air and vacuum for the underwriter pump, 381

  =Charcoal=, specific gravity of, 96

  =Check-nut=, def., 19
    valve, def., 19
    office of, 388
    of the underwriter pump, method of use, 387, 388
    wing pattern, ills. and des., 227

  =Chemicals, pump for handling=, ills. and des., 233

  =Chinese windlass=, des. and ills., 47, 62

  =“Chutes” of water wheel=, ills., 139

  =Circuit breakers=, 255

  =Circulating pump=, def., 19

  =Clack valve=, def., 19

  =Classification of pumps=, 185

  =Clay=, specific gravity of, 96

  =Clearance=, def., 19
    space of the underwriter steam fire pump, 356

  =Clepsydra=, des. and ills., 39

  =Coal=, specific gravity of, 96

  =Cock=, def., 19

  =Cocks, drain=, for the underwriter pump, 390

  =Coefficient of friction=, def., 99

  =Collecting-brushes=, part of dynamo, 248

  =Column pipe=, def., 19

  =Commutator=, ills. and des., 247, 262
    bars, des. and ills., 251

  =Compensator=, 256

  =Compound duplex pumps=, with the Deane switch valves, 343
    steam pumps, 65

  =Compounding=, what it consists of, 335

  =Compression gauge cock=, def., 20

  =Compton hydraulic motor=, des. and ills., 153

  =Computation of capacity of the underwriter fire pump=, method of,
    353-354

  =Computation relating to specific gravity= of various bodies, 95-98
    relating to the velocity of falling bodies, 89, 90

  =Conditions of service= required of a pump, 224

  =Cone=, discharge, of the underwriter pump, I, 384

  =Construction of the water ends= of single cylinder and duplex pumps,
    209

  =Contents=, Table of, part one, 15

  =Controllable valve arrangement=, des. and ills., for underwriter
    pump, 386

  =Copper=, specific gravity of, 96

  =Copyright=, page, VIII

  =Cork=, specific gravity of, 96

  =Corliss valves applied to the Riedler belt driven pumps=, 240

  =Cornish (engine) pump=, des., 65
    pumping engines, history of,  65

  =Corrosion=, def., 20

  =Covers, valve springs and guards= for the underwriter pump, 376

  =Crane, Anglo-Saxon=, historical ref. and ills., 48

  =Cranes=, lifts and hydraulic, 180

  =Crow=, def., 20

  =Cup leather packing=, 20, 154, 190

  =Current delivered from a dynamo=, how reversed, 264

  =Current electricity=, 244

  =Current water wheel=, des. and ills., 123

  =Cushioning=, def., 20

  =Cushion valves= of the underwriter fire pump, 362

  =Cylinder head or cylinder cover=, def., 20
    of hydraulic jack, des. and ills., 158, 159
    or barrel of a pump, des., 189
    pumps, why so called, 188

  =Cylinders for the water end= of the underwriter steam fire pump, 367
    of the underwriter fire pump, thicknesses of, 356


  =Davidson steam pump=, ills. and des., 287-289

  =Dead end of a pipe=, def., 20

  =Dean Bros. pump=, ills. and des., 326-328

  =Deane single acting triplex power pump=, 234
    switch valve, special features of, 34
    steam pump, ills. and des., 317-319

  =Dedication of work=, V

  =Delivery valves= of the underwriter pump, 376

  =Dial of pressure gauge= of the underwriter pump, how marked, 382

  =Diaphragm pumps=, why so called, 187

  =Direct acting duplex steam= pump, des., 69
    pumps, des., 66-68

  =Direct current motor=, des., 249

  =Discharge cone= of the underwriter pump, 384
    pipe connection, ills., 223
    how made, 204

  =Disk= or =disc=, def., 20

  =Domestic electric pumps=, ills. and des., 269

  =Double acting power pump=, with 4 check valves, ills. and des., 227
    pumps, how they do their work, 187, 188
    pump, when invented, 53

  =Double-eye or knuckle joint=, def., 20
    seated poppet valve, def., 21

  =Drafting water=, des., 21

  =Draft tube= of a water wheel, des., 135

  =Drain cocks= for the underwriter pump, 390

  =Drip-pipe=, des., 21

  =Driven or tube wells=, 202

  =Dry steam=, def., 286

  =Duct=, def., 21

  =Duplex fire pump=, shop name and shop number required on plate
      attached to underwriters, 355
    underwriters steam end, 356-366
    =oil pumps=, ills. and des., 339
    power pump not to be confounded with “Duplex pumps”, 230
    pump, ills. and des., 331-398
    outside packed plunger pattern for high pressure, 341
    setting valves of, 338
    pumps, history of, 65, 69
    only acceptable for fire pumps, 351
    with Deane switch valve, 343
    Worthington admiralty pattern of, ills. and des., 337
    steam fire pump, underwriters, water end of, 367-380
    steam pump, important note, 333
    valve motion, 333-334
    underwriters steam, fire pump, 343-398

  “=Dutchman=,” def., 21

  =“Duty” of pumps=, def., 20

  =Dynamics=, def., 245

  =Dynamo=, def., 247
    early Edison type, 248
    electric current from a, how reversed, 264
    five principal parts, 247
    when it becomes a motor, 260

  =Dynamometer=, turbine, des., 128


  =Eccentrics of the triplex power pump=, how set, 232

  =Edison dynamo=, early type, 248

  =Efficiency of an electric pump=, 268

  =Efflux of water= under pressure, 105-113

  =Elbow=, def., 21
    shown in piping, ills. and des., 223

  =Electric circuit breakers=, 255

  =Electric current=, action of, 257
    from a dynamo, how reversed, 264

  =Electric drive for fire pumps=, ills. and des., 273
    house tank pumping plant, ills. and des., 269

