How it Flies or, Conquest of the Air - The Story of Man's Endeavors to Fly and of the Inventions

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Title: How it Flies or, Conquest of the Air - The Story of Man's Endeavors to Fly and of the Inventions - by which He Has Succeeded
Author: Ferris, Richard
Language: English
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*** Start of this LibraryBlog Digital Book "How it Flies or, Conquest of the Air - The Story of Man's Endeavors to Fly and of the Inventions - by which He Has Succeeded" ***

[Illustration: ORVILLE WRIGHT IN THE 80-MILE-AN-HOUR “BABY WRIGHT”
RACER.]

How It Flies

or,

THE CONQUEST OF THE AIR

The Story of Man’s Endeavors to Fly and of the
Inventions by which He Has Succeeded

RICHARD FERRIS, B.S., C.E.

Illustrated by Over One Hundred and Fifty Half-tones and Line
Drawings, Showing the Stages of Development from the
Earliest Balloon to the Latest Monoplane and Biplane

New York

THOMAS NELSON AND SONS

381-385 Fourth Avenue

THOMAS NELSON & SONS

THE TROW PRESS, NEW YORK

PREFACE

In these pages, by means of simple language and suitable pictures, the
author has told the story of the Ships of the Air. He has explained
the laws of their flight; sketched their development to the present
day; shown how to build the flying machine and the balloon, and how
to operate them; recounted what man has done, and what he hopes to do
with their aid. In a word, all the essential facts that enter into the
Conquest of the Air have been gathered into orderly form, and are here
presented to the public.

We who live to-day have witnessed man’s great achievement; we have seen
his dream of ages come true. Man has learned to _fly_!

The air which surrounds us, so intangible and so commonplace that
it seldom arrests our attention, is in reality a vast, unexplored
ocean, fraught with future possibilities. Even now, the pioneers of
a countless fleet are hovering above us in the sky, while steadily,
surely these wonderful possibilities are unfolded.

The Publishers take pleasure in acknowledging their indebtedness to the
_Scientific American_ for their courtesy in permitting the use of many
of the illustrations appearing in this book.

NEW YORK, October 20, 1910.

CONTENTS

CHAPTER PAGE

PREFACE 7

I. INTRODUCTORY 11

II. THE AIR 20

III. LAWS OF FLIGHT 37

IV. FLYING MACHINES 55

V. FLYING MACHINES: THE BIPLANE 78

VI. FLYING MACHINES: THE MONOPLANE 112

VII. FLYING MACHINES: OTHER FORMS 141

VIII. FLYING MACHINES: HOW TO OPERATE 151

IX. FLYING MACHINES: HOW TO BUILD 174

X. FLYING MACHINES: MOTORS 193

XI. MODEL FLYING MACHINES 215

XII. THE GLIDER 241

XIII. BALLOONS 257

XIV. BALLOONS: THE DIRIGIBLE 296

XV. BALLOONS: HOW TO OPERATE 340

XVI. BALLOONS: HOW TO MAKE 351

XVII. MILITARY AERONAUTICS 363

XVIII. BIOGRAPHIES OF PROMINENT AERONAUTS 379

XIX. CHRONICLE OF AVIATION ACHIEVEMENTS 407

XX. EXPLANATION OF AERONAUTICAL
TERMS 452

HOW IT FLIES

Chapter I.

INTRODUCTORY.

The sudden awakening--Early successes--Influence of the gasoline
engine on aeroplanes--On dirigible balloons--Interested
inquiry--Some general terms defined.

In the year 1908 the world awakened suddenly to the realization that at
last the centuries of man’s endeavor to fly mechanically had come to
successful fruition.

There had been a little warning. In the late autumn of 1906,
Santos-Dumont made a flight of 720 feet in a power-driven machine.
There was an exclamation of wonder, a burst of applause--then a relapse
into unconcern.

In August, 1907, Louis Bleriot sped free of the ground for 470 feet;
and in November, Santos-Dumont made two flying leaps of barely 500
feet. That was the year’s record, and it excited little comment. It is
true that the Wright brothers had been making long flights, but they
were in secret. There was no public knowledge of them.

In 1908 came the revelation. In March, Delagrange flew in a Voisin
biplane 453 feet, carrying Farman with him as a passenger. Two weeks
later he flew alone nearly 2½ miles. In May he flew nearly 8 miles. In
June his best flight was 10½ miles. Bleriot came on the scene again
in July with a monoplane, in which he flew 3¾ miles. In September,
Delagrange flew 15 miles--in less than 30 minutes. In the same month
the Wrights began their wonderful public flights. Wilbur, in France,
made records of 41, 46, 62, and 77 miles, while Orville flew from 40 to
50 miles at Fort Myer, Va. Wilbur Wright’s longest flight kept him in
the air 2 hours and 20 minutes.

The goal had been reached--men had achieved the apparently impossible.
The whole world was roused to enthusiasm.

Since then, progress has been phenomenally rapid, urged on by the
striving of the inventors, the competition of the aircraft builders,
and the contests for records among the pilots.

By far the largest factor in the triumph of the aeroplane is the
improved gasoline engine, designed originally for automobiles. Without
this wonderful type of motor, delivering a maximum of power with a
minimum of weight, from concentrated fuel, the flying machine would
still be resting on the earth.

[Illustration: The Renard and Krebs airship _La France_, at
Chalais-Meudon.]

Nor has the influence of the gasoline motor been much less upon that
other great class of aircraft, the dirigible balloon. After 1885, when
Renard and Krebs’ airship _La France_ made its two historic voyages
from Chalais-Meudon to Paris, returning safely to its shed, under the
propulsion of an electric motor, the problem of the great airship lay
dormant, waiting for the discovery of adequate motive power. If the
development of the dirigible balloon seems less spectacular than that
of the aeroplane, it is because the latter had to be created; the
dirigible, already in existence, had only to be revivified.

Confronted with these new and strange shapes in the sky, some making
stately journeys of hundreds of miles, others whirring hither and
thither with the speed of the whirlwind, wonder quickly gives way to
the all-absorbing question: _How do they fly?_ To answer fully and
satisfactorily, it seems wise, for many readers, to recall in the
succeeding chapters some principles doubtless long since forgotten.

* * * * *

As with every great advance in civilization, this expansion of the
science of aeronautics has had its effect upon the language of the day.
Terms formerly in use have become restricted in application, and other
terms have been coined to convey ideas so entirely new as to find no
suitable word existent in our language. It seems requisite, therefore,
first to acquaint the reader with clear definitions of the more common
terms that are used throughout this book.

_Aeronautics_ is the word employed to designate the entire subject of
aerial navigation. An _aeronaut_ is a person who sails, or commands,
any form of aircraft, as distinguished from a passenger.

_Aviation_ is limited to the subject of flying by machines which are
not floated in the air by gas. An _aviator_ is an operator of such
machine.

[Illustration: A free balloon, with parachute.]

Both aviators and aeronauts are often called _pilots_.

A _balloon_ is essentially an envelope or bag filled with some gaseous
substance which is lighter, bulk for bulk, than the air at the surface
of the earth, and which serves to float the apparatus in the air. In
its usual form it is spherical, with a car or basket suspended below
it. It is a _captive balloon_ if it is attached to the ground by a
cable, so that it may not rise above a certain level, nor float away in
the wind. It is a _free balloon_ if not so attached or anchored, but is
allowed to drift where the wind may carry it, rising and falling at the
will of the pilot.

[Illustration: A dirigible balloon.]

A _dirigible balloon_, sometimes termed simply a dirigible, usually has
its gas envelope elongated in form. It is fitted with motive power to
propel it, and steering mechanism to guide it. It is distinctively the
_airship_.

_Aeroplanes_ are those forms of flying machines which depend for their
support in the air upon the spread of surfaces which are variously
called wings, sails, or planes. They are commonly driven by propellers
actuated by motors. When not driven by power they are called _gliders_.

[Illustration: A biplane glider.]

Aeroplanes exist in several types: the _monoplane_, with one spread
of surface; the _biplane_, with two spreads, one above the other; the
_triplane_, with three spreads, or decks; the _multiplane_, with more
than three.

The _tetrahedral plane_ is a structure of many small cells set one upon
another.

_Ornithopter_ is the name given to a flying machine which is operated
by flapping wings.

[Illustration: A parachute descending.]

_Helicopter_ is used to designate machines which are lifted vertically
and sustained in the air by propellers revolving in a horizontal plane,
as distinguished from the propellers of the aeroplane, which revolve in
vertical planes.

A _parachute_ is an umbrella-like contrivance by which an aeronaut may
descend gently from a balloon in mid-air, buoyed up by the compression
of the air under the umbrella.

For the definition of other and more technical terms the reader is
referred to the carefully prepared Glossary toward the end of the book.

Chapter II.

THE AIR.

Intangibility of air--Its
substance--Weight--Extent--Density--Expansion
by heat--Alcohol fire--Turbulence of the
air--Inertia--Elasticity--Viscosity--Velocity of
winds--Aircurrents--Cloud levels--Aerological stations--High
altitudes--Practical suggestions--The ideal highway.

The air about us seems the nearest approach to nothingness that we know
of. A pail is commonly said to be empty--to have nothing in it--when it
is filled only with air. This is because our senses do not give us any
information about air. We cannot see it, hear it, touch it.

When air is in motion (wind) we hear the noises it makes as it passes
among other objects more substantial; and we feel it as it blows by us,
or when we move rapidly through it.

We get some idea that it exists as a substance when we see dead leaves
caught up in it and whirled about; and, more impressively, when in the
violence of the hurricane it seizes upon a body of great size and
weight, like the roof of a house, and whisks it away as though it were
a feather, at a speed exceeding that of the fastest railroad train.

In a milder form, this invisible and intangible air does some of our
work for us in at least two ways that are conspicuous: it moves ships
upon the ocean, and it turns a multitude of windmills, supplying the
cheapest power known.

That this atmosphere is really a fluid ocean, having a definite
substance, and in some respects resembling the liquid ocean upon which
our ships sail, and that we are only crawling around on the bottom
of it, as it were, is a conception we do not readily grasp. Yet this
conception must be the foundation of every effort to sail, to fly, in
this aerial ocean, if such efforts are to be crowned with success.

As a material substance the air has certain physical properties, and
it is the part of wisdom for the man who would fly to acquaint himself
with these properties. If they are helpful to his flight, he wants to
use them; if they hinder, he must contrive to overcome them.

In general, it may be said that the air, being in a gaseous form,
partakes of the properties of all gases--and these may be studied
in any text-book on physics, Here we are concerned only with those
qualities which affect conditions under which we strive to fly.

Of first importance is the fact that air has _weight_. That is, in
common with all other substances, it is attracted by the mass of the
earth exerted through the force we call gravity. At the level of the
sea, this attraction causes the air to press upon the earth with a
weight of nearly fifteen pounds (accurately, 14.7 lbs.) to the square
inch, when the temperature is at 32° F. That pressure is the weight of
a column of air one inch square at the base, extending upward to the
outer limit of the atmosphere--estimated to be about 38 miles (some say
100 miles) above sea-level. The practical fact is that normal human
life cannot exist above the level of 15,000 feet, or a little less than
three miles; and navigation of the air will doubtless be carried on at
a much lower altitude, for reasons which will appear as we continue.

The actual weight of a definite quantity of dry air--for instance,
a cubic foot--is found by weighing a vessel first when full of air,
and again after the air has been exhausted from it with an air-pump.
In this way it has been determined that a cubic foot of dry air,
at the level of the sea, and at a temperature of 32° F., weighs 565
grains--about 0.0807 lb. At a height above the level of the sea, a
cubic foot of air will weigh less than the figure quoted, for its
density decreases as we go upward, the pressure being less owing to
the diminished attraction of the earth at the greater distance. For
instance, at the height of a mile above sea-level a cubic foot of air
will weigh about 433 grains, or 0.0619 lb. At the height of five miles
it will weigh about 216 grains, or 0.0309 lb. At thirty-eight miles
it will have no weight at all, its density being so rare as just to
balance the earth’s attraction. It has been calculated that the whole
body of air above the earth, if it were all of the uniform density of
that at sea-level, would extend only to the height of 26,166 feet.
Perhaps a clearer comprehension of the weight and pressure of the ocean
of air upon the earth may be gained by recalling that the pressure of
the 38 miles of atmosphere is just equal to balancing a column of water
33 feet high. The pressure of the air, therefore, is equivalent to the
pressure of a flood of water 33 feet deep.

[Illustration: Comparative Elevations of Earth and Air.]

But air is seldom dry. It is almost always mingled with the vapor
of water, and this vapor weighs only 352 grains per cubic foot at
sea-level. Consequently the mixture--damp air--is lighter than dry air,
in proportion to the moisture it contains.

[Illustration: Apparatus to show effects of heat on air currents. _a_,
alcohol lamp; _b_, ice. The arrows show direction of currents.]

Another fact very important to the aeronaut is that the air is in
_constant motion_. Owing to its ready expansion by heat, a body of
air occupying one cubic foot when at a temperature of 32° F. will
occupy more space at a higher temperature, and less space at a lower
temperature. Hence, heated air will flow upward until it reaches a
point where the natural density of the atmosphere is the same as its
expanded density due to the heating. Here another complication comes
into play, for ascending air is cooled at the rate of one degree for
every 183 feet it rises; and as it cools it grows denser, and the speed
of its ascension is thus gradually checked. After passing an altitude
of 1,000 feet the decrease in temperature is one degree for each 320
feet of ascent. In general, it may be stated that air is expanded
one-tenth of its volume for each 50° F. that its temperature is raised.

This highly unstable condition under ordinary changes of temperature
causes continual movements in the air, as different portions of it are
constantly seeking that position in the atmosphere where their density
at that moment balances the earth’s attraction.

Sir Hiram Maxim relates an incident which aptly illustrates the effect
of change of temperature upon the air. He says: “On one occasion,
many years ago, I was present when a bonded warehouse in New York
containing 10,000 barrels of alcohol was burned.... I walked completely
around the fire, and found things just as I expected. The wind was
blowing a perfect hurricane through every street in the direction of
the fire, although it was a dead calm everywhere else; the flames
mounted straight in the air to an enormous height, and took with them a
large amount of burning wood. When I was fully 500 feet from the fire,
a piece of partly burned one-inch board, about 8 inches wide and 4 feet
long, fell through the air and landed near me. This board had evidently
been taken up to a great height by the tremendous uprush of air caused
by the burning alcohol.”

That which happened on a small scale, with a violent change of
temperature, in the case of the alcohol fire, is taking place on a
larger scale, with milder changes in temperature, all over the world.
The heating by the sun in one locality causes an expansion of air
at that place, and cooler, denser air rushes in to fill the partial
vacuum. In this way winds are produced.

So the air in which we are to fly is in a state of constant motion,
which may be likened to the rush and swirl of water in the rapids of a
mountain torrent. The tremendous difference is that the perils of the
water are in plain sight of the navigator, and may be guarded against,
while those of the air are wholly invisible, and must be met as they
occur, without a moment’s warning.

[Illustration:

The solid arrows show the directions of a cyclonic wind on
the earth’s surface. At the centre the currents go directly
upward. In the upper air above the cyclone the currents have the
directions of the dotted arrows.]

Next in importance, to the aerial navigator, is the air’s _resistance_.
This is due in part to its density at the elevation at which he is
flying, and in part to the direction and intensity of its motion, or
the wind. While this resistance is far less than that of water to the
passage of a ship, it is of serious moment to the aeronaut, who must
force his fragile machine through it at great speed, and be on the
alert every instant to combat the possibility of a fall as he passes
into a rarer and less buoyant stratum.

[Illustration:

Diagram showing disturbance of wind currents by inequalities of
the ground, and the smoother currents of the upper air. Note the
increase of density at A and B, caused by compression against the
upper strata.]

Three properties of the air enter into the sum total of its
resistance--inertia, elasticity, and viscosity. Inertia is its tendency
to remain in the condition in which it may be: at rest, if it is still;
in motion, if it is moving. Some force must be applied to disturb this
inertia, and in consequence when the inertia is overcome a certain
amount of force is used up in the operation. Elasticity is that
property by virtue of which air tends to reoccupy its normal amount
of space after disturbance. An illustration of this tendency is the
springing back of the handle of a bicycle pump if the valve at the
bottom is not open, and the air in the pump is simply compressed, not
forced into the tire. Viscosity may be described as “stickiness”--the
tendency of the particles of air to cling together, to resist
separation. To illustrate: molasses, particularly in cold weather,
has greater viscosity than water; varnish has greater viscosity than
turpentine. Air exhibits some viscosity, though vastly less than that
of cold molasses. However, though relatively slight, this viscosity has
a part in the resistance which opposes the rapid flight of the airship
and aeroplane; and the higher the speed, the greater the retarding
effect of viscosity.

The inertia of the air, while in some degree it blocks the progress
of his machine, is a benefit to the aeronaut, for it is inertia which
gives the blades of his propeller “hold” upon the air. The elasticity
of the air, compressed under the curved surfaces of the aeroplane, is
believed to be helpful in maintaining the lift. The effect of viscosity
may be greatly reduced by using surfaces finished with polished
varnish--just as greasing a knife will permit it to be passed with
less friction through thick molasses.

In the case of winds, the inertia of the moving mass becomes what is
commonly termed “wind pressure” against any object not moving with it
at an equal speed. The following table gives the measurements of wind
pressure, as recorded at the station on the Eiffel Tower, for differing
velocities of wind:

+----------+------------+---------------+
| Velocity | Velocity | Pressure |
| in Miles | in Feet | in Pounds on |
| per Hour | per Second | a Square Foot |
+----------+------------+---------------+
| 2 | 2.9 | 0.012 |
| 4 | 5.9 | 0.048 |
| 6 | 8.8 | 0.108 |
| 8 | 11.7 | 0.192 |
| 10 | 14.7 | 0.300 |
| 15 | 22.0 | 0.675 |
| 20 | 29.4 | 1.200 |
| 25 | 36.7 | 1.875 |
| 30 | 44.0 | 2.700 |
| 35 | 51.3 | 3.675 |
| 40 | 58.7 | 4.800 |
| 45 | 66.0 | 6.075 |
| 50 | 73.4 | 7.500 |
| 60 | 88.0 | 10.800 |
| 70 | 102.7 | 14.700 |
| 80 | 117.2 | 19.200 |
| 90 | 132.0 | 24.300 |
| 100 | 146.7 | 30.000 |
+----------+------------+---------------+

In applying this table, the velocity to be considered is the net
velocity of the movements of the airship and of the wind. If the ship
is moving 20 miles an hour _against_ a head wind blowing 20 miles an
hour, the net velocity of the wind will be 40 miles an hour, and the
pressure 4.8 lbs. a square foot of surface presented. Therefore the
airship will be standing still, so far as objects on the ground are
concerned. If the ship is sailing 20 miles an hour _with_ the wind,
which is blowing 20 miles an hour, the pressure per square foot will be
only 1.2 lbs.; while as regards objects on the ground, the ship will be
travelling 40 miles an hour.

[Illustration:

Apparatus for the study of the action of air in motion; a blower
at the farther end of the great tube sends a “wind” of any
desired velocity through it. Planes and propellers of various
forms are thus tested.]

Systematic study of the movements of the air currents has not been
widespread, and has not progressed much beyond the gathering of
statistics which may serve as useful data in testing existing theories
or formulating new ones.

It is already recognized that there are certain “tides” in the
atmosphere, recurring twice daily in six-hour periods, as in the case
of the ocean tides, and perhaps from the same causes. Other currents
are produced by the earth’s rotation. Then there are the five-day
oscillations noted by Eliot in India, and daily movements, more or less
regular, due to the sun’s heat by day and the lack of it by night.
The complexity of these motions makes scientific research extremely
difficult.

Something definite has been accomplished in the determination of wind
velocities, though this varies largely with the locality. In the United
States the average speed of the winds is 9½ miles per hour; in Europe,
10⅓ miles; in Southern Asia, 6½ miles; in the West Indies, 6⅕ miles; in
England, 12 miles; over the North Atlantic Ocean, 29 miles per hour.
Each of these average velocities varies with the time of year and time
of day, and with the distance from the sea. The wind moves faster over
water and flat, bare land than over hilly or forest-covered areas.
Velocities increase as we go upward in the air, being at 1,600 feet
twice what they are at 100 feet. Observations of the movements of cloud
forms at the Blue Hill Observatory, near Boston, give the following
results:

In winter the speed of cirrus clouds may reach 96 miles per hour.

There are forty-nine stations scattered over Germany where statistics
concerning winds are gathered expressly for the use of aeronauts. At
many of these stations records have been kept for twenty years. Dr.
Richard Assman, director of the aerological observatory at Lindenburg,
has prepared a comprehensive treatise of the statistics in possession
of these stations, under the title of _Die Winde in Deutschland_. It
shows for each station, and for each season of the year, how often the
wind blows from each point of the compass; the average frequency of
the several degrees of wind; when and where aerial voyages may safely
be made; the probable drift of dirigibles, etc. It is interesting to
note that Friedrichshafen, where Count Zeppelin’s great airship sheds
are located, is not a favorable place for such vessels, having a yearly
record of twenty-four stormy days, as compared with but two stormy days
at Celle, four at Berlin, four at Cassel, and low records at several
other points.

In practical aviation, a controlling factor is the density of the air.
We have seen that at an altitude of five miles the density is about
three-eighths the density at sea-level. This means that the supporting
power of the air at a five-mile elevation is so small that the area of
the planes must be increased to more than 2½ times the area suited to
flying near the ground, or that the speed must be largely increased.
Therefore the adjustments necessary for rising at the lower level and
journeying in the higher level are too large and complex to make flying
at high altitudes practicable--leaving out of consideration the bitter
cold of the upper regions.

Mr. A. Lawrence Rotch, director of the Blue Hill Observatory, in his
valuable book, _The Conquest of the Air_, gives this practical summary
of a long series of studious observations: “At night, however, because
there are no ascending currents, the wind is much steadier than in the
daytime, making night the most favorable time for aerial navigation
of all kinds.... A suitable height in the daytime, unless a strong
westerly wind is sought, lies above the cumulus clouds, at the height
of about a mile; but at night it is not necessary to rise so high; and
in summer a region of relatively little wind is found at a height of
about three-fourths of a mile, where it is also warmer and drier than
in the daytime or at the ground.”

Notwithstanding all difficulties, the fact remains that, once they are
overcome, the air is the ideal highway for travel and transportation.
On the sea, a ship may sail to right or left on one plane only. In
the air, we may steer not only to right or left, but above and below,
and obliquely in innumerable planes. We shall not need to traverse
long distances in a wrong direction to find a bridge by which we may
cross a river, nor zigzag for toilsome miles up the steep slopes of a
mountain-side to the pass where we may cross the divide. The course of
the airship is the proverbial bee-line--the most economical in time as
well as in distance.

Chapter III.

LAWS OF FLIGHT.

The bird--Nature’s models--Man’s methods--Gravity--The
balloon--The airship--Resistance of the air--Winds--The
kite--Laws of motion and force--Application to
kite-flying--Aeroplanes.

If we were asked to explain the word “flying” to some foreigner who did
not know what it meant, we should probably give as an illustration the
bird. This would be because the bird is so closely associated in our
thoughts with flying that we can hardly think of the one without the
other.

It is natural, therefore, that since men first had the desire to fly
they should study the form and motions of the birds in the air, and
try to copy them. Our ancestors built immense flopping wings, into
the frames of which they fastened themselves, and with great muscular
exertion of arms and legs strove to attain the results that the bird
gets by apparently similar motions.

However, this mental coupling of the bird with the laws of flight has
been unfortunate for the achievement of flight by man. And this is
true even to the present day, with its hundreds of successful flying
machines that are not in the least like a bird. This wrongly coupled
idea is so strong that scientific publications print pages of research
by eminent contributors into the flight of birds, with the attempt
to deduce lessons therefrom for the instruction of the builders and
navigators of flying machines.

These arguments are based on the belief that Nature never makes a
mistake; that she made the bird to fly, and therefore the bird must be
the most perfect model for the successful flying machine. But the truth
is, the bird was not made primarily to fly, any more than man was made
to walk. Flying is an incident in the life of a bird, just as walking
is an incident in the life of a man. Flying is simply a bird’s way of
getting about from place to place, on business or on pleasure, as the
case may be.

Santos-Dumont, in his fascinating book, _My Air-Ships_, points out
the folly of blindly following Nature by showing that logically such
a procedure would compel us to build our locomotives on the plan of
gigantic horses, with huge iron legs which would go galloping about
the country in a ridiculously terrible fashion; and to construct our
steamships on the plan of giant whales, with monstrous flapping fins
and wildly lashing tails.

Sir Hiram Maxim says something akin to this in his work, _Artificial
and Natural Flight_: “It appears to me that there is nothing in Nature
which is more efficient, or gets a better grip on the water, than a
well-made screw propeller; and no doubt there would have been fish with
screw propellers, providing Dame Nature could have made an animal in
two pieces. It is very evident that no living creature could be made in
two pieces, and two pieces are necessary if one part is stationary and
the other revolves; however, the tails and fins very often approximate
to the action of propeller blades; they turn first to the right and
then to the left, producing a sculling effect which is practically the
same. This argument might also be used against locomotives. In all
Nature we do not find an animal travelling on wheels, but it is quite
possible that a locomotive might be made that would walk on legs at
the rate of two or three miles an hour. But locomotives with wheels
are able to travel at least three times as fast as the fleetest animal
with legs, and to continue doing so for many hours at a time, even when
attached to a very heavy load. In order to build a flying machine with
flapping wings, to exactly imitate birds, a very complicated system of
levers, cams, cranks, etc., would have to be employed, and these of
themselves would weigh more than the wings would be able to lift.”

As with the man-contrived locomotive, so the perfected airship will be
evolved from man’s understanding of the obstacles to his navigation
of the air, and his overcoming of them by his inventive genius. This
will not be in Nature’s way, but in man’s own way, and with cleverly
designed machinery such as he has used to accomplish other seeming
impossibilities. With the clearing up of wrong conceptions, the path
will be open to more rapid and more enduring progress.

When we consider the problem of flying, the first obstacle we encounter
is the attraction which the earth has for us and for all other objects
on its surface. This we call weight, and we are accustomed to measure
it in pounds.

Let us take, for example, a man whose body is attracted by the earth
with a force, or weight, of 150 pounds. To enable him to rise into the
air, means must be contrived not only to counteract his weight, but to
lift him--a force a little greater than 150 pounds must be exerted. We
may attach to him a bag filled with some gas (as hydrogen) for which
the earth has less attraction than it has for air, and which the air
will push out of the way and upward until a place above the earth is
reached where the attraction of air and gas is equal. A bag of this
gas large enough to be pushed upward with a force equal to the weight
of the man, plus the weight of the bag, and a little more for lifting
power, will carry the man up. This is the principle of the ordinary
balloon.

Rising in the air is not flying. It is a necessary step, but real
flying is to travel from place to place through the air. To accomplish
this, some mechanism, or machinery, is needed to propel the man after
he has been lifted into the air. Such machinery will have weight,
and the bag of gas must be enlarged to counterbalance it. When this
is done, the man and the bag of gas may move through the air, and
with suitable rudders he may direct his course. This combination of
the lifting bag of gas and the propelling machinery constitutes the
dirigible balloon, or airship.

[Illustration: Degen’s apparatus to lift the man and his flying
mechanism with the aid of a gas-balloon. See Chapter IV.]

The airship is affected equally with the balloon by prevailing winds.
A breeze blowing 10 miles an hour will carry a balloon at nearly that
speed in the direction in which it is blowing. Suppose the aeronaut
wishes to sail in the opposite direction? If the machinery will propel
his airship only 10 miles an hour in a calm, it will virtually stand
still in the 10-mile breeze. If the machinery will propel his airship
20 miles an hour in a calm, the ship will travel 10 miles an hour--as
related to places on the earth’s surface--against the wind. But so far
as the air is concerned, his speed through it is 20 miles an hour,
and each increase of speed meets increased resistance from the air,
and requires a greater expenditure of power to overcome. To reduce
this resistance to the least possible amount, the globular form of the
early balloon has been variously modified. Most modern airships have a
“cigar-shaped” gas bag, so called because the ends look like the tip
of a cigar. As far as is known, this is the balloon that offers less
resistance to the air than any other.

Another mechanical means of getting up into the air was suggested
by the flying of kites, a pastime dating back at least 2,000 years,
perhaps longer. Ordinarily, a kite will not fly in a calm, but with
even a little breeze it will mount into the air by the upward thrust
of the rushing breeze against its inclined surface, being prevented
from blowing away (drifting) by the pull of the kite-string. The same
effect will be produced in a dead calm if the operator, holding
the string, runs at a speed equal to that of the breeze--with this
important difference: not only will the kite rise in the air, but it
will travel in the direction in which the operator is running, a part
of the energy of the runner’s pull upon the string producing a forward
motion, provided he holds the string taut. If we suppose the pull on
the string to be replaced by an engine and revolving propeller in the
kite, exerting the same force, we have exactly the principle of the
aeroplane.

As it is of the greatest importance to possess a clear understanding of
the natural processes we propose to use, let us refer to any text-book
on physics, and review briefly some of the natural laws relating to
motion and force which apply to the problem of flight:

(_a_) Force is that power which changes or tends to change the
position of a body, whether it is in motion or at rest.

(_b_) A given force will produce the same effect, whether the
body on which it acts is acted upon by that force alone, or by
other forces at the same time.

(_c_) A force may be represented graphically by a straight
line--the point at which the force is applied being the beginning
of the line; the direction of the force being expressed by the
direction of the line; and the magnitude of the force being
expressed by the length of the line.

(_d_) Two or more forces acting upon a body are called component
forces, and the single force which would produce the same effect
is called the resultant.

(_e_) When two component forces act in different directions
the resultant may be found by applying the principle of the
parallelogram of forces--the lines (_c_) representing the
components being made adjacent sides of a parallelogram, and the
diagonal drawn from the included angle representing the resultant
in direction and magnitude.

(_f_) Conversely, a resultant motion may be resolved into its
components by constructing a parallelogram upon it as the
diagonal, either one of the components being known.

[Illustration: The Deutsch de la Muerthe dirigible balloon
_Ville-de-Paris_; an example of the “cigar-shaped” gas envelope.]

Taking up again the illustration of the kite flying in a calm, let us
construct a few diagrams to show graphically the forces at work upon
the kite. Let the heavy line AB represent the centre line of the kite
from top to bottom, and C the point where the string is attached, at
which point we may suppose all the forces concentrate their action
upon the plane of the kite. Obviously, as the flyer of the kite is
running in a horizontal direction, the line indicating the pull of
the string is to be drawn horizontal. Let it be expressed by CD. The
action of the air pressure being at right angles to the plane of the
kite, we draw the line CE representing that force. But as this is a
_pressing_ force at the point C, we may express it as a _pulling_ force
on the other side of the kite by the line CF, equal to CE and in the
opposite direction. Another force acting on the kite is its weight--the
attraction of gravity acting directly downward, shown by CG. We have
given, therefore, the three forces, CD, CF, and CG. We now wish to find
the value of the pull on the kite-string, CD, in two other forces, one
of which shall be a lifting force, acting directly upward, and the
other a propelling force, acting in the direction in which we desire
the kite to travel--supposing it to represent an aeroplane for the
moment.

We first construct a parallelogram on CF and CG, and draw the diagonal
CH, which represents the resultant of those two forces. We have then
the two forces CD and CH acting on the point C. To avoid obscuring the
diagram with too many lines, we draw a second figure, showing just
these two forces acting on the point C. Upon these we construct a new
parallelogram, and draw the diagonal CI, expressing their resultant.
Again drawing a new diagram, showing this single force CI acting upon
the point C, we resolve that force into two components--one, CJ,
vertically upward, representing the lift; the other, CK, horizontal,
representing the travelling power. If the lines expressing these forces
in the diagrams had been accurately drawn to scale, the measurement of
the two components last found would give definite results in pounds;
but the weight of a kite is too small to be thus diagrammed, and only
the principle was to be illustrated, to be used later in the discussion
of the aeroplane.

[Illustration]

Nor is the problem as simple as the illustration of the kite suggests,
for the air is compressible, and is moreover set in motion in the form
of a current by a body passing through it at anything like the ordinary
speed of an aeroplane. This has caused the curving of the planes (from
front to rear) of the flying machine, in contrast with the flat plane
of the kite. The reasoning is along this line: Suppose the main plane
of an aeroplane six feet in depth (from front to rear) to be passing
rapidly through the air, inclined upward at a slight angle. By the
time two feet of this depth has passed a certain point, the air at
that point will have received a downward impulse or compression which
will tend to make it flow in the direction of the angle of the plane.
The second and third divisions in the depth, each of two feet, will
therefore be moving with a partial vacuum beneath, the air having been
drawn away by the first segment. At the same time, the pressure of the
air from above remains the same, and the result is that only the front
edge of the plane is supported, while two-thirds of its depth is pushed
down. This condition not only reduces the supporting surface to that of
a plane two feet in depth, but, what is much worse, releases a tipping
force which tends to throw the plane over backward.

In order that the second section of the plane may bear upon the air
beneath it with a pressure equal to that of the first, it must be
inclined downward at double the angle (with the horizon) of the first
section; this will in turn give to the air beneath it a new direction.
The third section of the plane must then be set at a still deeper
angle to give it support. Connecting these several directions with a
smoothly flowing line without angles, we get the curved line of section
to which the main planes of aeroplanes are bent.

With these principles in mind, it is in order to apply them to the
understanding of how an aeroplane flies. Wilbur Wright, when asked
what kept his machine up in the air--why it did not fall to the
ground--replied: “It stays up because it doesn’t have time to fall.”
Just what he meant by this may be illustrated by referring to the
common sport of “skipping stones” upon the surface of still water. A
flat stone is selected, and it is thrown at a high speed so that the
flat surface touches the water. It continues “skipping,” again and
again, until its speed is so reduced that the water where it touches
last has time to get out of the way, and the weight of the stone
carries it to the bottom. On the same principle, a person skating
swiftly across very thin ice will pass safely over if he goes so fast
that the ice hasn’t time to break and give way beneath his weight. This
explains why an aeroplane must move swiftly to stay up in the air,
which has much less density than either water or ice. The minimum
speed at which an aeroplane can remain in the air depends largely upon
its weight. The heavier it is, the faster it must go--just as a large
man must move faster over thin ice than a small boy. At some aviation
contests, prizes have been awarded for the slowest speed made by an
aeroplane. So far, the slowest on record is that of 21.29 miles an
hour, made by Captain Dickson at the Lanark meet, Scotland, in August,
1910. As the usual rate of speed is about 46 miles an hour, that is
slow for an aeroplane; and as Dickson’s machine is much heavier than
some others--the Curtiss machine, for instance--it is remarkably slow
for that type of aeroplane.

Just what is to be gained by offering a prize for slowest speed is
difficult to conjecture. It is like offering a prize to a crowd of boys
for the one who can skate slowest over thin ice. The minimum speed is
the most dangerous with the aeroplane as with the skater. Other things
being equal, the highest speed is the safest for an aeroplane. Even
when his engine stops in mid-air, the aviator is compelled to keep up
speed sufficient to prevent a fall by gliding swiftly downward until
the very moment of landing.

The air surface necessary to float a plane is spread out in one area in
the monoplane, and divided into two areas, one above the other and 6
to 9 feet apart, in the biplane; if closer than this, the disturbance
of the air by the passage of one plane affects the supporting power
of the other. It has been suggested that better results in the line
of carrying power would be secured by so placing the upper plane that
its front edge is a little back of the rear edge of the lower plane,
in order that it may enter air that is wholly free from any currents
produced by the rushing of the lower plane.

As yet, there is a difference of opinion among the principal aeroplane
builders as to where the propeller should be placed. All of the
monoplanes have it in front of the main plane. Most of the biplanes
have it behind the main plane; some have it between the two planes. If
it is in front, it works in undisturbed air, but throws its wake upon
the plane. If it is in the rear, the air is full of currents caused
by the passage of the planes, but the planes have smooth air to glide
into. As both types of machine are eminently successful, the question
may not be so important as it seems to the disputants.

The exact form of curve for the planes has not been decided upon.
Experience has proven that of two aeroplanes having the same surface
and run at the same speed, one may be able to lift twice as much as
the other because of the better curvature of its planes. The action of
the air when surfaces are driven through it is not fully understood.
Indeed, the form of plane shown in the accompanying figure is called
the aeroplane paradox. If driven in either direction it leaves the air
with a _downward_ trend, and therefore exerts a proportional lifting
power. If half of the plane is taken away, the other half is pressed
downward. All of the lifting effect is in the curving of the top side.
It seems desirable, therefore, that such essential factors should be
thoroughly worked out, understood, and applied.

[Illustration: Section of the “paradox” aeroplane.]

Chapter IV.

FLYING MACHINES.

Mythological--Leonardo da Vinci--Veranzio--John
Wilkins--Besnier--Marquis de
Bacqueville--Paucton--Desforges--Meerwein--Stentzel--Henson--Von
Drieberg--Wenham--Horatio Phillips--Sir Hiram
Maxim--Lilienthal--Langley--Ader--Pilcher--Octave
Chanute--Herring--Hargrave--The Wright
brothers--Archdeacon--Santos-Dumont--Voisin--Bleriot.

The term Flying Machines is applied to all forms of aircraft which are
heavier than air, and which lift and sustain themselves in the air by
mechanical means. In this respect they are distinguished from balloons,
which are lifted and sustained in the air by the lighter-than-air gas
which they contain.

From the earliest times the desire to fly in the air has been one of
the strong ambitions of the human race. Even the prehistoric mythology
of the ancient Greeks reflected the idea in the story of Icarus, who
flew so near to the sun that the heat melted the wax which fastened his
wings to his body, and he fell into the sea.

Perhaps the first historical record in the line of mechanical flight
worthy of attention exists in the remarkable sketches and plans for a
flying mechanism left by Leonardo da Vinci at his death in 1519. He had
followed the model of the flying bird as closely as possible, although
when the wings were outspread they had an outline more like those of
the bat. While extremely ingenious in the arrangement of the levers,
the power necessary to move them fast enough to lift the weight of a
man was far beyond the muscular strength of any human being.