  =Electricity and electrical machinery=, 243
    how classified and defined, 244
    how measured, 246
    important note, 243
    in vibration, 244
    vitreous, negative, positive, etc., 245
    whence derived, 243

  =Electric mining pumps=, ills. and des., 274-276

  =Electric motor and air pump=, ills. and des., 271
    motor, des., 249
    operating a portable track pump, ills. and des., 276
    pump, ills. and des., 272-273
    pump, 241-276
    pumping installation, notable example, 275
    pumping machinery, 267-276
    pumps, care and management, 268
    properly power pumps, 208
    why so called, 187

  =Electric-rheostat=, transformer, compensator, 256

  =Electric-switches and switchboards=, 254-255

  =Electro-magnets=, ills. and des., 259

  =Electro-motive force=, def., 246

  =Elementary hydraulics=, 71-73

  =Elements, phial of four=, (mercury, water, alcohol and petroleum)
    des., 81

  =Elevator pumps=, why so called, 187

  =Emery=, specific gravity of, 96

  =E. M. F.=, def., 246

  =Energy=, mechanical and electrical, how transformed, 260

  =Engineering=, as a branch of hydraulics, 74

  =Engine, Rife hydraulic=, 177-179

  =English unit of heat=, ills. and des., 284

  =Equilibrium of superposed liquids=, data, 81

  =Equilibrium-valve=, def., 21

  =Ewbank, Thomas=, author, ref. to, 46

  “=Ewbank’s hydraulics=,” credit given for use of, 52

  =Ewers, golden=, used by rich Egyptians, 38

  =Expansion joint=, des., 21


  =Face=, def., 21

  =Factor of safety=, def., 22

  =Feather, or sunk key=, def., 22

  =Field magnets=, 247

  =Field, Marshall=, reference to, 273

  =Field spider=, electrical, def., 253

  =Fire-engine=, historical reference, 35

  =Fire-pumps=, electric drive for, ills. and des., 273
    national standard specification for the manufacture of, 351
    steam to be started once a week, 377
    underwriter, 344
    uniform requirements for the underwriter’s steam, 350

  =Flange packing=, hydraulic, ills. and des., 154

  =Flanges=, table of standard sizes for underwriter pump, 381

  =Flax, plaited=, recommended for packing power pumps, 230

  =Flow=, def., 22
    of water result of gravity, 89
    under pressure, 3 cases of, 105

  =Fluid condition of matter=, 73

  =Fluids, aeriform=, des., 15
    data relating to, 77-84
    division into liquids and vapors or gases, 73
    elastic, two classes of, 73
    friction of, des., 99

  =Flume=, def., 22
    for water wheel, size of, 138
    water, how to construct, 138

  =Flutter-wheels=, des., 121

  =Foot valve and strainer=, ills. and des., 223

  =Force pumps=, classification of, 187
    two-cylinder, 192
    when invented, 53

  =Formula= for obtaining the efficiency of hydraulic rams, 177

  =Foster steam pump=, ills. and des., 292-294

  =Foundations= for hand pumps, des., 204

  =Fourneyron’s turbine=, historical note, 128

  =Francis Weir table formula=, 122

  =Frictional Electricity=, 244
    resistance of water, three laws of, 100

  =Friction and viscosity of fluids=, def., 99
    sliding, def., 100
    two kinds of, 99

  =Fulcrum= of the lever of a hand pump, 195

  =Fusee windlass=, historical note, 62


  =Gaining and losing buckets=, historical, des. and ills., 59-60

  =Gang pumps=, triplex power, ills. and des., 231

  =Garner, Maj. Abram B.=, dedication of work to, V

  =Gas a condition= or state of matter def., 73

  =Gaseous condition of matter=, 73

  =Gases=, permanent, des., 73

  =Gas pumps=, why so called, 187

  =Gate valve=, des., 22
    of the underwriter pump, how marked, 389

  =Gate-wheel= of turbine water wheel, ills., 139

  =Gauge=, pressure, for the underwriter pump, 382

  =Gauges, hydraulic=, des. and ills., 115

  =Generator=, electric, def., 247
    four-pole, des. and ills., 251

  =Gland=, def., 22
    and stuffing-box, ills. and des., 211

  =Glass=, specific gravity of, 96

  =Globe valve=, def., 22

  =Glossary of pump and hydraulic terms=, 17-34

  =Gold=, specific gravity of, 96

  =Goose neck=, def., 22

  =Gould triplex single acting power pump=, ills. and des., 236, 237

  =Gourd=, ills., 35, 38

  =Granite=, specific gravity of, 96

  =Gravitation=, important note, 88
    universal, 85

  =Gravity=, law of, 85
    influence in weight of water, note, 80
    specific, 91

  =Gridiron valve=, def., 23

  =“Guides” of water wheels=, des., 131

  =Guild and Garrison steam pump=, ills. and des., 307-308

  =Gutter, double=, des. and ills., 54

  =Gyle and gyle-tun=, def., also note, 157

  =Gypsum=, specific gravity of, 96


  =Hand-nut=, def., 23

  =Hand pumps, classification of=, 187
    points for erecting and operating, 204

  =Hand rotary force pump=, ills. and des., 197

  =Hand wheel for safety valve= of the underwriter pump, ills., 383

  =“Hat” or flange hydraulic packing=, ills. and des., 154

  “=Head of water=,” def., 23

  =Heat units=, def., 23

  =Hercules= (turbine) wheel, des. and ills., 132, 133

  =Hero=, his first mention of steam, 200 years B. C., 279

  =Hero’s water clock=, des. and ills., 39

  “=Hesitates=,” def., 23

  =High pressure steam=, def., 286

  =High speed in pumps=, disadvantages of, 215

  =Hill steam pump=, ills. and des., 305-306

  =History of hydraulic engines=, 149
    invention of the duplex steam pump, 335

  =Holloway, J. F.=, historical quotation, 37
    note relating to pumping oil, 341

  =Hooker steam pump=, with outside valve gear, 301-303

  =Horizontal jack=, ills. and des., 163, 164
    pumps, why so called, 187
    turbine wheel, des., 133

  =Horse power apparatus=, combined pump, 201
    theoretic, of Niagara Falls water wheels, 143
    of a pump, def., 23

  =Hose valves=, sizes for the underwriter pump, 383

  “=Hump=,” def., 23

  =Hydrant=, def., 23

  =Hydraulic accumulator=, ills. and des., 171-173

  =Hydraulic apparatus=, 154-184
    pumps as, 181

  =Hydraulic belt=, def., 23
    pump, 200

  =Hydraulic bolt extractor=, ills. and des., 164
    data, 77-84
    engine of Huelgoat, interesting note, 149
    Ramsbottom’s, des. and ills., 148, 150-152
    Brotherhood three-cylinder, 150-152
    gauges, des. and ills., 115

  =Hydraulic intensifier=, des., 173

  =Hydraulic jack=, des. and ills., 158-162

  =Hydraulic jacks=, pulling, horizontal, etc., 163, 164
    relating to repairs and use, 161, 162
    lifts and cranes, 180
    machinery, broadly divided, 119
    machine tools, 183, 184
    motors, 147-153
    motors, resemblance to high pressure steam engines, 149

  =Hydraulic motor, the Compton=, 153
    packings, 153, 154
    pivot, def., 24
    press, des. and ills., 169, 170
    when invented, 53
    punch, des. and ills., 165-167

  =Hydraulic ram=, double, 177
    table of capacity, 174
    des. and ills., 180

  =Hydraulics=, as a branch of engineering, 73, 74
    as a term, how formed, 74
    def., 73

  =Hydraulics, elementary=, 71, 73-116

  =Hydraulic shears=, def., 24
    shock, def., 145
    tourniquet, des. and ills., 126
    valve, def., 24
    wheel, def., 24

  =Hydro-dynamics=, def., 73, 74

  =Hydro-mechanics=, def., 74
    as a branch of natural philosophy, 74
    stress considered in a pressure, is always, 147

  =Hydro-meters=, see note, 92

  =Hydro-pneumatics=, 15, 75

  =Hydrostatics=, def., 74

  =Hydrostatic balance=, des. and ills., 93
    paradox, data, ills., 78


  =Impact=, def., 24
    water wheels, 121

  =India rubber= best for fire pump valves, 377

  =Induction motors=, as used in mines, 275
    special electrical quality of, 252

  =Inspection shop=, required of the underwriters steam fire pump
    makers, 356

  =Installation of electric pumps=, 268

  =Intensifier=, hydraulic, des., 173

  =Introduction, historical=, 35-70

  =Introductory Considerations=, 70

  =Invention of pressure engines=, a new mode of employing water as a
    motive agent, 147

  =Inventions, successive=, 65
    water lifting, 53

  =Iron cases for turbine water wheels=, des. and ills., 136

  =Iron draft tube=, des., 137

  =Iron=, specific gravity of, 96

  =Italian mode of raising water=, des. and ills., 51


  =Jantu=, the historical, des. and ills., 54

  =Jet pumps=, why so called, 188

  =Jets=, direction of, from orifices, 113

  =Joseph’s well=, Cairo, ills., 45
    use of chain of pots in, 63, 64

  =Joule’s experiment=, 284


  =Knowles steam pump=, ills. and des., 310-312

  =Knuckle-joint=, def., 20


  =Laidlaw-Dunn-Gordon duplex underwriter pump=, ills. and des., 273
    steam pump, ills. and des., 290-292

  =Laminated pole piece=, def. and ills., 254

  =Law of gravity=, 85

  =Laws of falling bodies=, 86
    Table, 87

  =Lead=, specific gravity of, 96

  “=Leakage=,” def., 24

  =Leather collar hydraulics=, the invention of Bramah, 153, 154
    the, of a hand pump, how held in place, 191
    valve of hand pump, ills., 195

  =Leffel-Samson turbine= water wheel, des. and ills., 130

  =Leffel water wheel=, ills., 128, 130, 132, 134, 136, 144

  =Levator=, quotation from, X

  “=Lift and drop of a valve=,” def., 24

  =Lifting-jack=, def., 29

  =Lifts and cranes, hydraulic=, 180

  =Line of direction=, or line of a falling body, 88

  “=Liner=,” def., 24

  =Liquid=, def., 73

  =Liquids=, as a condition or state of matter, 73
    equilibrium of superposed, data, 81
    three cases of flow under pressure, 105
    veins, form and constitution of, 106, 107

  =Live steam=, def., 286

  “=Losing water=,” def., 25

  “=Lost motion=,” def., 25

  =Low pressure steam=, def., 286, 25

  “=Lug=,” def., 25


  =Magnetic current=, pressure necessary to produce a, 242
    field of how produced, 260
    needle, des., 266
    ills., 242