It was a century later, in 1617, that Veranzio, a Venetian, proved his
faith in his inventive ability by leaping from a tower in Venice with
a crude, parachute-like contrivance. He alighted without injury.

In 1684, an Englishman, John Wilkins, then bishop of Chester, built
a machine for flying in which he installed a steam-engine. No record
exists of its performance.

In 1678, a French locksmith by the name of Besnier devised what
seems now a very crude apparatus for making descending flights, or
glides, from elevated points. It was, however, at that date considered
important enough to be described in the _Journal of the Savants_. It
was a wholly unscientific combination of the “dog-paddle” motion in
swimming, with wing areas which collapsed on the upward motion and
spread out on the downward thrust. If it was ever put to a test it must
have failed completely.

In 1742, the Marquis de Bacqueville constructed an apparatus which
some consider to have been based on Besnier’s idea--which seems rather
doubtful. He fastened the surfaces of his aeroplane directly to his
arms and legs, and succeeded in making a long glide from the window
of his mansion across the garden of the Tuileries, alighting upon a
washerwoman’s bench in the Seine without injury.

Paucton, the mathematician, is credited with the suggestion of a flying
machine with two screw propellers, which he called “pterophores”--a
horizontal one to raise the machine into the air, and an upright one
to propel it. These were to be driven by hand. With such hopelessly
inadequate power it is not surprising that nothing came of it, yet
the plan was a foreshadowing of the machine which has in these days
achieved success.

The Abbé Desforges gained a place in the annals of aeronautics by
inventing a flying machine of which only the name “Orthoptere” remains.

[Illustration: Meerwein’s Flying Machine. _A_, shows the position of
the man in the wings, their comparative size, and the operating levers;
_B_, position when in flight.]

About 1780, Karl Friedrich Meerwein, an architect, and the Inspector of
Public Buildings for Baden, Germany, made many scientific calculations
and experiments on the size of wing surface needed to support a man
in the air. He used the wild duck as a standard, and figured that a
surface of 126 square feet would sustain a man in the air. This agrees
with the later calculations of such experimenters as Lilienthal and
Langley. Other of Meerwein’s conclusions are decidedly ludicrous. He
held that the build of a man favors a horizontal position in flying, as
his nostrils open in a direction which would be away from the wind, and
so respiration would not be interfered with! Some of his reasoning is
unaccountably astray; as, for instance, his argument that because the
man hangs in the wings the weight of the latter need not be considered.
It is almost needless to say that his practical trials were a total
failure.

[Illustration: Plan of Degen’s apparatus.]

The next prominent step forward toward mechanical flight was made by
the Australian watchmaker Degen, who balanced his wing surfaces with a
small gas balloon. His first efforts to fly not being successful, he
abandoned his invention and took to ballooning.

Stentzel, an engineer of Hamburg, came next with a machine in the form
of a gigantic butterfly. From tip to tip of its wings it measured 20
feet, and their depth fore and aft was 5½ feet. The ribs of the wings
were of steel and the web of silk, and they were slightly concave on
the lower side. The rudder-tail was of two intersecting planes, one
vertical and the other horizontal. It was operated by a carbonic-acid
motor, and made 84 flaps of the wings per minute. The rush of air it
produced was so great that any one standing near it would be almost
swept off his feet. It did not reach a stage beyond the model, for it
was able to lift only 75 lbs.

[Illustration: Stentzel’s machine.]

In 1843, the English inventor Henson built what is admitted to be the
first aeroplane driven by motive power. It was 100 feet in breadth
(spread) and 30 feet long, and covered with silk. The front edge was
turned slightly upward. It had a rudder shaped like the tail of a
bird. It was driven by two propellers run by a 20-horse-power engine.
Henson succeeded only in flying on a down grade, doubtless because of
the upward bend of the front of his plane. Later investigations have
proven that the upper surface of the aeroplane must be convex to gain
the lifting effect. This is one of the paradoxes of flying planes which
no one has been able to explain.

In 1845, Von Drieberg, in Germany, revived the sixteenth-century ideas
of flying, with the quite original argument that since the legs of
man were better developed muscularly than his arms, flying should be
done with the legs. He built a machine on this plan, but no successful
flights are recorded.

In 1868, an experimenter by the name of Wenham added to the increasing
sum of aeronautical knowledge by discovering that the lifting power of
a large supporting surface may be as well secured by a number of small
surfaces placed one above another. Following up these experiments, he
built a flying machine with a series of six supporting planes made
of linen fabric. As he depended upon muscular effort to work his
propellers, he did not succeed in flying, but he gained information
which has been valuable to later inventors.

[Illustration: Von Drieberg’s machine; view from above.]

[Illustration:

Wenham’s arrangement of many narrow surfaces in six tiers, or
decks. _a_, _a_, rigid framework; _b_, _b_, levers working
flapping wings; _e_, _e_, braces. The operator is lying prone.]

The history of flying machines cannot be written without deferential
mention of Horatio Phillips of England. The machine that he made in
1862 resembled a large Venetian blind, 9 feet high and over 21 feet
long. It was mounted on a carriage which travelled on a circular track
600 feet long, and it was driven by a small steam engine turning a
propeller. It lifted unusually heavy loads, although not large enough
to carry a man. It seems to open the way for experiments with an
entirely new arrangement of sustaining surfaces--one that has never
since been investigated. Phillips’s records cover a series of most
valuable experiments. Perhaps his most important work was in the
determination of the most advantageous form for the surfaces of
aeroplanes, and his researches into the correct proportion of motive
power to the area of such surfaces. Much of his results have not yet
been put to practical use by designers of flying machines.

[Illustration: Phillips’s Flying Machine--built of narrow slats like a
Venetian blind.]

The year 1888 was marked by the construction by Sir Hiram Maxim of his
great aeroplane which weighed three and one-half tons, and is said
to have cost over $100,000. The area of the planes was 3,875 square
feet, and it was propelled by a steam engine in which the fuel used
was vaporized naphtha in a burner having 7,500 jets, under a boiler of
small copper water tubes. With a steam pressure of 320 lbs. per square
inch, the two compound engines each developed 180 horse-power, and each
turned a two-bladed propeller 17½ feet in diameter. The machine was
used only in making tests, being prevented from rising in the air by a
restraining track. The thrust developed on trial was 2,164 lbs., and
the lifting power was shown to have been in excess of 10,000 lbs. The
restraining track was torn to pieces, and the machine injured by the
fragments. The dynamometer record proved that a dead weight of 4½ tons,
in addition to the weight of the machine and the crew of 4 men, could
have been lifted. The stability, speed, and steering control were
not tested. Sir Hiram Maxim made unnumbered experiments with models,
gaining information which has been invaluable in the development of the
aeroplane.

[Illustration: View of a part of Maxim’s aeroplane, showing one of the
immense propellers. At the top is a part of the upper plane.]

The experiments of Otto Lilienthal in gliding with a winged structure
were being conducted at this period. He held that success in flying
must be founded upon proficiency in the art of balancing the
apparatus in the air. He made innumerable glides from heights which
he continually increased until he was travelling distances of nearly
one-fourth of a mile from an elevation of 100 feet. He had reached the
point where he was ready to install motive power to drive his glider
when he met with a fatal accident. Besides the inspiration of his
daring personal experiments in the air, he left a most valuable series
of records and calculations, which have been of the greatest aid to
other inventors in the line of artificial flight.

[Illustration: Lilienthal in his biplane glider.]

In 1896, Professor Langley, director of the Smithsonian Institution
at Washington, made a test of a model flying machine which was the
result of years of experimenting. It had a span of 15 feet, and a
length of 8½ feet without the extended rudder. There were 4 sails or
planes, 2 on each side, 30 inches in width (fore-and-aft measurement).
Two propellers revolving in opposite directions were driven by a
steam engine. The diameter of the propellers was 3 feet, and the
steam pressure 150 lbs. per square inch. The weight of the machine
was 28 lbs. It is said to have made a distance of 1 mile in 1 minute
45 seconds. As Professor Langley’s experiments were conducted in
strict secrecy, no authoritative figures are in existence. Later a
larger machine was built, which was intended to carry a man. It had
a spread of 46 feet, and was 35 feet in length. It was four years in
building, and cost about $50,000. In the first attempt to launch it,
from the roof of a house-boat, it plunged into the Potomac River. The
explanation given was that the launching apparatus was defective. This
was remedied, and a second trial made, but the same result followed.
It was never tried again. This machine was really a double, or tandem,
monoplane. The framework was built of steel tubing almost as thin
as writing paper. Every rib and pulley was hollowed out to reduce
the weight. The total weight of the engine and machine was 800 lbs.,
and the supporting surface of the wings was 1,040 square feet. The
aeroplanes now in use average from 2 to 4 lbs. weight to the square
foot of sustaining surface.

About the same time the French electrician Ader, after years of
experimenting, with the financial aid of the French Government, made
some secret trials of his machine, which had taken five years to build.
It had two bat-like wings spreading 54 feet, and was propelled by two
screws driven by a 4-cylinder steam engine which has been described as
a marvel of lightness. The inventor claimed that he was able to rise
to a height of 60 feet, and that he made flights of several hundred
yards. The official tests, however, were unsatisfactory, and nothing
further was done by either the inventor or the government to continue
the experiments. The report was that in every trial the machines had
been wrecked.

The experiments of Lilienthal had excited an interest in his ideas
which his untimely death did not abate. Among others, a young English
marine engineer, Percy S. Pilcher, took up the problem of gliding
flight, and by the device of using the power exerted by running boys
(with a five-fold multiplying gear) he secured speed enough to float
his glider horizontally in the air for some distance. He then built an
engine which he purposed to install as motive power, but before this
was done he was killed by a fall from his machine while in the air.

[Illustration: Plan of Chanute’s movable-wing glider.]

Before the death of Lilienthal his efforts had attracted the attention
of Octave Chanute, a distinguished civil engineer of Chicago, who,
believing that the real problem of the glider was the maintenance of
equilibrium in the air, instituted a series of experiments along that
line. Lilienthal had preserved his equilibrium by moving his body about
as he hung suspended under the wings of his machine. Chanute proposed
to accomplish the same end by moving the wings automatically. His
attempts were partially successful. He constructed several types of
gliders, one of these with two decks exactly in the form of the present
biplane. Others had three or more decks. Upward of seven hundred glides
were made with Chanute’s machines by himself and assistants, without
a single accident. It is of interest to note that a month before the
fatal accident to Lilienthal, Chanute had condemned that form of
glider as unsafe.

[Illustration: Chanute’s two-deck glider.]

In 1897, A. M. Herring, who had been one of the foremost assistants of
Octave Chanute, built a double-deck (biplane) machine and equipped it
with a gasoline motor between the planes. The engine failed to produce
sufficient power, and an engine operated by compressed air was tried,
but without the desired success.

In 1898, Lawrence Hargrave of Sydney, New South Wales, came into
prominence as the inventor of the cellular or box kite. Following the
researches of Chanute, he made a series of experiments upon the path
of air currents under variously curved surfaces, and constructed some
kites which, under certain conditions, would advance against a wind
believed to be absolutely horizontal. From these results Hargrave was
led to assert that “soaring sails” might be used to furnish propulsion,
not only for flying machines, but also for ships on the ocean sailing
against the wind. The principles involved remain in obscurity.

During the years 1900 to 1903, the brothers Wright, of Dayton, Ohio,
had been experimenting with gliders among the sand dunes of Kitty
Hawk, North Carolina, a small hamlet on the Atlantic Coast. They
had gone there because the Government meteorological department had
informed them that at Kitty Hawk the winds blew more steadily than at
any other locality in the United States. Toward the end of the summer
of 1903, they decided that the time was ripe for the installation of
motive power, and on December 17, 1903, they made their first four
flights under power, the longest being 853 feet in 59 seconds--against
a wind blowing nearly 20 miles an hour, and from a starting point on
level ground.

[Illustration: Wilbur Wright gliding at Kitty Hawk, N. C., in 1903.]

During 1904 over one hundred flights were made, and changes in
construction necessary to sail in circles were devised. In 1905, the
Wrights kept on secretly with their practice and development of their
machine, first one and then the other making the flights until both
were equally proficient. In the latter part of September and early
part of October, 1905, occurred a series of flights which the Wrights
allowed to become known to the public. At a meeting of the Aeronautical
Society of Great Britain, held in London on December 15, 1905, a letter
from Orville Wright to one of the members was read. It was dated
November 17, 1905, and an excerpt from it is as follows:

“During the month of September we gradually improved in our practice,
and on the 26th made a flight of a little over 11 miles. On the 30th we
increased this to 12⅕th miles; on October 3, to 15⅓ miles; on October
4, to 20¾ miles, and on October 5, to 24¼ miles. All these flights
were made at about 38 miles an hour, the flight of October 5 occupying
30 minutes 3 seconds. Landings were caused by the exhaustion of the
supply of fuel in the flights of September 26 and 30, and October 8,
and in those of October 3 and 4 by the heating of the bearings in the
transmission, of which the oil cups had been omitted. But before the
flight on October 5, oil cups had been fitted to all the bearings, and
the small gasoline can had been replaced with one that carried enough
fuel for an hour’s flight. Unfortunately, we neglected to refill the
reservoir just before starting, and as a result the flight was limited
to 38 minutes....

[Illustration: A Wright machine in flight.]

“The machine passed through all of these flights without the slightest
damage. In each of these flights we returned frequently to the
starting point, passing high over the heads of the spectators.”

These statements were received with incredulity in many parts of
Europe, the more so as the Wrights refused to permit an examination of
their machine, fearing that the details of construction might become
known before their patents were secured.

[Illustration: The Archdeacon machine on the Seine.]

During the summer of 1905, Captain Ferber and Ernest Archdeacon of
Paris had made experiments with gliders. One of the Archdeacon machines
was towed by an automobile, having a bag of sand to occupy the place
of the pilot. It rose satisfactorily in the air, but the tail became
disarranged, and it fell and was damaged. It was rebuilt and tried
upon the waters of the Seine, being towed by a fast motor-boat at a
speed of 25 miles an hour. The machine rose about 50 feet into the air
and sailed for about 500 feet.

Archdeacon gathered a company of young men about him who speedily
became imbued with his enthusiasm. Among them were Gabriel Voisin,
Louis Bleriot, and Leon Delagrange. The two former, working together,
built and flew several gliders, and when Santos-Dumont made his
historic flight of 720 feet with his multiple-cell machine on November
13, 1906 (the first flight made in Europe), they were spurred to new
endeavors.

Within a few months Voisin had finished his first biplane, and
Delagrange made his initial flight with it--a mere hop of 30 feet--on
March 16, 1907.

Bleriot, however, had his own ideas, and on August 6, 1907, he flew
for 470 feet in a monoplane machine of the tandem type. He succeeded
in steering his machine in a curved course, a feat which had not
previously been accomplished in Europe.

In October of the same year, Henri Farman, then a well-known automobile
driver, flew the second Voisin biplane in a half circle of 253 feet--a
notable achievement at that date.

But Santos-Dumont had been pushing forward several different types of
machines, and in November he flew first a biplane 500 feet, and a few
days later a monoplane 400 feet.

At this point in our story the past seems to give place to the
present. The period of early development was over, and the year 1908
saw the first of those remarkable exploits which are recorded in the
chapter near the end of this work entitled, “Chronicle of Aviation
Achievements.”

It is interesting to note that the machines then brought out are those
of to-day. Practically, it may be said that there has been no material
change from the original types. More powerful engines have been put
in them, and the frames strengthened in proportion, but the Voisin,
the Bleriot, and the Wright types remain as they were at first. Other
and later forms are largely modifications and combinations of their
peculiar features.

Chapter V.

FLYING MACHINES: THE BIPLANE.

Successful types of aeroplanes--Distinguishing features--The
Wright biplane--Construction--New type--Five-passenger
machine--The Voisin biplane--New racing type--The Curtiss
biplane--The Cody biplane--The Sommer biplane--The
Baldwin biplane--New stabilizing plane--The Baddeck No.
2--Self-sustaining radiator--The Herring biplane--Stabilizing
fins.

In the many contests for prizes and records, two types of flying
machines have won distinctive places for themselves--the biplane and
the monoplane. The appearance of other forms has been sporadic, and
they have speedily disappeared without accomplishing anything which had
not been better done by the two classes named.

This fact, however, should not be construed as proving the futility of
all other forms, nor that the ideal flying machine must be of one of
these two prominent types. It is to be remembered that record-making
and record-breaking is the most serious business in which any machines
have so far been engaged; and this, surely, is not the field of
usefulness to humanity which the ships of the air may be expected
ultimately to occupy. It may yet be proved that, successful as these
machines have been in what they have attempted, they are but transition
forms leading up to the perfect airship of the future.

[Illustration: The Wright biplane in flight.]

The distinguishing feature of the biplane is not alone that it has two
main planes, but that they are placed one above the other. The double
(or tandem) monoplane also has two main planes, but they are on the
same level, one in the rear of the other.

A review of the notable biplanes of the day must begin with the Wright
machine, which was not only the first with which flights were made, but
also the inspiration and perhaps the pattern of the whole succeeding
fleet.

THE WRIGHT BIPLANE.

The Wright biplane is a structure composed of two main surfaces,
each 40 feet long and 6 feet 6 inches wide, set one above the other,
parallel, and 6 feet apart. The planes are held rigidly at this
distance by struts of wood, and the whole structure is trussed with
diagonal wire ties. It is claimed by the Wrights that these dimensions
have been proven by their experiments to give the maximum lift with
the minimum weight.

[Illustration:

Diagram showing the construction of the Wright biplane. The lever
_R_ is connected by the bar _A_ with the rudder gearing _C_, and
is pivoted at the bottom on a rolling shaft _B_, through which
the warping wires _W_^1, _W_^2 are operated. The semicircular
planes _F_ aid in stabilizing the elevator system.]

The combination of planes is mounted on two rigid skids, or runners
(similar to the runners of a sleigh), which are extended forward and
upward to form a support for a pair of smaller planes in parallel,
used as the elevator (for directing the course of the aeroplane upward
or downward). It has been claimed by the Wrights that a rigid skid
under-structure takes up the shock of landing, and checks the momentum
at that moment, better than any other device. But it necessitated
a separate starting apparatus, and while the starting impulse thus
received enabled the Wrights to use an engine of less power (to keep
the machine going when once started), and therefore of less dead
weight, it proved a handicap to their machines in contests where they
were met by competing machines which started directly with their own
power. A later model of the Wright biplane is provided with a wheeled
running gear, and an engine of sufficient power to raise it in the air
after a short run on the wheels.

Two propellers are used, run by one motor. They are built of wood, are
of the two-bladed type, and are of comparatively large diameter--8
feet. They revolve in opposite directions at a speed of 450
revolutions per minute, being geared down by chain drive from the
engine speed of 1,500 revolutions per minute.

The large elevator planes in front have been a distinctive feature of
the Wright machine. They have a combined area of 80 square feet, adding
that much more lifting surface to the planes in ascending, for then
the under side of their surfaces is exposed to the wind. If the same
surfaces were in the rear of the main planes their top sides would have
to be turned to the wind when ascending, and a depressing instead of a
lifting effect would result.

To the rear of the main planes is a rudder composed of two parallel
vertical surfaces for steering to right or left.

The feature essential to the Wright biplane, upon which the letters
patent were granted, is the flexible construction of the tips of the
main planes, in virtue of which they may be warped up or down to
restore disturbed equilibrium, or when a turn is to be made. This
warping of the planes changes the angle of incidence for the part of
the plane which is bent. (The angle of incidence is that which the
plane makes with the line in which it is moving. The bending downward
of the rear edge would enlarge the angle of incidence, in that way
increasing the compression of the air beneath, and lifting that end
of the plane.) The wing-warping controls are actuated by the lever
at the right hand of the pilot, which also turns the rudder at the
rear--that which steers the machine to right or to left. The lever at
the left hand of the pilot moves the elevating planes at the front of
the machine.

[Illustration: Sketch showing relative positions of planes and of the
operator in the Wright machine: _A_, _A_, the main planes; _B_, _B_,
the elevator planes. The motor is placed beside the operator.]

The motor has 4 cylinders, and develops 25 to 30 horse-power, giving
the machine a speed of 39 miles per hour.

A newer model of the Wright machine is built without the large
elevating planes in front, a single elevating plane being placed just
back of the rear rudder. This arrangement cuts out the former lifting
effect described above, and substitutes the depressing effect due to
exposing the top of a surface to the wind.

[Illustration: _Courtesy of N. Y. Times._

The new model Wright biplane--without forward elevator.]

The smallest of the Wright machines, popularly called the “Baby
Wright,” is built upon this plan, and has proven to be the fastest of
all the Wright series.

THE VOISIN BIPLANE.

While the Wrights were busily engaged in developing their biplane in
America, a group of enthusiasts in France were experimenting with
gliders of various types, towing them with high speed automobiles along
the roads, or with swift motor-boats upon the Seine. As an outcome
of these experiments, in which they bore an active part, the Voisin
brothers began building the biplanes which have made them famous.

As compared with the Wright machine, the Voisin aeroplane is of much
heavier construction. It weighs 1,100 pounds. The main planes have a
lateral spread of 37 feet 9 inches, and a breadth of 7 feet, giving
a combined area of 540 square feet, the same as that of the Wright
machine. The lower main plane is divided at the centre to allow the
introduction of a trussed girder framework which carries the motor and
propeller, the pilot’s seat, the controlling mechanism, and the running
gear below; and it is extended forward to support the elevator. This
is much lower than in the Wright machine, being nearly on the level of
the lower plane. It is a single surface, divided at the centre, half
being placed on each side of the girder. It has a combined area of 42
square feet, about half of that of the Wright elevator, and it is only
4 feet from the front edge of the main planes, instead of 10 feet as in
the Wright machine. A framework nearly square in section, and about 25
feet long, extends to the rear, and supports a cellular, or box-like,
tail, which forms a case in which is the rudder surface for steering
to right or to left.

[Illustration: Diagram showing details of construction of the Voisin
biplane. _C_, _C_, the curtains forming the stabilizing cells.]

A distinctive feature of the Voisin biplane is the use of four vertical
planes, or curtains, between the two main planes, forming two nearly
square “cells” at the ends of the planes.

At the rear of the main planes, in the centre, is the single propeller.
It is made of steel, two-bladed, and is 8 feet 6 inches in diameter.
It is coupled directly to the shaft of the motor, making with it 1,200
revolutions per minute. The motor is of the V type, developing 50
horse-power, and giving a speed of 37 miles per hour.

[Illustration: Diagram showing the simplicity of control of the Voisin
machine, all operations being performed by the wheel and its sliding
axis.]

The controls are all actuated by a rod sliding back and forth
horizontally in front of the pilot’s seat, having a wheel at the end.
The elevator is fastened to the rod by a crank lever, and is tilted
up or down as the rod is pushed forward or pulled back. Turning
the wheel from side to side moves the rudder in the rear. There are
no devices for controlling the equilibrium. This is supposed to be
maintained automatically by the fixed vertical curtains.

[Illustration:

Voisin biplanes at the starting line at Rheims in August, 1909.
They were flown by Louis Paulhan, who won third prize for
distance, and Henri Rougier, who won fourth prize for altitude.
In the elimination races to determine the contestants for the
Bennett Cup, Paulhan won second place with the Voisin machine,
being defeated only by Tissandier with a Wright machine. Other
noted aviators who fly the Voisin machine are M. Bunau-Varilla
and the Baroness de la Roche.]

The machine is mounted on two wheels forward, and two smaller wheels
under the tail.

This description applies to the standard Voisin biplane, which has
been in much favor with many of the best known aviators. Recently
the Voisins have brought out a new type in which the propeller has
been placed in front of the planes, exerting a pulling force upon the
machine, instead of pushing it as in the earlier type. The elevating
plane has been removed to the rear, and combined with the rudder.

A racing type also has been produced, in which the vertical curtains
have been removed and a parallel pair of long, narrow ailerons
introduced between the main planes on both sides of the centre. This
machine, it is claimed, has made better than 60 miles per hour.

The first Voisin biplane was built for Delagrange, and was flown by him
with success.

THE FARMAN BIPLANE.

The second biplane built by the Voisins went into the hands of Henri
Farman, who made many flights with it. Not being quite satisfied with
the machine, and having an inventive mind, he was soon building a
biplane after his own designs, and the Farman biplane is now one of the
foremost in favor among both professional and amateur aviators.

It is decidedly smaller in area of surface than the Wright and Voisin
machines, having but 430 square feet in the two supporting planes. It
has a spread of 33 feet, and the planes are 7 feet wide, and set 6 feet
apart. In the Farman machine the vertical curtains of the Voisin have
been dispensed with. The forward elevator is there, but raised nearly
to the level of the upper plane, and placed 9 feet from the front edge
of the main planes. To control the equilibrium, the two back corners
of each plane are cut and hinged so that they hang vertically when not
in flight. When in motion these flaps or ailerons stream out freely
in the wind, assuming such position as the speed of the passing air
gives them. They are pulled down by the pilot at one end or the other,
as may be necessary to restore equilibrium, acting in very much the
same manner as the warping tips of the Wright machine. A pair of tail
planes are set in parallel on a framework about 20 feet in the rear of
the main planes, and a double rudder surface behind them. Another model
has hinged ailerons on these tail planes, and a single rudder surface
set upright between them. These tail ailerons are moved in conjunction
with those of the main planes.

[Illustration: The Farman biplane, showing the position of the hinged
ailerons when at rest. At full speed these surfaces stream out in the
wind in line with the planes to which they are attached.]

[Illustration: Diagram of the Farman biplane. A later type has the
hinged ailerons also on the tail planes.]

The motor has 4 cylinders, and turns a propeller made of wood, 8 feet 6
inches in diameter, at a speed of 1,300 revolutions per minute--nearly
three times as fast as the speed of the Wright propellers, which are
about the same size. The propeller is placed just under the rear edge
of the upper main plane, the lower one being cut away to make room
for the revolving blades. The motor develops 45 to 50 horse-power, and
drives the machine at a speed of 41 miles per hour.

The “racing Farman” is slightly different, having the hinged ailerons
only on one of the main planes. The reason for this is obvious. Every
depression of the ailerons acts as a drag on the air flowing under the
planes, increasing the lift at the expense of the speed.

[Illustration: Sketch of Farman machine, showing position of operator.
_A_, _A_, main planes; _B_, elevator; _C_, motor; _P_, tail planes.]

The whole structure is mounted upon skids with wheels attached by a
flexible connection. In case of a severe jar, the wheels are pushed up
against the springs until the skids come into play.

The elevator and the wing naps are controlled by a lever at the
right hand of the pilot. This lever moves on a universal joint, the
side-to-side movement working the flaps, and the forward-and-back
motion the elevator. Steering to right or left is done with a bar
operated by the feet.

[Illustration: Henri Farman carrying a passenger across country.]

Farman has himself made many records with his machine, and so have
others. With a slightly larger and heavier machine than the one
described, Farman carried two passengers a distance of 35 miles in one
hour.

THE CURTISS BIPLANE.

This American rival of the Wright biplane is the lightest machine
of this type so far constructed. The main planes are but 29 feet in
spread, and 4 feet 6 inches in width, and are set not quite 5 feet
apart. The combined area of the two planes is 250 square feet. The main
planes are placed midway of the length of the fore-and-aft structure,
which is nearly 30 feet. At the forward end is placed the elevator, and
at the rear end is the tail--one small plane surface--and the vertical
rudder surface in two parts, one above and the other below the tail
plane. Equilibrium is controlled by changing the slant of two small
balancing planes which are placed midway between the main planes at the
outer ends, and in line with the front edges. These balancing planes
are moved by a lever standing upright behind the pilot, having two arms
at its upper end which turn forward so as to embrace his shoulders. The
lever is moved to right or to left by the swaying of the pilot’s body.

[Illustration: Glenn H. Curtiss in his machine ready to start. The fork
of the balancing lever is plainly seen at his shoulders. Behind him is
the radiator, with the engine still further back.]

The motor is raised to a position where the shaft of the propeller is
midway between the levels of the main planes, and within the line of
the rear edges, so that they have to be cut away to allow the passing
of the blades. The motor is of the V type, with 8 cylinders. It is 30
horse-power and makes 1,200 revolutions per minute. The propeller is of
steel, two-bladed, 6 feet in diameter, and revolves at the same speed
as the shaft on which it is mounted. The high position of the engine
permits a low running gear. There are two wheels under the rear edges
of the main planes, and another is placed half-way between the main
planes and the forward rudder, or elevator. A brake, operated by the
pilot’s foot, acts upon this forward wheel to check the speed at the
moment of landing.

Another type of Curtiss machine has the ailerons set in the rear of the
main planes, instead of between them.

The Curtiss is the fastest of the biplanes, being excelled in speed
only by some of the monoplanes. It has a record of 51 miles per hour.

THE CODY BIPLANE.

The Cody biplane has the distinction of being the first successful
British aeroplane. It was designed and flown by Captain S. F. Cody, at
one time an American, but for some years an officer in the British army.

It is the largest and heaviest of all the biplanes, weighing about
1,800 lbs., more than three times the weight of the Curtiss machine.
Its main planes are 52 feet in lateral spread, and 7 feet 6 inches in
width, and are set 9 feet apart. The combined area of these sustaining
surfaces is 770 square feet. The upper plane is arched, so that the
ends of the main planes are slightly closer together than at the centre.

The elevator is in two parts placed end to end, about 12 feet in front
of the main planes. They have a combined area of 150 square feet.
Between them and above them is a small rudder for steering to right or
left in conjunction with the large rudder at the rear of the machine.
The latter has an area of 40 square feet.

There are two small balancing planes, set one at each end of the main
planes, their centres on the rear corner struts, so that they project
beyond the tips of the planes and behind their rear lines.

[Illustration: The Cody biplane in flight. Captain Cody has both hands
raised above his head, showing the automatic stability of his machine.]

The biplane is controlled by a lever rod having a wheel at the end.
Turning the wheel moves the rudders; pushing or pulling the wheel works
the elevator; moving the wheel from side to side moves the balancing
planes.

There are two propellers, set one on each side of the engine, and well
forward between the main planes. They are of wood, of the two-bladed
type, 7 feet in diameter. They are geared down to make 600 revolutions
per minute. The motor has 8 cylinders and develops 80 horse-power at
1,200 revolutions per minute.

The machine is mounted on a wheeled running gear, two wheels under the
front edge of the main planes and one a short distance forward in the
centre. There is also a small wheel at each extreme end of the lower
main plane.

The Cody biplane has frequently carried a passenger, besides the pilot,
and is credited with a speed of 38 miles per hour.

The first aeroplane flights ever made in England were by Captain Cody
on this biplane, January 2, 1909.

THE SOMMER BIPLANE.

The Sommer biplane is closely similar to the Farman machine, but has
the hinged ailerons only on the upper plane. Another difference is that
the tail has but one surface, and the rudder is hung beneath it. Its
dimensions are:--Spread of main planes, 34 feet; depth (fore-and-aft),
6 feet 8 inches; they are set 6 feet apart. The area of the main planes
is 456 square feet; area of tail, 67 square feet; area of rudder, 9
square feet. It is driven by a 50-horsepower Gnome motor, turning an
8-foot, two-bladed propeller.

M. Sommer has flown with three passengers, a total weight of 536 lbs.,
besides the weight of the machine.

THE BALDWIN BIPLANE.

The Baldwin biplane, designed by Captain Thomas S. Baldwin, the
distinguished balloonist, resembles the Farman type in some features,
and the Curtiss in others. It has the Curtiss type of ailerons, set
between the wings, but extending beyond them laterally. The elevator is
a single surface placed in front of the machine, and the tail is of the
biplane type with the rudder between. The spread of the main planes is
31 feet 3 inches, and their depth 4 feet 6 inches. A balancing plane of
9 square feet is set upright (like a fin) above the upper main plane,
on a swivel. This is worked by a fork fitting on the shoulders of the
pilot, and is designed to restore equilibrium by its swinging into
head-resistance on one side or the other as may be necessary.

[Illustration: The Baldwin biplane, showing balancing plane above upper
main plane.]

The motive power is a 4-cylinder Curtiss motor, which turns a propeller
7 feet 6 inches in diameter, set just within the rear line of the main
planes, which are cut away to clear the propeller blades.

THE BADDECK BIPLANE.

The newest biplane of the Aerial Experiment Association follows in
general contour its successful precursor, the “Silver Dart,” with
which J. A. D. McCurdy made many records. The “Baddeck No. 2” is of
the biplane type, and both the planes are arched toward each other.
They have a spread of 40 feet, and are 7 feet in depth at the centre,
rounding to 5 feet at the ends, where the wing tips, 5 feet by 5 feet,
are hinged. The elevator is also of the biplane type, two surfaces each
12 feet long and 28 inches wide, set 30 inches apart. This is mounted
15 feet in front of the main planes. The tail is mounted 11 feet in the
rear of the main planes, and is the same size and of the same form as
the elevator.

The controls are operated by the same devices as in the Curtiss
machine. The propeller is 7 feet 8 inches in diameter, and is turned
by a six-cylinder automobile engine of 40 horse-power running at 1,400
revolutions per minute. The propeller is geared down to run at 850
revolutions per minute. The motor is placed low down on the lower
plane, but the propeller shaft is raised to a position as nearly as
possible that of the centre of resistance of the machine. The speed
attained is 40 miles per hour.

[Illustration: The McCurdy biplane, “Baddeck No. 2.”]

A unique feature of the mechanism is the radiator, which is built of
30 flattened tubes 7 feet 6 inches long, and 3 inches wide, and very
thin. They are curved from front to rear like the main planes, and give
sufficient lift to sustain their own weight and that of the water
carried for cooling the cylinders. The running gear is of three wheels
placed as in the Curtiss machine. The “Baddeck No. 2” has made many
satisfactory flights with one passenger besides the pilot.

THE HERRING BIPLANE.

At the Boston Aircraft Exhibition in February, 1910, the Herring
biplane attracted much attention, not only because of its superiority
of mechanical finish, but also on account of its six triangular
stabilizing fins set upright on the upper plane. Subsequent trials
proved that this machine was quite out of the ordinary in action. It
rose into the air after a run of but 85 feet, and at a speed of only
22 miles per hour, and made a 40-degree turn at a tipping angle of 20
degrees. As measured by the inventor, the machine rose in the air with
the pilot (weighing 190 lbs.), with a thrust of 140 lbs., and required
only a thrust of from 80 to 85 lbs. to keep it flying.

The spread of the planes is 28 feet, and they are 4 feet in depth,
with a total supporting surface of 220 feet. A 25 horse-power Curtiss
motor turns a 4-bladed propeller of 6 feet diameter and 5-foot pitch
(designed by Mr. Herring) at the rate of 1,200 revolutions per minute.

[Illustration: The L. A. W. (League of American Wheelmen) biplane at
the Boston Aircraft Exhibition, February, 1910. Note the peculiar
curve of the divided planes. The motor is of the rotating type, of 50
horse-power.]

The elevator consists of a pair of parallel surfaces set upon hollow
poles 12 feet in front of the main planes. The tail is a single surface.

The stabilizing fins act in this manner: when the machine tips to one
side, it has a tendency to slide down an incline of air toward the
ground. The fins offer resistance to this sliding, retarding the upper
plane, while the lower plane slides on and swings as a pendulum into
equilibrium again.

THE BREGUET BIPLANE.

The Breguet biplane is conspicuous in having a biplane tail of so
large an area as to merit for the machine the title “tandem biplane.”
The main planes have a spread of 41 feet 8 inches, and an area of 500
square feet. The tail spreads 24 feet, and its area is about 280 square
feet. The propeller is three-bladed, 8 feet in diameter, and revolves
at a speed of 1,200 revolutions per minute. It is placed in front of
the main plane, after the fashion of the monoplanes. The motive power
is an 8-cylinder R-E-P engine, developing 55 horse-power.

[Illustration: _Courtesy of N. Y. Sun._

The Seddon tandem biplane, constructed by Lieutenant Seddon of the
British Navy. The area of its planes is 2,000 square feet. Compare its
size with that of the monoplane in the background. It is intended to
carry ten persons.]

[Illustration:

Wright biplane. Curtiss biplane.

Comparative build and area of prominent American biplanes.]

[Illustration:

Voisin biplane. Breguet biplane.

Comparative build and area of prominent European biplanes.]

Chapter VI.

FLYING MACHINES: THE MONOPLANE.

The common goal--Interchanging features--The Bleriot
machine--First independent flyer--Construction and controls--The
“Antoinette”--Large area--Great stability--Santos-Dumont’s
monoplane--Diminutive size--R-E-P monoplane--encased
structure--Hanriot machine--Boat body--Sturdy build--Pfitzner
machine--Lateral type--Thrusting propeller--Fairchild,
Burlingame, Cromley, Chauviere, Vendome, and Moisant monoplanes.

In all the ardent striving of the aviators to beat each other’s
records, a surprisingly small amount of personal rivalry has been
developed. Doubtless this is partly because their efforts to perform
definite feats have been absorbing; but it must also be that these men,
who know that they face a possible fall in every flight they make,
realize that their competitors are as brave as themselves in the face
of the same danger; and that they are actually accomplishing marvellous
wonders even if they do no more than just escape disastrous failure.
Certain it is that each, realizing the tremendous difficulties all must
overcome, respects the others’ ability and attainments.

Consequently we do not find among them two distinctly divergent
schools of adherents, one composed of the biplanists, the other of the
monoplanists. Nor are the two types of machines separated in this book
for any other purpose than to secure a clearer understanding of what
is being achieved by all types in the progress toward the one common
goal--the flight of man.

The distinctive feature of the monoplane is that it has but one main
plane, or spread of surface, as contrasted with the two planes, one
above the other, of the biplane. Besides the main plane, it has a
secondary plane in the rear, called the tail. The office of this tail
is primarily to secure longitudinal, or fore-and-aft, balance; but
the secondary plane has been so constructed that it is movable on a
horizontal axis, and is used to steer the machine upward or downward.
While most of the biplanes now have a horizontal tail-plane, they were
not at first so provided, but carried the secondary plane (or planes)
in front of the main planes. Even in the latest type brought out by the
conservative Wright brothers, the former large-surfaced elevator in
front has been removed, and a much smaller tail-plane has been added in
the rear, performing the same function of steering the machine up or
down, but also providing the fore-and-aft stabilizing feature formerly
peculiar to the monoplane. Another feature heretofore distinctively
belonging to the monoplane has been adopted by some of the newer
biplanes, that of the traction propeller--pulling the machine behind it
through the air, instead of pushing it along by a thrusting propeller
placed behind the main planes.

The continual multiplication of new forms of the monoplane makes it
possible to notice only those which exhibit the wider differences.

THE BLERIOT MONOPLANE.

The Bleriot monoplane has the distinction of being the first wholly
successful flying machine. Although the Wright machine was making
flights years before the Bleriot had been built, it was still dependent
upon a starting device to enable it to leave the ground. That is, the
Wright machine was not complete in itself, and was entirely helpless
at even a short distance from its starting tower, rail, and car, which
it was unable to carry along. Because of its completeness, M. Bleriot
was able to drive his machine from Toury to Artenay, France (a distance
of 8¾ miles) on October 31, 1908, make a landing, start on the return
trip, make a second landing, and again continue his journey back to
Toury, all under his own unassisted power. This feat was impossible to
the Wright machine as it was then constructed, thus leaving the Bleriot
monoplane in undisputed pre-eminence in the history of aviation.

[Illustration: A Bleriot monoplane, “No. XI,” in flight.]

At a little distance, where the details of construction are not
visible, the Bleriot machine has the appearance of a gigantic bird. The
sustaining surface, consisting of a single plane, is divided into two
wings made of a stiff parchment-like material, mounted one on each side
of a framework of the body, which is built of mahogany and whitewood
trussed with diagonal ties of steel wire.

The main plane has a lateral spread of 28 feet and a depth of 6 feet,
and is rounded at the ends. It has an area of about 150 square feet,
and is slightly concave on the under side. The tail-plane is 6 feet
long and 2 feet 8 inches in depth; at its ends are the elevators,
consisting of pivoted wing tips each about 2 feet 6 inches square
with rounded extremities. The rudder for steering to left or right
is mounted at the extreme rear end of the body, and has an area of 9
square feet.

[Illustration: The Bleriot “No. XII.,” showing new form of tail, and
the complete encasing with fabric.]

The body is framed nearly square in front and tapers to a wedge-like
edge at the rear. It extends far enough in front of the main plane to
give room for the motor and propeller. The seat for the pilot is on a
line with the rear edge of the main plane, and above it. The forward
part of the body is enclosed with fabric.

[Illustration: Forward chassis of Bleriot monoplane, showing caster
mounting of wheels. The framing of the body is shown by the dotted
lines.]

The machine is mounted on three wheels attached to the body: two at
the front, with a powerful spring suspension and pivoted like a caster,
and the other rigidly at a point just forward of the rudders.

The lateral balance is restored by warping the tips of the main plane;
if necessary, the elevator tips at the rear may be operated to assist
in this. All the controls are actuated by a single lever and a drum to
which the several wires are attached.

[Illustration:

Diagram of Bleriot “No. XI.,” from the rear. _A_, _A_, main
plane; _B_, tail; _C_, body; _D_, _D_, wing tips of tail; _E_,
rudder; _H_, propeller; _M_, motor; _O_, axis of wing tips; _R_,
radiator; _a_, _a_, _b_, _b_, spars of wings; _h_, _h_, guy
wires; _p_, _k_, truss.]

The motors used on the Bleriot machines have varied in type and power.
In the “No. XI.,” with which M. Bleriot crossed the English Channel,
the motor was a 3-cylinder Anzani engine, developing 24 horse-power at
1,200 revolutions per minute. The propeller was of wood, 2-bladed, and
6 feet 9 inches in diameter. It was mounted directly on the shaft, and
revolved at the same speed, giving the machine a velocity of 37 miles
per hour. This model has also been fitted with a 30 horse-power R-E-P
(R. Esnault-Pelterie) motor, having 7 cylinders. The heavier type “No.
XII.” has been fitted with the 50 horse-power Antoinette 8-cylinder
engine, or the 7-cylinder rotating Gnome engine, also of 50 horse-power.

[Illustration: Sketches showing relative size, construction, and
position of pilot in the Bleriot machines; “No. XI.” (the upper), and
“No. XII.” (the lower).]

The total weight of the “No. XI.” monoplane is 462 pounds, without the
pilot.

THE ANTOINETTE MONOPLANE.

The Antoinette is the largest and heaviest of the monoplanes. It
was designed by M. Levavasseur, and has proved to be one of the
most remarkable of the aeroplanes by its performances under adverse
conditions; notably, the flight of Hubert Latham in a gale of 40 miles
per hour at Blackpool in October, 1909.

The Antoinette has a spread of 46 feet, the surface being disposed
in two wings set at a dihedral angle; that is, the outer ends of the
wings incline upward from their level at the body, so that at the front
they present the appearance of a very wide open “V.” These wings are
trapezoidal in form, with the wider base attached to the body, where
they are 10 feet in depth (fore and aft). They are 7 feet in depth at
the tips, and have a total combined area of 377 square feet. The great
depth of the wings requires that they be made proportionally thick to
be strong enough to hold their form. Two trussed spars are used in each
wing, with a short mast on each, half-way to the tip, reaching below
the wing as well as above it. To these are fastened guy wires, making
each wing an independent truss. A mast on the body gives attachment
for guys which bind the whole into a light and rigid construction. The
framework of the wings is covered on both sides with varnished fabric.

[Illustration: The Antoinette monoplane in flight.]

The body is of triangular section. It is a long girder; at the front,
in the form of a pyramid, expanding to a prism at the wings, and
tapering toward the tail. It is completely covered with the fabric,
which is given several coats of varnish to secure the minimum of skin
friction.

[Illustration: Diagram showing construction of the Antoinette
monoplane.]

The tail is 13 feet long and 9 feet wide, in the form of a
diamond-shaped kite. The rear part of it is hinged to be operated as
the elevator. There is a vertical stabilizing fin set at right angles
to the rigid part of the tail. The rudder for steering to right or
left is in two triangular sections, one above and the other below the
tail-plane. The entire length of the machine is 40 feet, and its weight
is 1,045 pounds.

It is fitted with a motor of the “V” type, having 8 cylinders, and
turning a 2-bladed steel propeller 1,100 revolutions per minute,
developing from 50 to 55 horse-power.

The control of the lateral balance is by ailerons attached to the rear
edges of the wings at their outer ends. These are hinged, and may be
raised as well as lowered as occasion demands, working in opposite
directions, and thus doubling the effect of similar ailerons on the
Farman machine, which can only be pulled downward.

The machine is mounted on two wheels under the centre of the main
plane, with a flexible wood skid projecting forward. Another skid is
set under the tail.

It is claimed for the Antoinette machine that its inherent stability
makes it one of the easiest of all for the beginner in aviation. With
as few as five lessons many pupils have become qualified pilots, even
winning prizes against competitors of much wider experience.

[Illustration: Diagrams showing comparative size and position of
surfaces and structure of the Bleriot (left) and Antoinette (right)
monoplanes.]

THE SANTOS-DUMONT MONOPLANE.

This little machine may be called the “runabout” of the aeroplanes. It
has a spread of only 18 feet, and is but 20 feet in total length. Its
weight is about 245 pounds.

The main plane is divided into two wings, which are set at the body
at a dihedral angle, but curve downward toward the tips, forming an
arch. The depth of the wings at the tips is 6 feet. For a space on each
side of the centre they are cut away to 5 feet in depth, to allow the
propeller to be set within their forward edge. The total area of the
main plane is 110 square feet.

The tail-plane is composed of a vertical surface and a horizontal
surface intersecting. It is arranged so that it may be tilted up or
down to serve as an elevator, or from side to side as a rudder. Its
horizontal surface has an area of about 12 square feet.

The engine is placed above the main plane and the pilot’s seat below
it. The body is triangular in section, with the apex uppermost,
composed of three strong bamboo poles with cross-pieces held in place
by aluminum sockets, and cross braced with piano wire.

[Illustration: Santos-Dumont’s _La Demoiselle_ in flight.]

The motor is of the opposed type, made by Darracq, weighing only 66
pounds, and developing 30 horse-power at 1,500 revolutions per minute.
The propeller is of wood, 2-bladed, and being mounted directly on the
shaft of the motor, revolves at the same velocity. The speed of the
Santos-Dumont machine is 37 miles per hour.

[Illustration: The Darracq motor and propeller of the Santos-Dumont
machine. The conical tank in the rear of the pilot’s seat holds the
gasoline.]

The lateral balance is preserved by a lever which extends upward and
enters a long pocket sewed on the back of the pilot’s coat. His leaning
from side to side warps the rear edges of the wings at their tips. The
elevator is moved by a lever, and the rudder by turning a wheel.

While this machine has not made any extended flights, Santos-Dumont has
travelled in the aggregate upward of 2,000 miles in one or another of
this type.

The plans, with full permission to any one to build from them, he gave
to the public as his contribution to the advancement of aviation.
Several manufacturers are supplying them at a cost much below that of
an automobile.

[Illustration: Sketch showing position of pilot in Santos-Dumont
machine. _A_, main plane; _B_, tail plane; _C_, motor.]

THE R-E-P MONOPLANE.

The Robert Esnault-Pelterie (abbreviated by its inventor to R-E-P)
monoplane, viewed from above, bears a striking resemblance to a bird
with a fan-shaped tail. It is much shorter in proportion to its spread
than any other monoplane, and the body being entirely covered with
fabric, it has quite a distinct appearance.

The plane is divided into two wings, in form very much like the wings
of the Antoinette machine. Their spread, however, is but 35 feet. Their
depth at the body is 8 feet 6 inches, and at the tips, 5 feet. Their
total combined area is 226 square feet.

The body of the R-E-P machine has much the appearance of a boat, being
wide at the top and coming to a sharp keel below. The boat-like prow in
front adds to this resemblance. As the body is encased in fabric, these
surfaces aid in maintaining vertical stability.

A large stabilizing fin extends from the pilot’s seat to the tail. The
tail is comparatively large, having an area of 64 square feet. Its rear
edge may be raised or lowered to serve as an elevator. The rudder for
steering to right or left is set below in the line of the body, as in a
boat. It is peculiar in that it is of the “compensated” type; that is,
pivoted near the middle of its length, instead of at the forward end.

The control of the lateral balance is through warping the wings. This
is by means of a lever at the left hand of the pilot, with a motion
from side to side. The same lever moved forward or backward controls
the elevator. The steering lever is in front of the pilot’s seat, and
moves to right or to left.

[Illustration: Elevation, showing large stabilizing fin; boat-like body
encased in fabric; and compensated rudder, pivoted at the rear end of
the fin.]

[Illustration: Plan, showing comparative spread of surfaces, and the
attachment of wheels at the wing tips.

Graphic sketch showing elevation and plan of the R-E-P monoplane.]

The motor is an invention of M. Esnault-Pelterie, and may be of 5, 7,
or 10 cylinders, according to the power desired. The cylinders are
arranged in two ranks, one in the rear of the other, radiating outward
from the shaft like spokes in a wheel. The propeller is of steel,
4-bladed, and revolves at 1,400 revolutions per minute, developing 35
horse-power, and drawing the machine through the air at a speed of 47
miles per hour.

THE HANRIOT MONOPLANE.

Among the more familiar machines which have been contesting for records
at the various European meets during the season of 1910, the Hanriot
monoplane earned notice for itself and its two pilots, one of them the
fifteen-year-old son of the inventor. At Budapest the Hanriot machine
carried off the honors of the occasion with a total of 106 points for
“best performances,” as against 84 points for the Antoinette, and 77
points for the Farman biplane. A description of its unusual features
will be of interest by way of comparison.

In general appearance it is a cross between the Bleriot and the
Antoinette, the wings being shaped more like the latter, but rounded
at the rear of the tips like the Bleriot. Its chief peculiarity is in
the body of the machine, which is in form very similar to a racing
shell--of course with alterations to suit the requirements of the
aeroplane. Its forward part is of thin mahogany, fastened upon ash
ribs, with a steel plate covering the prow. The rear part of the
machine is covered simply with fabric.

The spread of the plane is 24 feet 7 inches, and it has an area of 170
square feet. The length of the machine, fore-and-aft, is 23 feet. Its
weight is 463 pounds. It is mounted on a chassis having both wheels
and skids, somewhat like that of the Farman running gear, but with two
wheels instead of four.

The Hanriot machine is sturdily built all the way through, and has
endured without damage some serious falls and collisions which would
have wrecked another machine.

It is fitted either with a Darracq or a Clerget motor, and speeds at
about 44 miles per hour.

THE PFITZNER MONOPLANE.

The Pfitzner monoplane has the distinction of being the first American
machine of the single-plane type. It was designed and flown by the
late Lieut. A. L. Pfitzner, and, though meeting with many mishaps, has
proved itself worthy of notice by its performances, through making use
of an entirely new device for lateral stability. This is the sliding
wing tip, by which the wing that tends to fall from its proper level
may be lengthened by 15 inches, the other wing being shortened as much
at the same time.

There is no longitudinal structure, as in the other monoplanes, the
construction being transverse and built upon four masts set in the
form of a square, 6 feet apart, about the centre. These are braced by
diagonal struts, and tied with wires on the edges of the squares. They
also support the guys reaching out to the tips of the wings.

[Illustration: The Pfitzner monoplane from the rear, showing the
sliding wing tips; dihedral angle of the wings; square body; and
transverse trussed construction.]

The plane proper is 31 feet in spread, to which the wing tips add 2½
feet, and is 6 feet deep, giving a total area of 200 square feet. A
light framework extending 10 feet in the rear carries a tail-plane 6
feet in spread and 2 feet in depth. Both the elevator and the rudder
planes are carried on a similar framework, 14 feet in front of the main
plane.

[Illustration: The Pfitzner monoplane, showing the structure of the
body; the two conical gasoline tanks above; the propeller in the rear.
Lieutenant Pfitzner at the wheel.]

The wings of the main plane incline upward from the centre toward the
tips, and are trussed by vertical struts and diagonal ties.

The motor is placed in the rear of the plane, instead of in front, as
in all other monoplanes. It is a 4-cylinder Curtiss motor, turning a
6-foot propeller at 1,200 revolutions per minute, and developing 25
horse-power.

The Pfitzner machine has proved very speedy, and has made some
remarkably sharp turns on an even keel.

OTHER MONOPLANES.

Several machines of the monoplane type have been produced, having some
feature distinct from existing forms. While all of these have flown
successfully, few of them have made any effort to be classed among the
contestants for honors at the various meets.

One of these, the Fairchild monoplane, shows resemblances to the R-E-P,
the Antoinette, and the Bleriot machines, but differs from them all
in having two propellers instead of one; and these revolve in the
same direction, instead of in contrary directions, as do those of all
other aeroplanes so equipped. The inventor claims that there is little
perceptible gyroscopic effect with a single propeller, and even less
with two. The propeller shafts are on the level of the plane, but the
motor is set about 5 feet below, connections being made by a chain
drive.

[Illustration: The Beach type of the Antoinette, an American
modification of the French machine, at the Boston Exhibition, 1910.]

The Burlingame monoplane has several peculiarities. Its main plane is
divided into two wings, each 10 feet in spread and 5 feet in depth,
and set 18 inches apart at the body. They are perfectly rigid. The
tail is in two sections, each 4 feet by 5 feet, and set with a gap of
6 feet between the sections, in which the rudder is placed. Thus the
spread of the tail from tip to tip is 16 feet, as compared with the 21½
foot spread of the main plane. The sections of the tail are operated
independently, and are made to serve as ailerons to control the lateral
balance, and also as the elevator.

The Cromley monoplane, another American machine, is modelled after the
Santos-Dumont _Demoiselle_. It has a main plane divided into two wings,
each 9 feet by 6 feet 6 inches, with a gap of 2 feet between at the
body; the total area being 117 square feet. At the rear of the outer
ends are hinged ailerons, like those of the Farman biplane, to control
the lateral balance. The tail is 12 feet in the rear, and is of the
“box” type, with two horizontal surfaces and two vertical surfaces.
This is mounted with a universal joint, so that it can be moved in any
desired direction. The complete structure, without the motor, weighs
but 60 pounds.

The Chauviere monoplane is distinct in having a rigid spar for the
front of the plane, but no ribs. The surface is allowed to spread out
as a sail and take form from the wind passing beneath. The rear edges
may be pulled down at will to control the lateral balance. It is driven
by twin screws set far back on the body, nearly to the tail.

[Illustration:

The Morok monoplane at the Boston Exhibition. It has the body of
the Bleriot, the wings of the Santos-Dumont, and the sliding wing
tips of the Pfitzner.]

The smallest and lightest monoplane in practical use is that of M.
Raoul Vendome. It is but 16 feet in spread, and is 16 feet fore and
aft. It is equipped with a 12 horse-power motor, and flies at a speed
of nearly 60 miles per hour. Without the pilot, its entire weight is
but 180 pounds. The wings are pivoted so that their whole structure may
be tilted to secure lateral balance.

The new Moisant monoplane is built wholly of metal. The structure
throughout is of steel, and the surfaces of sheet aluminum in a
succession of small arches from the centre to the tips. No authentic
reports of its performances are available.

In the Tatin monoplane, also called the Bayard-Clement, the main plane
is oval in outline, and the tail a smaller oval. The surfaces are
curved upward toward the tips for nearly half their length in both
the main plane and the tail. The propeller is 8½ feet in diameter,
and is turned by a Clerget motor, which can be made to develop 60
horse-power for starting the machine into the air, and then cut down to
30 horse-power to maintain the flight.

Chapter VII.

FLYING MACHINES: OTHER FORMS.

The triplane--The quadruplane--The multiplane--Helicopters--Their
principle--Obstacles to be overcome--The Cornu helicopter--The
Leger helicopter--The Davidson gyropter--The Breguet
gyroplane--The de la Hault ornithopter--The Bell
tetrahedrons--The Russ flyer.

While the efforts of inventors have been principally along the lines
of the successful monoplanes and biplanes, genius and energy have also
been active in other directions. Some of these other designs are not
much more than variations from prevailing types, however.

Among these is the English Roe triplane, which is but a biplane
with an extra plane added; the depths of all being reduced to give
approximately the same surface as the biplane of the same carrying
power. The tail is also of the triplane type, and has a combined area
of 160 square feet--just half that of the main planes. The triplane
type has long been familiar to Americans in the three-decker glider
used extensively by Octave Chanute in his long series of experiments
at Chicago.

[Illustration: The Roe triplane in flight.]

The quadruplane of Colonel Baden-Powell, also an English type, is
practically the biplane with unusually large forward and tail planes.

The multiplane of Sir Hiram Maxim should also be remembered, although
he never permitted it to have free flight. His new multiplane, modelled
after the former one, but equipped with an improved gasoline motor
instead of the heavy steam-engine of the first model, will doubtless be
put to a practical test when experiments with it are completed.

[Illustration: Sir Hiram Maxim standing beside his huge multiplane.]

Quite apart from these variants of the aeroplanes are the helicopters,
ornithopters, gyropters, gyroplanes, and tetrahedral machines.

HELICOPTERS.

The result aimed at in the helicopter is the ability to rise vertically
from the starting point, instead of first running along the ground
for from 100 to 300 feet before sufficient speed to rise is attained,
as the aeroplanes do. The device employed to accomplish this result is
a propeller, or propellers, revolving horizontally above the machine.
After the desired altitude is gained it is proposed to travel in any
direction by changing the plane in which the propellers revolve to one
having a small angle with the horizon.

[Illustration:

The force necessary to keep the aeroplane moving in its
horizontal path is the same as that required to move the
automobile of equal weight up the same gradient--much less than
its total weight.]

The great difficulty encountered with this type of machine is that the
propellers must lift the entire weight. In the case of the aeroplane,
the power of the engine is used to slide the plane up an incline of
air, and for this much less power is required. For instance, the weight
of a Curtiss biplane with the pilot on board is about 700 pounds,
and this weight is easily slid up an inclined plane of air with a
propeller thrust of about 240 pounds.

Another difficulty is that the helicopter screws, in running at the
start before they can attain speed sufficient to lift their load, have
established downward currents of air with great velocity, in which the
screws must run with much less efficiency. With the aeroplanes, on the
contrary, their running gear enables them to run forward on the ground
almost with the first revolution of the propeller, and as they increase
their speed the currents--technically called the “slip”--become less
and less as the engine speed increases.

In the Cornu helicopter, which perhaps has come nearer to successful
flight than any other, these downward currents are checked by
interposing planes below, set at an angle determined by the operator.
The glancing of the currents of air from the planes is expected to
drive the helicopter horizontally through the air. At the same time
these planes offer a large degree of resistance, and the engine power
must be still further increased to overcome this, while preserving the
lift of the entire weight. With an 8-cylinder Antoinette motor, said
to be but 24 horse-power, turning two 20-foot propellers, the machine
is reported as lifting itself and two persons--a total weight of 723
pounds--to a height of 5 feet, and sustaining itself for 1 minute. Upon
the interposing of the planes to produce the horizontal motion the
machine came immediately to the ground.

[Illustration: Diagram showing principle of the Cornu helicopter. _P_,
_P_, propelling planes. The arrow shows direction of travel with planes
at angle shown.]

This performance must necessarily be compared with that of the
aeroplanes, as, for instance, the Wright machine, which, with a 25 to
30 horse-power motor operating two 8-foot propellers, raises a weight
of 1,050 pounds and propels it at a speed of 40 miles an hour for
upward of 2 hours.

Another form of helicopter is the Leger machine, so named after its
French inventor. It has two propellers which revolve on the same
vertical axis, the shaft of one being tubular, encasing that of the
other. By suitable gearing this vertical shaft may be inclined after
the machine is in the air in the direction in which it is desired to
travel.

[Illustration: The Vitton-Huber helicopter at the Paris aeronautical
salon in 1909. It has the double concentric axis of the Leger
helicopter and the propelling planes of the Cornu machine.]

The gyropter differs from the Cornu type of helicopter in degree rather
than in kind. In the Scotch machine, known as the Davidson gyropter,
the propellers have the form of immense umbrellas made up of curving
slats. The frame of the structure has the shape of a T, one of the
gyropters being attached to each of the arms of the T. The axes upon
which the gyropters revolve may be inclined so that their power may be
exerted to draw the apparatus along in a horizontal direction after it
has been raised to the desired altitude.

The gyropters of the Davidson machine are 28 feet in diameter, the
entire structure being 67 feet long, and weighing 3 tons. It has been
calculated that with the proposed pair of 50 horse-power engines the
gyropters will lift 5 tons. Upon a trial with a 10 horse-power motor
connected to one of the gyropters, that end of the apparatus was lifted
from the ground at 55 revolutions per minute--the boiler pressure being
800 lbs. to the square inch, at which pressure it burst, wrecking the
machine.

An example of the gyroplane is the French Breguet apparatus, a blend of
the aeroplane and the helicopter. It combines the fixed wing-planes of
the one with the revolving vanes of the other. The revolving surfaces
have an area of 82 square feet, and the fixed surfaces 376 square feet.
The total weight of machine and operator is about 1,350 lbs. Fitted
with a 40 horse-power motor, it rose freely into the air.

The ornithopter, or flapping-wing type of flying machine, though the
object of experiment and research for years, must still be regarded as
unsuccessful. The apparatus of M. de la Hault may be taken as typical
of the best effort in that line, and it is yet in the experimental
stage. The throbbing beat of the mechanism, in imitation of the bird’s
wings, has always proved disastrous to the structure before sufficient
power was developed to lift the apparatus.

The most prominent exponent of the tetrahedral type--that made up of
numbers of small cells set one upon another--is the _Cygnet_ of Dr.
Alexander Graham Bell, which perhaps is more a kite than a true flying
machine. The first _Cygnet_ had 3,000 cells, and lifted its pilot to a
height of 176 feet. The _Cygnet II_. has 5,000 tetrahedral cells, and
is propelled by a 50 horse-power motor. It has yet to make its record.

One of the most recently devised machines is that known as the Fritz
Russ flyer. It has two wings, each in the form of half a cylinder, the
convex curve upward. It is driven by two immense helical screws, or
spirals, set within the semi-cylinders. No details of its performances
are obtainable.

Chapter VIII.

FLYING MACHINES: HOW TO OPERATE.

Instinctive balance--When the motor skips--Progressive
experience--Plum Island School methods--Lilienthal’s
conclusions--The Curtiss mechanism and controls--Speed
records--Cross-country flying--Landing--Essential
qualifications--Ground practice--Future relief.

Any one who has learned to ride a bicycle will recall the great
difficulty at first experienced to preserve equilibrium. But once the
knack was gained, how simple the matter seemed! Balancing became a
second nature, which came into play instinctively, without conscious
thought or effort. On smooth roads it was not even necessary to grasp
the handle-bars. The swaying of the body was sufficient to guide the
machine in the desired direction.

Much of this experience is paralleled by that of the would-be aviator.
First, he must acquire the art of balancing himself and his machine in
the air without conscious effort. Unfortunately, this is even harder
than in the case of the bicycle. The cases would be more nearly alike
if the road beneath and ahead of the bicyclist were heaving and falling
as in an earthquake, with no light to guide him; for the air currents
on which the aviator must ride are in constant and irregular motion,
and are as wholly invisible to him as would be the road at night to the
rider of the wheel.

And there are other things to distract the attention of the pilot of an
aeroplane--notably the roar of the propeller, and the rush of wind in
his face, comparable only to the ceaseless and breath-taking force of
the hurricane.

The well-known aviator, Charles K. Hamilton, says:--“So far as the air
currents are concerned, I rely entirely on instinctive action; but my
ear is always on the alert. The danger signal of the aviator is when
he hears his motor miss an explosion. Then he knows that trouble is
in store. Sometimes he can speed up his engine, just as an automobile
driver does, and get it to renew its normal action. But if he fails
in this, and the motor stops, he must dip his deflecting planes, and
try to negotiate a landing in open country. Sometimes there is no
preliminary warning from the motor that it is going to cease working.
That is the time when the aviator must be prepared to act quickly.
Unless the deflecting planes are manipulated instantly, aviator and
aeroplane will rapidly land a tangled mass on the ground.”

[Illustration: Result of a failure to deflect the planes quickly enough
when the engine stopped. The operator fortunately escaped with but a
few bruises.]

At the same time, Mr. Hamilton says: “Driving an aeroplane at a speed
of 120 miles an hour is not nearly so difficult a task as driving an
automobile 60 miles an hour. In running an automobile at high speed
the driver must be on the job every second. Nothing but untiring
vigilance can protect him from danger. There are turns in the road, bad
stretches of pavement, and other like difficulties, and he can never
tell at what moment he is to encounter some vehicle, perhaps travelling
in the opposite direction. But with an aeroplane it is a different
proposition. Once a man becomes accustomed to aeroplaning, it is a
matter of unconscious attention.... He has no obstacles to encounter
except cross-currents of air. Air and wind are much quicker than a man
can think and put his thought into action. Unless experience has taught
the aviator to maintain his equilibrium instinctively, he is sure to
come to grief.”

The Wright brothers spent years in learning the art of balancing in
the air before they appeared in public as aviators. And their method
of teaching pupils is evidence that they believe the only road to
successful aviation is through progressive experience, leading up from
the use of gliders for short flights to the actual machines with motors
only after one has become an instinctive equilibrist.

At the Plum Island school of the Herring-Burgess Company the learner is
compelled to begin at the beginning and work the thing out for himself.
He is placed in a glider which rests on the ground. The glider is
locked down by a catch which may be released by pulling a string. To
the front end of the glider is attached a long elastic which may be
stretched more or less, according to the pull desired. The beginner
starts with the elastic stretched but a little. When all is ready he
pulls the catch free, and is thrown forward for a few feet. As practice
gains for him better control, he makes a longer flight; and when he
can show a perfect mastery of his craft for a flight of 300 feet, and
not till then, he is permitted to begin practice with a motor-driven
machine.

[Illustration: A French apparatus for instructing pupils in aviation.]

The lamented Otto Lilienthal, whose experience in more than 2,000
flights gives his instructions unquestionable weight, urges that the
“gradual development of flight should begin with the simplest apparatus
and movements, and without the complication of dynamic means. With
simple wing surfaces ... man can carry out limited flights ... by
gliding through the air from elevated points in paths more or less
descending. The peculiarities of wind effects can best be learned by
such exercises.... The maintenance of equilibrium in forward flight
is a matter of practice, and can be learned only by repeated personal
experiment.... Actual practice in individual flight presents the best
prospects for developing our capacity until it leads to perfected free
flight.”

The essential importance of thorough preparation in the school of
experience could scarcely be made plainer or stronger. If it seems that
undue emphasis has been laid upon this point, the explanation must be
found in the deplorable death record among aviators from accidents in
the air. With few exceptions, the cause of accident has been reported
as, “The aviator seemed to lose control of his machine.” If this is
the case with professional flyers, the need for thorough preliminary
training cannot be too strongly insisted upon.

Having attained the art of balancing, the aviator has to learn
the mechanism by which he may control his machine. While all of
the principal machines are but different embodiments of the same
principles, there is a diversity of design in the arrangement of the
means of control. We shall describe that of the Curtiss biplane, as
largely typical of them all.

In general, the biplane consists of two large sustaining planes, one
above the other. Between the planes is the motor which operates a
propeller located in the rear of the planes. Projecting behind the
planes, and held by a framework of bamboo rods, is a small horizontal
plane, called the tail. The rudder which guides the aeroplane to the
right or the left is partially bisected by the tail. This rudder is
worked by wires which run to a steering wheel located in front of
the pilot’s seat. This wheel is similar in size and appearance to
the steering wheel of an automobile, and is used in the same way for
guiding the aeroplane to the right or left. (See illustration of the
Curtiss machine in Chapter V.)

In front of the planes, supported on a shorter projecting framework,
is the altitude rudder, a pair of planes hinged horizontally, so that
their front edges may tip up or down. When they tilt up, the air
through which the machine is passing catches on the under sides and
lifts them up, thus elevating the front of the whole aeroplane and
causing it to glide upward. The opposite action takes place when these
altitude planes are tilted downward. This altitude rudder is controlled
by a long rod which runs to the steering wheel. By pushing on the wheel
the rod is shoved forward and turns the altitude planes upward. Pulling
the wheel turns the rudder planes downward. This rod has a backward and
forward thrust of over two feet, but the usual movement in ordinary
wind currents is rarely more than an inch. In climbing to high levels
or swooping down rapidly the extreme play of the rod is about four or
five inches.

Thus the steering wheel controls both the horizontal and vertical
movements of the aeroplane. More than this, it is a feeler to the
aviator, warning him of the condition of the air currents, and for
this reason must not be grasped too firmly. It is to be held steady,
yet loosely enough to transmit any wavering force in the air to the
sensitive touch of the pilot, enabling him instinctively to rise or dip
as the current compels.

[Illustration: _Courtesy N. Y. Times._

View of the centre of the new Wright machine, showing method of
operating. Archibald Hoxsey in the pilot’s seat. In his right
hand he holds a lever with two handles, one operating the warping
of the wing tips, and the other the rudder. Both handles may be
grasped at once, operating both rudder and wing tips at the same
moment. In his left hand Hoxsey grasps the lever operating the
elevating plane--at the rear in this type. The passenger’s seat
is shown at the pilot’s right.]

The preserving of an even keel is accomplished in the Curtiss machine
by small planes hinged between the main planes at the outer ends.
They serve to prevent the machine from tipping over sideways. They
are operated by arms, projecting from the back of the aviator’s seat,
which embrace his shoulders on each side, and are moved by the swaying
of his body. In a measure, they are automatic in action, for when the
aeroplane sags downward on one side, the pilot naturally leans the
other way to preserve his balance, and that motion swings the ailerons
(as these small stabilizing planes are called) in such a way that the
pressure of the wind restores the aeroplane to an even keel. The wires
which connect them with the back of the seat are so arranged that when
one aileron is being pulled down at its rear edge the rear of the
other one is being raised, thus doubling the effect. As the machine is
righted the aviator comes back to an upright position, and the ailerons
become level once more.

[Illustration: Starting a Wright machine. When the word is given both
assistants pull vigorously downward on the propeller blades.]

There are other controls which the pilot must operate consciously.
In the Curtiss machine these are levers moved by the feet. With a
pressure of the right foot he short-circuits the magneto, thus cutting
off the spark in the engine cylinders and stopping the motor. This
lever also puts a brake on the forward landing wheels, and checks the
speed of the machine as it touches the ground. The right foot also
controls the pump which forces the lubricating oil faster or slower to
the points where it is needed.

The left foot operates the lever which controls the throttle by which
the aviator can regulate the flow of gas to the engine cylinders. The
average speed of the 7-foot propeller is 1,100 revolutions per minute.
With the throttle it may be cut down to 100 revolutions per minute,
which is not fast enough to keep afloat, but will help along when
gliding.

Obviously, travelling with the wind enables the aviator to make his
best speed records, for the speed of the wind is added to that of his
machine through the air. Again, since the wind is always slower near
the ground, the aviator making a speed record will climb up to a level
where the surface currents no longer affect his machine. But over hilly
and wooded country the air is often flowing or rushing in conflicting
channels, and the aviator does not know what he may be called upon to
face from one moment to the next. If the aeroplane starts to drop, it
is only necessary to push the steering wheel forward a little--perhaps
half an inch--to bring it up again. Usually, the machine will drop
on an even keel. Then, in addition to the motion just described, the
aviator will lean toward the higher side, thus moving the ailerons by
the seat-back, and at the same time he will turn the steering wheel
toward the lower side. This movement of the seat-back is rarely more
than 2 inches.

[Illustration:

Diagram showing action of wind on flight of aeroplane. The force
and direction of the wind being represented by the line _A B_,
and the propelling force and steered direction being _A C_, the
actual path travelled will be _A D_.]

In flying across country a sharp lookout is kept on the land below. If
it be of a character unfit for landing, as woods, or thickly settled
towns, the aviator must keep high up in the air, lest his engine stop
and he be compelled to glide to the earth. A machine will glide forward
3 feet for each foot that it drops, if skilfully handled. If he is up
200 feet, he will have to find a landing ground within 600 feet. If
he is up 500 feet, he may choose his alighting ground anywhere within
1,500 feet. Over a city like New York, a less altitude than 1,500 feet
would hardly be safe, if a glide became necessary.

Mr. Clifford B. Harmon, who was an aeronaut of distinction before he
became an aviator, under the instruction of Paulhan, has this to say:
“It is like riding a bicycle, or running an automobile. You have to try
it alone to really learn how. When one first handles a flying machine
it is advisable to keep on the ground, just rolling along. This is a
harder mental trial than you will imagine. As soon as one is seated in
a flying machine he wishes to fly. It is almost impossible to submit to
staying near the earth. But until the manipulation of the levers and
the steering gear has become second nature, this must be done. It is
best to go very slow in the beginning. Skipping along the ground will
teach a driver much. When one first gets up in the air it is necessary
to keep far from all obstacles, like buildings, trees, or crowds. There
is the same tendency to run into them that an amateur bicycle rider
has in regard to stones and ruts on the ground. When he keeps his eye
on them and tries with all his might to steer clear of them, he runs
right into them.”

[Illustration: Practicing with a monoplane, 20 feet above the ground.]

When asked what he regarded the fundamental requirements in an aviator,
Mr. Harmon said: “First, he must be muscularly strong; so that he
will not tire. Second, he should have a thorough understanding of the
mechanism of the machine he drives. Third, mental poise--the ability to
think quick and to act instantly upon your thought. Fourth, a feeling
of confidence in the air, so that he will not feel strange or out of
place. This familiarity with the air can be best obtained by first
being a passenger in a balloon, then by controlling one alone, and
lastly going up in a flying machine.”

[Illustration: Grahame-White on his Bleriot No. XII. The lever in front
of him operates all the controls through the movement of the drum at
its base.]

Mr. Claude Grahame-White, the noted English aviator, has this to say of
his first experience with his big “No. XII.” Bleriot monoplane--which
differs in many important features from the “No. XI.” machine in which
M. Bleriot crossed the English Channel: “After several disappointments,
I eventually obtained the delivery of my machine in working order....
As I had gathered a good deal of information from watching the antics
and profiting by the errors made by other beginners on Bleriot
monoplanes, I had a good idea of what _not_ to do when the engine
was started up and we were ready for our first trial.... It was a
cold morning, but the engine started up at the first quarter turn.
After many warnings from M. Bleriot’s foreman not on any account to
accelerate my engine too much, I mounted the machine along with my
friend as passenger, and immediately gave the word to let go, and we
were soon speeding along the ground at a good sixty kilometers (about
37 miles) per hour.... Being very anxious to see whether the machine
would lift off the ground, I gave a slight jerk to the elevating
plane, and soon felt the machine rise into the air; but remembering
the warnings of the foreman, and being anxious not to risk breaking
the machine, I closed the throttle and contented myself with running
around on the ground to familiarize myself with the handling of the
machine.... The next day we got down to Issy about five o’clock in
the morning, some two hours before the Bleriot mechanics turned up.
However, we got the machine out, and tied it to some railings, and then
I had my first experience of starting an engine, which to a novice
at first sight appears a most hazardous undertaking; for unless the
machine is either firmly held by several men, or is strongly tied up,
it has a tendency to immediately leap forward. We successfully started
the engine, and then rigged up a leash, and when we had mounted the
machine, we let go; and before eight o’clock we had accomplished
several very successful flights, both with and against the wind. These
experiences we continued throughout the day, and by nightfall I felt
quite capable of an extended flight, if only the ground had been large
enough.... The following day M. Bleriot returned, and he sent for me
and strongly urged me not to use the aeroplane any more at Issy, as he
said the ground was far too small for such a powerful machine.”

[Illustration:

Diagram of Bleriot monoplane, showing controlling lever _L_
and bell-shaped drum _C_, to which all controlling wires are
attached. When the bell is rocked back and forward the elevator
tips on the rear plane are moved; rocking from side to side moves
the stabilizing tips of the main plane. Turning the bell around
moves the rudder.]

[Illustration:

The Marmonier gyroscopic pendulum, devised to secure automatic
stability of aeroplanes. The wheels are driven by the aeroplane
motor at high speed. The pendulum rod is extended upward above
the axis and carries a vane which is engaged by any gust of wind
from either side of the aeroplane, tending to tilt the pendulum,
and bringing its gyroscopic resistance into play to warp the
wings, or operate ailerons.]