  =Magnetism=, 244

  =Magneto-electricity=, 245

  =Magnets, electro=, ills. and des., 259

  =Magnitudes=, three-time, length and quality, 87, 88

  “=Main=,” def., 25

  =Manual power=, 187

  =Marble=, specific gravity of, 96

  =Mason, Chas. J.=, quotation from, VII

  =Mason steam pump=, ills. and des., 297-299

  =Matter=, def., 88
    solid, liquid and gaseous, states of, 73
    three physical conditions, des., 73

  =McGowan steam pump=, ills. and des., 308-310

  =Mean gradient=, def., 25

  =Measurement of water pressure=, 113

  =Mercury=, specific gravity of, 96

  =Mica=, specific gravity of, 96

  =Mica=, where used, 251

  =Millstone=, specific gravity of, 96

  =Miner’s inch=, def., 25

  =Mining outfit=, how divided, 275

  =Mississippi River gauge cock=, def., 25

  =Model= of suctions and force pumps, glass, 181

  “=Modulus=” of a steam pump, def., 25

  =Momenta=, equal, principle of applied to fluids, 83

  =Montgolfier’s hydraulic ram=, note, 175

  =Moore steam pump=, ills. and des., 313-315

  =Motor=, alternating induction, des. and ills., 252
    and centrifugal pump, ills. and des., 272
    direct current, des., 249
    electric, and air pump, ills. and des., 271
    electric, des., 249
    electric, why revolves, explanation, 258

  =Motors=, division of water, des., 119
    giving names to pumps, 187
    hydraulic, 147, 153
    induction, as used in mines, 275

  =Motor=, water, simplicity of, 120
    note, 120
    when it becomes a dynamo, 260

  =Mud, pump for handling=, ills. and des., 233


  =National standard duplex fire pump=, ills. and des., 343-398
    points of difference between it and the trade pump, 395
    pump, 349
    specifications for the manufacture of steam fire pumps, 349, 351

  =National steam pump=, ills. and des., 303, 304

  =Natural philosophy=, hydro-mechanics as a branch of, 74

  =Needle, magnetic=, des., 266
    ills., 242

  =Negative electricity=, 245

  =Newcomen pumping engines=, history of, 65
    Thomas, historical ref., 36

  =Niagara Falls turbine wheels=, notes, 142, 143
    des. and ills., 140, 144

  =Nipple=, def., 26

  =Nitrogen=, what part of air, 15

  =Noria=, the, or Egyptian wheel, des. and ills., 57

  =Nozzles=, kind of, to be used in connections with the national steam
    fire pump, 353


  =Oak=, specific gravity of, 96

  =Oil pump=, ills. and des., 233
    duplex, ills. and des., 339

  =Olive oil=, specific gravity of, 96

  =Oscillating pumps=, why so called, 188

  =Outboard delivery pipe=, def., 26

  =“Outfit” of underwriter pump=, 273

  =“Out-put” of electric motor=, 249

  =Over-shot water wheel=, des. and ills., 123, 125

  =Oxygen=, what part of air, 15


  =Packings, hydraulic=, 153, 154
    most suitable for power pumps, 230

  =Packing of hand pumps=, 204
    loss of power in use of hydraulic, 154

  =Parts of a pump=, 209

  =Parts of pitcher pump=, ills. and des., 195

  =Penstock=, ills., 134, 135
    def., 26

  =Persian wheel=, des. and ills., 58

  =Pet-cock=, def., 26

  =Pewter=, specific gravity of, 96

  =Picotah of Hindostan=, des. and ills., 49

  =Pine=, specific gravity of, 96

  =Piston=, actual velocity of, 374

  =Piston= and valve rods of the underwriter fire pump, ills. and des.,
    364

  =Pistons, steam=, of the underwriter steam fire pumps, 359

  =Piston=, the, is nucleus of power of pumps and engines, 149

  =Pitcher pump=, def., 26
    spout pump, des. and ills., 195

  =“Pitman” of a pump=, des., 190

  =Pipe-clamp=, def., 26

  =Pipe sizes, table of=, for underwriter pump, 380

  “=Pipette=,” def., 26

  =Piping a pump=, ills. and des., 222, 223

  =Pipkin=, ills., 35

  =Phial of four elements= (mercury, water, alcohol and petroleum),
    des., 81

  =Phosphorus=, specific gravity of, 96

  =Plate, capacity=, of underwriter steam fire pump, 355

  =Platinum=, specific gravity of, 96

  =Plug-valve=, def., 26

  =Plumb-bob=, def., 26

  =Plunger of a pump=, how indicated in Fig. 181 and succeeding ills.,
      209
    of hand pump, ills., 195
    pumps, single acting, ills. of two, 228, 229

  =Plungers=, proportion of water and steam, advised by the
      Underwriters Associat’n, 352, 353
    water, of the underwriter steam fire pump, 368

  =Pneumatics=, 15
    def., 74
    hydro, 15

  =“Points” for erecting and operating hand pumps=, 204

  =Pole-piece=, laminated, def. and ills., 254

  =Pole-pieces=, part of dynamo, 247

  =Poplar=, specific gravity of, 96

  =Porcelain=, specific gravity of, 96

  =Positive electricity=, 245

  =Pots=, chain of, des. and ills., 63

  =Power or steam ends of pumps=, 211

  =Power pump=, double acting (4 check valves), 227
    duplex, ills. and des., 230, 231
    classification of, 187, 207

  =Power transmission by water pressure engines=, 145

  =Preface=, II

  =Press=, hydraulic, des. and ills., 169, 170

  =Pressure gauge= for the underwriter pump, 382
    necessary to produce a magnetic current, 242
    of electric currents, how measured, 256
    of water, table of, 114
    reducing valve, def., 27