The caution shown by these experienced aviators cannot be too closely
followed by a novice. These men do not say that their assiduous
practice on the ground was the fruit of timidity. On the contrary,
although they are long past the preliminary stages, their advice to
beginners is uniformly in the line of caution and thorough practice.

[Illustration:

When the aeroplane is steered to the left, the pendulum swings to
the right and depresses the right side of the plane, as in (_c_).
The reaction of the air raises the right side of the plane until
both surfaces are perpendicular to the inclined pendulum, as in
(_d_).

Diagrams showing action of Marmonier gyroscopic pendulum.]

Even after one has become an expert, the battle is not won, by any
means. While flying in calm weather is extremely pleasurable, a
protracted flight is very fatiguing; and when it is necessary to
wrestle with gusts of high wind and fickle air currents, the strain
upon the strongest nerve is a serious source of danger in that the
aviator is liable to be suddenly overcome by weariness when he most
needs to be on the alert.

[Illustration:

In that inclined position the aeroplane makes the turn, and
when the course again becomes straight, both the gyroscopic and
centrifugal forces cease, and the pendulum under the influence
of gravity becomes vertical. In this position it is inclined to
the left with respect to the planes, on which its effect is to
depress the left wing and so right the aeroplane, as in (_e_).

Diagram showing action of Marmonier gyroscopic pendulum.]

Engine troubles are much fewer than they used to be, and a more
dependable form of motor relieves the mind of the aviator from such
mental disturbance. Some device in the line of a wind-shield would be
a real boon, for even in the best weather there is the ceaseless rush
of air into one’s face at 45 to 50 miles an hour. The endurance of this
for hours is of itself a tax upon the most vigorous physique.

With the passing of the present spectacular stage of the art of flying
there will doubtless come a more reliable form of machine, with
corresponding relief to the operator. Automatic mechanism will supplant
the intense and continual mental attention now demanded; and as this
demand decreases, the joys of flying will be considerably enhanced.

[Illustration:

If, when pursuing a straight course, the aeroplane is tilted by
a sideways wind (_b_), the action of the pendulum as described
above restores it to an even keel, as in (_a_).

Diagrams showing action of Marmonier gyroscopic pendulum.]

Chapter IX.

FLYING MACHINES: HOW TO BUILD.

Santos-Dumont’s gift--_La Demoiselle_--Mechanical skill
required--Preparatory practice--General dimensions--The
frame--The motor--The main planes--The rudder-tail--The
propeller--Shaping the blades--Maxim’s experience--The running
gear--The controls--Scrupulous workmanship.

When Santos-Dumont in 1909 gave to the world the unrestricted
privilege of building monoplanes after the plans of his famous No.
20--afterward named _La Demoiselle_--he gave not only the best he knew,
but as much as any one knows about the building of flying machines.
Santos-Dumont has chosen the monoplane for himself because his long
experience commends it above others, and _La Demoiselle_ was the
crowning achievement of years spent in the construction and operation
of airships of all types. In view of Santos-Dumont’s notable successes
in his chosen field of activity, no one will go astray in following his
advice.

Of course, the possession of plans and specifications for an aeroplane
does not make any man a skilled mechanic. It is well to understand at
the start that a certain degree of mechanical ability is required in
building a machine which will be entirely safe. Nor does the possession
of a successful machine make one an aeronaut. As in the case of
bicycling, there is no substitute for actual experience, while in the
airship the art of balancing is of even greater importance than on the
bicycle.

The would-be aviator is therefore advised to put himself through a
course of training of mind and body.

Intelligent experimenting with some one of the models described in
Chapter XI. will teach much of the action of aeroplanes in calms
and when winds are blowing; and practice with an easily constructed
glider (see Chapter XII.) will give experience in balancing which
will be of the greatest value when one launches into the air for the
first time with a power-driven machine. An expert acquaintance with
gasoline motors and magnetos is a prime necessity. In short, every bit
of information on the subject of flying machines and their operation
cannot fail to be useful in some degree.

The dimensions of the various parts of the Santos-Dumont monoplane are
given on the original plans according to the metric system. In reducing
these to “long measure” inches, all measurements have been given to the
nearest eighth of an inch.

In general, we may note some of the peculiarities of _La Demoiselle_.
The spread of the plane is 18 feet from tip to tip, and it is 20 feet
over all from bow to stern. In height, it is about 4 feet 2 inches when
the propeller blades are in a horizontal position. The total weight
of the machine is 265 lbs., of which the engine weighs about 66 lbs.
The area of the plane is 115 square feet, so that the total weight
supported by each square foot with Santos-Dumont (weighing 110 lbs.) on
board is a trifle over 3 lbs.

The frame of the body of the monoplane is largely of bamboo, the three
main poles being 2 inches in diameter at the front, and tapering to
about 1 inch at the rear. They are jointed with brass sockets just back
of the plane, for convenience of taking apart for transportation. Two
of these poles extend from the axle of the wheels backward and slightly
upward to the rudder-post. The third extends from the middle of the
plane between the wings, backward and downward to the rudder-post.
In cross-section the three form a triangle with the apex at the top.
These bamboo poles are braced about every 2 feet with struts of steel
tubing of oval section, and the panels so formed are tied by diagonals
of piano wire fitted with turn-buckles to draw them taut.

[Illustration:

Side view of the Santos-Dumont monoplane. _MP_, main plane with
radiator, _R_, hung underneath; _RP_, rudder plane worked by
wires _HC_, attached to lever _L_; _VC_, vertical control wires;
_WT_, tube through which run the warping wires worked by lever
_K_, in a pocket of the pilot’s coat; _B_, _B_, bamboo poles of
frame; _S_, _S_, brass, or aluminum sockets; _D_, _D_, struts
of bicycle tubing; _G_, gasoline; _RG_, reserve gasoline; _M_,
motor; _P_, propeller; _Q_, _Q_, outer rib of plane, showing
camber; _N_, skid.]

In the Santos-Dumont machine a 2-cylinder, opposed Darracq motor of
30 horse-power was used. It is of the water-cooled type, the cooling
radiator being a gridiron of very thin ⅛-inch copper tubing, and hung
up on the under side of the plane on either side of the engine. The
cylinders have a bore of about 4⅛ inches, and a stroke of about 4¾
inches. The propeller is 2-bladed, 6½ feet across, and is run at 1,400
revolutions per minute, at which speed it exerts a pull of 242 lbs.

Each wing of the main plane is built upon 2 transverse spars extending
outward from the upper bamboo pole, starting at a slight angle upward
and bending downward nearly to the horizontal as they approach the
outer extremities. These spars are of ash, 2 inches wide, and tapering
in thickness from 1⅛ inches at the central bamboo to about ⅞ inch at
the tips of the wings. They are bent into shape by immersion in hot
water, and straining them around blocks nailed to the floor of the
workshop, in the form shown at QQ, p. 177.

[Illustration:

Front view of the Santos-Dumont monoplane, showing position
of tubular struts supporting the engine and the wings; also
the guys, and warping wires entering the tubes inside the
wheels. _MP_, the main plane; _TP_, tail plane in the rear;
_R_, radiators; _M_, motor; _P_, propeller, the arrow showing
direction of revolution.]

The front spar is set about 9 inches back from the front edge of the
plane, and the rear one about 12 inches forward of the back edge of
the plane. Across these spars, and beneath them, running fore and aft,
are bamboo rods about ¾ of an inch in diameter at the forward end,
and tapering toward the rear. They are set 8½ inches apart (centre
to centre), except at the tips of the wings. The two outer panels
are 10¼ inches from centre to centre of the rods, to give greater
elasticity in warping. These fore-and-aft rods are 6 feet 5 inches
long, except directly back of the propeller, where they are 5 feet 8
inches long; they are bound to the spars with brass wire No. 25, at the
intersections. They also are bent to a curved form, as shown in the
plans, by the aid of the hot-water bath. Diagonal guys of piano wire
are used to truss the frame in two panels in each wing.

Around the outer free ends of the rods runs a piano wire No. 20, which
is let into the tips of the rods in a slot ⅜ inch deep. To prevent
the splitting of the bamboo, a turn or two of the brass wire may be
made around the rod just back of the slot; but it is much better to
provide thin brass caps for the ends of the rods, and to cut the slots
in the metal as well as in the rods. Instead of caps, ferrules will do.
When the slots are cut, let the tongue formed in the cutting be bent
down across the bamboo to form the floor to the slot, upon which the
piano wire may rest. The difference in weight and cost is very little,
and the damage that may result from a split rod may be serious.

[Illustration: Plan and details of construction of _La Demoiselle_.]

After the frame of the plane is completed it is to be covered with
cloth on both sides, so as entirely to enclose the frame, except only
the tips of the rods, as shown in the plans. In the Santos-Dumont
monoplane the cloth used is of closely woven silk, but a strong,
unbleached muslin will do--the kind made especially for aeroplanes is
best.

Both upper and lower surfaces must be stretched taut, the edges front
and back being turned over the piano wire, and the wire hemmed in.
The upper and lower surfaces are then sewed together--“through and
through,” as a seamstress would say--along both sides of each rod, so
that the rods are practically in “pockets.” Nothing must be slighted,
if safety in flying is to be assured.

[Illustration: Sectional diagram of 2-cylinder Darracq opposed motor.]

[Illustration: Diagram of 4-cylinder Darracq opposed motor.]

[Illustration: Diagram of 3-cylinder Anzani motor.

Motors suitable for _La Demoiselle_ monoplane.]

The tail of the monoplane is a rigid combination of two planes
intersecting each other at right angles along a central bamboo pole
which extends back 3 feet 5½ inches from the rudder-post, to which it
is attached by a double joint, permitting it to move upon either the
vertical or the horizontal axis.

Although this tail, or rudder, may seem at first glance somewhat
complicated in the plans, it will not be found so if the frame of the
upright or vertical plane be first constructed, and that of the level
or horizontal plane afterward built fast to it at right angles.

As with the main plane, the tail is to be covered on both sides with
cloth, the vertical part first; the horizontal halves on either side so
covered that the cloth of the latter may be sewed above and below the
central pole. All of the ribs in the tail are to be stitched in with
“pockets,” as directed for the rods of the main plane.

The construction of the motor is possible to an expert machinist only,
and the aeroplane builder will save time and money by buying his engine
from a reliable maker. It is not necessary to send to France for a
Darracq motor. Any good gasoline engine of equal power, and about the
same weight, will serve the purpose.

The making of the propeller is practicable for a careful workman. The
illustrations will give a better idea than words of how it should be
done. It should be remembered, however, that the safety of the aviator
depends as much upon the propeller as upon any other part of the
machine. The splitting of the blades when in motion has been the cause
of serious accidents. The utmost care, therefore, should be exercised
in the selection of the wood, and in the glueing of the several
sections into one solid mass, allowing the work to dry thoroughly under
heavy pressure.

[Illustration:

Diagram showing how the layers of wood are placed for glueing:
_A_, at the hub; _B_, half way to the tip of the blade; _C_, at
the tip. The dotted lines show the form of the blade at these
points.]

The forming of the blades requires a good deal of skill, and some
careful preliminary study. It is apparent that the speed of a point
at the tip of a revolving blade is much greater than that of a point
near the hub, for it traverses a larger circle in the same period of
time. But if the propeller is to do effective work without unequal
strain, the twist in the blade must be such that each point in the
length of the blade is exerting an equal pull on the air. It is
necessary, therefore, that the slower-moving part of the blade, near
the hub, or axis, shall cut “deeper” into the air than the more swiftly
moving tip of the blade. Consequently the blade becomes continually
“flatter” (approaching the plane in which it revolves) as we work
from the hub outward toward the tip. This “flattening” is well shown
in the nearly finished blade clamped to the bench at the right of the
illustration--which shows a four-bladed propeller, instead of the
two-bladed type needed for the monoplane.

The propeller used for propulsion in air differs from the
propeller-wheel used for ships in water, in that the blades are curved
laterally; the forward face of the blade being convex, and the rearward
face concave. The object of this shaping is the same as for curving the
surface of the plane--to secure smoother entry into the air forward,
and a compression in the rear which adds to the holding power on
the substance of the air. It is extremely difficult to describe this
complex shape, and the amateur builder of a propeller will do well to
inspect one made by a professional, or to buy it ready made with his
engine.

[Illustration: Forming a 4-blade propeller out of 8 layers of wood
glued firmly together.]

The following quotation from Sir Hiram Maxim’s account of his most
effective propeller may aid the ambitious aeroplane builder: “My large
screws were made with a great degree of accuracy; they were perfectly
smooth and even on both sides, the blades being thin and held in
position by a strip of rigid wood on the back of the blade.... Like
the small screws, they were made of the very best kind of seasoned
American white pine, and when finished were varnished on both sides
with hot glue. When this was thoroughly dry, they were sand-papered
again, and made perfectly smooth and even. The blades were then covered
with strong Irish linen fabric of the smoothest and best make. Glue
was used for attaching the fabric, and when dry another coat of glue
was applied, the surface rubbed down again, and then painted with
zinc white in the ordinary way and varnished. These screws worked
exceedingly well.”

The covering of the blades with linen glued fast commends itself to the
careful workman as affording precaution against the splintering of the
blades when in rapid motion. Some propellers have their wooden blades
encased with thin sheet aluminum to accomplish the same purpose, but
for the amateur builder linen is far easier to apply.

[Illustration:

This method of mounting the wheels of the chassis has been found
the most satisfactory. The spring takes up the shock of a sudden
landing and the pivot working in the hollow post allows the
entire mounting to swing like a caster, and adapt itself to any
direction at which the machine may strike the ground.]

The wheels are of the bicycle type, with wire spokes, but with hubs six
inches long. The axle is bent to incline upward at the ends, so that
the wheels incline outward at the ground, the better to take the shock
of a sideways thrust when landing. The usual metal or wood rims may be
used, but special tires of exceptionally light construction, made for
aeroplanes, should be purchased.

The controlling wires or cords for moving the rudder (or tail) and for
warping the tips of the wings are of flexible wire cable, such as is
made for use as steering rope on small boats. The cable controlling
the horizontal plane of the rudder-tail is fastened to a lever at the
right hand of the operator. The cable governing the vertical plane
of the rudder-tail is attached to a wheel at the left hand of the
operator. The cables which warp the tips of the wings are fastened to
a lever which projects upward just back of the operator’s seat, and
which is slipped into a long pocket sewed to the back of his coat, so
that the swaying of his body in response to the fling of the tipping
machine tends to restore it to an even keel. Springs are attached to
all of these controlling wires, strong enough to bring them back to a
normal position when the operator removes his hands from the steering
apparatus.

The brass sockets used in connecting the tubular struts to the main
bamboos and the rudder-post, and in fastening the axle of the wheels to
the lower bamboos and elsewhere, should be thoroughly made and brazed
by a good mechanic, for no one should risk the chance of a faulty
joint at a critical spot, when an accident may mean the loss of life.

[Illustration: Diagram of Bleriot monoplane showing sizes of parts, in
metres. Reduced to feet and inches these measurements are:

0.60 metres 1 ft. 11½ in.
1.50 metres 4 ft. 11 in.
2.10 metres 6 ft. 10½ in.
3.50 metres 11 ft. 6 in.
8.00 metres 26 ft. 3 in.
8.60 metres 28 ft. 2½ in.

The diagram being drawn to scale other dimensions may be found.
In both the plan (upper figure) and elevation (lower figure),
_A_, _A_, is the main plane; _B_, tail plane; _C_, body; _D_,
elevator wing-tips; _E_, rudder; _a_, _a_, rigid spar; _b_, _b_,
flexible spar; _r_, _r_, points of attachment for warping-wires;
_h_, _h_, guys; _H_, propeller; _M_, motor; _R_, radiator; _S_,
pilot’s seat; _P_, chassis.]

For the rest, it has seemed better to put the details of construction
on the plans themselves, where they will be available to the aeroplane
builder without the trouble of continually consulting the text.

Some of the work on an aeroplane will be found simple and easy; some of
it, difficult and requiring much patience; and some impracticable to
any one but a trained mechanic. But in all of it, the worker’s motto
should be, “Fidelity in every detail.”

Chapter X.

FLYING MACHINES: MOTORS.

Early use of steam--Reliability necessary--The gasoline
motor--Carburetion--Compression--Ignition--Air-cooling--Water-cooling--Lubrication--The
magneto--Weight--Types of motors--The propeller--Form, size, and
pitch--Slip--Materials--Construction.

The possibility of the existence of the flying machine as we have it
to-day has been ascribed to the invention of the gasoline motor. While
this is not to be denied, it is also true that the gasoline motors
designed and built for automobiles and motor-boats have had to be
wellnigh revolutionized to make them suitable for use in the various
forms of aircraft. And it is to be remembered, doubtless to their
greater credit, that Henson, Hargrave, Langley, and Maxim had all
succeeded in adapting steam to the problem of the flight of models, the
two latter using gasoline to produce the steam.

Perhaps the one predominant qualification demanded of the aeroplane
motor is reliability. A motor-car or motor-boat can be stopped, and
engine troubles attended to with comparatively little inconvenience.
The aeroplane simply cannot stop without peril. It is possible for
a skilful pilot to reach the earth when his engine stops, if he is
fortunately high enough to have space for the downward glide which will
gain for him the necessary headway for steering. At a lesser height he
is sure to crash to the earth.

An understanding of the principles on which the gasoline motor works
is essential to a fair estimate of the comparative advantages of the
different types used to propel aeroplanes. In the first place, the
radical difference between the gasoline motor and other engines is the
method of using the fuel. It is not burned in ordinary fashion, but the
gasoline is first vaporized and mixed with a certain proportion of air,
in a contrivance called a carburetor. This gaseous mixture is pumped
into the cylinder of the motor by the action of the motor itself,
compressed into about one-tenth of its normal volume, and then exploded
by a strong electric spark at just the right moment to have its force
act most advantageously to drive the machinery onward.

[Illustration: The “Fiat” 8-cylinder air-cooled motor, of the “V” type,
made in France.]

It is apparent that there are several chances for failure in this
series. The carburetor may not do its part accurately. The mixture of
air and vapor may not be in such proportions that it will explode; in
that case, the power from that stroke will be missing, and the engine
will falter and slow down. Or a leakage in the cylinder may prevent
the proper compression of the mixture, the force from the explosion
will be greatly reduced, with a corresponding loss of power and speed.
Or the electric spark may not be “fat” enough--that is, of sufficient
volume and heat to fire the mixture; or it may not “spark” at just
the right moment; if too soon, it will exert its force against the
onward motion: if too late, it will not deliver the full power of the
explosion at the time when its force is most useful. The necessity for
absolute perfection in these operations is obvious.

[Illustration: A near view of the Holmes engine from the driving side.]

[Illustration: The Holmes rotative engine, 7-cylinder 35 horse-power,
weighing 160 pounds.

An American engine built in Chicago, Ill.]

Other peculiarities of the gasoline motor affect considerably its
use for aeroplanes. The continual and oft-repeated explosions of the
gaseous mixture inside of the cylinder generate great heat, and this
not only interferes with its regularity of movement, but within a
very brief time checks it altogether. To keep the cylinder cool enough
to be serviceable, two methods are in use: the air-cooling system and
the water-cooling system. In the first, flanges of very thin metal
are cast on the outside of the cylinder wall. These flanges take up
the intense heat, and being spread out over a large surface in this
way, the rushing of the air through them as the machine flies (or
sometimes blown through them with a rotary fan) cools them to some
degree. With the water-cooling system, the cylinder has an external
jacket, the space between being filled with water which is made to
circulate constantly by a small pump. In its course the water which
has just taken up the heat from the cylinder travels through a radiator
in which it is spread out very thin, and this radiator is so placed
in the machine that it receives the full draught from the air rushing
through the machine as it flies. The amount of water required for
cooling a motor is about 1⅕ lbs. per horse-power. With an 8-cylinder 50
horse-power motor, this water would add the very considerable item of
60 lbs. to the weight the machine has to carry. As noted in a previous
chapter, the McCurdy biplane has its radiator formed into a sustaining
plane, and supports its own weight when travelling in the air.

[Illustration: The 180 horse-power engine of Sir Hiram Maxim; of the
“opposed” type, compound, and driven by steam.]

[Illustration:

The Anzani motor and propeller which carried M. Bleriot across
the English Channel. The curved edge of the propeller blades is
the entering edge, the propeller turning from the right of the
picture over to the left. The Anzani is of the “radiant” type and
is of French build.]

It is an unsettled point with manufacturers whether the greater
efficiency (generally acknowledged) of the water-cooled engine more
than compensates for the extra weight of the water.

Another feature peculiar to the gasoline motor is the necessity for
such continual oiling that it is styled “lubrication,” and various
devices have been invented to do the work automatically, without
attention from the pilot further than the watching of his oil-gauge to
see that a full flow of oil is being pumped through the oiling system.

The electric current which produces the spark inside of the cylinder
is supplied by a magneto, a machine formed of permanent magnets of
horseshoe form, between the poles of which a magnetized armature is
made to revolve rapidly by the machinery which turns the propeller.
This magneto is often connected with a small storage battery, or
accumulator, which stores up a certain amount of current for use when
starting, or in case the magneto gives out.

[Illustration: Sectional drawings showing details of construction of
the Anzani motor. The flanges of the air-cooling system are distinctly
shown. The section at the left is from the side; that at the right,
from the front. All measurements are in millimètres. A millimètre is
0.039 inch.]

The great rivalry of the builders of motors has been in cutting down
the weight per horse-power to the lowest possible figure. It goes
without saying that useless weight is a disadvantage in an aeroplane,
but it has not been proven that the very lightest engines have made a
better showing than those of sturdier build.

[Illustration: The “Gobron” engine of the “double opposed,” or
cross-shaped type. A water-cooled engine, with 8 cylinders.]

One of the items in the weight of an engine has been the fly-wheel
found necessary on all motors of 4 cylinders or less to give steadiness
to the running. With a larger number of cylinders, and a consequently
larger number of impulses in the circuit of the propeller, the
vibration is so reduced that the fly-wheel has been dispensed with.

[Illustration: The Emerson 6-cylinder aviation engine, of the “tandem”
type, water-cooled; 60 horse-power; made at Alexandria, Va.]

There are several distinct types of aircraft engines, based on the
arrangement of the cylinders. The “tandem” type has the cylinders
standing upright in a row, one behind another. There may be as many as
eight in a row. The Curtiss and Wright engines are examples. Another
type is the “opposed” arrangement, the cylinders being placed in a
horizontal position and in two sets, one working opposite the other.
An example of this type is seen in the Darracq motor used on the
Santos-Dumont monoplane. Another type is the “V” arrangement, the
cylinders set alternately leaning to right and to left, as seen in
the “Fiat” engine. Still another type is the “radiant,” in which the
cylinders are all above the horizontal, and disposed like rays from
the rising sun. The 3-cylinder Anzani engine and the 5- and 7-cylinder
R-E-P engines are examples. The “star” type is exemplified in the 5
and 7-cylinder engines in which the cylinders radiate at equal angles
all around the circle. The “double opposed” or cross-shaped type is
shown in the “Gobron” engine. In all of these types the cylinders are
stationary, and turn the propeller shaft either by cranks or by gearing.

[Illustration: The Elbridge engine, of the “tandem” type and
water-cooled. It is an American engine, built at Rochester, N. Y.]

An entirely distinct type of engine, and one which has been devised
solely for the aeroplane, is the rotative--often miscalled the rotary,
which is totally different. The rotative type may be illustrated by the
Gnome motor. In this engine the seven cylinders turn around the shaft,
which is stationary. The propeller is fastened to the cylinders, and
revolves with them. This ingenious effect is produced by an offset
of the crank-shaft of half the stroke of the pistons, whose rods are
all connected with the crank-shaft. The entire system revolves around
the main shaft as a centre, the crank-shaft being also stationary.

[Illustration:

The famous Gnome motor; 50 horse-power, 7-cylinder, air-cooled;
of the rotative type; made in France. This illustration shows the
Gnome steel propeller.]

[Illustration: Sectional diagram of the 5-cylinder R-E-P motor; of the
“radiant” type.]

[Illustration: Sectional diagram of the 5-cylinder Bayard-Clement
motor; of the “star” type.]

Strictly speaking, the propeller is not a part of the motor of the
flying machine, but it is so intimately connected with it in the
utilization of the power created by the motor, that it will be treated
of briefly in this chapter.

The form of the air-propeller has passed through a long and varied
development, starting with that of the marine propeller, which was
found to be very inefficient in so loose a medium as air. On account
of this lack of density in the air, it was found necessary to act on
large masses of it at practically the same time to gain the thrust
needed to propel the aeroplane swiftly, and this led to increasing the
diameter of the propeller to secure action on a proportionally larger
area of air. The principle involved is simply the geometric rule that
the areas of circles are to each other as the squares of their radii.
Thus the surface of air acted on by two propellers, one of 6 feet
diameter and the other of 8 feet diameter, would be in the proportion
of 9 to 16; and as the central part of a propeller has practically no
thrust effect, the efficiency of the 8-foot propeller is nearly twice
that of the 6-foot propeller--other factors being equal. But these
other factors may be made to vary widely. For instance, the number of
revolutions may be increased for the smaller propeller, thus engaging
more air than the larger one at a lower speed; and, in practice, it is
possible to run a small propeller at a speed that would not be safe for
a large one. Another factor is the pitch of the propeller, which may
be described as the distance the hub of the propeller would advance in
one complete revolution if the blades moved in an unyielding medium,
as a section of the thread of an ordinary bolt moves in its nut. In
the yielding mass of the air the propeller advances only a part of its
pitch, in some cases not more than half. The difference between the
theoretical advance and the actual advance is called the “slip.”

[Illustration:

The Call Aviation Engine, of the opposed type; water-cooled. The
cylinders are large and few in number. The 100 horse-power engine
has but 4 cylinders, and weighs only 250 pounds. (The Gnome 100
horse-power engine has 14 cylinders.) This is an American engine,
built at Girard, Kansas.]

In practical work the number of blades which have been found to be most
effective is two. More blades than two seem to so disturb the air that
there is no hold for the propeller. In the case of slowly revolving
propellers, as in most airship mechanisms, four-bladed propellers are
used with good effect. But where the diameter of the propeller is
about 8 feet, and the number of revolutions about 1,200 per minute, the
two-bladed type is used almost exclusively.

The many differing forms of the blades of the propeller is evidence
that the manufacturers have not decided upon any definite shape as
being the best. Some have straight edges nearly or quite parallel;
others have the entering edge straight and the rear edge curved; in
others the entering edge is curved, and the rear edge straight; or
both edges may be curved. The majority of the wooden propellers are
of the third-mentioned type, and the curve is fashioned so that at
each section of its length the blade presents the same area of surface
in the same time. Hence the outer tip, travelling the fastest, is
narrower than the middle of the blade, and it is also much thinner to
lessen the centrifugal force acting upon it at great speeds. Near the
hub, however, where the travel is slowest, the constructional problem
demands that the blade contract in width and be made stout. In fact, it
becomes almost round in section.

Many propellers are made of metal, with tubular shanks and blades of
sheet metal, the latter either solid sheets or formed with a double
surface and hollow inside. Still others have a frame of metal with
blades of fabric put on loosely, so that it may adapt itself to the
pressure of the air in revolving. That great strength is requisite
becomes plain when it is considered that the speed of the tip of
a propeller blade often reaches seven miles a minute! And at this
velocity the centrifugal force excited--tending to tear the blades to
splinters--is prodigious.

Just as the curved surface of the planes of an aeroplane is more
effective than a flat surface in compressing the air beneath them,
and thus securing a firmer medium on which to glide, so the propeller
blades are curved laterally (across their width) to compress the air
behind them and thus secure a better hold. The advancing side of the
blade is formed with a still greater curve, to gain the advantage due
to the unexplained lift of the paradox aeroplane.

Where the propeller is built of wood it is made of several layers,
usually of different kinds of wood, with the grain running in slightly
different directions, and all carefully glued together into a solid
block. Ash, spruce, and mahogany, in alternating layers, are a favorite
combination. In some instances the wooden propeller is sheathed in
sheet aluminum; in others, it is well coated with glue which is
sandpapered down very smooth, then varnished, and then polished to the
highest lustre--to reduce the effect of the viscosity of the air to the
minimum.

[Illustration:

Two propellers, the one on the left of left-hand pitch; the
other of right-hand pitch. Both are thrusting propellers, and
are viewed from the rear. These fine models are of the laminated
type, and are of American make; the one to the left a Paragon
propeller made in Washington, D. C.; the other a Brauner
propeller made in New York.]

In order to get the best results, the propeller and the motor must be
suited to each other. Some motors which “race” with a propeller which
is slightly too small, work admirably with one a little heavier, or
with a longer diameter.

The question as to whether one propeller, or two, is the better
practice, has not been decided. The majority of aeroplanes have but
one. The Wright and the Cody machines have two. The certainty of
serious consequences to a machine having two, should one of them be
disabled, or even broken so as to reduce the area, seems to favor the
use of but one.

Chapter XI.

MODEL FLYING MACHINES.

Awakened popular interest--The workshop’s share--Needed
devices--Super-sensitive inventions--Unsolved problems--Tools
and materials--A model biplane--The propeller--The body--The
steering plane--The main planes--Assembling the parts--The
motive power--Flying the model--A monoplane model--Carving a
propeller--Many ideas illustrated--Clubs and competitions--Some
remarkable records.

It is related of Benjamin Franklin that when he went out with his
famous kite with the wire string, trying to collect electricity from
the thundercloud, he took a boy along to forestall the ridicule that he
knew would be meted out to him if he openly flew the kite himself.

Other scientific experimenters, notably those working upon the problem
of human flight in our own time, have encountered a similar condition
of the public mind, and have chosen to conduct their trials in secret
rather than to contend with the derision, criticism, and loss of
reputation which a sceptical world would have been quick to heap upon
them.

But such a complete revolution of thought has been experienced in these
latter days that groups of notable scientific men gravely flying kites,
or experimenting with carefully made models of flying machines, arouse
only the deepest interest, and their smallest discoveries are eagerly
seized upon by the daily press as news of the first importance.

So much remains to be learned in the field of aeronautics that no
builder and flyer of the little model aeroplanes can fail to gain
valuable information, if that is his intention. On the other hand, if
it be the sport of racing these model aeroplanes which appeals to him,
the instruction given in the pages following will be equally useful.

The earnest student of aviation is reminded that the progressive work
in this new art of flying is not being done altogether, nor even in
large part, by the daring operators who, with superb courage, are
performing such remarkable feats with the flying machines of the
present moment. Not one of them would claim that his machine is all
that could be desired. On the contrary, these intrepid men more than
any others are fully aware of the many and serious defects of the
apparatus they use for lack of better. The scientific student in his
workshop, patiently experimenting with his models, and working to
prove or disprove untested theories, is doubtless doing an invaluable
part in bringing about the sort of flying which will be more truly
profitable to humanity in general, though less spectacular.

[Illustration: A model flying machine built and flown by Louis Paulhan,
the noted aviator, at a prize contest for models in France. The design
is after Langley’s model, with tandem monoplane surfaces placed at a
dihedral angle.]

One of the greatest needs of the present machines is an automatic
balancer which shall supersede the concentrated attention which the
operator is now compelled to exercise in order to keep his machine
right side up. The discovery of the principle upon which such a
balancer must be built is undoubtedly within the reach of the builder
and flyer of models. It has been asserted by an eminent scientific
experimenter in things aeronautic that “we cannot hope to make a
sensitive apparatus quick enough to take advantage of the rising
currents of the air,” etc. With due respect to the publicly expressed
opinion of this investigator, it is well to reassure ourselves against
so pessimistic an outlook by remembering that the construction of just
such supersensitive apparatus is a task to which man has frequently
applied his intellectual powers with signal success. Witness the
photomicroscope, which records faithfully an enlarged view of
objects too minute to be even visible to the human eye; the aneroid
barometer, so sensitive that it will indicate the difference in level
between the table and the floor; the thermostat, which regulates the
temperature of the water flowing in the domestic heating system with a
delicacy impossible to the most highly constituted human organism; the
seismograph, detecting, recording, and almost locating earth tremors
originating thousands of miles away; the automatic fire sprinkler;
the safety-valve; the recording thermometer and other meteorological
instruments; and last, if not of least importance, the common
alarm-clock. And these are but a few of the contrivances with which
man does by blind mechanism that which is impossible to his sentient
determination.

Even if the nervous system could be schooled into endurance of the
wear and tear of consciously balancing an aeroplane for many hours, it
is still imperative that the task be not left to the exertion of human
wits, but controlled by self-acting devices responding instantly to
unforeseen conditions as they occur.

[Illustration: Diagram showing turbulent air currents produced when a
flat plane is forced through the air at a large angle of incidence in
the direction A-B.]

[Illustration: Diagram showing smoothly flowing air currents caused by
correctly shaped plane at proper angle of incidence.]

Some of the problems of which the model-builder may find the solution
are: whether large screws revolving slowly, or small screws revolving
rapidly, are the more effective; how many blades a propeller should
have, and their most effective shape; what is the “perfect” material
for the planes (Maxim found that with a smooth wooden plane he could
lift 2½ times the weight that could be lifted with the best made
fabric-covered plane); whether the centre of gravity of the aeroplane
should be above or below the centre of lift, or should coincide with
it; new formulas for the correct expression of the lift in terms of the
velocity, and angle of inclination--the former formulas having been
proved erroneous by actual experience; how to take the best advantage
of the “tangential force” announced by Lilienthal, and reasserted by
Hargrave; and many others. And there is always the “paradox aeroplane”
to be explained--and when explained it will be no longer a paradox, but
will doubtless open the way to the most surprising advance in the art
of flying.

It is not assumed that every reader of this chapter will become a
studious experimenter, but it is unquestionably true that every
model-builder, in his effort to produce winning machines, will be more
than likely to discover some fact of value in the progress making
toward the ultimate establishment of the commercial navigation of the
air.

The tools and materials requisite for the building of model aeroplanes
are few and inexpensive. For the tools--a small hammer; a small iron
“block” plane; a fine-cut half-round file; a pair of round-nose pliers;
three twist drills (as used for drilling metals), the largest 1/16 inch
diameter, and two smaller sizes, with an adjustable brad-awl handle
to hold them; a sharp pocket knife; and, if practicable, a small hand
vise. The vise may be dispensed with, and common brad-awls may take the
place of the drills, if necessary.

For the first-described model--the simplest--the following materials
are needed: some thin whitewood, 1/16 inch thick (as prepared for
fret-sawing); some spruce sticks, ¼ inch square (sky-rocket sticks are
good); a sheet of heavy glazed paper; a bottle of liquid glue; some of
the smallest (in diameter) brass screws, ¼ to ½ inch long; some brass
wire, 1/20 inch in diameter; 100 inches of square rubber (elastic)
“cord,” such as is used on return-balls, but 1/16 inch square; and a
few strips of draughtsman’s tracing cloth.

[Illustration:

_A_, _B_, blank from which propeller is shaped; _P_, _P_, pencil
lines at centre of bend; _C_, _D_, sections of blade at points
opposite; _E_, _G_, propeller after twisting; _H_, view of
propeller endwise, showing outward twist of tips; also shaft.]

As the propeller is the most difficult part to make, it is best
to begin with it. The flat blank is cut out of the whitewood, and
subjected to the action of steam issuing from the spout of an actively
boiling tea-kettle. The steam must be hot; mere vapor will not do the
work. When the strip has become pliable, the shaping is done by slowly
bending and twisting at the same time--perhaps “coaxing” would be the
better word, for it must be done gently and with patience--and the
steam must be playing on the wood all the time, first on one side of
the strip, then on the other, at the point where the fibres are being
bent. The utmost care should be taken to have the two blades bent
exactly alike--although, of course, with a contrary twist, the one to
the right and the other to the left, on each side of the centre. A
lead-pencil line across each blade at exactly the same distance from
the centre will serve to fix accurately the centre of the bend. If
two blocks are made with slots cut at the angle of 1 inch rise to 2¼
inches base, and nailed to the top of the work bench just far enough
apart to allow the tips of the screw to be slid into the slots, the
drying in perfect shape will be facilitated. The centre may be held to
a true upright by two other blocks, one on each side of the centre.
Some strips of whitewood may be so rigid that the steam will not make
them sufficiently supple. In this case it may be necessary to dip them
bodily into the boiling water, or even to leave them immersed for a few
minutes; afterward bending them in the hot steam. But a wetted stick
requires longer to dry and set in the screw shape. When the propeller
is thoroughly dry and set in proper form, it should be worked into the
finished shape with the half-round file, according to the several
sections shown beside the elevation for each part of the blade. The
two strengthening piece’s are then to be glued on at the centre of the
screw, and when thoroughly dry, worked down smoothly to shape. When
all is dry and hard it should be smoothed with the finest emery cloth
and given a coat of shellac varnish, which, in turn, may be rubbed to
a polish with rotten stone and oil.

It may be remarked, in passing, that this is a crude method of making a
propeller, and the result cannot be very good. It is given here because
it is the easiest way, and the propeller will work. A much better way
is described further on--and the better the propeller, the better any
model will fly. But for a novice, no time will be lost in making this
one, for the experience gained will enable the model-builder to do
better work with the second one than he could do without it.

For the aeroplane body we get out a straight spar of spruce, ¼ inch
square and 15½ inches long. At the front end of this--on the upper
side--is to be glued a small triangular piece of wood to serve as a
support for the forward or steering plane, tilting it up at the front
edge at the angle represented by a rise of 1 in 8. This block should
be shaped on its upper side to fit the curve of the under side of the
steering-plane, which will be screwed to it.

The steering-plane is cut according to plan, out of 1/16 inch
whitewood, planed down gradually to be at the ends about half that
thickness. This plane is to be steamed and bent to a curve (fore and
aft) as shown in the sectional view. The steam should play on the
_convex_ side of the bend while it is being shaped. To hold it in
proper form until it is set, blocks with curved slots may be used, or
it may be bound with thread to a moulding block of equal length formed
to the proper curve. When thoroughly dry it is to be smoothed with the
emery cloth, and a strip of tracing cloth--glossy face out--is to be
glued across each end, to prevent breaking in case of a fall. It is
then to be varnished with shellac, and polished, as directed for the
propeller. Indeed, it should be said once for all that every part of
the model should be as glossy as it is possible to make it without
adding to the weight, and that all “entering edges” (those which push
into and divide the air when in flight) should be as sharp as is
practicable with the material used.