  =Priming=, def., 27
    arrangement, des., 390
    pipe of pump connections, 223
    place for the underwriter pump, ills. and des., 387

  =Prizometer or pressure guage=, def., 115

  =Properties of steam=, explanation, 281-285

  =Pulley and bucket=, historical des. and ills., 46, 48
    and windlass, historical, des., 60, 61

  =Pulling-jack=, hydraulic, des. and ills., 161, 163

  =Pump and combined horse power= apparatus, 201
    bag, ills. and des., 198
    bellows, ills. and des., 186, 198, 199

  =Pump-box=, def., 27

  =Pump-brake=, def., 27

  =Pump, Buffalo single cylinder=, ills. and des., 319-321

  =Pump, Burnham steam=, ills. and des., 324-326

  =Pump-chain=, def., 27

  =Pump-cheeks=, def., 27

  =Pump, conditions of service= required of a, 224

  =Pump, Dean Bros.=, ills. and des., 326-328
    =Deane single acting triplex power pump=, ills. and des., 234, 235
    Deane steam, ills. and des., 317-319
    double acting low service, belt driven, 227
    duplex, ills. and des., 331-398
    duplex, outside packed plunger pattern for high pressure, 341
    duplex power, ills. and des., 230
    duplex steam, explanation, 333
    electric, direct driven motor, ills. and des., 272-273
    electric induction motor, ills. and des., 276
    electric mining, ills. and des., 274-276
    Gould single acting triplex power pump, ills. and des., 236, 237

  =Pump, Guild and Garrison steam=, ills. and des., 307-308
    hand rotary force, ills. and des., 197
    hydraulic belt, 200

  =Pumping engine=, historical reference, 36

  =Pumping machinery, electric=, 267-276

  =Pump, Knowles steam=, ills. and des., 310-312
    Laidlaw-Dunn-Gordon, ills. and des., 290-292
    Laidlaw-Dunn-Gordon duplex underwriter, ills. and des., 275
    McGowan steam, ills. and des., 308-310
    Moore steam, ills. and des., 313-315

  =Pump parts=, ills. and des., 209

  =Pump=, parts of a, 189
    pitcher spout, des. and ills., 195
    quintuplex, used for mining operations, 275
    rope, ills. and des., 200

  =Pumps and Hydraulics=, in two parts, Part One, I-III

  =Pumps as hydraulic apparatus=, 181

  =Pumps=, belted, des. and ills., 225
    boiler feed, ills. and des., 225-234
    duplex oil, ills. and des., 339
    for thick stuff, 233
    high speed in, a disadvantage, 215
    single acting triplex plunger, ills. and des., 233

  =Pump sizes and capacities=, standard of, given in underwriter table,
    352

  =Pump slip or slippage=, 214

  =Pump, Smith-Vaile single=, ills. and des., 329-330
    Snow steam, ills, and des., 315-317

  =Pumps, power driven=, how classified, 207

  =Pump, spray hand=, ills. and des., 201

  =Pumps, single acting=, ills. of two, 228, 229
    stationary, for mine use, how classified, 275
    steam end of, explanation, 279-285
    steam, ills. and des., 277-330
    suction and force, models of, glass, 181
    suction, for vessels and irrigation, 193
    steam, the Mason, ills. and des., 297-299
    their operation and management, 208
    triplex power, gang, ills. and des., 231
    two-cylinder force, 193
    underwriter fire, 344
    water ends of, des. and ills., 209

  =Pump, the air=, 13
    the Blakeslee steam, ills. and des., 299-301
    the Cameron steam, ills. and des., 295, 296
    the Davidson steam, ills. and des., 287-289
    the Foster steam, ills. and des., 292-294
    the Hill steam, ills. and des., 305-306
    the Hooker steam, with outside gear, ills. and des., 301-303
    the National steam, ills. and des., 303, 304
    the practical operation of a, note, 189
    the Riedler belt driven, ills. and des., 238-240
    the Riedler express, 240
    the theoretical action of a, 189

  =Pump valves=, des. and ills., 209
    of the underwriter steam fire pump, 372
    reinforced, des. and ills., 215
    size and number of, for the underwriter pump, 373

  =Pump=, Weinman steam, ills. and des., 322-324

  =Pump-well=, def., 27

  =Pump=, Worthington duplex, 336
    Worthington house tank, ills. and des., 269-270

  =Punch, hydraulic=, des. and ills., 165-166


  =Quintuplex pump=, used in mining operations, 275

  =Quotations=, I, II


  =Radiated electricity=, 245

  =Rain-gauge=, def., 28

  =Ram, double hydraulic=, 177
    hydraulic, table of capacity, 174
    des. and ills., 180
    of hydraulic jack, des. and ills., 158, 159
    Rife hydraulic, 177

  =Ramsbottom hydraulic engine=, des. and ills., 148, 150-152

  =Reaction turbine water wheel=, 127
    water wheel, des. and ills., 126

  =Reducing-coupling=, def., 28

  =Riedler express pump=, 240
    the belt driven pump, ills. and des., 238-240

  =Reinforced pump valves=, des. and ills., 215

  =Relief valve= of the underwriter pump, 384

  =Resinous electricity=, 245

  =Resistance=, def., 28
    three laws of, in flow of water, 100

  =Rheostat=, des., 256

  =Rife hydraulic ram=, or engine, 177-179

  =Right-hand thread=, def., 28

  =Rock shafts, cranks, links=, etc., of the underwriter fire pump, 361

  =Racks, water=, for water wheels, how best made, 131

  =Roberts torpedo= for clearing wells, note, 202

  =Roman screw= for raising water, des. and ills., 52
    wells, historical ref., 48

  =Rope pump=, ills. and des., 200
    pumps, why so called, 187
    socket, def., 28

  =Rotary, hand, force pump=, ills. and des., 197
    pumps, why so called, 188

  =Rotative engine pumps=, des., 65

  =Rubber=, how to determine quality of, 372

  =Rule for calculating capacity of accumulator=, 172
    for finding the specific gravity of a solid body, 95
    for velocity of water in flume, pipes and tail race, 138
    relating to the velocities of fluids flowing from orifices, 105, 106
    relating to velocity of falling bodies, 89
    to find weight of a cubic foot of anything in the table of specific
      gravities, 97

  “=Runner=” of turbine wheels, des., 131

  =Rust-joint=, def., 28


  =Safety valve= for the underwriter pump, des., 383

  =Salt=, specific gravity of, 96

  =Sand=, specific gravity of, 96

  =Saturated steam=, def., 286

  =Savery, Capt. Thomas=, historical ref., 36

  =Scoop wheel=, des. and ills., 56

  =Screw jack= or lifting jack, def., 29
    Roman, for raising water, des. and ills., 52

  =Sea injection=, def., 29

  =Seats, valve=, of the underwriter pump, 377

  =Sea water=, how many cubic feet to ton, 97
    specific gravity of, 96

  =Selden’s packing=, recommended for packing power pumps, 230

  =Semi-liquids=, def., 75
    pump for handling, ills. and des., 233

  =Setting of a turbine wheel= in penstock, des. and ills., 134

  =Setting chamber of duplex pump=, des., 336

  =Sewage=, pump for handling, ills. and des., 232

  =Shawinigan turbine wheel=, des., 133
    ills., II, IV

  =Shield for prevention of accident in gear pumps=, 233

  =Ship pumps=, working, by ropes, ills., 14

  “=Shocks=,” def., 29

  =Shop name=, and shop number required on plate attached to the
    underwriter steam fire pump, 355

  =Siloah’s fountain=, historical ref., 49

  =Silver=, specific gravity of, 96

  =Single acting pumps=, how they do their work, 188
    why so called, 187

  “=Slams=,” def., 29

  =Slate=, specific gravity of, 96

  =Sleeve-coupling=, def., 29

  =Sliding friction=, def., 100

  “=Slippage=,” def., 29
    of water in pumps, 214

  =Sluice=, def., 29

  =Slurry pump=, def., 29

  =Smith-Vaile single pump=, ills. and des., 329-330

  =Snow steam pump=, ills. and des., 315-317

  =Soap, pump for handling=, ills. and des., 233

  =Solid=, def., 73

  =Solids=, a condition or state of matter, 73

  =Socket-wrench=, def., 29

  =Spanner=, def., 29

  =Specific gravity of liquids=, 96
    of steam, 286
    rule for finding the, of a solid body, 95
    standard for, 91
    tables, rule to find weight of anything in, 97

  =Spline or feather=, def., 29

  =Split-pin or cutter=, def., 29

  =Spray pump=, ills. and des., 201

  “=Spread=,” def., 29

  =Spring, a conical=, employed to hold the valve to its seat, 209

  =Spring-seat=, def., 29

  =Springs, valve, guards and covers= for the underwriter pump, 376

  =Standard, National=, specification for the manufacture of steam fire
    pumps, 351

  =Statics=, def., 244
    what it treats of, 74
    electricity, 244

  =Steam end of a pump=, def., 30, 279-285
    of the underwriter steam fire pump, details of, 356-366

  =Steam engines, compound=, adapted to pump, 70

  =Steam fire pumps, to be started once a week=, 377

  =Steam gas=, def., 286
    =history of steam and the steam engine=, 280
    how produced, 285
    or power ends of pumps, 209
    parts of the underwriter steam fire pump, 356
    properties of, explanation, 281-285
    properties which make it valuable, 286

  =Steam pump=, ills. and early patent of H. R. Worthington, 278-330
    how classified, 188
    why so called, 187

  =Steam, relative volume of=, diagram, 282
    specific gravity of, 286
    thrown valves, def., 30
    total heat of, 286
    useful definitions relating to, 285-286

  =Steel=, specific gravity of, 96

  =Stems, valve=, of the underwriter pump, 379

  =Step= for water wheel, danger of heating, 137

  “=Sticking of valves=,” def., 30
    des., 377

  =Strainer=, def., 30
    foot valve, ills. and des., 223
    for suction pipe, ills., 204
    for tube wells, ills. and des., 203

  =Streams, velocities of=, ills., 110

  =“Stroke” of pump=, def., 30

  =Stub-end=, def., 30

  =Stud-bolt=, def., 30

  =Stuffing-box=, def., 30
    and gland, ills. and des., 211
    of the underwriter steam fire pump, 365

  =Submerged pump=, def., 30

  =Sucker-rod=, couplings, des. and ills., 203, 204

  “=Sucking wind=,” def., 31

  =Suction and force pumps=, classification of, 187
    glass models of, 181
    two-cylinder, arranged with extension levers, ills., 196

  =Suction-force pump= with air chamber, ills. and des., 226

  =Suction or lift pumps=, classification of, 187
    pump, for vessels, ills., 193
    pipe, how made and placed, 204
    pipe, proper, ills. and des., 223
    valve area of the underwriter pump, 373
    of the Riedler express pump, peculiarities of, 240