The steering-plane is to be fastened in place by a single screw long
enough to pierce the plane and the supporting block, and enter the
spar. The hole for this screw (as for all screws used) should be
drilled carefully, to avoid the least splitting of the wood, and just
large enough to have the screw “bite” without forcing its way in. This
screw which holds the plane is to be screwed “home” but not too tight,
so that in case the flying model should strike upon it in falling,
the slender plane will swivel, and not break. It will be noticed that
while this screw passes through the centre of the plane sideways, it is
nearer to the forward edge than to the rear edge.

If the work has been accurate, the plane will balance if the spar
is supported--upon the finger, perhaps, as that is sensitive to any
tendency to tipping. If either wing is too heavy, restore the balance
by filing a little from the tip of that wing.

The main planes are next to be made. The lower deck of the biplane is
of the 1/16 inch whitewood, and the upper one is of the glazed paper
upon a skeleton framework of wood. The upright walls are of paper.
The wooden deck is to be bent into the proper curve with the aid of
steam, and when dry and set in form is to be finished and polished. The
frame for the upper deck is made of the thin whitewood, and is held
to its position by two diagonal struts of whitewood bent at the ends
with steam, and two straight upright struts or posts. It is better to
bend all cross-pieces into the curve of the plane with steam, but they
may be worked into the curve on the top side with plane and file, and
left flat on the lower side. The drawings show full details of the
construction, drawn accurately to scale.

It is best to glue all joints, and in addition to insert tiny screws,
where shown in the plans, at the time of gluing.

When all the wooden parts are in place the entire outline of the upper
plane and the upright walls is to be formed of silk thread carried
from point to point, and tied upon very small pins (such as are used
in rolls of ribbon at the stores) inserted in the wood. The glazed
paper is put on double, glossy side out. Cut the pieces twice as large
(and a trifle more) than is needed, and fold so that the smooth crease
comes to the front and the cut edges come together at the rear. The two
inner walls should be put in place first, so as to enclose the thread
front and back, and the post, between the two leaves of the folded
paper. Cutting the paper half an inch too long will give one fourth of
an inch to turn flat top and bottom to fasten to the upper and lower
decks respectively. The two outer walls and the upper deck may be cut
all in one piece, the under leaf being slit to pass on either side of
the inner walls. A bit of glue here and there will steady the parts to
their places. The cut edges at the rear of the deck and walls should
be caught together with a thin film of glue, so as to enclose the rear
threads.

[Illustration:

_A_, _B_, plan, and _C_, section, of steering plane; _H_, section
of lower main plane; _L_, wood skeleton of upper plane; _T_,
_T_, silk thread; _O_, _O_, posts; _J_, _J_, braces; _E_, rubber
strands; _D_, forward hook; _G_, shaft; _F_, thrust-block; _K_,
upper plane of paper; _M_, elevation of main planes, from the
rear.]

When the biplane is completed it is to be fastened securely to the spar
in such a position that it is accurately balanced--from side to side.
The spar may be laid on a table, and the biplane placed across it in
its approximate position. Then move the plane to one side until it tips
down, and mark the spot on the rear edge of the plane. Repeat this
operation toward the other side, and the centre between the two marks
should be accurately fastened over the centre line of the spar. Even
with the greatest care there may still be failure to balance exactly,
but a little work with a file on the heavy side, or a bit of chewing
gum stuck on the lighter side, will remedy the matter.

The body of the aeroplane being now built, it is in order to fit it
with propelling mechanism. The motive power to whirl the propeller we
have already prepared is to be the torsion, or twisting strain--in this
case the force of untwisting--of india rubber. When several strands
of pure rubber cord are twisted up tight, their elasticity tends to
untwist them with considerable force. The attachment for the rubber
strands at the front end of the spar is a sort of bracket made of the
brass wire. The ends of the wire are turned up just a little, and they
are set into little holes in the under side of the spar. Where the wire
turns downward to form the hook it is bound tightly to the spar with
silk thread. The hook-shaped tip is formed of the loop of the wire
doubled upon itself. The rear attachment of the rubber strands is a
loop upon the propeller shaft itself. As shown in the drawings, this
shaft is but a piece of the brass wire. On one end (the rear) an open
loop is formed, and into this is slipped the centre of the propeller.
The short end of the loop is then twisted around the longer shank--very
carefully, lest the wire cut into and destroy the propeller. Two turns
of the wire is enough, and then the tip of the twisted end should be
worked down flat with the file, to serve as a bearing for the propeller
against the thrust-block. This latter is made of a piece of sheet brass
(a bit of printers’ brass “rule” is just the thing) about 1/40 of an
inch thick. It should be ¼ of an inch wide except at the forward end,
where it is to be filed to a long point and bent up a trifle to enter
the wood of the spar. The rear end is bent down (not too sharply, lest
it break) to form the bearing for the propeller, a hole being drilled
through it for the propeller shaft, just large enough for the shaft to
turn freely in it. Another smaller hole is to be drilled for a little
screw to enter the rear end of the spar. Next pass the straight end
of the propeller shaft through the hole drilled for it, and with the
pliers form a round hook for the rear attachment of the rubber strands.
Screw the brass bearing into place, and for additional strength, wind
a binding of silk thread around it and the spar.

Tie the ends of the rubber cord together, divide it into ten even
strands, and pass the loops over the two hooks--and the machine is
ready for flight.

To wind up the rubber it will be necessary to turn the propeller in
the opposite direction to which it will move when the model is flying.
About 100 turns will be required. After it is wound, hold the machine
by the rear end of the spar, letting the propeller press against the
hand so it cannot unwind. Raise it slightly above the head, holding the
spar level, or inclined upward a little (as experience may dictate),
and launch the model by a gentle throw forward. If the work has been
well done it may fly from 150 to 200 feet.

Many experiments may be made with this machine. If it flies too high,
weight the front end of the spar; if too low, gliding downward from the
start, weight the rear end. A bit of chewing gum may be enough to cause
it to ride level and make a longer and prettier flight.

A very graceful model is that of the monoplane type illustrated in
the accompanying reproductions from photographs. The front view shows
the little machine just ready to take flight from a table. The view
from the rear is a snap-shot taken while it was actually flying. This
successful model was made by Harold S. Lynn, of Stamford, Conn. Before
discussing the details of construction, let us notice some peculiar
features shown by the photographs. The forward plane is arched; that
is, the tips of the plane bend slightly downward from the centre. On
the contrary, the two wings of the rear plane bend slightly upward from
the centre, making a dihedral angle, as it is called; that is, an angle
between two surfaces, as distinguished from an angle between two lines.
The toy wheels, Mr. Lynn says, are put on principally for “looks” but
they are also useful in permitting a start to be made from a table or
even from the floor, instead of the usual way of holding the model in
the hands and giving it a slight throw to get it started. However, the
wheels add to the weight, and the model will not fly quite so far with
them as without.

[Illustration: Front view of the Lynn model of the monoplane type,
about to take flight.]

The wood from which this model was made was taken from a bamboo
fish-pole, such as may be bought anywhere for a dime. The pole was
split up, and the suitable pieces whittled and planed down to the
proper sizes, as given in the plans. In putting the framework of the
planes together, it is well to notch very slightly each rib and spar
where they cross. Touch the joint with a bit of liquid glue, and wind
quickly with a few turns of sewing silk and tie tightly. This must be
done with delicacy, or the frames will be out of true. If the work is
done rapidly the glue will not set until all the ties on the plane are
finished. Another way is to touch the joinings with a drop of glue,
place the ribs in position on the spars, and lay a board carefully on
the work, leaving it there until all is dry, when the tying can be
done. It either case the joinings should be touched again with the
liquid glue and allowed to dry hard.

[Illustration: The Lynn model monoplane in flight, from below and from
the rear.]

The best material for covering these frames is the thinnest of China
silk. If this is too expensive, use the thinnest cambric. But the model
will not fly so far with the cambric covering. The material is cut
one-fourth of an inch too large on every side, and folded over, and the
fold glued down. Care should be taken that the frame is square and true
before the covering is glued on.

The motive power is produced by twisting up rubber tubing. Five and
three-quarter feet of pure rubber tubing are required. It is tied
together with silk so as to form a continuous ring. This is looped
over two screw-hooks of brass, one in the rear block and the other
constituting the shaft. This looped tubing is twisted by turning the
propeller backward about two hundred turns. As it untwists it turns the
propeller, which, in this model, is a “traction” screw, and pulls the
machine after it as it advances through the air.

[Illustration:

Details and plans of the Harold Lynn model monoplane. _W_, tail
block; _Y_, thrust-block; _S_, mounting of propeller showing
glass bead next the thrust-block, and one leather washer outside
the screw; _B_, glass bead; _C_, tin washer; _M_, _M_, tin lugs
holding axle of wheels.]

The propeller in this instance is formed from a piece of very thin
tin, such as is used for the tops of cans containing condensed milk.
Reference to the many illustrations throughout this book showing
propellers of flying machines will give one a very good idea of the
proper way to bend the blades. The mounting with the glass bead and the
two leather washers is shown in detail in the plans.

[Illustration:

Method of forming propeller of the laminated, or layer, type. The
layers of wood are glued,in the position shown and the blades
carved out according to the sections. Only one blade is shown
from the axle to the tip. This will make a right hand propeller.
]

The wheels are taken from a toy wagon, and a pair of tin ears will
serve as bearings for the axle.

The sport of flying model aeroplanes has led to the formation of many
clubs in this country as well as in Europe. Some of the mechanisms that
have been devised, and some of the contrivances to make the models
fly better and further, are illustrated in the drawings.

[Illustration:

At _A_ is shown a method of mounting the propeller with a glass
or china bead to reduce friction, and a brass corner to aid
in strengthening. _B_ shows a transmission of power by two
spur wheels and chain. _C_ is a device for using two rubber
twists acting on the two spur wheels _S_, _S_, which in turn
are connected with the propeller with a chain drive. _D_ shows
a launching apparatus for starting. _W_, the model; _V_, the
carriage; _F_, the trigger guard; _T_, trigger; _E_, elastic cord
for throwing the carriage forward to the stop _K_.]

Records have been made which seem marvellous when it is considered
that 200 feet is a very good flight for a model propelled by rubber.
For instance, at the contest of the Birmingham Aero Club (England) in
September, one of the contestants won the prize with a flight of 447
feet, lasting 48 seconds. The next best records for duration of flight
were 39 seconds and 38 seconds. A model aeroplane which is “guaranteed
to fly 1,000 feet,” according to the advertisement in an English
magazine, is offered for sale at $15.

The American record for length of flight is held by Mr. Frank Schober,
of New York, with a distance of 215 feet 6 inches. His model was of the
Langley type of tandem monoplane, and very highly finished. The problem
is largely one of adequate power without serious increase of weight.

Chapter XII.

THE GLIDER.

Aerial balancing--Practice necessary--Simplicity of the glider
Materials--Construction--Gliding--Feats with the Montgomery
glider--Noted experimenters--Glider clubs.

It is a matter of record that the Wright brothers spent the better part
of three years among the sand dunes of the North Carolina sea-coast
practising with gliders. In this way they acquired that confidence
while in the air which comes from intimate acquaintance with its
peculiarities, and which cannot be gained in any other way. It is true
that the Wrights were then developing not only themselves, but also
their gliders; but the latter work was done once for all. To develop
aviators, however, means the repeating of the same process for each
individual--just as each for himself must be taught to read. And the
glider is the “First Reader” in aeronautics.

The long trail of wrecks of costly aeroplanes marking the progress in
the art of flying marks also the lack of preparatory training, which
their owners either thought unnecessary, or hoped to escape by some
royal road less wearisome than persistent personal practice. But they
all paid dearly to discover that there is no royal road. Practice, more
practice, and still more practice--that is the secret of successful
aeroplane flight.

For this purpose the glider is much superior to the power-driven
aeroplane. There are no controls to learn, no mechanism to manipulate.
One simply launches into the air, and concentrates his efforts upon
balancing himself and the apparatus; not as two distinct bodies,
however, but as a united whole. When practice has made perfect the
ability to balance the glider instinctively, nine-tenths of the art of
flying an aeroplane has been achieved. Not only this, but a new sport
has been laid under contribution; one beside which coasting upon a
snow-clad hillside is a crude form of enjoyment.

Fortunately for the multitude, a glider is easily made, and its cost is
even less than that of a bicycle. A modest degree of skill with a few
carpenter’s tools, and a little “gumption” about odd jobs in general,
is all that is required of the glider builder.

[Illustration: A gliding slope with starting platform, erected for club
use.]

The frame of the glider is of wood, and spruce is recommended, as it
is stronger and tougher for its weight than other woods. It should be
of straight grain and free from knots; and as there is considerable
difference in the weight of spruce from different trees, it is well
to go over the pile in the lumber yard and pick out the lightest
boards. Have them planed down smooth on both sides, and to the required
thickness, at the mill--it will save much toilsome hand work. The
separate parts may also be sawed out at the mill, if one desires to
avoid this labor.

The lumber needed is as follows:

4 spars 20 ft. long, 1¼ in. wide, ¾ in. thick.
12 struts 3 ft. long, 1¼ in. wide, ¾ in. thick.
2 rudder bars 8 ft. long, ¾ in. wide, ½ in. thick.
12 posts 4 ft. long, 1½ in. wide, ½ in. thick.
41 ribs 4 ft. long, ½ in. wide, ½ in. thick.
2 arm rests 4 ft. long, 2 in. wide, 1 in. thick.
For rudder frame. 24 running ft., 1 in. wide, 1 in. thick.

If it be impossible to find clear spruce lumber 20 feet in length,
the spars may be built up by splicing two 10-foot sticks together.
For this purpose, the splicing stick should be as heavy as the single
spar--1¼ inches wide, and ¾ inches thick--and at least 4 feet long, and
be bolted fast to the spar with six ⅛ inch round-head carriage bolts
with washers of large bearing surface (that is, a small hole to fit the
bolt, and a large outer diameter) at both ends of the bolt, to prevent
crushing the wood. A layer of liquid glue brushed between will help to
make the joint firmer.

[Illustration: Otto Lilienthal in his single-plane glider. The swinging
forward of his feet tends to turn the glider toward the ground, and
increase its speed.]

Wherever a bolt is put in, a hole should be bored for it with a bit of
such size that the bolt will fit snug in the hole without straining the
grain of the wood.

The corners of the finished spar are to be rounded off on a large
curvature.

The ends of the struts are to be cut down on a slight slant of about
1/16 inch in the 1¼ inches that it laps under the spar--with the idea
of tipping the top of the spar forward so that the ribs will spring
naturally from it into the proper curve.

The ribs should be bent by steaming, and allowed to dry and set in
a form, or between blocks nailed upon the floor to the line of the
correct curve. They are then nailed to the frames, the front end first:
21 to the frame of the upper plane, and 20 to that of the lower plane,
omitting one at the centre, where the arm pieces will be placed.

Some builders tack the ribs lightly into place with small brads, and
screw clamps formed from sheet brass or aluminum over them. Others
use copper nails and clinch them over washers on the under side. Both
methods are shown in the plans, but the clamps are recommended as
giving greater stiffness, an essential feature.

At the front edge of the frames the ribs are fastened flush, and being
4 feet long and the frame but 3 feet wide, they project over the rear
about 1 foot.

The arm pieces are bolted to the spars of the lower frame 6½ inches
on each side of the centre, so as to allow a free space of 13 inches
between them. This opening may be made wider to accommodate a stouter
person.

[Illustration: Plan and details of Glider. The upper plane has a rib at
the centre instead of the two arm pieces.]

The posts are then put into place and bolted to the struts and the
spars, as shown, with ⅛inch bolts.

The entire structure is then to be braced diagonally with No. 16 piano
wire. The greatest care must be taken to have these diagonals pull just
taut, so that they shall not warp the lines of the frames out of true.
A crooked frame will not fly straight, and is a source of danger when
making a landing.

The frames are now to be covered. There is a special balloon cloth
made which is best for the purpose, but if that cannot be procured,
strong cambric muslin will answer. Thirty yards of goods 1 yard wide
will be required for the planes and the rudder. From the piece cut off
7 lengths for each plane, 4 feet 6 inches long. These are to be sewed
together, selvage to selvage, so as to make a sheet about 19 feet 6
inches long and 4 feet 6 inches wide. As this is to be tacked to the
frame, the edges must be double-hemmed to make them strong enough to
resist tearing out at the tacks. Half an inch is first folded down
all around; the fold is then turned back on the goods 2½ inches and
sewed. This hem is then folded back 1 inch upon itself, and again
stitched. Strips 3 inches wide and a little over 4 feet long are
folded “three-double” into a width of 1 inch, and sewed along both
edges to the large sheet exactly over where the ribs come. These are to
strengthen the fabric where the ribs press against it. Sixteen-ounce
tacks are used, being driven through a felt washer the size of a gun
wad at intervals of four inches. If felt is not readily obtainable,
common felt gun wads will do. The tacking is best begun at the middle
of the frame, having folded the cloth there to get the centre. Then
stretch smoothly out to the four corners and tack at each. It may
then be necessary to loosen the two centre tacks and place them over
again, to get rid of wrinkles. The next tacks to drive are at the ends
of the struts; then half-way between; and so on until all are in, and
the sheet is taut and smooth. For a finer finish, brass round-head
upholsterer’s nails may be used.

The rudder, so-called, is rather a tail, for it is not movable and does
not steer the glider. It does steady the machine, however, and is very
important in preserving the equilibrium when in flight. It is formed of
two small planes intersecting each other at right angles and covered
on both sides with the cloth, the sections covering the vertical part
being cut along the centre and hemmed on to the upper and lower faces
of the horizontal part. The frame for the vertical part is fastened to
the two rudder bars which stretch out toward the rear, one from the
upper plane, and the other from the lower. The whole construction is
steadied by guys of the piano wire.

[Illustration: Lilienthal in his double-deck glider. It proved
unmanageable and fell, causing his death. The hill is an artificial one
built for his own use in experimenting.]

All wooden parts should be smoothed off with sandpaper, and given a
coat of shellac varnish.

To make a glide, the machine is taken to an elevated point on a
slope, not far up to begin with. Lift the glider, get in between the
arm rests, and raise the apparatus until the rests are snug under the
arms. Run swiftly for a few yards and leap into the air, holding the
front of the planes slightly elevated. If the weight of the body is
in the right position, and the speed sufficient, the glider will take
the air and sail with you down the slope. It may be necessary at first
to have the help of two assistants, one at each end, to run with the
glider for a good start.

[Illustration: Diagram showing differing lines of flight as controlled
by changing the position of the body. The wind must be blowing against
the direction of flight; in the illustration this would be from left to
right.]

The position of the body on the arm rests can best be learned by a few
experiments. No two gliders are quite alike in this respect, and no
rule can be given. As to the requisite speed, it must be between 15 and
20 miles an hour; and as this speed is impossible to a man running, it
is gained by gliding against the wind, and thus adding the speed of the
wind to the speed of the runner. The Wrights selected the sand dunes of
the North Carolina coast for their glider experiments because of the
steady winds that blow in from the ocean, across the land. These winds
gave them the necessary speed of air upon which to sail their gliders.

The first flights attempted should be short, and as experience is
gained longer ones may be essayed.

Balancing the glider from side to side is accomplished by swaying the
lower part of the body like a pendulum, the weight to go toward the
side which has risen. Swinging the body forward on the arm rests will
cause the machine to dip the planes and glide more swiftly down the
incline. Holding the weight of the body back in the arm rests will
cause the machine to fly on a higher path and at a slower speed. This
is objectionable because the glider is more manageable at a higher
speed, and therefore safer. The tendency at first is to place the
weight too far back, with a consequent loss of velocity, and with that
a proportionate loss of control. The proper position of the body is
slightly forward of the mechanical centre of the machine.

The landing is accomplished by shoving the body backward, thus tilting
up the front of the plane. This checks the speed, and when the feet
touch the ground a little run, while holding back, will bring the glide
to an end. Landing should be practised often with brief glides until
skill is gained, for it is the most difficult operation in gliding.

After one becomes expert, longer flights may be secured by going to
higher points for the start. From an elevation of 300 feet a glide of
1,200 feet is possible.

[Illustration: Gliding with a Chanute three-decker. A start with two
assistants.]

While it is necessary to make glides against the wind, it is not wise
to attempt flights when the wind blows harder than 10 miles an hour.
While the flight may be successful, the landing may be disastrous.

The accomplished glider operator is in line for the aeroplane, and it
is safe to say that he will not be long without one. The skilful and
practised operator of a glider makes the very best aeroplane pilot.

This chapter would not be complete without an adequate reference to the
gliders devised by Professor Montgomery of Santa Clara, California.
These machines were sent up with ordinary hot-air balloons to various
heights, reaching 4,000 feet in some instances, when they were cut
loose and allowed to descend in a long glide, guided by their pilots.
The time of the descent from the highest altitude was twenty minutes,
during which the glider travelled about eight miles. The landing was
made accurately upon a designated spot, and so gently that there was no
perceptible jar. Two of the pilots turned completely over sideways, the
machine righting itself after the somersault and continuing its regular
course. Professor Montgomery has made the assertion that he can fasten
a bag of sand weighing 150 lbs. in the driver’s seat of his glider,
and send it up tied upside down under a balloon, and that after being
cut loose, the machine will right itself and come safely to the ground
without any steering.

Lilienthal in Germany, Pilcher in England, and Chanute in the United
States are names eminent in connection with the experiments with
gliders which have been productive of discoveries of the greatest
importance to the progress of aviation. The illustration of the Chanute
glider shows its peculiarities plainly enough to enable any one to
comprehend them.

The establishment of glider clubs in several parts of the country has
created a demand for ready-made machines, so that an enthusiast who
does not wish to build his own machine may purchase it ready made.

Chapter XIII.

BALLOONS.

First air vehicle--Principle of Archimedes--Why balloons
rise--Inflating gases--Early history--The Montgolfiers--The
hot-air balloon--Charles’s hydrogen balloon--Pilatre de
Rozier--The first aeronaut--The first balloon voyage--Blanchard
and Jeffries--Crossing the English Channel--First English
ascensions--Notable voyages--Recent long-distance journeys
and high ascensions--Prize balloon races--A fascinating
sport--Some impressions, adventures, and hardships--Accident
record--Increasing interest in ballooning.

The balloon, though the earliest and crudest means of getting up in the
air, has not become obsolete. It has been in existence practically in
its present general form for upwards of 500 years. Appliances have been
added from time to time, but the big gas envelope enclosing a volume of
some gas lighter than an equal volume of air, and the basket, or car,
suspended below it, remain as the typical form of aerial vehicle which
has not changed since it was first devised in times so remote as to lie
outside the boundaries of recorded history.

The common shape of the gas bag of a balloon is that of the sphere, or
sometimes of an inverted pear. It is allowed to rise and float away in
the air as the prevailing wind may carry it. Attempts have been made to
steer it in a desired direction, but they did not accomplish much until
the gas bag was made long horizontally, in proportion to its height and
width. With a drag-rope trailing behind on the ground from the rear end
of the gas bag, and sails on the forward end, it was possible to guide
the elongated balloon to some extent in a determined direction.

In explaining why a balloon rises in the air, it is customary to quote
the “principle of Archimedes,” discovered and formulated by that famous
philosopher centuries before the Christian era. Briefly stated, it is
this: Every body immersed in a fluid is acted upon by a force pressing
upward, which is equal to the weight of the amount of the fluid
displaced by the immersed body.

It remained for Sir Isaac Newton to explain the principle of Archimedes
(by the discovery of the law of gravitation), and to show that the
reason why the immersed body is apparently pushed upward, is that the
displaced fluid is attracted downward. In the case of a submerged
bag of a gas lighter than air, the amount of force acting on the
surrounding air is greater than that acting on the gas, and the latter
is simply crowded out of the way by the descending air, and forced up
to a higher level where its lighter bulk is balanced by the gravity
acting upon it.

The fluid in which the balloon is immersed is the air. The force
with which the air crowds down around and under the balloon is its
weight--weight being the measure of the attraction which gravity exerts
upon any substance.

The weight of air at a temperature of 32° Fahr., at the normal
barometer pressure at the sea-level (29.92 inches of mercury), is
0.0807 lbs. per cubic foot. The gas used to fill a balloon must
therefore weigh less than this, bulk for bulk, in order to be crowded
upward by the heavier air--and thus exert its “lifting power,” as it is
commonly called.

In practice, two gases have been used for inflating balloons--hydrogen,
and illuminating gas, made ordinarily from coal, and called “coal gas.”
Hydrogen is the lightest substance known; that is, it is attracted less
by gravity than any other known substance, in proportion to its bulk.

[Illustration: One of the earliest attempts to steer a spherical
balloon by retarding its speed with the drag-rope, and adjusting the
sail to the passing wind.]

A cubic foot of hydrogen weighs but 0.0056 lbs., and it will
therefore be pushed upward in air by the difference in weight, or
0.0751 lbs. per cubic foot. A cubic foot of coal gas weighs about
0.0400 lbs., and is crowded upward in air with a force of 0.0407 lbs.

[Illustration:

Apparatus to illustrate the principle of Archimedes. At the left,
the small solid glass ball and large hollow glass sphere are
balanced in the free air. When the balance is moved under the
bell-glass of the air pump (at the right), and the air exhausted,
the large sphere drops, showing that its previous balance was due
to the upward pressure of the air, greater because of its larger
bulk.]

It is readily seen that a very large bulk of hydrogen must be used
if any considerable weight is to be lifted. For to the weight of the
gas must be added the weight of the containing bag, the car, and the
network supporting it, the ballast, instruments, and passengers, and
there must still be enough more to afford elevating power sufficient to
raise the entire load to the desired level.

Let us assume that we have a balloon with a volume of 20,000 cubic
feet, which weighs with its appurtenances 500 pounds. The hydrogen
it would contain would weigh about 112 pounds, and the weight of
the air it would displace would be about 1,620 pounds. The total
available lifting power would be about 1,000 pounds. If a long-distance
journey is to be undertaken at a comparatively low level, this will
be sufficient to carry the necessary ballast, and a few passengers.
If, however, it is intended to rise to a great height, the problem
is different. The weight of the air, and consequently its lifting
pressure, decreases as we go upwards. If the balloon has not been
entirely filled, the gas will expand as the pressure is reduced in the
higher altitude. This has the effect of carrying the balloon higher.
Heating of the contained gas by the sun will also cause a rise. On
the other hand, the diffusion of the gas through the envelope into
the air, and the penetration of air into the gas bag will produce a
mixture heavier than hydrogen, and will cause the balloon to descend.
The extreme cold of the upper air has the same effect, as it tends to
condense to a smaller bulk the gas in the balloon. To check a descent
the load carried by the gas must be lightened by throwing out some of
the ballast, which is carried simply for this purpose. Finally a level
is reached where equilibrium is established, and above which it is
impossible to rise.

The earliest recorded ascent of a balloon is credited to the Chinese,
on the occasion of the coronation of the Emperor Fo-Kien at Pekin in
the year 1306. If this may be called historical, it gives evidence also
that it speedily became a lost art. The next really historic record
belongs in the latter part of the seventeenth century, when Cyrano de
Bergerac attempted to fly with the aid of bags of air attached to his
person, expecting them to be so expanded by the heat of the sun as to
rise with sufficient force to lift him. He did not succeed, but his
idea is plainly the forerunner of the hot-air balloon.

In the same century Francisco de Lana, who was clearly a man of
much intelligence and keen reasoning ability, having determined by
experiment that the atmosphere had weight, decided that he would be
able to rise into the air in a ship lifted by four metal spheres 20
feet in diameter from which the air had been exhausted. After several
failures he abandoned his efforts upon the religious grounds that the
Almighty doubtless did not approve such an overturning in the affairs
of mankind as would follow the attainment of the art of flying.

In 1757, Galen, a French monk, published a book, “The Art of Navigating
in the Air,” in which he advocated filling the body of the airship
with air secured at a great height above the sea-level, where it was
“a thousand times lighter than water.” He showed by mathematical
computations that the upward impulse of this air would be sufficient
to lift a heavy load. He planned in detail a great airship to carry
4,000,000 persons and several million packages of goods. Though it may
have accomplished nothing more, this book is believed to have been the
chief source of inspiration to the Montgolfiers.

The discovery of hydrogen by Cavendish in 1776 gave Dr. Black the
opportunity of suggesting that it be used to inflate a large bag and
so lift a heavy load into the air. Although he made no attempt to
construct such an apparatus, he afterward claimed that through this
suggestion he was entitled to be called the real inventor of the
balloon.

This is the meagre historical record preceding the achievements of
the brothers Stephen and Joseph Montgolfier, which marked distinctly
the beginning of practical aeronautics. Both of these men were highly
educated, and they were experienced workers in their father’s paper
factory. Joseph had made some parachute drops from the roof of his
house as early as 1771.

After many experiments with steam, smoke, and hydrogen gas, with which
they tried ineffectually to inflate large paper bags, they finally
succeeded with heated air, and on June 5, 1783, they sent up a great
paper hot-air balloon, 35 feet in diameter. It rose to a height of
1,000 feet, but soon came to earth again upon cooling. It appears that
the Montgolfiers were wholly ignorant of the fact that it was the
rarefying of the air by heating that caused their balloon to rise, and
they made no attempt to keep it hot while the balloon was in the air.

[Illustration: An early Montgolfier balloon.]

About the same time the French scientist, M. Charles, decided that
hydrogen gas would be better than hot air to inflate balloons. Finding
that this gas passed readily through paper, he used silk coated with a
varnish made by dissolving rubber. His balloon was 13 feet in diameter,
and weighed about 20 pounds. It was sent up from the Champ de Mars
on August 29, 1783, amidst the booming of cannon, in the presence of
300,000 spectators who assembled despite a heavy rain. It rose swiftly,
disappearing among the clouds, and soon burst from the expansion of
the gas in the higher and rarer atmosphere--no allowance having been
made for this unforeseen result. It fell in a rural region near Paris,
where it was totally destroyed by the inhabitants, who believed it to
be some hideous form of the devil.

The Montgolfiers had already come to Paris, and had constructed a
balloon of linen and paper. Before they had opportunity of sending it
up it was ruined by a rainstorm with a high wind. They immediately
built another of waterproof linen which made a successful ascension on
September 19, 1783, taking as passengers a sheep, a cock, and a duck.
The balloon came safely to earth after being up eight minutes--falling
in consequence of a leak in the air-bag near the top. The passengers
were examined with great interest. The sheep and the duck seemed in
the same excellent condition as when they went up, but the cock was
evidently ailing. A consultation of scientists was held and it was the
consensus of opinion that the fowl could not endure breathing the rarer
air of the high altitude. At this juncture some one discovered that the
cock had been trodden upon by the sheep, and the consultation closed
abruptly.

The Montgolfier brothers were loaded with honors, Stephen receiving the
larger portion; and the people of Paris entered enthusiastically into
the sport of making and flying small balloons of the Montgolfier type.

Stephen began work at once upon a larger balloon intended to carry
human passengers. It was fifty feet in diameter, and 85 feet high, with
a capacity of 100,000 cubic feet. The car for the passengers was swung
below from cords in the fashion that has since become so familiar.

In the meantime Pilatre de Rozier had constructed a balloon on the
hot-air principle, but with an arrangement to keep the air heated by a
continuous fire in a pan under the mouth of the balloon. He made the
first balloon ascent on record on October 15, 1783, rising to a height
of eighty feet, in the captive balloon. On November 21, in the same
year, de Rozier undertook an expedition in a free balloon with the
Marquis d’Arlandes as a companion. The experiment was to have been made
with two condemned criminals, but de Rozier and d’Arlandes succeeded in
obtaining the King’s permission to make the attempt, and in consequence
their names remain as those of the first aeronauts. They came safely
to the ground after a voyage lasting twenty-five minutes. After this,
ascensions speedily became a recognized sport, even for ladies.

The greatest altitude reached by these hot-air balloons was about 9,000
feet.

[Illustration: Pilatre de Rozier’s balloon.]

The great danger from fire, however, led to the closer consideration
of the hydrogen balloon of Professor Charles, who was building one of
30 feet diameter for the study of atmospheric phenomena. His mastery
of the subject is shown by the fact that his balloon was equipped with
almost every device afterward in use by the most experienced aeronauts.
He invented the valve at the top of the bag for allowing the escape
of gas in landing, the open neck to permit expansion, the network of
cords to support the car, the grapnel for anchoring, and the use of a
small pilot balloon to test the air-currents before the ascension. He
also devised a barometer by which he was able to measure the altitude
reached by the pressure of the atmosphere.

To provide the hydrogen gas required he used the chemical method of
pouring dilute sulphuric acid on iron filings. The process was so
slow that it took continuous action for three days and three nights
to secure the 14,000 cubic feet needed, but his balloon was finally
ready on December 1, 1783. One of the brothers Robert accompanied
Charles, and they travelled about 40 miles in a little less than 4
hours, alighting at Nesles. Here Robert landed and Charles continued
the voyage alone. Neglecting to take on board ballast to replace
the weight of M. Robert, Charles was carried to a great height, and
suffered severely from cold and the difficulty of breathing in the
highly rarefied air. He was obliged to open his gas valve and descend
after half an hour’s flight alone.

Blanchard, another French inventor, about this time constructed a
balloon with the intention of being the first to cross the English
Channel in the air. He took his balloon to Dover and with Dr. Jeffries,
an American, started on January 7, 1785. His balloon was leaky and he
had loaded it down with a lot of useless things in the way of oars,
provisions, and other things. All of this material and the ballast
had to be thrown overboard at the outset, and books and parts of the
balloon followed. Even their clothing had to be thrown over to keep the
balloon out of the sea, and at last, when Dr. Jeffries had determined
to jump out to enable his friend to reach the shore, an upward current
of wind caught them and with great difficulty they landed near Calais.
The feat was highly lauded and a monument in marble was erected on the
spot to perpetuate the record of the achievement.

De Rozier lost his life soon after in the effort to duplicate this trip
across the Channel with his combination hydrogen and hot-air balloon.
His idea seems to have been that he could preserve the buoyancy of
his double balloon by heating up the air balloon at intervals.
Unfortunately, the exuding of the hydrogen as the balloons rose formed
an explosive mixture with the air he was rising through, and it was
drawn to his furnace, and an explosion took place which blew the entire
apparatus into fragments at an altitude of over 1,000 feet.

[Illustration: Car and hoop of the Blanchard balloon, the first to
cross the English Channel.]

Count Zambeccari, an Italian, attempted to improve the de Rozier
method of firing a balloon by substituting a large alcohol lamp for
the wood fire. In the first two trial trips he fell into the sea, but
was rescued. On the third trip his balloon was swept into a tree, and
the overturned lamp set it on fire. To escape being burned, he threw
himself from the balloon and was killed by the fall.

The year before these feats on the Continent two notable balloon
ascensions had taken place in England. On August 27, 1784, an aeronaut
by the name of Tytler made the first balloon voyage within the
boundaries of Great Britain. His balloon was of linen and varnished,
and the record of his ascension indicates that he used hydrogen gas to
inflate it. He soared to a great height, and descended safely.

A few weeks later, the Italian aeronaut Lunardi made his first ascent
from London. The spectacle drew the King and his councillors from their
deliberations, and the balloon was watched until it disappeared. He
landed in Standon, near Ware, where a stone was set to record the
event. On October 12, he made his famous voyage from Edinburgh over the
Firth of Forth to Ceres; a distance of 46 miles in 35 minutes, or at
the rate of nearly 79 miles per hour; a speed rarely equalled by the
swiftest railroad trains.

From this time on balloons multiplied rapidly and the ascents were too
numerous for recording in these pages. The few which have been selected
for mention are notable either for the great distances traversed, or
for the speed with which the journeys were made. It should be borne
in mind that the fastest method of land travel in the early part of
the period covered was by stage coach; and the sailing ship was the
only means of crossing the water. It is no wonder that often the
people among whom the aeronauts landed on a balloon voyage refused to
believe the statements made as to the distance they had come, and the
marvellously short time it had taken. And even as compared with the
most rapid transit of the present day, the speeds attained in many
cases have never been equalled.

A remarkable English voyage was made in June, 1802, by the French
aeronaut Garnerin and Captain Snowdon. They ascended from Chelsea
Gardens and landed in Colchester, 60 miles distant, in 45 minutes: an
average speed of 80 miles an hour.

On December 16, 1804, Garnerin ascended from the square in front
of Notre Dame, Paris; passing over France and into Italy, sailing
above St. Peter’s at Rome, and the Vatican, and descending into Lake
Bracciano--a distance of 800 miles in 20 hours. This voyage was made
as a part of the coronation ceremonies of Napoleon I. The balloon was
afterwards hung up in a corridor of the Vatican.

On October 7, 1811, Sadler and Burcham voyaged from Birmingham to
Boston (England), 112 miles in 1 hour 40 minutes, a speed of 67 miles
per hour.

On November 17, 1836, Charles Green and Monck Mason started on a voyage
in the great balloon of the Vauxhall Gardens. It was pear-shaped, 60
feet high and 50 feet in diameter, and held 85,000 cubic feet of gas.
It was cut loose at half-past one in the afternoon, and in 3 hours had
reached the English Channel, and in 1 hour more had crossed it, and
was nearly over Calais. During the night it floated on over France
in pitchy darkness and such intense cold that the oil was frozen. In
the morning the aeronauts descended a few miles from Weilburg, in
the Duchy of Nassau, having travelled about 500 miles in 18 hours. At
that date, by the fastest coaches the trip would have consumed three
days. The balloon was rechristened “The Great Balloon of Nassau” by the
enthusiastic citizens of Weilburg.

[Illustration:

Prof. T. S. C. Lowe’s mammoth balloon “City of New York,” a
feature of the year 1860, in which it made many short voyages in
the vicinity of New York and Philadelphia.]