  =Sulphur=, specific gravity of, 96

  =Superheated steam=, def., 286

  =Supplemental piston=, def., 31

  =Supply channel=, leading water from falls, 119

  =Swape or sweep=, historical ref. and ills., 48

  =Swing check valve=, def., 31

  =Switch=, automatic, 269

  =Switch-cock or valve=, def., 31

  =Switches and switch boards=, des. and ills., 254-255

  =Switch valve=, Deane, with duplex pump, 393

  =Syphon=, des., 40
    ills., 41-44
    cock, def., 31

  =Syringe=, des., 44


  =Table= for underwriter pump, pipe sizes, 380
    of capacity, etc., of boiler feed pumps, 226
    etc., of triplex power pumps, 231
    for single acting triplex plunger pump, 233
    of hydraulic ram, 174
    of Worthington house tank pump, 270
    sizes, etc., of two-cylinder force and suction pump, 196

  =Table of Contents of Part One=, 15
    diameters of waste pipe of the underwriter pump, 384
    temperatures of water, 75
    National standard of sizes for duplex steam fire pumps, 352
    pressure of water, 114
    pressure of water at different depths, 77
    size, capacities, etc., Worthington admiralty pattern boiler feed
      pump, 337
    sizes, etc., of belted pumps, 225
    sizes of vacuum and air chambers for the underwriter pump, 382

  =Table of specific gravities=, 96
    standard flanges for the underwriter pump, 381
    suction valve area of the underwriter pump, 373
    test of the internal friction of the underwriter pump, 392
    valve port area and valve outlet area for underwriter pumps, 375
    volume of one pound of water, 76
    weight of one cubic foot of water, 76
    inch of water, 76
    weight, volume and pressure of water, 75-77

  =Table=, showing relation of time, space and velocity, 87

  =Tail race leading from water falls=, 119
    =water=, des., 131
    level of, ills., 134, 136
    of turbine, des., 135

  =Tank=, electric house pumping plant, ills. and des., 269

  =Tan-liquor=, pump for handling, ills. and des., 233

  =Tar=, pump for handling, ills. and des., 233

  =Test for acceptance= of the underwriter pump, 391-393
    maximum delivery, 394

  =Test of the quality of rubber=, 372

  =Thumb-nut=, def., 32

  =Tide water wheel=, des. and ills., 123

  =Tin=, specific gravity of, 96

  =Tobin-bronze=, def., 32

  =“Toe” upon a disc of pump=, des., 190

  =Tools, hydraulic machine=, 183

  =Torpedo, Robert’s=, for clearing wells, note, 202

  =Torricelli’s theorem=, relating to flow of fluids flowing from an
    orifice, and note, 105

  =Tourniquet=, hydraulic, des. and ills., 126

  =Trade pumps=, underwriters criticism of, 351

  “=Trailing water=,” def., 32

  =Transformer=, des., 256

  =Transmission of power by water pressure engines=, 145

  =Triplex power gang pump=, table of capacity, etc., 231
    pump, how to set the 6 eccentric, 232

  “=Trompe=,” def., 32

  =Tube=, or driven wells, 202

  =Tube-plug=, def., 32
   wells, how driven, ills. and des., 203

  =Turbine=, def., 32

  =Turbine-dynamometer=, des. of, 128
    Fourneyron’s, des. and ills., 128
    pump, def., 32
    water-tight, des. and ills., 139
    water-wheels, des. and ills., 126-144
    outward, vertical and central discharge of, 127
    des. of parallel flow, 128
    the Hercules, des. and ills., 132, 133
    horizontal, des., 133

  =Turbine wheels, Niagara Falls=, des. and ills., 140-144

  =Turbine wheel=, setting of, in penstock, des. and ills., 134

  =Turpentine oil=, specific gravity of, 96

  =Tweddel=, design of the hydraulic accumulator, 172

  =Two cylinder force pump=, 192
    arranged with extension levers, 196

  =Tympanum, The=, des. and ills., 55


  =Undershot water wheel=, des. and ills., 122

  =Underwriter fire pumps=, 344
    list of attachments for, 345
    area for suction valve for the, 373
    test for acceptance of, 391

  =Underwriter steam fire pump=, des. and ills., 343-398

  =Union=, def., 33

  =Unit of heat, English=, ills. and des., 384


  =V packing, hydraulic=, ills. and des., 154

  =Vacuum=, def., 33
    and air chambers practically the reverse of each other, 221
    for the underwriter pump, 381
    ills. and des., 220

  =Vacuum pumps, how classified=, 188

  =Valve=, def., 33
    air, def., and marking of, for the underwriter pump, 385
    areas, size necessary for, 374
    gate of the underwriter pump, how marked, 389
    motion of duplex pump, 333, 334
    of the Worthington duplex pump, 336
    of hand pump, lower or suction, ills., 195

  =Valve of Riedler belt-driven pump=, ills. and des., 238-240

  =Valve port area= and valve outlet area, table of, for underwriter
      pump, 374, 375
    relief of the underwriter pump, 384
    seats, bolts and springs should be of the best composition, metal,
      etc., 218

  =Valve setting of the Blakeslee steam pump=, 301
    Buffalo single cylinder pump, 321
    Burnham steam pump, 326
    Cameron steam pump, 296
    Davidson steam pump, 287-289
    Dean Bros’ steam pump, 328
    Deane steam pump, 319
    Duplex steam pump, 338
    Foster steam pump, 292-294
    Guild and Garrison steam pump, 308
    Hill steam pump, 306
    Hooker steam pump with outside valve gear, 303
    Knowles steam pump, 311
    Dunn-Gordon steam pump, 290
    Laidlaw, 292
    Mason steam pump, 299
    McGowan steam pump, 310
    Moore steam pump, 315
    National steam pump, 304
    Smith-Vaile single steam pump, 330
    Snow steam pump, 316
    Weinman steam pump, 323