In 1849, M. Arban crossed the Alps in a balloon, starting at Marseilles
and landing at Turin--a distance of 400 miles in 8 hours. This
remarkable record for so long a distance at a high speed has rarely
been equalled. It was exceeded as to distance at the same speed by the
American aeronaut, John Wise, in 1859.

One of the most famous balloons of recent times was the “Geant,” built
by M. Nadar, in Paris, in 1853. The immense gas-bag was made of silk of
the finest quality costing at that time about $1.30 a yard, and being
made double, it required 22,000 yards. It had a capacity of 215,000
cubic feet of gas, and lifted 4½ tons. The car was 13 feet square,
and had an upper deck which was open. On its first ascent it carried
15 passengers, including M. Nadar as captain, and the brothers Godard
as lieutenants. A few weeks later this balloon was set free for a
long-distance journey, and 17 hours after it left Paris it landed at
Nieuburg in Hanover, having traversed 750 miles, a part of the time at
the speed of fully 90 miles per hour.

In July, 1859, John Wise, an American aeronaut, journeyed from St.
Louis, Mo., to Henderson, N. Y., a distance of 950 miles in 19 hours.
His average speed was 50 miles per hour. This record for duration at so
high a rate of speed has never been exceeded.

During the siege of Paris in 1870, seventy-three balloons were sent
out from that city carrying mail and dispatches. These were under
Government direction, and receive notice in a subsequent chapter
devoted to Military Aeronautics. One of these balloons is entitled to
mention among those famous for rapid journeys, having travelled to the
Zuyder Zee, a distance of 285 miles, in 3 hours--an average speed of 95
miles per hour. Another of these postal balloons belongs in the extreme
long-distance class, having come down in Norway nearly 1,000 miles from
Paris.

In July, 1897, the Arctic explorer Andrée started on his voyage to the
Pole. As some of his instruments have been recently recovered from
a wandering band of Esquimaux, it is believed that a record of his
voyage may yet be secured.

In the same year a balloon under the command of Godard ascended
at Leipsic, and after a wandering journey in an irregular course,
descended at Wilna. The distance travelled was estimated at 1,032
miles, but as balloon records are always based on the airline distance
between the places of ascent and descent, this record has not been
accepted as authoritative. The time consumed was 24¼ hours.

In 1899, Captain von Sigsfield, Captain Hildebrandt, and a companion
started from Berlin in a wind so strong that it prevented the taking
on of an adequate load of ballast. They rose into a gale, and in two
hours were over Breslau, having made the distance at a speed of 92
miles per hour. In the grasp of the storm they continued their swift
journey, landing finally high up in the snows of the Carpathian Alps in
Austria. They were arrested by the local authorities as Russian spies,
but succeeded in gaining their liberty by telegraphing to an official
more closely in touch with the aeronautics of the day.

In 1900 there were several balloon voyages notable for their length.
Jacques Balsan travelled from Vincennes to Dantzig, 757 miles; Count
de la Vaulx journeyed from Vincennes to Poland, 706 miles; Jacques
Faure from Vincennes to Mamlity, 753 miles. In a subsequent voyage
Jacques Balsan travelled from Vincennes to Rodom, in Russia, 843 miles,
in 27½ hours.

[Illustration: The balloon in which Coxwell and Glaisher made their
famous ascent of 29,000 feet.]

One of the longest balloon voyages on record in point of time consumed
is that of Dr. Wegener of the Observatory at Lindenberg, in 1905. He
remained in the air for 52¾ hours.

The longest voyage, as to distance, up to 1910, was that of Count de
La Vaulx and Count Castillon de Saint Victor in 1906, in the balloon
“Centaur.” This was a comparatively small balloon, having a capacity
of only 55,000 cubic feet of gas. The start was made from Vincennes on
October 9th, and the landing at Korostischeff, in Russia, on October
11th. The air-line distance travelled was 1,193 miles, in 35¾ hours.
The balloon “Centaur” was afterward purchased by the Aero Club of
America, and has made many voyages in this country.

The Federation Aeronautique Internationale, an association of the
aeronauts of all nations, was founded in 1905. One of its functions is
an annual balloon race for the International Challenge Cup, presented
to the association by James Gordon Bennett, to be an object for
competition until won three times by some one competing national club.

The first contest took place in September, 1906, and was won by the
American competitor, Lieut. Frank P. Lahm, with a voyage of 402 miles.

The second contest was from St. Louis, Mo., in 1907. There were three
German, two French, one English, and three American competitors. The
race was won by Oscar Erbslöh, one of the German competitors, with an
air-line voyage of 872¼ miles, landing at Bradley Beach, N. J. Alfred
Leblanc, now a prominent aviator, was second with a voyage of 867
miles, made in 44 hours. He also landed in New Jersey.

The third race started at Berlin in October, 1908, and was won by the
Swiss balloon “Helvetia,” piloted by Colonel Schaeck, which landed in
Norway after having been 74 hours in the air, and covering a journey of
750 miles. This broke the previous duration record made by Dr. Wegener
in 1905.

The fourth contest began on October 3, 1909, from Zurich, Switzerland.
There were seventeen competing balloons, and the race was won by E. W.
Mix, representing the Aero Club of America, with a voyage of 589 miles.

The fifth contest began at St. Louis, October 17, 1910. It was won by
Alan P. Hawley and Augustus Post, with the “America II.” They travelled
1,355 miles in 46 hours, making a new world’s record for distance.

Among other notable voyages may be mentioned that of the “Fielding”
in a race on July 4, 1908, from Chicago. The landing was made at West
Shefford, Quebec, the distance travelled being 895 miles.

In November of the same year A. E. Gaudron, Captain Maitland, and C. C.
Turner, made the longest voyage on record from England. They landed at
Mateki Derevni, in Russia, having travelled 1,117 miles in 31½ hours.
They were driven down to the ground by a severe snowstorm.

On December 31, 1908, M. Usuelli, in the balloon “Ruwenzori” left the
Italian lakes and passed over the Alps at a height of 14,750 feet,
landing in France. This feat was followed a few weeks later--February
9, 1909--by Oscar Erbslöh, who left St. Moritz with three passengers,
crossing the Alps at an altitude of 19,000 feet, and landed at Budapest
after a voyage of 33 hours. Many voyages over and among the Alps
have been made by Captain Spelterini, the Swiss aeronaut, and he has
secured some of the most remarkable photographs of the mountain scenery
in passing. In these voyages at such great altitudes it is necessary
to carry cylinders of oxygen to provide a suitable air mixture for
breathing. In one of his recent voyages Captain Spelterini had the good
fortune to be carried almost over the summit of Mont Blanc. He ascended
with three passengers at Chamounix, and landed at Lake Maggiore seven
hours later, having reached the altitude of 18,700 feet, and travelled
93 miles.

[Illustration: Photograph of the Alps from a balloon by Captain
Spelterini.]

In the United States there were several balloon races during the year
1909, the most important being the St. Louis Centennial race, beginning
on October 4th. Ten balloons started. The race was won by S. von Phul,
who covered the distance of 550 miles in 40 hours 40 minutes. Clifford
B. Harmon and Augustus Post in the balloon “New York” made a new
duration record for America of 48 hours 26 minutes. They also reached
the highest altitude attained by an American balloon--24,200 feet.

On October 12th, in a race for the Lahm cup, A. Holland Forbes and Col.
Max Fleischman won. They left St. Louis, Mo., and landed 19 hours and
15 minutes later at Beach, Va., near Richmond, having travelled 697
miles.

In 1910, in the United States, a remarkable race, with thirteen
competitors, started at Indianapolis. This was the elimination race
for the International race on October 17th. It was won by Alan P.
Hawley and Augustus Post in the balloon “America II.” They crossed the
Alleghany Mountains at an elevation of about 20,000 feet, and landed
at Warrenton, Va., after being 44 hours 30 minutes in the air; and
descended only to escape being carried out over Chesapeake Bay.

In recent years the greatest height reached by a balloon was attained
by the Italian aeronauts Piacenza and Mina in the “Albatross,” on
August 9, 1909. They went up from Turin to the altitude of 30,350 feet.
The world’s height record rests with Professors Berson and Suring of
Berlin, who on July 31, 1901, reached 35,500 feet. The record of 37,000
feet claimed by Glaisher and Coxwell in their ascension on September 5,
1862, has been rejected as not authentic for several discrepancies in
their observations, and on the ground that their instruments were not
of the highest reliability. As they carried no oxygen, and reported
that for a time they were both unconscious, it is estimated that the
highest point they could have reached under the conditions was less
than 31,000 feet.

The greatest speed ever recorded for any balloon voyage was that
of Captain von Sigsfield and Dr. Linke in their fatal journey from
Berlin to Antwerp, during which the velocity of 125 miles per hour was
recorded.

Ballooning as a sport has a fascination all its own. There is much of
the spice of adventure in the fact that one’s destiny is quite unknown.
Floating with the wind, there is no consciousness of motion. Though
the wind may be travelling at great speed, the balloon seems to be
in a complete calm. A lady passenger, writing of a recent trip, has
thus described her experience:--“The world continues slowly to unroll
itself in ever-varying but ever-beautiful panorama--patchwork fields,
shimmering silver streaks, toy box churches and houses, and white roads
like the joints of a jig-saw puzzle. And presently cotton-wool billows
come creeping up, with purple shadows and fleecy outlines and prismatic
rainbow effects. Sometimes they invade the car, and shroud it for a
while in clinging warm white wreaths, and anon they fall below and
shut out the world with a glorious curtain, and we are all alone in
perfect silence, in perfect peace, and in a realm made for us alone.

“And so the happy, restful hours go smoothly by, until the earth has
had enough of it, and rising up more or less rapidly to invade our
solitude, hits the bottom of our basket, and we step out, or maybe roll
out, into every-day existence a hundred miles away.”

The perfect smoothness of motion, the absolute quiet, and the absence
of distracting apparatus combine to render balloon voyaging the most
delightful mode of transit from place to place. Some of the most
fascinating bits of descriptive writing are those of aeronauts. The
following quotation from the report of Capt. A. Hildebrandt, of the
balloon corps of the Prussian army, will show that although his
expeditions were wholly scientific, he was far from indifferent to the
sublimer influences of nature by which he was often surrounded.

In his account of the journey from Berlin to Markaryd, in Sweden, with
Professor Berson as a companion aeronaut, he says: “The view over Rügen
and the chalk cliffs of Stubbenkammer and Arkona was splendid: the
atmosphere was perfectly clear. On the horizon we could see the coasts
of Sweden and Denmark, looking almost like a thin mist; east and west
there was nothing but the open sea.

“About 3:15 the balloon was in the middle of the Baltic; right in the
distance we could just see Rügen and Sweden. The setting of the sun at
4 P.M. was a truly magnificent spectacle. At a height of 5,250 feet, in
a perfectly clear atmosphere, the effect was superb. The blaze of color
was dimly reflected in the east by streaks of a bluish-green. I have
seen sunsets over France at heights of 10,000 feet, with the Alps, the
Juras, and the Vosges Mountains in the distance; but this was quite as
fine.

“The sunsets seen by the mountaineer or the sailor are doubtless,
magnificent; but I hardly think the spectacle can be finer than that
spread out before the gaze of the balloonist. The impression is
increased by the absolute stillness which prevails; no sound of any
kind is heard.

[Illustration: Landscape as seen from a balloon at an altitude of 3,000
feet.]

“As soon as the sun went down, it was necessary to throw out some
ballast, owing to the decrease of temperature.... We reached the
Swedish coast about 5 o’clock, and passed over Trelleborg at a
height of 2,000 feet. The question then arose whether to land, or to
continue through the night. Although it was well past sunset, there
was sufficient light in consequence of the snow to see our way to
the ground, and to land quite easily.... However, we wanted to do more
meteorological work, and it was thought that there was still sufficient
ballast to take us up to a much greater height. We therefore proposed
to continue for another sixteen hours during the night, in spite of the
cold.... Malmö was therefore passed on the left, and the university
town of Lund on the right. After this the map was of no further use,
as it was quite dark and we had no lamp. The whole outlook was like a
transformation scene. Floods of light rose up from Trelleborg, Malmö,
Copenhagen, Landskrona, Lund, Elsinore, and Helsingborg, while the
little towns beneath our feet sparkled with many lights. We were now at
a height of more than 10,000 feet, and consequently all these places
were within sight. The glistening effect of the snow was heightened by
the blaze which poured from the lighthouses along the coasts of Sweden
and Denmark. The sight was as wonderful as that of the sunset, though
of a totally different nature.”

Captain Hildebrandt’s account of the end of this voyage illustrates the
spice of adventure which is likely to be encountered when the balloon
comes down in a strange country. It has its hint also of the hardships
for which the venturesome aeronaut has to be prepared. He says:--

“Sooner or later the balloon would have been at the mercy of the
waves. The valve was opened, and the balloon descended through the
thick clouds. We could see nothing, but the little jerks showed us
that the guide-rope was touching the ground. In a few seconds we saw
the ground, and learned that we were descending into a forest which
enclosed a number of small lakes. At once more ballast was thrown out,
and we skimmed along over the tops of the trees. Soon we crossed a big
lake, and saw a place that seemed suitable for a descent. The valve
was then opened, both of us gave a tug at the ripping cord, and after
a few bumps we found ourselves on the ground. We had come down in deep
snow on the side of a wood, about 14 miles from the railway station at
Markaryd.

[Illustration: Making a landing with the aid of bystanders to pull down
upon the trail-rope and a holding rope.]

“We packed up our instruments, and began to look out for a cottage;
but this is not always an easy task in the dead of night in a foreign
country. However, in a quarter of an hour we found a farm, and
succeeded in rousing the inmates. A much more difficult job was to
influence them to open their front door to two men who talked some
sort of double Dutch, and who suddenly appeared at a farmyard miles
off the highway in the middle of the night and demanded admittance.
Berson can talk in six languages, but unfortunately Swedish is not one
of them. He begged in the most humble way for shelter ... and at the
end of three-quarters of an hour the farmer opened the door. We showed
him some pictures of a balloon we had with us, and then they began
to understand the situation. We were then received with truly Swedish
hospitality, and provided with supper. They even proposed to let us
have their beds; but this we naturally declined with many thanks....
The yard contained hens, pigs, cows, and sheep; but an empty corner
was found, which was well packed with straw, and served as a couch for
our tired limbs. We covered ourselves with our great-coats, and tried
to sleep. But the temperature was 10° Fahr., and as the place was only
an outhouse of boards roughly nailed together, and the wind whistling
through the cracks and crevices, we were not sorry when the daylight
came.”

Lest the possibility of accident to travellers by balloon be judged
greater than it really is, it may be well to state that records
collected in Germany in 1906 showed that in 2,061 ascents in which
7,570 persons participated, only 36 were injured--or but 1 out of 210.
Since that time, while the balloon itself has remained practically
unchanged, better knowledge of atmospheric conditions has aided in
creating an even more favorable record for recent years.

That the day of ordinary ballooning has not been dimmed by the advent
of the airship and the aeroplane is evidenced by the recently made
estimate that not less than 800 spherical balloons are in constant
use almost daily in one part or another of Christendom. And it seems
entirely reasonable to predict that with a better comprehension of the
movements of air-currents--to which special knowledge the scientific
world is now applying its investigations as never before--they will
come a great increase of interest in simple ballooning as a recreation.

Chapter XIV.

BALLOONS: THE DIRIGIBLE.

Elongation of
gas-bag--Brisson--Meusnier--Air-ballonnets--Scott--Giffard--Haenlein--Tissandier--Renard
and Krebs--Schwartz--Santos-Dumont--Von
Zeppelin--Roze--Severo--Bradsky-Leboun--The Lebaudy
dirigible--Zeppelin II--Parseval I--Unequal wind
pressures--Zeppelin III--Nulli Secundus--La
Patrie--Ville-de-Paris--Zeppelin IV--Gross I--Parseval
II--Clement-Bayard I--Ricardoni’s airship--Gross II--The
new Zeppelin II--La Republique--The German fleet of
dirigibles--Parseval V--The Deutschland--The Erbslöh--Gross
III--Zeppelin VI--The America--Clement-Bayard III--The Capazza
lenticular dirigible.

The dirigible balloon, or airship, is built on the same general
principles as the ordinary balloon--that is, with the envelope to
contain the lifting gas, the car to carry the load, and the suspending
cordage--but to this is added some form of propelling power to enable
it to make headway against the wind, and a rudder for steering it.

Almost from the very beginning of ballooning, some method of directing
the balloon to a pre-determined goal had been sought by inventors.
Drifting at the fickle pleasure of the prevailing wind did not accord
with man’s desire for authority and control.

The first step in this direction was the change from the spherical
form of the gas-bag to an elongated shape, the round form having an
inclination to turn round and round in the air while floating, and
having no bow-and-stern structure upon which steering devices could
operate. The first known proposal in this direction was made by
Brisson, a French scientist, who suggested building the gas-bag in the
shape of a horizontal cylinder with conical ends, its length to be
five or six times its diameter. His idea for its propulsion was the
employment of large-bladed oars, but he rightly doubted whether human
strength would prove sufficient to work these rapidly enough to give
independent motion to the airship.

About the same time another French inventor had actually built a
balloon with a gas-bag shaped like an egg and placed horizontally with
the blunt end foremost. The reduction in the resistance of the air to
this form was so marked that the elongated gas-bag quickly displaced
the former spherical shape. This balloon was held back from travelling
at the full speed of the wind by the clever device of a rope dragging
on the ground; and by a sail rigged so as to act on the wind which
blew past the retarded balloon, the navigator was able to steer it
within certain limits. It was the first dirigible balloon.

In the same year the brothers Robert, of Paris, built an airship for
the Duke of Chartres, under the direction of General Meusnier, a French
officer of engineers. It was cylindrical, with hemispherical ends, 52
feet long and 32 feet in diameter, and contained 30,000 cubic feet of
gas. The gas-bag was made double to prevent the escape of the hydrogen,
which had proved very troublesome in previous balloons, and it was
provided with a spherical air balloon inside of the gas-bag, which
device was expected to preserve the form of the balloon unchanged by
expanding or contracting, according to the rising or falling of the
airship. When the ascension was made on July 6, 1784, the air-balloon
stuck fast in the neck of the gas-bag, and so prevented the escape of
gas as the hydrogen expanded in the increasing altitude. The gas-bag
would have burst had not the Duke drawn his sword and slashed a vent
for the imprisoned gas. The airship came safely to earth.

It was General Meusnier who first suggested the interior ballonnet of
air to preserve the tense outline of the form of the airship, and the
elliptical form for the gas-bag was another of his inventions. In the
building of the airship of the Duke de Chartres he made the further
suggestion that the space between the two envelopes be filled with
air, and so connected with the air-pumps that it could be inflated
or deflated at will. For the motive power he designed three screw
propellers of one blade each, to be turned unceasingly by a crew of
eighty men.

Meusnier was killed in battle in 1793, and aeronautics lost its most
able developer at that era.

[Illustration: The Scott airship, showing the forward “pocket”
partially drawn in.]

In 1789, Baron Scott, an officer in the French army, devised a
fish-shaped airship with two outside balloon-shaped “pockets” which
could be forcibly drawn into the body of the airship to increase its
density, and thus cause its descent.

It began to be realized that no adequate power existed by which
balloons could be propelled against even light winds to such a degree
that they were really controllable, and balloon ascensions came to
be merely an adjunct of the exhibit of the travelling showman. For
this reason the early part of the nineteenth century seems barren of
aeronautical incident as compared with the latter part of the preceding
century.

In 1848, Hugh Bell, an Englishman, built a cylindrical airship with
convex pointed ends. It was 55 feet long and 21 feet in diameter. It
had a keel-shaped framework of tubes to which the long narrow car was
attached, and there was a screw propeller on each side, to be worked by
hand, and a rudder to steer with. It failed to work.

In 1852, however, a new era opened for the airship. Henry Giffard, of
Paris, the inventor of the world-famed injector for steam boilers,
built an elliptical gas-bag with cigar-shaped ends, 144 feet long,
and 40 feet in diameter, having a cubic content of 88,000 cubic feet.
The car was suspended from a rod 66 feet long which hung from the
net covering the gas-bag. It was equipped with a 3-horse-power steam
engine which turned a two-bladed screw propeller 11 feet in diameter,
at the rate of 110 revolutions per minute. Coke was used for fuel.
The steering was done with a triangular rudder-sail. Upon trial on
September 24, 1852, the airship proved a success, travelling at the
rate of nearly 6 miles an hour.

[Illustration: The first Giffard dirigible.]

Giffard built a second airship in 1855, of a much more elongated
shape--235 feet long and 33 feet in diameter. He used the same engine
which propelled his first ship. After a successful trial trip, when
about to land, the gas-bag unaccountably turned up on end, allowing
the net and car to slide off, and, rising slightly in the air, burst.
Giffard and his companion escaped unhurt.

Giffard afterward built the large captive balloon for the London
Exhibition in 1868, and the still larger one for the Paris Exposition
in 1878. He designed a large airship to be fitted with two boilers and
a powerful steam-engine, but became blind, and died in 1882.

[Illustration: The Haenlein airship inflated with coal gas and driven
by a gas-engine.]

In 1865, Paul Haenlein devised a cigar-shaped airship to be inflated
with coal gas. It was to be propelled by a screw at the front to be
driven by a gas-engine drawing its fuel from the gas in the body of the
ship. An interior air-bag was to be expanded as the gas was consumed,
to keep the shape intact. A second propeller revolving horizontally was
intended to raise or lower the ship in the air.

It was not until 1872 that he finally secured the building of an
airship, at Vienna, after his plans. It was 164 feet long, and 30
feet in diameter. The form of the gas-bag was that described by the
keel of a ship rotated around the centre line of its deck as an axis.
The engine was of the Lenoir type, with four horizontal cylinders,
developing about 6 horse-power, and turned a propeller about 15 feet
in diameter at the rate of 40 revolutions per minute. The low lifting
power of the coal gas with which it was inflated caused it to float
quite near the ground. With a consumption of 250 cubic feet of gas per
hour, it travelled at a speed of ten miles an hour. The lack of funds
seems to have prevented further experiments with an invention which was
at least very promising.

[Illustration: Sketch of the De Lome airship.]

In the same year a dirigible balloon built by Dupuy de Lome for use by
the French Government during the siege of Paris, was given a trial. It
was driven by a screw propeller turned by eight men, and although it
was 118 feet long, and 49 feet in diameter, it made as good a speed
record as Giffard’s steam-driven airship--six miles an hour.

[Illustration: Car of the Tissandier dirigible; driven by electricity.]

In 1881, the brothers Albert and Gaston Tissandier exhibited at the
Electrical Exhibition in Paris a model of an electrically driven
airship, originally designed to establish communication with Paris
during the siege of the Franco-Prussian War. In 1883, the airship
built after this model was tried. It was 92 feet long, and 30 feet at
its largest diameter. The motive power was a Siemens motor run by 24
bichromate cells of 17 lbs. each. At full speed the motor made 180
revolutions per minute, developing 1½ horse-power. The pull was 26 lbs.
The propeller was 9 feet in diameter, and a speed of a little more than
6 miles an hour was attained.

[Illustration: Sketch of the Renard and Krebs airship _La France_,
driven by a storage battery.]

In 1884, two French army engineers, Renard and Krebs, built an airship,
the now historic _La France_, with the shape of a submarine torpedo. It
was 165 feet long and about 27 feet in diameter at the largest part. It
had a gas content of 66,000 cubic feet. A 9 horse-power Gramme electric
motor was installed, driven by a storage battery. This operated the
screw propeller 20 feet in diameter, which was placed at the forward
end of the long car. The trial was made on the 9th of August, and was
a complete success. The ship was sailed with the wind for about 2½
miles, and then turned about and made its way back against the wind
till it stood directly over its starting point, and was drawn down to
the ground by its anchor ropes. The trip of about 5 miles was made in
23 minutes. In seven voyages undertaken the airship was steered back
safely to its starting point five times.

This first airship which really deserved the name marked an era in the
development of this type of aircraft. In view of its complete success
it is astonishing that nothing further was done in this line in France
for fifteen years, when Santos-Dumont began his series of record-making
flights. Within this period, however, the gasoline motor had been
adapted to the needs of the automobile, and thus a new and light-weight
engine, suitable in every respect, had been placed within the reach of
aeronauts.

In the meantime, a new idea had been brought to the stage of actual
trial. In 1893, in St. Petersburg, David Schwartz built a rigid
airship, the gas receptacle of which was sheet aluminum. It was braced
by aluminum tubes, but while being inflated the interior work was so
badly broken that it was abandoned.

Schwartz made a second attempt in Berlin in 1897. The airship was
safely inflated, and managed to hold its position against a wind
blowing 17 miles an hour, but could not make headway against it. After
the gas had been withdrawn, and before it could be put under shelter,
a severe windstorm damaged it, and the mob of spectators speedily
demolished it in the craze for souvenirs of the occasion.

[Illustration: Wreck of the Schwartz aluminum airship, at Berlin, in
1897.]

[Illustration:

The type of the earlier Santos-Dumont dirigibles. This shape
showed a tendency to “buckle,” or double up in the middle like a
jackknife. To avoid this the later Santos-Dumonts were of much
larger proportional diameter amidships.]

In 1898, the young Brazilian, Santos-Dumont, came to Paris imbued with
aeronautic zeal, and determined to build a dirigible balloon that
would surpass the former achievements of Giffard and Renard, which he
felt confident were but hints of what might be accomplished by that
type of airship. He began the construction of the series of dirigible
balloons which eventually numbered 12, each successive one being an
improvement on the preceding. He made use of the air-bag suggested
by Meusnier for the balloon of the Duke of Chartres in 1784, although
in an original way, at first using a pneumatic pump to inflate it, and
later a rotatory fan. Neither prevented the gas-bag from “buckling” and
coming down with consequences more or less serious to the airship--but
Santos-Dumont himself always escaped injury. His own record of his
voyages in his book, _My Air-Ships_, gives a more detailed account
of his contrivances and inventions than can be permitted here. If
Santos-Dumont did not greatly surpass his predecessors, he is at least
to be credited with an enthusiasm which aroused the interest of the
whole world in the problems of aeronautics; and his later achievements
in the building and flying of aeroplanes give him a unique place in the
history of man’s conquest of the air.

[Illustration: Type of the later Santos-Dumont’s dirigibles.]

In 1900, Count von Zeppelin’s great airship, which had been building
for nearly two years, was ready for trial. It had the form of a prism
of 24 sides, with the ends arching to a blunt point. It was 420 feet
long, and 38 feet in diameter. The structure was rigid, of aluminum
lattice work, divided into 17 compartments, each of which had a
separate gas-bag shaped to fit its compartment. Over all was an outer
envelope of linen and silk treated with pegamoid. A triangular keel of
aluminum lattice strengthened the whole, and there were two cars of
aluminum attached to the keel. Each car held a 16 horse-power Daimler
gasoline motor, operating two four-bladed screw propellers which were
rigidly connected with the frame of the ship a little below the level
of its axis. A sliding weight was run to either end of the keel as
might be required to depress the head or tail, in order to rise or fall
in the air. The cars were in the shape of boats, and the ship was built
in a floating shed on the Lake of Constance near Friedrichshafen.
At the trial the airship was floated out on the lake, the car-boats
resting on the water. Several accidents happened, so that though the
ship got up into the air it could not be managed, and was brought down
to the water again without injury. In a second attempt a speed of 20
miles an hour was attained. The construction was found to be not strong
enough for the great length of the body, the envelope of the balloon
was not sufficiently gas tight, and the engines were not powerful
enough. But few trips were made in it, and they were short. The Count
set himself to work to raise money to build another ship, which he did
five years later.

[Illustration: View of the Zeppelin I, with portion of the aluminum
shell and external fabric removed to show the internal framing and
separate balloons. In the distance is shown the great balloon shed.]

In 1901, an inventor named Roze built an airship in Colombo, having two
gas envelopes with the engines and car placed between them. He expected
to do away with the rolling and pitching of single airships by the
double form, but the ship did not work satisfactorily, ascending to
barely 50 feet.

In 1902, Augusto Severo, a Brazilian, arranged an airship with the
propelling screws at the axis of the gas-bag, one at each end of the
ship. Instead of a rudder, he provided two small propellers to work in
a vertical plane and swing the ship sideways. Soon after ascending
it was noticed that the propellers were not working properly, and a
few minutes later the car was seen to be in flames and the balloon
exploded. Severo and his companion Sache were killed, falling 1,300
feet.

[Illustration: Sketch of the Severo airship, showing arrangement of
the driving propellers on the axis of the gas-bag, and the steering
propellers.]

[Illustration:

End view of Severo’s airship, showing the longitudinal division
of the gas-bag to allow the driving shaft of the propellers to be
placed at the axis of the balloon.]

In the same year Baron Bradsky-Leboun built an airship with partitions
in the gas-bag which was just large enough to counterbalance the weight
of the ship and its operators. It was lifted or lowered by a propeller
working horizontally. Another propeller drove the ship forward. Through
some lack of stability the car turned over, throwing out the two
aeronauts, who fell 300 feet and were instantly killed.

[Illustration: The first Lebaudy airship.]

In 1902, a dirigible balloon was built for the brothers Lebaudy by the
engineer Juillot and the aeronaut Surcouf. The gas envelope was made
cigar-shaped and fastened rigidly to a rigid elliptical keel-shaped
floor 70 feet long and 19 feet wide, made of steel tubes--the object
being to prevent rolling and pitching. It was provided with both
horizontal and vertical rudders. A 35 horse-power Daimler-Mercedes
motor was used to turn two twin-bladed screws, each of 9 feet in
diameter. Between the 25th of October, 1902, and the 21st of November,
1903, 33 experimental voyages were made, the longest being 61 miles in
2 hours and 46 minutes; 38.7 miles in 1 hour and 41 minutes; 23 miles
in 1 hour and 36 minutes.

[Illustration: Framing of the floor and keel of the Lebaudy airship.]

In 1904 this ship was rebuilt. It was lengthened to 190 feet and the
rear end rounded off. Its capacity was increased to 94,000 cubic feet,
and a new covering of the yellow calico which had worked so well on the
first model was used on the new one. It was coated with rubber both on
the outside and inside. The interior air-bag was increased in size to
17,650 cubic feet, and partitioned into three compartments. During 1904
and 1905 30 voyages were made, carrying in all 195 passengers.

[Illustration: The car and propellers of the Lebaudy airship.]

The success of this airship led to a series of trials under the
direction of the French army, and in all of these trials it proved
satisfactory. After the 76th successful voyage it was retired for the
winter of 1905-6.

In November, 1905, the rebuilt Zeppelin airship was put upon trial.
While superior to the first one, it met with serious accident, and was
completely wrecked by a windstorm in January, 1906.

In May, 1906, Major von Parseval’s non-rigid airship passed through
its first trials successfully. This airship may be packed into small
compass for transportation, and is especially adapted for military
use. In plan it is slightly different from previous types, having
two air-bags, one in each end of the envelope, and the front end is
hemispherical instead of pointed.

As the airship is designed to force its way through the air, instead
of floating placidly in it, it is evident that it must have a certain
tenseness of outline in order to retain its shape, and resist being
doubled up by the resistance it encounters. It is estimated that the
average velocity of the wind at the elevation at which the airship
sails is 18 miles per hour. If the speed of the ship is to be 20
miles per hour, as related to stations on the ground, and if it is
obliged to sail against the wind, it is plain that the wind pressure
which it is compelled to meet is 38 miles per hour--a gale of no mean
proportions. When the large expanse of the great gas-bags is taken into
consideration, it is evident that ordinary balloon construction is not
sufficient.

Attempts have been made to meet the outside pressure from the wind and
air-resistance by producing mechanically a counter-pressure from the
inside. Air-bags are placed inside the cavity of the gas-bag, usually
one near each end of the airship, and these are inflated by pumping
air into them under pressure. In this way an outward pressure of as
much as 7 lbs. to the square foot may be produced, equivalent to the
resistance of air at a speed (either of the wind, or of the airship, or
of both combined) of 48 miles per hour. It is evident, however, that
the pressure upon the front end of an airship making headway against a
strong wind will be much greater than the pressure at the rear end, or
even than that amidships. It was this uneven pressure upon the outside
of the gas-bag that doubled up the first two airships of Santos-Dumont,
and led him to increase the proportional girth at the amidship section
in his later dirigibles. The great difficulty of adjusting these
varying pressures warrants the adherence of Count von Zeppelin to his
design with the rigid structure and metallic sheathing.

The loss of the second Zeppelin airship so discouraged its designer
that he decided to withdraw from further aeronautical work. But the
German Government prevailed on him to continue, and by October, 1906,
he had the Zeppelin III in the air. This airship was larger than
Zeppelin II in both length and diameter, and held 135,000 cubic feet
more of gas. The motive power was supplied by two gasoline motors,
each of 85 horse-power. The gas envelope had 16 sides, instead of 24,
as in the earlier ship. At its trial the Zeppelin III proved highly
successful. It made a trip of 69 miles, with 11 passengers, in 2¼
hours--a speed of about 30 miles an hour.

[Illustration: The Zeppelin III backing out of the floating shed at
Friedrichshafen. The illustration shows the added fin at the top, the
rudders, dipping planes, and balancing planes.]

The German Government now made an offer of $500,000 for an airship
which would remain continuously in the air for 24 hours, and be able to
land safely. Count von Zeppelin immediately began work upon his No. IV,
in the effort to meet these requirements, in the meantime continuing
trips with No. III. The most remarkable of these trips was made in
September, 1907, a journey of 211 miles in 8 hours.

In October, 1907, the English airship “Nulli Secundus” was given its
first trial. The gas envelope had been made of goldbeater’s skins,
which are considered impermeable to the contained gas, but are very
expensive. This airship was of the non-rigid type. It made the trip
from Aldershot to London, a distance of 50 miles, in 3½ hours--an
apparent speed of 14 miles per hour, lacking information as to the aid
or hindrance of the prevailing wind. Several other trials were made,
but with small success.

The offer of the German Government had stimulated other German builders
besides Count von Zeppelin, and on October 28, 1907, the Parseval I,
which had been improved, and the new Gross dirigible, competed for the
government prize, at Berlin. The Parseval kept afloat for 6½ hours, and
the Gross for 8¼ hours.

Meanwhile, in France, the Lebaudys had been building a new airship
which was named “La Patrie.” It was 197 feet long and 34 feet in
diameter. In a trial for altitude it was driven to an elevation of
4,300 feet. On November 23, 1907, the “Patrie” set out from Paris for
Verdun, a distance of 146 miles. The journey was made in 6¾ hours,
at an average speed of 25 miles per hour, and the fuel carried was
sufficient to have continued the journey 50 miles further. Soon after
reaching Verdun a severe gale tore the airship away from the regiment
of soldiers detailed to assist the anchors in holding it down, and it
disappeared into the clouds. It is known to have passed over England,
for parts of its machinery were picked up at several points, and some
days later the gas-bag was seen floating in the North Sea.

[Illustration: The “Ville-de-Paris” of M. de la Meurthe.]

Following close upon the ill-fated “Patrie” came the “Ville-de-Paris,”
a dirigible which had been built by Surcouf for M. Henri Deutsch de
la Meurthe, an eminent patron of aeronautic experiments. In size this
airship was almost identical with the lost “Patrie,” but it was quite
different in appearance. It did not have the flat framework at the
bottom of the gas envelope, but was entirely round in section, and the
long car was suspended below. At the rear the gas-bag was contracted
to a cylindrical form, and four groups of two ballonnets each were
attached to act as stabilizers. It was offered by M. de la Meurthe to
the French Government to take the place of the “Patrie” in the army
manœuvres at Verdun, and on January 15, 1908, made the trip thither
from Paris in about 7 hours. It was found that the ballonnets exerted
considerable drag upon the ship.

In June, 1908, the great “Zeppelin IV” was completed and given its
preliminary trials, and on July 1 it started on its first long journey.
Leaving Friedrichshafen, its route was along the northerly shore of
Lake Constance nearly to Schaffhausen, then southward to and around
Lake Lucerne, thence northward to Zurich, thence eastward to Lake
Constance, and to its shed at Friedrichshafen. The distance traversed
was 236 miles, and the time consumed 12 hours. This voyage without a
single mishap aroused the greatest enthusiasm among the German people.
After several short flights, during which the King of Württemberg, the
Queen, and some of the royal princes were passengers, the Zeppelin IV
set out on August 4 to win the Government reward by making the 24-hour
flight. Sailing eastward from Friedrichshafen it passed over Basle,
then turning northward it followed the valley of the Rhine, passing
over Strasburg and Mannheim, and had nearly reached Mayence when a
slight accident necessitated a landing. Repairs were made, and the
journey resumed after nightfall. Mayence was reached at 11 P. M., and
the return trip begun. When passing over Stuttgart, at 6 A. M., a leak
was discovered, and a landing was made at Echterdingen, a few miles
farther on. Here, while repairs were being made, a squall struck the
airship and bumped it heavily on the ground. Some gasoline was spilled,
in some unknown way, which caught fire, and in a few moments the great
balloon was totally destroyed. It had been in continuous flight 11
hours up to the time of the first landing, and altogether 20¾ hours,
and had travelled 258 miles.

The German people immediately started a public subscription to provide
Count von Zeppelin with the funds needed to build another airship,
and in a few days the sum of $1,500,000 was raised and turned over to
the unfortunate inventor. The “Zeppelin III” was taken in hand, and
lengthened, and more powerful engines installed.

The “Gross II” was ready to make its attempt for the Government prize
on September 11, 1908. It sailed from Tegel to Magdeburg and back to
Tegel, a distance of 176 miles, in 13 hours, without landing.

[Illustration: The Clement-Bayard dirigible entering its shed.]

Four days later the “Parseval II” made a trip between the same points
in 11½ hours, but cut the distance travelled down to 157 miles. In
October, the “Parseval II” was sent up for an altitude test, and rose
to a height of 5,000 feet above Tegel, hovering over the city for
upward of an hour.

During 1908, an airship designed by M. Clement, the noted motor-car
builder, was being constructed in France. It made its first voyage on
October 29, carrying seven passengers from Sartrouville to Paris and
back, at a speed of from 25 to 30 miles per hour. The illustration
gives a very good idea of the peculiar ballonnets attached to the rear
end of the gas envelope. These ballonnets open into the large gas-bag,
and are practically a part of it.

In Italy a remarkable dirigible has been built by Captain Ricaldoni,
for military purposes. It has the form of a fish, blunt forward, and
tapering straight away to the rear. It has a large finlike surface on
the under side of the gas-bag toward the rear. Its performances show
that its efficiency as compared with its motive power is larger than
any other dirigible in commission.

[Illustration: Engine of the Clement-Bayard dirigible; 7-cylinder; 55
horse-power; weighing only 155 pounds.]

In May, 1909, the rebuilt “Zeppelin III,” now rechristened “Zeppelin
II,” after many successful short flights was prepared for the
Government trial. On May 29, 1909, with a crew of six men, Count von
Zeppelin started from Friedrichshafen for Berlin, 360 miles away. The
great ship passed over Ulm, Nuremburg, Bayreuth, and Leipzig; and
here it encountered so strong a head wind from the north, that it was
decided to turn about at Bitterfeld and return to Friedrichshafen. The
distance travelled had been nearly 300 miles in 21 hours. The course
followed was quite irregular, and took the ship over Wurtzburg, and
by a wide detour to Heilbron and Stuttgart. The supply of gasoline
running low, it was decided to land at Goeppingen, where more could be
obtained. It was raining heavily, and through some mistake in steering,
or some sudden veering of the wind, the prow of the great dirigible
came into collision with a tree upon the hillside. The envelope was
badly torn, and a part of the aluminum inner structure wrecked.
However, the mechanics on board were able to make such repairs that
the ship was able to resume the voyage the next day, and made port
without further mishap. The vessel having been 38 hours in the air at
the time of the accident, so much of the Government’s stipulations
had been complied with. But it had not succeeded in landing safely.
Nevertheless it was accepted by the Government. The entire journey has
been variously estimated at from 680 to 900 miles, either figure being
a record for dirigibles.

[Illustration: Accident to the new “Zeppelin II” at Goeppingen. The
damage was repaired and the airship continued its voyage the next day.]

On August 4, the dirigible “Gross II” made a voyage from Berlin to
Apolda, and returned; a distance of 290 miles in 16 hours. This airship
also was accepted by the German Government and added to its fleet.

In August, the Zeppelin II was successfully sailed to Berlin, where
Count von Zeppelin was welcomed by an immense and enthusiastic
multitude of his countrymen, including the Emperor and the royal family.

On September 26, the new French dirigible, “La Republique,” built on
the model of the successful Lebaudy airships, met with an accident
while in the air. A blade of one of the propellers broke and slashed
into the envelope. The ship fell from a height of 6,000 feet, and its
crew of four men lost their lives.

[Illustration: View of the damaged Zeppelin from the front, showing the
tree against which it collided.]

On April 22, 1910, a fleet of German dirigibles, comprising the
“Zeppelin II,” the “Gross II,” and the “Parseval I,” sailed from
Cologne to Hamburg, where they were reviewed by Emperor William. A
strong wind having arisen, the “Gross II,” which is of the semi-rigid
type, was deflated, and shipped back to Cologne by rail. The non-rigid
“Parseval” made the return flight in safety. The rigid “Zeppelin II”
started on the return voyage, but was compelled to descend at Limburg,
where it was moored. The wind increasing, it was forced away, and
finally was driven to the ground at Weilburg and demolished.

In May, 1910, the “Parseval V,” the smallest dirigible so far
constructed, being but 90 feet in length, was put upon its trial trip.
It made a circular voyage of 80 miles in 4 hours.

For several months a great Zeppelin passenger dirigible had been
building by a stock company financed by German capital, under the
direction of the dauntless Count von Zeppelin. It was 490 feet long,
with a capacity of 666,900 cubic feet. A passenger cabin was built with
¼-inch mahogany veneer upon a framework of aluminum, the inside being
decorated with panels of rosewood inlaid with mother-of-pearl. The
seats were wicker chairs, and the window openings had no glass. It was
christened the “Deutschland.”

After many days waiting for propitious weather the first “air-liner”
set sail on June 22, 1910, from Friedrichshafen for Düsseldorf,
carrying 20 passengers who had paid $50 each for their passage. In
addition there were 13 other persons on board.

The start was made at three o’clock in the morning, and the course
laid was up the valley of the Rhine, as far as Cologne. Düsseldorf was
reached at three o’clock in the afternoon, the airline distance of 300
miles having been covered in 9 hours of actual sailing. From Mannheim
to Düsseldorf, favored by the wind, the great ship reached the speed of
50 miles per hour, for this part of the trip, outstripping the fastest
express trains which consume 6 hours in the winding track up the valley.

The next morning the “Deutschland” left Düsseldorf on an excursion
trip, carrying several ladies among its passengers. The voyage was in
every way a great success, and public enthusiasm was widespread.

On June 29, a test trip was decided upon. No passengers were taken,
but 19 newspaper correspondents were invited guests. The Count had
been warned of weather disturbances in the neighborhood, but he either
disregarded them or felt confidence in his craft. It was intended that
the voyage should last four hours, but the airship soon encountered a
storm, and after 6 hours of futile striving against it, the fuel gave
out. Caught in an upward draft, the “Deutschland” rose to an altitude
of over 5,000 feet, losing considerable gas, and then, entering a
rainstorm, was heavily laden with moisture. Suddenly, without definite
reason, it began to fall vertically, and in a few moments had crashed
into the tops of the trees of the Teutoberg forest. No one on board
received more than slight injury, and all alighted safely by means of
ladders. The “Deutschland” was a wreck, and was taken apart and shipped
back to Friedrichshafen.

On July 13, another giant passenger airship, designed by Oscar Erbslöh,
who won the international balloon race in 1907 by a voyage from St.
Louis to Asbury Park, met with fatal disaster. It was sailing near
Cologne at an altitude of about 2,500 feet when it burst, and Erbslöh
and his four companions were killed in the fall.

On July 28, the “Gross III” left Berlin with the object of beating
the long distance record for dirigibles. Soon after passing Gotha the
airship returned to that place, and abandoned the attempt. In 13 hours
a distance of 260 miles had been traversed.

Undismayed by the catastrophes which had destroyed his airships almost
as fast as he built them, Count von Zeppelin had his number VI ready
to sail on September 3. With a crew of seven and twelve passengers he
sailed from Baden to Heidelberg--53 miles in 65 minutes. It was put
into commission as an excursion craft, and made several successful
voyages. On September 14, as it was being placed in its shed at the
close of a journey, it took fire unaccountably, and was destroyed
together with the shed, a part of the framework only remaining.

On October 15, 1910, the Wellman dirigible “America” which had been
in preparation for many weeks, left Asbury Park in an attempt to
cross the Atlantic. Its balloon was 228 feet long, with a diameter
of 52 feet, containing 345,000 cubic feet of gas. The car was 156
feet in length, and was arranged as a tank in which 1,250 gallons of
gasoline were carried. A lifeboat was attached underneath the car.
There were two engines, each of 80 horse-power, and an auxiliary motor
of 10 horse-power. Sleeping quarters were provided for the crew of
six, and the balloon was fitted with a wireless telegraph system.
All went well until off the island of Nantucket, where strong north
winds were encountered, and the dirigible was swept southward toward
Bermuda. As an aid in keeping the airship at an elevation of about 200
feet above the sea, an enlarged trail-rope, called the equilibrator,
had been constructed of cans which were filled with gasoline. This
appendage weighed 1½ tons, and the lower part of it was expected to
float upon the sea. In practice it was found that the jarring of this
equilibrator, when the sea became rough, disarranged the machinery,
so that the propellers would not work, and the balloon was compelled
to drift with the wind. Toward evening of the second day a ship was
sighted, and the America’s crew were rescued. The airship floated away
in the gale, and was soon out of sight.

On October 16, a new Clement-Bayard dirigible, with seven men on board,
left Paris at 7.15 o’clock in the morning, and sailed for London. At
1 P. M. it circled St. Paul’s Cathedral, and landed at the hangar at
Wormwood Scrubbs a half hour later. The distance of 259 miles (airline)
was traversed at the rate of 41 miles per hour, and the journey
surpassed in speed any previous journey by any other form of conveyance.

[Illustration:

_Copyright by Pictorial News Company._

Wellman dirigible “America” starting for Europe, October 15, 1910.]

On November 5, 1910, the young Welsh aeronaut, Ernest T. Willows, who
sailed his small dirigible from Cardiff to London in August, made a
trip from London across the English Channel to Douai, France. This is
the third time within a month that the Channel had been crossed by
airships.

[Illustration:

Diagram of the Capazza dirigible from the side. _A A_,
stabilizing fins; _B_, air-ballonnet; _R_, rudder; _M M_, motors;
_FS_, forward propeller; _SS_, stern propeller.]

Toward the close of 1910, 52 dirigibles were in commission or in
process of construction. In the United States there were 7; in Belgium,
2; in England, 6; in France, 12; in Germany, 14; in Italy, 5; in
Russia, 1; in Spain, 1.

The new Capazza dirigible is a decided departure from all preceding
constructions, and may mark a new era in the navigation of the air.
Its gas envelope is shaped like a lens, or a lentil, and is arranged to
sail flatwise with the horizon, thus partaking of the aeroplane as well
as the balloon type. No definite facts concerning its achievements have
been published.

[Illustration: Capazza dirigible from the front. From above it is an
exact circle in outline.]

Chapter XV.

BALLOONS: HOW TO OPERATE.

Preliminary
inspection--Instruments--Accessories--Ballast--Inflating--Attaching
the car--The ascension--Controls--Landing--Some things to be
considered--After landing--Precautions.

The actual operation of a balloon is always entrusted to an experienced
pilot, or “captain” as he is often called, because he is in command,
and his authority must be recognized instantly whenever an order
is given. Nevertheless, it is often of great importance that every
passenger shall understand the details of managing the balloon in case
of need; and a well-informed passenger is greatly to be preferred to an
ignorant one.

It is ordinarily one of the duties of the captain to inspect the
balloon thoroughly; to see that there are no holes in the gas-bag, that
the valve is in perfect working order, and particularly that the valve
rope and the ripping cord are not tangled. He should also gather the
instruments and equipment to be carried.

The instruments are usually an aneroid barometer, and perhaps a mercury
barometer, a barograph (recording barometer), a psychrometer (recording
thermometer), a clock, a compass, and an outfit of maps of the country
over which it is possible that the balloon may float. Telegraph blanks,
railroad time tables, etc., may be found of great service. A camera
with a supply of plates will be indispensable almost, and the camera
should be provided with a yellow screen for photographing clouds or
distant objects.

The ballast should be inspected, to be sure that it is of dry sand,
free from stones; or if water is used for ballast, it should have the
proper admixture of glycerine to prevent freezing.

It is essential that the inflating be properly done, and the captain
should be competent to direct this process in detail, if necessary.
What is called the “circular method” is the simplest, and is entirely
satisfactory unless the balloon is being filled with pure hydrogen for
a very high ascent, in which case it will doubtless be in the hands of
experts.

When inflating with coal-gas, the supply is usually taken from a
large pipe adapted for the purpose. At a convenient distance from the
gas-main the ground is made smooth, and the ground cloths are spread
out and pegged down to keep them in place.

The folded balloon is laid out on the cloths with the neck opening
toward the gas-pipe. The balloon is then unfolded, and so disposed that
the valve will be uppermost, and in the centre of a circle embracing
the upper half of the sphere of the balloon, the opening of the neck
projecting a few inches beyond the rim of the circle. The hose from the
gas-main may then be connected with the socket in the neck.

[Illustration: Balloon laid out in the circular method, ready for
inflation. The valve is seen at the centre. The neck is at the right.]

Having made sure that the ripping cord and the valve rope are free from
each other, and properly connected with their active parts, and that
the valve is fastened in place, the net is laid over the whole, and
spread out symmetrically. A few bags of ballast are hooked into the net
around the circumference of the balloon as it lies, and the assistants
distributed around it. It should be the duty of one man to hold the
neck of the balloon, and not to leave it for any purpose whatever. The
gas may then be turned on, and, as the balloon fills, more bags of
ballast are hung symmetrically around the net; and all are continually
moved downward as the balloon rises.

Constant watching is necessary during the inflation, so that the
material of the balloon opens fully without creases, and the net
preserves its correct position. When the inflation is finished the hoop
and car are to be hooked in place. The car should be fitted up and hung
with an abundance of ballast. Disconnect the gas hose and tie the neck
of the balloon in such fashion that it may be opened with a pull of the
cord when the ascent begins.

The ballast is then transferred to the hoop, or ring, and the balloon
allowed to rise until this is clear of the ground. The car is then
moved underneath, and the ballast moved down from the ring into it. The
trail-rope should be made fast to the car directly under the ripping
panel, the object being to retard that side of the balloon in landing,
so that the gas may escape freely when the panel is torn open, and not
underneath the balloon, as would happen if the balloon came to earth
with the ripping panel underneath.

The balloon is now ready to start, and the captain and passengers
take their places in the car. The neck of the balloon is opened, and
a glance upward will determine if the valve rope hangs freely through
it. The lower end of this should be tied to one of the car ropes. The
cord to the ripping panel should be tied in a different place, and in
such fashion that no mistake can be made between them. The assistants
stand around the edge of the basket, holding it so that it shall not
rise until the word is given. The captain then adjusts the load of
ballast, throwing off sufficient to allow the balloon to pull upward
lightly against the men who are holding it. A little more ballast is
then thrown off, and the word given to let go. The trail-rope should be
in charge of some one who will see that it lifts freely from the ground.

The balloon rises into the air to an altitude where a bulk of the
higher and therefore lighter air equal to the bulk of the balloon has
exactly the same weight. This is ordinarily about 2,000 feet. If the
sun should be shining the gas in the balloon will be expanded by the
heat, and some of it will be forced out through the neck. This explains
the importance of the open neck. In some of the early ascensions no
such provision for the expansion of the gas was made, and the balloons
burst with disastrous consequences.

[Illustration: Inflating a military balloon. The net is being adjusted
smoothly as the balloon rises. The bags of ballast surround the balloon
ready to be attached as soon as the buoyancy of the gas lifts it from
the earth.]

When some of the gas has been driven out by the heat, there is less
_weight_ of gas in the balloon, though it occupies the same space. It
therefore has a tendency to rise still higher. On the other hand, if
it passes into a cloud, or the sun is otherwise obscured, the volume
of the gas will contract; it will become denser, and the balloon will
descend. To check the descent the load carried by the balloon must
be lightened, and this is accomplished by throwing out some ballast;
generally, a few handfuls is enough.

There is always more or less leakage of gas through the envelope as
well as from the neck, and this also lessens the lifting power. To
restore the balance, more ballast must be thrown out, and in this way
an approximate level is kept during the journey.

When the ballast is nearly exhausted it will be necessary to come down,
for a comfortable landing cannot be made without the use of ballast.
A good landing place having been selected, the valve is opened, and
the balloon brought down within a few yards of the ground. The ripping
cord is then pulled and ballast thrown out so that the basket will
touch as lightly as possible. Some aeronauts use a small anchor or
grapnel to assist in making a landing, but on a windy day, when the car
is liable to do some bumping before coming to rest, the grapnel often
makes matters much worse for the passengers by a series of holdings and
slippings, and sometimes causes a destructive strain upon the balloon.

In making an ascent with a balloon full of gas there is certain to be a
waste of gas as it expands. This expansion is due not only to the heat
of the sun, but also to the lighter pressure of the air in the upper
altitudes. It is therefore the custom with some aeronauts to ascend
with a partially filled balloon, allowing the expansion to completely
fill it. This process is particularly advised if a very high altitude
is sought. When it is desired to make a long voyage it is wise to make
the start at twilight, and so avoid the heat of the sun. The balloon
will then float along on an almost unchanging level without expenditure
of ballast. Rain and even the moisture from clouds will sometimes wet
the balloon so that it will cause a much greater loss of ballast than
would have been required to be thrown out to rise above the cloud or
storm. Such details in the handling of a balloon during a voyage will
demand the skilled judgment of the captain.

[Illustration: A balloon ready for ascent. Notice that the neck is
still tied.]

The trail-rope is a valuable adjunct when the balloon is travelling
near the ground. The longer the part of the trail-rope that is dragging
on the ground the less weight the balloon is carrying. And at night,
when it is impossible to tell the direction in which one is travelling
in any other way, the line of the trailing rope will show the direction
from which the wind is blowing, and hence the drift of the balloon.

The care of the balloon and its instruments upon landing falls upon
the captain, for he is not likely to find assistants at hand competent
to relieve him of any part of the necessary work. The car and the ring
are first detached. The ropes are laid out free and clear, and the
valve is unscrewed and taken off. The material of the balloon is folded
smoothly, gore by gore. The ballast bags are emptied. After all is
bundled up it should be packed in the car, the covering cloth bound on
with ropes, and definite instructions affixed for transportation to the
starting-point.

It is apparent that the whole of the gas is lost at the end of the
journey. The cost of this is the largest expense of ballooning. For a
small balloon of about 50,000 cubic feet, the coal-gas for inflating
will cost about $35 to $40. If hydrogen is used, it will cost probably
ten times as much.

In important voyages it is customary to send up pilot balloons, to
discover the direction of the wind currents at the different levels,
so that the level which promises the best may be selected before the
balloon leaves the ground. A study of the weather conditions throughout
the surrounding country is a wise precaution, and no start should
be made if a storm is imminent. The extent of control possible in
ballooning being so limited, all risks should be scrupulously avoided,
both before and during the voyage, and nothing left to haphazard.

Chapter XVI.

BALLOONS: HOW TO MAKE.

The fabrics used--Preliminary varnishing--Varnishes--Rubberized
fabrics--Pegamoid--Weight of varnish--Latitudes of the
balloon--Calculating gores--Laying out patterns and
cutting--Sewing--Varnishing--Drying--Oiling--The neck--The
valve--The net--The basket.

The making of a balloon is almost always placed in the hands of a
professional balloon-maker. But as the use of balloons increases, and
their owners multiply, it is becoming a matter of importance that the
most improved methods of making them should be known to the intending
purchaser, as well as to the amateur who wishes to construct his own
balloon.

The fabric of which the gas envelope is made may be either silk,
cotton (percale), or linen. It should be of a tight, diagonal weave,
of uniform and strong threads in both warp and woof, unbleached, and
without dressing, or finish. If it is colored, care should be exercised
that the dye is one that will not affect injuriously the strength or
texture of the fabric. Lightness in weight, and great strength (as
tested by tearing), are the essentials.

The finest German percale weighs about 2½ ounces per square yard;
Russian percale, 3⅓ ounces, and French percale, 3¾ounces, per square
yard. The white silk used in Russian military balloons weighs about
the same as German percale, but is very much stronger. Pongee silk is
a trifle heavier. The silk used for sounding balloons is much lighter,
weighing only a little over one ounce to the square yard.

Goldbeater’s skin and rubber have been used to some extent, but the
great cost of the former places it in reach only of governmental
departments, and the latter is of use only in small balloons for
scientific work--up to about 175 cubic feet capacity.

The fabric is first to be varnished, to fill up the pores and render
it gas-tight. For this purpose a thin linseed-oil varnish has been
commonly used. To 100 parts of pure linseed-oil are added 4 parts of
litharge and 1 part of umber, and the mixture is heated to about 350°
Fahr., for six or seven hours, and stirred constantly. After standing a
few days the clear part is drawn off for use. For the thicker varnish
used on later coats, the heat should be raised to 450° and kept at
about that temperature until it becomes thick. This operation is
attended with much danger of the oil taking fire, and should be done
only by an experienced varnish-maker.

The only advantages of the linseed-oil varnish are its ease of
application, and its cheapness. Its drawbacks are stickiness--requiring
continual examination of the balloon envelope, especially when the
deflated bag is stored away--its liability to spontaneous combustion,
particularly when the varnish is new, and its very slow drying
qualities, requiring a long wait between the coats.

Another varnish made by dissolving rubber in benzine, has been
largely used. It requires vulcanizing after application. It is
never sticky, and is always soft and pliable. However, the rubber
is liable to decomposition from the action of the violet ray of
light, and a balloon so varnished requires the protection of an outer
yellow covering--either of paint, or an additional yellow fabric.
Unfortunately, a single sheet of rubberized material is not gas-tight,
and it is necessary to make the envelope of two, or even three, layers
of the fabric, thus adding much to the weight.

The great gas-bags of the Zeppelin airships are varnished with
“Pegamoid,” a patent preparation the constituents of which are not
known. Its use by Count Zeppelin is the highest recommendation possible.

The weight of the varnish adds largely to the weight of the envelope.
French pongee silk after receiving its five coats of linseed-oil
varnish, weighs 8 ounces per square yard. A double bag of percale with
a layer of vulcanized rubber between, and a coating of rubber on the
inside, and painted yellow on the outside, will weigh 11 ounces per
square yard. Pegamoid material, which comes ready prepared, weighs but
about 4 ounces per square yard, but is much more costly.

In cutting out the gores of the envelope it is possible to waste fully
⅓ of the material unless the work is skilfully planned. Taking the
width of the chosen material as a basis, we must first deduct from ¾
of an inch to 1½ inches, in proportion to the size of the proposed
balloon, for a broad seam and the overlapping necessary. Dividing the
circumference at the largest diameter--the “equator” of the balloon--by
the remaining width of the fabric gives the number of gores required.
To obtain the breadth of each gore at the different “latitudes”
(supposing the globe of the balloon to be divided by parallels
similar to those of the earth) the following table is to be used; 0°
representing the equator, and 90° the apex of the balloon. The breadth
of the gore in inches at any latitude is the product of the decimal
opposite that latitude in the table by the original width of the fabric
in inches, thus allowing for seams.

[Illustration:

Finsterwalder’s method of cutting material for a spherical
balloon, by which over one-fourth of the material, usually
wasted in the common method, may be saved. It has the further
advantage of saving more than half of the usual sewing. The
balloon is considered as a spherical hexahedron (a six-surfaced
figure similar to a cube, but with curved sides and edges). The
circumference of the sphere divided by the width of the material
gives the unit of measurement. The dimensions of the imagined
hexahedron may then be determined from the calculated surface
and the cutting proceed according to the illustration above,
which shows five breadths to each of the six curved sides. The
illustration shows the seams of the balloon made after the
Finsterwalder method, when looking down upon it from above.]

TABLE FOR CALCULATING SHAPE OF GORES FOR SPHERICAL BALLOONS

0° 1.000
3° 0.998
6° 0.994
9° 0.988
12° 0.978
15° 0.966
18° 0.951
21° 0.934
24° 0.913
27° 0.891
30° 0.866
33° 0.839
36° 0.809
39° 0.777
42° 0.743
45° 0.707
48° 0.669
51° 0.629
54° 0.588
57° 0.544
60° 0.500
63° 0.454
66° 0.407
69° 0.358
72° 0.309
75° 0.259
78° 0.208
81° 0.156
84° 0.104
87° 0.052⅓

In practice, the shape of the gore is calculated by the above table,
and plotted out on a heavy pasteboard, generally in two sections for
convenience in handling. The board is cut to the plotted shape and used
as the pattern for every gore. In large establishments all the gores
are cut at once by a machine.

The raw edges are hemmed, and folded into one another to give a flat
seam, and are then sewn together “through and through,” in twos and
threes: afterward these sections are sewn together. Puckering must be
scrupulously avoided. In the case of rubberized material, the thread
holes should be smeared with rubber solution, and narrow strips of the
fabric cemented over the seams with the same substance.

Varnishing is the next process, the gores being treated in turn.
Half of the envelope is varnished first, and allowed to dry in a
well-ventilated place out of reach of the sun’s rays. The other half is
varnished when the first is dry. A framework which holds half of the
balloon in the shape of a bell is usually employed. In case of haste,
the balloon may be blown up with air, but this must be constantly
renewed to be of any service.

The first step in varnishing is to get one side (the outer, or the
inner) coated with a varnish thin enough to penetrate the material:
then turn the envelope the other side out and give that a coat of the
thin varnish. Next, after all is thoroughly dry, give the outer side
a coat of thick varnish closing all pores. When this is dry give the
inner side a similar coat. Finally, after drying thoroughly, give
both sides a coat of olive oil to prevent stickiness. The amount of
varnish required is, for the first coat 1½ times the weight of the
envelope, and for the second coat ½ the weight--of the thin varnish.
For the thick coat on the outer side ⅓ of the weight of the envelope,
and on the inner side about half as much. For the olive-oil coat, about
⅛ of the weight of the envelope will be needed. These figures are
approximate, some material requiring more, some less; and a wasteful
workman will cause a greater difference.

The neck of the balloon (also called the tail) is in form a cylindrical
tube of the fabric, sewn to an opening in the bottom of the balloon,
which has been strengthened by an extra ring of fabric to support it.
The lower end of the tube, called the mouth, is sewn to a wooden ring,
which stiffens it. The size of the neck is dependent upon the size of
the balloon. Its diameter is determined by finding the cube of one-half
the diameter of the balloon, and dividing it by 1,000. In length, the
neck should be at least four times its diameter.

The apex of the balloon envelope is fitted with a large valve to permit
the escape of gas when it is desired that the balloon shall descend.
The door of the valve is made to open inward into the envelope, and
is pulled open by the valve-cord which passes through the neck of the
balloon into the basket, or car. This valve is called the manœuvring
valve, and there are many different designs equally efficient. As they
may be had ready made, it is best for the amateur, unless he is a
machinist, to purchase one. The main point to see to is that the seat
of the valve is of soft pliable rubber, and that the door of the valve
presses a comparatively sharp edge of metal or wood so firmly upon the
seat as to indent it; and the springs of the valve should be strong
enough to hold it evenly to its place.

The making of the net of the balloon is another part of the work which
must be delegated to professionals. The material point is that the net
distributes the weight evenly over the surface of the upper hemisphere
of the envelope. The strength of the cordage is an item which must be
carefully tested. Different samples of the same material show such wide
variations in strength that nothing but an actual test will determine.
In general, however, it may be said that China-grass cordage is four
times as strong as hemp cordage, and silk cordage is ten times as
strong as hemp--for the same size cords.

The meshes of the net should be small, allowing the use of a small
cord. Large cords mean large knots, and these wear seriously upon the
balloon envelope, and are very likely to cause leaks. In large meshes,
also, the envelope puffs out between the cords and becomes somewhat
stretched, opening pores through which much gas is lost by diffusion.

The “star,” or centre of the net at the apex of the balloon, must be
fastened immovably to the rim of the valve. The suspension cords begin
at from 30° to 45° below the equator of the envelope, and are looped
through rings in what are called “goose-necks.” These allow a measure
of sliding motion to the cordage as the basket sways in the wind.

For protecting the net against rotting from frequent wetting, it is
recommended to saturate it thoroughly with a solution of acetate of
soda, drying immediately. Paraffin is sometimes used with more or less
success, but tarring should be avoided, as it materially weakens the
cordage. Oil or grease are even worse.

At the bottom of the net proper the few large cords into which the many
small cords have been merged are attached to the ring of the balloon.
This is either of steel or of several layers of wood well bound
together. The ropes supporting the basket are also fastened to this
ring, and from it hang the trail-rope and the holding ropes.

[Illustration:

Sketch showing the diamond mesh of balloon cordage and the method
of distributing the rings for the goose-necks; also the merging
of netting cords into the suspension cords which support the car.
The principal knots used in tying balloon nets are shown on the
right.]

The basket is also to be made by a professional, as upon its
workmanship may depend the lives of its occupants, though every other
feature of the balloon be faultless. It must be light, and still very
strong to carry its load and withstand severe bumping. It should be
from 3 to 4 feet deep, with a floor space of 4 feet by 5 feet. It is
usually made of willow and rattan woven substantially together. The
ropes supporting the car are passed through the bottom and woven in
with it. Buffers are woven on to the outside, and the inside is padded.
The seats are small baskets in which is stored the equipment. With
the completion of these the balloon is ready for its furnishings and
equipment, which come under the direction of the pilot, or captain, as
detailed in the preceding chapter.

Chapter XVII.

MILITARY AERONAUTICS.

The pioneer Meusnier--L’Entreprenant--First aerostiers--First
aerial warship--Bombardment by balloons--Free balloons
in observations--Ordering artillery from balloon--The
postal balloons of Paris--Compressed hydrogen--National
experiments--Bomb dropping--Falling explosives--Widespread
activity in gathering fleets--Controversies--Range of
vision--Reassuring outlook.

Almost from the beginning of success in traversing the air the great
possibilities of all forms of aircraft as aids in warfare have been
recognized by military authorities, and, as has so often been the case
with other inventions by non-military minds, the practically unlimited
funds at the disposal of national war departments have been available
for the development of the balloon at first, then the airship, and now
of the aeroplane.

The Montgolfiers had scarcely proved the possibility of rising into
the air, in 1783, before General Meusnier was busily engaged in
inventing improvements in their balloon with the expressed purpose of
making it of service to his army, and before he was killed in battle
he had secured the appointment of a commission to test the improved
balloon as to its efficiency in war. The report of the committee
being favorable, a balloon corps was formed in April, 1794, and the
balloon _L’Entreprenant_ was used during the battle of Fleurus, on
June 26th, by Meusnier’s successor, General Jourdan, less than a year
after Meusnier’s death. In 1795 this balloon was used in the battle of
Mayence. In both instances it was employed for observation only.

But when the French entered Moscow, they found there, and captured, a
balloon laden with 1,000 pounds of gunpowder which was intended to have
been used against them.

In 1796 two other balloons were used by the French army then in front
of Andernach and Ehrenbreitstein, and in 1798 the 1st Company of
Aerostiers was sent to Egypt, and operated at the battle of the Nile,
and later at Cairo. In the year following, this balloon corps was
disbanded.

In 1812 Russia secured the services of a German balloon builder named
Leppich, or Leppig, to build a war balloon. It had the form of a
fish, and was so large that the inflation required five days, but the
construction of the framework was faulty, and some important parts
gave way during inflation, and the airship never left the ground. As it
was intended that this balloon should be dirigible and supplied with
explosives, and take an active part in attacks on enemies, it may be
regarded as the first aerial warship.

[Illustration: A military dirigible making a tour of observation.]

In 1849, however, the first actual employment of the balloon in warfare
took place. Austria was engaged in the bombardment of Venice, and the
range of the besieging batteries was not great enough to permit shells
to be dropped into the city. The engineers formed a balloon detachment,
and made a number of Montgolfiers out of paper. These were of a size
sufficient to carry bombs weighing 30 pounds for half an hour before
coming down. These war balloons were taken to the windward side of
the city, and after a pilot balloon had been floated over the point
where the bombs were to fall, and the time consumed in the flight
ascertained, the fuses of the bombs were set for the same time, and
the war balloons were released. The actual damage done by the dropping
of these bombs was not great, but the moral effect upon the people of
the city was enormous. The balloon detachment changed its position as
the wind changed, and many shells were exploded in the heart of the
city, one of them in the market place. But the destruction wrought was
insignificant as compared with that usually resulting from cannonading.
As these little Montgolfiers were sent up unmanned, perhaps they are
not strictly entitled to be dignified by the name of war balloon, being
only what in this day would be called aerial bombs.

The next use of the balloon in warfare was by Napoleon III, in 1859.
He sent up Lieutenant Godard, formerly a manufacturer of balloons, and
Nadar, the balloonist, at Castiglione. It was a tour of observation
only, and Godard made the important discovery that the inhabitants were
gathering their flocks of domestic animals and choking the roads with
them, to oppose the advance of the French.

The first military use of balloons in the United States was at the time
of the Civil War. Within a month after the war broke out, Professor T.
S. C. Lowe, of Washington, put himself and his balloon at the command
of President Lincoln, and on June 18, 1861, he sent to the President a
telegram from the balloon--the first record of the kind in history.

After the defeat at Manassas, on July 24, 1861, Professor Lowe made a
free ascent, and discovered the true position of the Confederates, and
proved the falsity of rumors of their advance. The organization of
a regular balloon corps followed, and it was attached to McClellan’s
army, and used in reconnoitering before Yorktown. The balloons were
operated under heavy artillery fire, but were not injured.

[Illustration: A small captive military balloon fitted for observation.
A cylinder of compressed hydrogen to replace leakage is seen at F.]

On May 24th, for the first time in history, a general officer--in this
case, General Stoneman--directed the fire of artillery at a hidden
enemy from a balloon.

Later in the month balloons were used at Chickahominy, and again at
Fair Oaks and Richmond, being towed about by locomotives. On the
retreat from before Richmond, McClellan’s balloons and gas generators
were captured and destroyed.

In 1869, during the siege of a fort at Wakamatzu by the Imperial
Japanese troops, the besieged sent up a man-carrying kite. After making
observations, the officer ascended again with explosives, with which he
attempted to disperse the besieging army, but without success.

During the siege of Paris, in 1870, there were several experienced
balloonists shut up in the city, and the six balloons at hand were
quickly repaired and put to use by the army for carrying dispatches
and mail beyond the besieging lines. The first trips were made by
the professional aeronauts, but, as they could not return, there was
soon a scarcity of pilots. Sailors, and acrobats from the Hippodrome,
were pressed into the service, and before the siege was raised 64 of
these postal balloons had been dispatched. Fifty-seven out of the 64
landed safely on French territory, and fulfilled their mission; 4
were captured by the Germans; 1 floated to Norway; 1 was lost, with
its crew of two sailors, who faithfully dropped their dispatches on
the rocks near the Lizard as they were swept out to sea; and 1 landed
on the islet Hoedic, in the Atlantic. In all, 164 persons left Paris
in these balloons, always at night, and there were carried a total of
9 tons of dispatches and 3,000,000 letters. At first dogs were carried
to bring back replies, but none ever returned. Then carrier pigeons
were used successfully. Replies were set in type and printed. These
printed sheets were reduced by photography so that 16 folio pages of
print, containing 32,000 words, were reduced to a space of 2 inches
by 1¼ inches on the thinnest of gelatine film. Twenty of these films
were packed in a quill, and constituted the load for each pigeon. When
received in Paris, the films were enlarged by means of a magic lantern,
copied, and delivered to the persons addressed.

[Illustration:

Spherical canister of compressed hydrogen for use in inflating
military balloons. A large number of these canisters may be
tapped at the same time and the inflation proceed rapidly; a
large balloon being filled in two hours.]

In more recent times the French used balloons at Tonkin, in 1884; the
English, in Africa, in 1885; the Italians, in Abyssinia, in 1888; and
the United States, at Santiago, in 1898. During the Boer War, in 1900,
balloons were used by the British for directing artillery fire, and
one was shot to pieces by well-aimed Boer cannon. At Port Arthur, both
the Japanese and the Russians used balloons and man-carrying kites for
observation. The most recent use is that by Spain, in her campaign
against the Moors, in 1909.

The introduction of compressed hydrogen in compact cylinders, which are
easily transported, has simplified the problem of inflating balloons in
the field, and of restoring gas lost by leakage.

The advent of the dirigible has engaged the active attention of the
war departments of all the civilized nations, and experiments are
constantly progressing, in many instances in secret. It is a fact
at once significant and interesting, as marking the rapidity of the
march of improvement, that the German Government has lately refused
to buy the newest Zeppelin dirigible, on the ground that it is built
of aluminum, which is out of date since the discovery of its lighter
alloys.

[Illustration: The German military non-rigid dirigible Parseval II. It
survived the storm which wrecked the Zeppelin II in April, 1910, and
reached its shed at Cologne in safety.]

Practically all the armies are being provided with fleets of
aeroplanes, ostensibly for use in scouting. But there have been many
contests by aviators in “bomb-dropping” which have at least proved
that it is possible to drop explosives from an aeroplane with a great
degree of accuracy. The favorite target in these contests has been
the life-sized outline of a battleship.

[Illustration: The German military Zeppelin dirigible, which took part
in the manœuvres at Hamburg in April, 1910, and was wrecked by a high
wind at Weilburg on the return journey to Cologne.]

Glenn Curtiss, after his trip down the Hudson from Albany, declared
that he could have dropped a large enough torpedo upon the Poughkeepsie
Bridge to have wrecked it. His subsequent feats in dropping “bombs,”
represented by oranges, have given weight to his claims.

By some writers it is asserted that the successful navigation of the
air will guarantee universal peace; that war with aircraft will be so
destructive that the whole world will rise against its horrors. Against
a fleet of flying machines dropping explosives into the heart of great
cities there can be no adequate defence.

On the other hand, Mr. Hudson Maxim declares that the exploding of
the limited quantities of dynamite that can be carried on the present
types of aeroplanes, on the decks of warships would not do any vital
damage. He also says that many tons of dynamite might be exploded in
Madison Square, New York City, with no more serious results than the
blowing out of the windows of the adjacent buildings as the air within
rushed out to fill the void caused by the uprush of air heated by the
explosion.

[Illustration: The Lebaudy airship “La Patrie.” As compared with the
first Lebaudy, it shows the rounded stern with stabilizing planes, and
the long fin beneath, with rudder and dipping planes.]

As yet, the only experience that may be instanced is that of the
Russo-Japanese War, where cast-iron shells, weighing 448 lbs.,
containing 28 lbs. of powder, were fired from a high angle into Port
Arthur, and did but little damage.

In 1899 the Hague Conference passed a resolution prohibiting the use of
aircraft to discharge projectiles or explosives, and limited their use
in war to observation. Germany, France, and Italy withheld consent upon
the proposition.

In general, undefended places are regarded as exempt from attack by
bombardment of any kind.

Nevertheless, there are straws which show how the wind is blowing.
German citizens and clubs which purchase a type of airship approved
by the War Office of the German Empire are to receive a substantial
subsidy, with the understanding that in case of war the aircraft is to
be at the disposal of the Government. Under this plan it is expected
that the German Government will control a large fleet of ships of the
air without being obliged to own them.

And, in France, funds were raised recently, by popular subscription,
sufficient to provide the nation with a fleet of fourteen airships
(dirigibles) and thirty aeroplanes. These are already being built,
and it will not be long before France will have the largest air-fleet
afloat.

The results of the German manœuvres with a fleet of four dirigibles in
a night attack upon strong fortresses have been kept a profound secret,
as if of great value to the War Office.