  =Valve slam=, def., 374

  =Valve springs=, guards and covers for the underwriter pump, 376

  =Valve stems of the underwriter pump=, 379

  =Valves, delivery=, of the underwriter pump, 376
    hose, size for the underwriter pump, 383
    pump, des. and ills., 309

  =Valves, pump=, size and number of, for the underwriter pump, 373
    reinforced pump, des. and ills., 215-216
    small ones preferable, 213
    steam slide of the underwriter fire pump, 360

  =Valves, sticking of=, def., 377
    the lift of valves, 214

  =Vapors=, des., 73

  =Vapor, when it becomes a gas=, 73

  =Velocity of falling bodies=, valves to find, 89
    fluids flowing from an orifice, 105, 106
    streams, ills., 110
    water in flumes and pipes, 138
    in tail-race, Rule, 138
    in water pressure engines, 145

  =Ventres=, def., 106

  =Vertical pumps=, why so called, 187

  =Vinegar=, specific gravity of, 96

  =Viscosity=, def., 33, 75
    of fluids, des., 99, 102

  =Vis viva=, def., 102

  =Vitreous electricity=, 245

  =Vitruvius=, quotation from, 57

  =Volt=, def., 256

  =Voltaic electricity=, 246

  =Voltmeters=, def., 256

  =V thread=, def., 33


  =Washer=, def., 33

  =Waste channel of water-falls=, 119

  =Waste pipe=, sizes for the underwriter pump, 384

  =Water and steam=, one an elastic and the other a non-elastic liquid,
    149

  =Water arch=, def., 33

  =Water as an example of a fluid=, 73

  =Water-bellows=, def., 33

  =Water, boiling point of=, 76
    cap, def., 33
    chemical composition of, 75
    clocks, des. and ills., 39
    conditions of, 75-77
    considered from a chemical standpoint, 75
    data relating to, 75

  =Water dust=, French term for steam, 285
    end, def., 33
    of the underwriter steam fire pump, ills. and des., 367-380
    pumps, des. and ills., 209

  =Waterfalls=, des. of supply and waste channels, 119
    division of parts deriving energy, 119

  =Water, flow of, result of gravity=, 89
    four notable temperatures of, 75

  =Water-hammer=, def., 34
    or valve slam, def., 374
    influence of gravity on weight of, note, 80

  =Water-lifting inventions=, 53-70
    of what composed, 285
    practically non-elastic, data, 75-77
    pressure engines, care of, to prevent freezing, etc., 145, 146

  =Water pressure machines=, 117-154
    measurement of, 113
    due to its weight, data, 83
    pressure of, table, 114
    pressure on column of, data, 77
    how transmitted, data and ills., 79
    proportioned to its depth, data, 83
    table, 77

  =Water pressure or hydraulic motors=, des., 147

  =Water pumps=, why so called, 187
    racks for turbine wheels, how best made, 131

  =Water ram=, def., 34
    rises to same level in opposite arms of tube, data, 83
    salt, boiling point of, 76
    sea, how many cubic feet to ton, 97
    tables of weight and volume, etc., 76
    temperature of, for calculations, 75

  =Water=, theoretical and actual flow, note, 106
    three laws of frictional resistance of, 100

  =Water-tight turbine=, ills. and des., 139
    under pressure, efflux of, 105-113
    velocity of, in flumes and pipes, rule, 138
    tail race, rule, 138
    weight and volume of, tables, 76, 77
    in round numbers, 76
    one cubic foot of, 76

  =Water wheel=, 132, 133

  =Water wheels=, 119-144
    des. and ills. of “chutes,” gate-seats, “gates” and “buckets” of
      turbine, des. and ills., 139
    des. and ills. of flutter wheels, etc., 121-125
    des. of “runners,” “guides” and water racks, 130
    des. of the “step” buckets, etc., 130
    des. “tail water” and “draft tube”, 135
    setting of, in penstock, 134
    Leffel, 130
    when the water is measured, 130

  =Water will rise as high as its source=, data, 83

  =Watt, Jas., account of his discovery= of the properties of steam,
    280, 281

  =Watt, Jas.=, historical, ref., 35

  =Weinman steam pump=, ills. and des., 322-324

  =Weirs=, def., 122

  =Weir tables=, allusion to in note, 122

  =Wells=, des. and ills., 45-52
    driven or tube, 202
    historical note, 50
    Roman, historical ref., 48
    tube, how driven, ills. and des., 203
    with stairs, historical des., 51

  =Wet steam=, def., 286

  =Wheel and axle=, use of, in wells, 64

  =Wheel, scoop=, des. and ills., 56

  =Wheel, the Egyptian=, des. and ills., 57

  =Wheel, the Noria=, des. and ills., 57
    the Persian, des. and ills., 58

  =Whirlpool-chamber=, def., 35

  =Why an electric motor revolves=, 258

  =Willow, specific gravity of=, 96

  =Windlass, Chinese=, historical ref. and ills., 47, 62

  =Wind pumps=, why so called, 187

  =Wing-nut=, def., 35
    pattern check valve, ills. and des., 227

  =Working barrel=, def., 34

  =Work=, useful, done in water pressure engines, 145

  =Worthington, Henry Rossiter=, historical notes, 68-70
    engraved portrait of, vi
    death of, 70
    ills. of first patented steam pump, 278

  =Worthington duplex pump=, 336


  =Y=, def., 35

  =Yoke=, def., 35
    of the underwriter steam fire pump, 356


  =Zinc=, specific gravity of, 96





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