In the United States the Signal Corps has been active in operating the
Baldwin dirigible and the Wright aeroplanes owned by the Government.
To the latter, wireless telegraphic apparatus has been attached and is
operated successfully when the machines are in flight. In addition,
the United States Aeronautical Reserve has been formed, with a large
membership of prominent amateur and professional aviators.

Some military experts, however, assert that the dirigible is hopelessly
outclassed for warfare by the aeroplane, which can operate in winds
in which the dirigible dare not venture, and can soar so high above
any altitude that the dirigible can reach as to easily destroy it.
Another argument used against the availability of the dirigible as a
war-vessel is, that if it were launched on a wind which carried it over
the enemy’s country, it might not be able to return at sufficient speed
to escape destruction by high-firing guns, even if its limited fuel
capacity did not force a landing.

Even the observation value of the aircraft is in some dispute. The
following table is quoted as giving the ranges possible to an observer
in the air:

Altitude in feet. Distance of horizon.

500 30 miles.
1,000 42 “
2,000 59 “
3,000 72 “
4,000 84 “
5,000 93 “

As a matter of fact, the moisture ordinarily in the air effectually
limits the range of both natural vision and the use of the camera for
photographing objects on the ground. The usual limit of practical range
of the best telescope is eight miles.

All things considered, however, it is to be expected that the
experimenting by army and navy officers all over the world will lead to
such improvement and invention in the art of navigating the air as will
develop its benevolent, rather than its malevolent, possibilities--“a
consummation devoutly to be wished.”

Chapter XVIII.

BIOGRAPHIES OF PROMINENT AERONAUTS.

The Wright Brothers--Santos-Dumont--Louis Bleriot--Gabriel
Voisin--Leon Delagrange--Henri Farman--Robert
Esnault-Pelterie--Count von Zeppelin--Glenn H. Curtiss--Charles
K. Hamilton--Hubert Latham--Alfred Leblanc--Claude
Grahame-White--Louis Paulhan--Clifford B. Harmon--Walter
Brookins--John B. Moisant--J. Armstrong Drexel--Ralph Johnstone.

On January 1, 1909, it would have been a brief task to write a few
biographical notes about the “prominent” aviators. At that date
there were but five who had made flights exceeding ten minutes in
duration--the Wright brothers, Farman, Delagrange, and Bleriot. At the
close of 1910 the roll of aviators who have distinguished themselves by
winning prizes or breaking previous records has increased to more than
100, and the number of qualified pilots of flying machines now numbers
over 300. The impossibility of giving even a mention of the notable
airmen in this chapter is apparent, and the few whose names have been
selected are those who have more recently in our own country come into
larger public notice, and those of the pioneers whose names will never
lose their first prominence.

THE WRIGHT BROTHERS.

The Wright Brothers have so systematically linked their individual
personalities in all their work, in private no less than in public,
that the brief life story to be told here is but one for them both. In
fact, until Wilbur went to France in 1908, and Orville to Washington,
the nearest approach to a separation is illustrated by a historic
remark of Wilbur’s to an acquaintance in Dayton, one afternoon:
“Orville flew 21 miles yesterday; I am going to beat that to-day.” And
he did--by 3 miles.

Their early life in their home town of Dayton, Ohio, was unmarked by
significant incident. They were interested in bicycles, and at length
went into the business of repairing and selling these machines.

Their attention seems to have been strongly turned to the subject of
human flight by the death of Lilienthal in August, 1896, at which time
the press published some of the results of his experiments. A magazine
article by Octave Chanute, himself an experimenter with gliders, led
to correspondence with him, and the Wrights began a series of similar
investigations with models of their own building.

By 1900 they had succeeded in flying a large glider by running with a
string, as with a kite, and in the following year they had made some
flights on their gliders, of which they had several of differing types.
For two years the Wrights studied and tested and disproved nearly every
formula laid down by scientific works for the relations of gravity to
air, and finally gave themselves up to discovering by actual trial
what the true conditions were, and to the improvement of their gliders
accordingly. Meanwhile they continued their constant personal practice
in the air.

The most of this experimental work was done at Kitty Hawk, N. C.; for
the reason that there the winds blow more uniformly than at any other
place in the United States, and the great sand dunes there gave the
Wrights the needed elevation from which to leap into the wind with
their gliders. Consequently, when at last they were ready to try a
machine driven by a motor, it was at this secluded spot that the first
flights ever made by man with a heavier-than-air machine took place. On
December 17, 1903, their first machine left the ground under its own
power, and remained in the air for twelve seconds. From this time on
progress was even slower than before, on account of the complications
added by the motive power; but by the time another year had passed they
were making flights which lasted five minutes, and had their machine in
such control that they could fly in a circle and make a safe landing
within a few feet of the spot designated.

[Illustration: Turpin, Taylor, Orville Wright, Wilbur Wright, Brookins,
and Johnstone discussing the merits of the Wright machine.]

On the 5th of October, 1905, Wilbur Wright made his historic flight
of 24 miles at Dayton, Ohio, beating the record of Orville, made the
day before, of 21 miles. The average speed of these flights was 38
miles an hour. No contention as to the priority of the device known
as wing-warping can ever set aside the fact that these long practical
flights were made more than a year before any other man had flown 500
feet, or had remained in the air half a minute, with a heavier-than-air
machine driven by power.

The Wrights are now at the head of one of the largest aeroplane
manufactories in the world, and devote the larger part of their time to
research work in the line of the navigation of the air.

ALBERTO SANTOS-DUMONT.

ALBERTO SANTOS-DUMONT was born in Brazil in 1877. When but a lad he
became intensely interested in aeronautics, having been aroused by
witnessing the ascension at a show of an ordinary hot-air balloon.
Within the next few years he had made several trips to Paris, and
in 1897 made his first ascent in a balloon with the balloon builder
Machuron, the partner of the famous Lachambre.

In 1898 he began the construction of his notable series of dirigibles,
which eventually reached twelve in number. With his No. 6 he won the
$20,000 prize offered by M. Deutsch (de la Meurthe) for the first trip
from the Paris Aero Club’s grounds to and around the Eiffel Tower in 30
minutes or less. The distance was nearly 7 miles. It is characteristic
of M. Santos-Dumont that he should give $15,000 of the prize to relieve
distress among the poor of Paris, and the remainder to his mechanicians
who had built the balloon.

His smallest dirigible was the No. 9, which held 7,770 cubic feet of
gas; the largest was the No. 10, which held 80,000 cubic feet.

In 1905, when Bleriot, Voisin, and their comrades were striving to
accomplish flight with machines heavier than air, Santos-Dumont turned
his genius upon the same problem, and on August 14, 1906, he made
his first flight with a cellular biplane driven by a 24 horse-power
motor. On November 13th of the same year he flew 720 feet with the same
machine. These were the first flights of heavier-than-air machines in
Europe, and the first public flights anywhere. Later he turned to the
monoplane type, and with “La Demoiselle” added new laurels to those
already won with his dirigibles.

LOUIS BLERIOT.

LOUIS BLERIOT, designer and builder of the celebrated Bleriot
monoplanes, and himself a pilot of the first rank, was born in Cambrai,
France, in 1872. He graduated from a noted technical school, and soon
attached himself to the group of young men--all under thirty years of
age--who were experimenting with gliders in the effort to fly. His
attempts at first were with the flapping-wing contrivances, but he soon
gave these up as a failure, and devoted his energy to the automobile
industry; and the excellent Bleriot acetylene headlight testifies to
his constructive ability in that field.

Attracted by the experiments of M. Ernest Archdeacon he joined his
following, and with Gabriel Voisin engaged in building gliders of the
biplane type. By 1907 he had turned wholly to the monoplane idea,
and in April of that year made his first leap into the air with a
power-driven monoplane. By September he had so improved his machine
that he was able to fly 600 feet, and in June, 1908, he broke the
record for monoplanes by flying nearly a mile. Again and again he beat
his own records, and at length the whole civilized world was thrilled
by his triumphant flight across the British Channel on July 25, 1909.

The Bleriot machines hold nearly all the speed records, and many of
those in other lines of achievement, and M. Bleriot enjoys the double
honor of being an eminently successful manufacturer as well as a
dauntless aviator of heroic rank.

GABRIEL VOISIN.

GABRIEL VOISIN, the elder of the two Voisin brothers, was born in
1879 at Belleville-sur-Saone, near the city of Lyons, France. He was
educated as an architect, but early became interested in aeronautics,
and engaged in gliding, stimulated by the achievements of Pilcher,
in England, and Captain Ferber, in his own country. He assisted M.
Archdeacon in his experiments on the Seine, often riding the gliders
which were towed by the swift motor boats.

In 1906 he associated himself with his brother in the business of
manufacturing biplane machines, and in March, 1907, he himself made
the first long flight with a power-driven machine in Europe. This
aeroplane was built for his friend Delagrange, and was one in which
the latter was soon breaking records and winning prizes. The second
machine was for Farman, who made the Voisin biplane famous by winning
the Deutsch-Archdeacon prize of $10,000 for making a flight of 1,093
yards in a circle.

The Voisin biplane is distinctive in structure, and is accounted one of
the leading aeroplanes of the present day.

LEON DELAGRANGE.

LEON DELAGRANGE was born at Orleans, France, in 1873. He entered
the School of Arts as a student in sculpture, about the same time
that Henri Farman went there to study painting, and Gabriel Voisin,
architecture. He exhibited at the Salon, and won several medals.
In 1905, he took up aeronautics, assisted at the experiments of M.
Archdeacon. His first aeroplane was built by Voisin, and he made his
first flight at Issy, March 14, 1907. Less than a month later--on April
11--he made a new record for duration of flight, remaining in the air
for 9 minutes and 15 seconds--twice as long as the previous record made
by Farman.

[Illustration: Leblanc, Bleriot, and Delagrange, (from left to right)
in aviation dress, standing in front of the Bleriot machine which
crossed the English Channel.]

At Rheims, in 1909, he appeared with a Bleriot monoplane, and continued
to fly with that type of machine until his death. At Doncaster,
England, he made the world record for speed up to that time, travelling
at the rate of 49.9 miles per hour. He was killed at Bordeaux, France,
in January, 1910, by the fall of his machine.

HENRI FARMAN.

HENRI FARMAN, justly regarded as the most prominent figure in the
aviation world today, was born in France in 1873. His father was an
Englishman.

While a mere boy he became locally famous as a bicycle racer, and later
achieved a wider fame as a fearless and skillful driver in automobile
races. In 1902 he won the Paris-Vienna race.

In September, 1907, he made his first attempt to fly, using the second
biplane built by his friend Gabriel Voisin, and in the following
year he won with it the Deutsch-Archdeacon prize of $10,000. He then
built a machine after his own ideas, which more resembles the Wright
machine than the Voisin, and with it he has won many prizes, and made
many world records. Demands for machines, and for teaching the art of
handling them, have poured in upon him, necessitating a continual
increase of manufacturing facilities until it may safely be said that
he has the largest plant for building flying machines in the world,
turning out the largest number of machines, and through his school for
aviators is instructing a larger number of pupils annually than any
other similar establishment.

ROBERT ESNAULT-PELTERIE.

ROBERT ESNAULT-PELTERIE was born in 1880, and educated in the city of
Paris. He early showed a mechanical turn of mind, and was interested
particularly in scientific studies. He became an enthusiast in matters
aeronautic, and devoted himself to the construction of gasoline engines
suitable for aviation purposes. After satisfying his ideal in this
direction with the now famous “R-E-P” motor, he designed a new type
of flying machine which is known as the “R-E-P monoplane.” His first
flights were made at Buc in October, 1907, and while they were short,
they proved the possibility of steering a flying machine so that it
would describe a curved line--at that time a considerable achievement
among European aviators. In April, 1908, he flew for ¾ of a mile, and
reached a height of 100 feet. This feat eclipsed all previous records
for monoplanes.

His fame, however, rests upon his motors, which are quite original in
design and construction.

COUNT FERDINAND VON ZEPPELIN.

COUNT FERDINAND VON ZEPPELIN was born in 1838, on the shores of the
Lake Constance, where his great airships have had their initial trials.

It is an interesting fact that Count von Zeppelin made his first
balloon ascension in a war-balloon attached to the army corps commanded
by his friend, Carl Schurz, during the Civil War.

It was only after years of absorbing study of all that human knowledge
could contribute that Count von Zeppelin decided upon the type of
dirigible which bears his name. Under the patronage of the King of
Würtemberg he began his first airship, having previously built an
immense floating shed, which, swinging by a cable, always had its doors
facing away from the wind.

The successful flights of the series of magnificent Zeppelin airships
have been marvellous in an age crowded with wonders. And the misfortune
which has followed close upon their superb achievements with complete
destruction would long ago have undone a man of less energy and courage
than the dauntless Count. It should be borne in mind, however, that
of the hundreds of passengers carried in his ships of the air, all
have come to land safely--a record that it would be difficult to match
with any other form of travel. The accidents which have destroyed the
Zeppelins have never happened in the air, excepting only the wrecking
of the _Deutschland_ by a thunderstorm.

The indefatigable Count is now constructing another airship with the
new alloy, electron, instead of aluminum. He estimates that 5,000
pounds’ weight can be saved in this way.

CAPTAIN THOMAS S. BALDWIN.

CAPTAIN THOMAS S. BALDWIN, balloonist and aviator, was born in
Mississippi in 1855. His first aeronautical experience was as a
parachute rider from a balloon in the air. He invented the parachute
he used, and received for it a gold medal from the Balloon Society
of Great Britain. Exhibiting this parachute, Captain Baldwin made an
extensive tour of the civilized world.

In 1892 he built his first airship, a combination of a balloon, a
screw propeller, and a bicycle, the last to furnish the motive power.
It was not until 1902, when be installed an automobile engine in his
airship, that he succeeded in making it sail. It was not yet dirigible,
however; but after two years of devising and experimenting, he sailed
away from Oakland, Cal., on August 2, 1904, against the wind, and
after a short voyage, turned and came back to his balloon-shed. From
this time on he made several successful dirigibles, and in 1908 he met
all the requirements of the United States Government for a military
dirigible, and sold to it the only dirigible it possesses.

He became interested in the experiments of Curtiss and McCurdy at
Hammondsport, in 1908, and aided in building the remarkable series of
biplanes with which record flights were made. The newer design, known
as the Baldwin biplane, is unique in the pivoted balancing plane set
upright above the upper plane, a device entirely distinct from the
warping or other manipulation of horizontal surfaces for the purpose of
restoring lateral balance.

GLENN HAMMOND CURTISS.

GLENN HAMMOND CURTISS was born at Hammondsport, N. Y., on the shore
of Lake Keuka, in 1878. From boyhood he was a competitor and winner
in all sorts of races where speed was the supreme test. By nature a
mechanic, he became noted for his ingenious contrivances in this line,
and built a series of extremely fast motor-cycles, with one of which he
made the record of one mile in 26⅖ seconds, which still stands as the
fastest mile ever made by man with any form of mechanism.

Through the purchasing of one of his light engines by Captain Baldwin
for his dirigible, Curtiss became interested in aeronautical matters,
and soon built a glider with which he sailed down from the Hammondsport
hills. The combination of his motor and the glider was the next step,
and on July 4, 1908, he flew 1½ miles with the _June Bug_, winning the
_Scientific American_ trophy.

Learning that the United States was not to be represented at the Rheims
meet in August, 1909, he hastily built a biplane and went there. He won
the first prize for the course of 30 kilometres (18.6 miles), second
prize for the course of 10 kilometres, the James Gordon Bennett cup,
and the tenth prize in the contest for distance. From Rheims he went to
Brescia, Italy, and there won the first prize for speed. In all these
contests he was matching his biplane against monoplanes which were
acknowledged to be a faster type than the biplane.

On May 29, 1910, Mr. Curtiss made the first stated aeroplane tour to
take place in this country, travelling from Albany to New York City,
137 miles, with but one stop for fuel. With this flight he won a prize
of $10,000.

He has made many other notable flights and stands in the foremost rank
of the active aviators. At the same time he is busily engaged in the
manufacture of the Curtiss biplane and the Curtiss engine, both staple
productions in their line.

CHARLES KEENEY HAMILTON.

CHARLES KEENEY HAMILTON is justly regarded as one of the most skilful
of aviators. He was born in Connecticut in 1881, and showed his “bent”
by making distressing, and often disastrous, leaps from high places
with the family umbrella for a parachute.

In 1904 he worked with Mr. Israel Ludlow, who at that time was
experimenting with gliders of his own construction, and when Mr. Ludlow
began towing them behind automobiles, Hamilton rode on the gliders and
steered them. Later he became interested in ballooning, and made a
tour of Japan with a small dirigible.

[Illustration: Hamilton and Latham.]

He early became famous in the aviation world by his spectacular
glides from a great height. He has said that the first of these was
unintentional, but his motor having stopped suddenly while he was high
in the air, he had only the other alternative of falling vertically.
The sensation of the swift gliding having pleased him, he does it
frequently “for the fun of it.” These glides are made at so steep an
angle that they have gained the distinctive name, “Hamilton dives.”

Hamilton came most prominently before the public at large with his
flight from Governor’s Island to Philadelphia and back, on June 13,
1910. Following close upon Curtiss’s flight from Albany to New York, it
was not only a record-breaking achievement, but helped to establish in
this country the value of the aeroplane as a vehicle for place-to-place
journeyings.

HUBERT LATHAM.

HUBERT LATHAM, the famous Antoinette pilot, is a graduate of Oxford.
His father was a naturalized Frenchman.

His first aeronautical experience was as companion to his cousin,
Jacques Faure, the balloonist, on his famous trip from London to Paris
in 6½ hours, the fastest time ever made between the two places until
the Clement-Bayard dirigible surpassed it by a few minutes on October
16, 1910.

The Antoinette monoplane with which M. Latham has identified himself
began with the ingenious engine of Levavasseur, which was speedily
made use of for aeroplanes by Santos-Dumont, Bleriot, and Farman.
Levavasseur also had ideas about aeroplanes, and persuaded some
capitalists to back him in the enterprise. When it was done, no one
could be found to fly it. Here M. Latham, a lieutenant of miners and
sappers in the French army, stepped into the breach, and has made a
name for himself and for the Antoinette machine in the forefront of the
progress of aviation.

After winning several contests he set out, on July 19, 1909, to cross
the British Channel. After flying about half the distance he fell into
the sea. Six days later Bleriot made the crossing successfully, and
Latham made a second attempt on July 27th, and this time got within a
mile of the Dover coast before he again came down in the water.

He has shown unsurpassed daring and skill in flying in gales blowing
at 40 miles per hour, a record which few other aviators have cared to
rival.

ALFRED LEBLANC.

ALFRED LEBLANC, the champion cross-country flier of the world, was
born in France in 1879. By profession he is a metallurgist. A friend
of Bleriot, he became interested in monoplane flying, the more readily
because he was already a skilled balloonist.

At the time Bleriot made his historic flight across the British
Channel, Leblanc preceded him, and, standing on the Dover shore,
signalled Bleriot where to strike the land.

He organized Bleriot’s school for aviators at Pau, and became its
director. Its excellence is exhibited in the quality of its pupils;
among them Chavez, Morane, and Aubrun.

The achievement through which Leblanc is most widely known is his
winning of the 489-mile race over the northern part of France in
August, 1910, and with the victory the prize of $20,000 offered.

CLAUDE GRAHAME-WHITE.

CLAUDE GRAHAME-WHITE, the most famous of British aviators, learned to
fly in France, under the tutelage of M. Bleriot, Having accomplished
so much, he went to Mourmelon, the location of Farman’s establishment,
and made himself equally proficient on the Farman biplane. While in
France he taught many pupils, among them Armstrong Drexel. Returning
to England, he opened a school for English aviators.

He came into prominent public notice in his contest with Paulhan in the
race from London to Manchester, and although Paulhan won the prize,
Grahame-White received a full share of glory for his plucky persistence
against discouraging mishaps.

At the Boston-Harvard meet, in September, 1910, Grahame-White carried
off nearly all the prizes, and in addition won for himself a large
measure of personal popularity.

On October 14th he flew from the Benning Race Track 6 miles away, over
the Potomac River, around the dome of the Capitol, the Washington
Monument, and over the course of Pennsylvania Avenue, up to the State,
War, and Navy Department building, alighting accurately with his
40-foot biplane in the 60-foot street. Having ended his “call,” he
mounted his machine and rose skilfully into the air and returned to his
starting point.

At the Belmont Park meet, in October, Grahame-White captured the
international speed prize with his 100-horse-power Bleriot monoplane,
and finished second in the race around the Statue of Liberty, being
beaten by only 43 seconds.

LOUIS PAULHAN.

LOUIS PAULHAN was, in January, 1909, a mechanic in Mourmelon, France,
earning the good wages in that country of $15 per week. He became
an aviator, making his first flight on July 10, 1909, of 1¼ miles.
Five days later he flew over 40 miles, remaining in the air 1 hour
17 minutes, and rising to an altitude of 357 feet, then the world’s
record. He flew constantly in public through the remainder of 1909,
winning many prizes and breaking and making records.

In January, 1910, he was the most prominent aviator at the Los Angeles
meet, and there made a new world’s record for altitude, 4,166 feet.

Within the 13 months and 3 weeks (up to October 1, 1910) that he has
been flying, he has won over $100,000 in prizes, besides receiving many
handsome fees for other flights and for instruction to pupils.

CLIFFORD B. HARMON.

CLIFFORD B. HARMON has the double distinction of being not only the
foremost amateur aviator of America, but his feats have also at times
excelled those of the professional airmen. On July 2, 1910, Mr. Harmon
made a continuous flight of more than 2 hours, breaking all American
records, and this he held for several months.

Mr. Harmon’s first experience in the air was as a balloonist, and in
this capacity he held the duration record of 48 hours 26 minutes for a
year. On this same voyage, at the St. Louis Centennial, he made a new
record in America for altitude attained, 24,400 feet.

At the Los Angeles aviation meet, in January, 1910, where he went with
his balloon _New York_, he met Paulhan, and became his pupil. At that
meet Paulhan made a new world’s record for altitude with a Farman
biplane, and this machine Mr. Harmon bought, and brought to Mineola, L.
I., where he practised assiduously, crowning his minor achievements by
flying from there across Long Island Sound to Greenwich, Conn.

At the Boston-Harvard aviation meet, in September, 1910, Mr. Harmon won
every prize offered to amateur contestants.

WALTER BROOKINS.

WALTER BROOKINS is one of the youngest of noted aviators. He was born
in Dayton, Ohio, in 1890, and went to school to Miss Katherine Wright,
sister of the Wright brothers. Young Walter was greatly interested
in the experiments made by the Wrights, and Orville one day promised
him that when he grew up they would build a flying machine for him.
Brookins appeared at Dayton in the early part of 1910, after several
years’ absence, during which he had grown up, and demanded the promised
flying machine. The Wrights met the demand, and developed Brookins into
one of the most successful American aviators.

Brookins’s first leap into prominence was at the Indianapolis meet,
in June, 1910, where he made a new world’s record for altitude, 4,803
feet. This being beaten soon after in Europe, by J. Armstrong Drexel,
with 6,600 feet, Brookins attempted, at Atlantic City, in September, to
excel Drexel’s record, and rose to a height of 6,175 feet, being forced
to come down by the missing of his motor.

On September 29, 1910, he left Chicago for Springfield, Ill. He made
two stops on the way for repairs and fuel, and reached Springfield in
7 hours 9 minutes elapsed time. His actual time in the air was 5 hours
47 minutes. The air-line distance between the two cities is 187 miles,
but as Brookins flew in the face of a wind blowing 10 miles an hour,
he actually travelled 250 miles. During the journey Brookins made a new
cross-country record for America in a continuous flight for 2 hours 38
minutes.

JOHN B. MOISANT.

JOHN B. MOISANT is an architect of Chicago, born there of Spanish
parentage in 1883. Becoming interested in aviation, he went to France
in 1909, and began the construction of two aeroplanes, one of them
entirely of metal. He started to learn to fly on a Bleriot machine, and
one day took one of his mechanicians aboard and started for London. The
mechanician had never before been up in an aeroplane. After battling
with storms and repairing consequent accidents to his machine, Moisant
landed his passenger in London three weeks after the start. It was
the first trip between the two cities for an aeroplane carrying a
passenger, and although Moisant failed to win the prize which had been
offered for such a feat, he received a great ovation, and a special
medal was struck for him.

At the Belmont Park meet, in October, 1910, Moisant, after wrecking
his own machine in a gale, climbed into Leblanc’s Bleriot, which had
been secured for him but a few minutes before, and made the trip around
the Statue of Liberty in New York Bay and returned to the Park in 34
minutes 38 seconds. As the distance is over 34 miles, the speed was
nearly a mile a minute. This feat won for him, and for America, the
grand prize of the meet--$10,000.

J. ARMSTRONG DREXEL.

J. ARMSTRONG DREXEL is a native of Philadelphia. He was taught to
fly a Bleriot machine at Pau by Grahame-White, and he has frequently
surpassed his instructor in contests where both took part. At the
English meets in 1910 he won many of the prizes, being excelled in this
respect only by Leon Morane.

At Lanark, Scotland, he established a new world’s record for altitude,
6,600 feet. At the Belmont Park meet he passed his former record with
an altitude of 7,185 feet, making this the American record, though it
had been excelled in Europe. At Philadelphia, November 23, 1910, he
reached an altitude of 9,970 feet, according to the recording barometer
he carried, thus making a new world’s record. This record was disputed
by the Aero Club, and it may be reduced. A millionaire, he flies for
sheer love of the sport.

RALPH JOHNSTONE.

RALPH JOHNSTONE was born in Kansas City, Mo., in 1880. He became an
expert bicycle rider, and travelled extensively in many countries
giving exhibitions of trick bicycle riding, including the feat known
as “looping the loop.” He joined the staff of the Wright Brothers’
aviators in April, 1910, and speedily became one of the most skilful
aeroplane operators.

He made a specialty of altitude flying, breaking his former records day
after day, and finally, at the International Aviation Meet at Belmont
Park, L. I., in October, 1910, he made a new world’s altitude record
of 9,714 feet, surpassing the previous record of 9,121 feet made by
Wynmalen at Mourmelon, on October 1st.

Johnstone was instantly killed at Denver, Col., on November 14, 1910,
by a fall with his machine owing to the breaking of one of the wings at
a height of 800 feet.

Chapter XIX.

CHRONICLE OF AVIATION ACHIEVEMENTS.

How feeble the start, and how wondrously rapid the growth of the art
of flying! Nothing can better convey a full idea of its beginnings
and its progress than the recorded facts as given below. And these
facts show beyond dispute that the credit of laying the foundation for
every accomplishment in the entire record must be largely due to the
men whose names stand alone for years as the only aeroplanists in the
world--the Wright Brothers.

After the first flight on December 17, 1903, the Wrights worked
steadily toward improving their machines, and gaining a higher degree
of the art of balancing, without which even the most perfect machines
would be useless. Most of their experimenting having been done in
secret, the open record of their results from time to time is very
meagre. It may be noted, however, that for nearly three years no one
else made any records at all.

The next name to appear on the roll is that of Santos-Dumont, already
famous for his remarkable achievements in building and navigating
dirigible balloons, or airships. His first aeroplane flight was on
August 22, 1906, and was but little more than rising clear of the
ground.

It was nearly seven months later when Delagrange added his name to the
three then on the list of practical aviators. In about five months
Bleriot joined them, and in a few more weeks Farman had placed his name
on the roll. It is interesting to compare the insignificant figures of
the first flights of these men with their successive feats as they gain
in experience.

Up to October 19, 1907, the flights recorded had been made with
machines of the biplane type, but on that date, R. Esnault-Pelterie
made a few short flights with a monoplane. A month later Santos-Dumont
had gone over to the monoplane type, and the little group of seven had
been divided into two classes--five biplanists and two monoplanists.

On March 29, 1908, Delagrange started a new column in the record book
by taking a passenger up with him, in this case, Farman. They flew only
453 feet, but it was the beginning of passenger carrying.

During the first six months of 1908 only two more names were added to
the roll--Baldwin and McCurdy--both on the biplane side. On July 4,
1908, Curtiss comes into the circle with his first recorded flight,
in which he used a biplane of his own construction. The same day in
France, Bleriot changed to the ranks of the monoplane men, with a
flight measured in miles, instead of in feet. Two days later, Farman
advanced his distance record from 1.24 miles to 12.2 miles, and his
speed record from about 21 miles an hour to nearly 39 miles an hour. In
two days more, Delagrange had taken up the first woman passenger ever
carried on an aeroplane; and a month later, Captain L. F. Ferber had
made his first flights in public, and added his name to the growing
legion of the biplanists.

In the latter part of 1908, the Wrights seem to take possession of the
record--Orville in America, and Wilbur in Europe--surpassing their own
previous feats as well as those of others. Bleriot and Farman also
steadily advance their performances to a more distinguished level.

The record for 1909 starts off with three new names--Moore-Brabazon,
and Legagneux in France, and Cody in England. Richardson, Count de
Lambert, Calderara, Latham, Tissandier, Rougier, join the ranks of the
aviators before the year is half gone, and a few days later Sommer and
Paulhan add their names.

Of these only Latham flies the monoplane type of machine, but at the
Rheims tournament Delagrange appears as a monoplanist, increasing the
little group to four; but, with Le Blon added later, they perform some
of the most remarkable feats on record.

The contest at Rheims in August is a succession of record-breaking and
record-making achievements. But it is at Blackpool and Doncaster that
the most distinct progress of the year is marked, by the daring flights
of Le Blon and Latham in fierce gales. Spectators openly charged these
men with foolhardiness, but it was of the first importance that it
should be demonstrated that these delicately built machines can be
handled safely in the most turbulent weather; and the fact that it has
been done successfully will inspire every other aviator with a greater
degree of confidence in his ability to control his machine in whatever
untoward circumstances he may be placed. And such confidence is by far
the largest element in safe and successful flying.

NOTABLE AVIATION RECORDS TO CLOSE OF 1910

_December 17, 1903_--Wilbur Wright with biplane, at Kitty
Hawk, N. C., makes the first successful flight by man with
power-propelled machine, a distance of 852 feet, in 59 seconds.

_November 9, 1904_--Wilbur Wright with biplane, at Dayton, O.,
flies 3 miles in 4 minutes and 30 seconds. (He and Orville made
upward of 100 unrecorded flights in that year.)

_September 26, 1905_--Wilbur Wright with biplane “White Flier,”
at Dayton, O., flies 11 miles in 18 minutes and 9 seconds.

_September 29, 1905_--Orville Wright, with “White Flier,” at
Dayton, O., flies 12 miles in 19 minutes and 55 seconds.

_October 3, 1905_--Wilbur Wright, with “White Flier” at Dayton,
O., flies 15 miles in 25 minutes and 5 seconds.

_October 4, 1905_--Orville Wright with biplane “White Flier,” at
Dayton, O., flies 21 miles in 33 minutes and 17 seconds.

_October 5, 1905_--Wilbur Wright with “White Flier,” at Dayton,
O., flies 24 miles in 38 minutes. (He made many unrecorded
flights in that year.)

_August 22, 1906_--A. Santos-Dumont with biplane at Bagatelle,
France, made his first public flight with an aeroplane, hardly
more than rising clear of the ground.

_September 14, 1906_--Santos-Dumont with biplane, at Bagatelle,
flies for 8 seconds.

[Illustration: Santos-Dumont flying at Bagatelle in his cellular
biplane.]

_October 24, 1906_--Santos-Dumont with biplane, at Bagatelle,
flies 160 feet in 4 seconds.

_November 13, 1906_--Santos-Dumont with biplane, at Bagatelle,
flies 722 feet in 21 seconds. This feat is recorded as the first
aeroplane flight made in Europe.

_March 16, 1907_--Leon Delagrange with first Voisin biplane, at
Bagatelle, flies 30 feet.

_August 6, 1907_--Louis Bleriot with a Langley machine, at Issy,
France, flies 470 feet.

_October 15, 1907_--Henry Farman with biplane, at Issy, flies 937
feet in 21 seconds.

_October 19, 1907_--R. Esnault-Pelterie with monoplane, at Buc,
France, makes short flights.

_October 26, 1907_--Farman with biplane, at Issy, flies 2,529
feet in a half circle, in 52 seconds.

_November 17, 1907_--Santos-Dumont with biplane, at Issy, makes
several short flights, the longest being about 500 feet.

_November 21, 1907_--Santos-Dumont with monoplane at Bagatelle,
makes several short flights, the longest being about 400 feet.

_January 13, 1908_--Farman with biplane, at Issy, makes the
first flight in a circular course--3,279 feet in 1 minute and 28
seconds.

_March 12, 1908_--F. W. Baldwin with biplane “Red Wing,” at
Hammondsport, N. Y., flies 319 feet.

_March 21, 1908_--Farman with biplane, at Issy, flies 1.24 miles
in 3 minutes and 31 seconds.

_March 29, 1908_--Delagrange with biplane, at Ghent, Belgium,
makes first recorded flight with one passenger (Farman), 453 feet.

_April 11, 1908_--Delagrange with biplane at Issy, flies 2.43
miles in 6 minutes and 30 seconds, winning the Archdeacon cup.

_May 18, 1908_--J. A. D. McCurdy with biplane “White Wing” at
Hammondsport, flies 600 feet.

_May 27, 1908_--Delagrange with biplane, at Rome, in the presence
of the King of Italy, flies 7.9 miles in 15 minutes and 25
seconds.

[Illustration: The early Voisin biplane flown by Farman at Issy.]

_May 30, 1908_--Farman with biplane, at Ghent, flies 0.77 miles
with one passenger (Mr. Archdeacon).

_June 8, 1908_--Esnault-Pelterie with monoplane, at Buc, flies
0.75 miles, reaching an altitude of 100 feet.

_June 22, 1908_--Delagrange with biplane, at Milan, Italy, flies
10.5 miles in 16 minutes and 30 seconds.

_July 4, 1908_--Glenn H. Curtiss with biplane, at Hammondsport,
flies 5,090 feet, in 1 minute and 42 seconds, winning _Scientific
American_ cup.

[Illustration: The “June Bug” flown by Curtiss winning the _Scientific
American_ cup, July 4, 1908.]

_July 4, 1908_--Bleriot with monoplane, at Issy, flies 3.7 miles
in 5 minutes and 47 seconds, making several circles.

_July 6, 1908_--Farman in biplane, at Ghent, flies 12.2 miles in
19 minutes and 3 seconds, winning the Armengand prize.

_July 8, 1908_--Delagrange with biplane, at Turin, Italy, flies
500 feet with the first woman passenger ever carried on an
aeroplane--Mrs. Peltier.

_August 9, 1908_--Wilbur Wright with biplane, at Le Mans, France,
makes several short flights to prove the ease of control of his
machine.

_August 8, 1908_--L. F. Ferber with biplane, at Issy, makes first
trial flights.

_September 6, 1908_--Delagrange with biplane, at Issy, flies
15.2 miles in 29 minutes and 52 seconds, beating existing French
records.

_September 8, 1908_--Orville Wright with biplane, at Fort Myer,
Va., flies 40 miles in 1 hour and 2 minutes, rising to 100 feet.

_September 9, 10, 11, 1908_--Orville Wright with biplane, at
Fort Myer, makes several flights, increasing in duration from 57
minutes to 1 hour ten minutes and 24 seconds.

_September 12, 1908_--Orville Wright with biplane, at Fort Myer,
flies 50 miles in 1 hour, 14 minutes and 20 seconds, the longest
flight on record.

_September 12, 1908_--Orville Wright with biplane, at Fort Myer,
flies for 9 minutes and 6 seconds with one passenger (Major
Squier), making a new record.

_September 17, 1908_--Orville Wright with biplane, at Fort Myer,
flies 3 miles in 4 minutes, with Lieutenant Selfridge. The
machine fell: Selfridge was killed and Wright severely injured.

_September 19, 1908_--L. F. Ferber with biplane, at Issy, flies
1,640 feet.

_September 21, 1908_--Wilbur Wright with biplane, at Auvours,
flies 41 miles in 1 hour and 31 minutes.

_September 25, 1908_--Wilbur Wright with biplane, at Le Mans,
France, flies 11 minutes and 35 seconds, with one passenger,
making a new record.

_October 3, 1908_--Wilbur Wright with biplane, at Le Mans,
France, flies 55 minutes and 37 seconds, with one passenger,
making new record.

_October 6, 1908_--Wilbur Wright with biplane, at Le Mans, flies
1 hour 4 minutes and 26 seconds, with one passenger, breaking all
records.

_October 10, 1908_--Wilbur Wright with biplane, at Auvours,
flies 46 miles in 1 hour and 9 minutes, with one passenger (Mr.
Painleve). Also carried 35 others on different trips, one at a
time.

_October 21, 1908_--Bleriot with monoplane, at Toury, France,
flies 4.25 miles in 6 minutes and 40 seconds.

_October 30, 1908_--Farman with biplane at Chalons, France, makes
a flight across country to Rheims--17 miles in 20 minutes.

_October 31, 1908_--Farman with biplane, at Chalons, flies 23
minutes, reaching a height of 82 feet.

_October 31, 1908_--Bleriot with monoplane, at Toury, flies 8.7
miles to Artenay, in 11 minutes, lands, and returns to Toury.

_December 18, 1908_--Wilbur Wright with biplane, at Auvours,
flies 62 miles in 1 hour and 54 minutes, rising to 360
feet--making a world record.

_December 31, 1908_--Wilbur Wright with biplane, at Le Mans,
flies 76.5 miles in 2 hours 18 minutes and 53 seconds, making a
new world record, and winning the Michelin prize. The distance
traversed (unofficial) is claimed to have been actually over 100
miles.

_January 28, 1909_--Moore-Brabazon with biplane, at Chalons,
flies 3.1 miles, in practice with a Voison machine.

_February 14, 1909_--Legagneux with biplane, at Mourmelon,
France, flies 1.2 miles, and in a second flight of 6.2 miles (10
kilometres), traces two circles.

_February 22, 1909_--S. F. Cody with biplane, at Aldershot,
England, flies 1,200 feet in a 12-mile wind.

_February 23, 1909_--J. A. D. McCurdy, with the biplane “Silver
Dart,” at Baddeck, Cape Breton, flies 2,640 feet.

_February 24, 1909_--McCurdy, with the biplane “Silver Dart,” at
Baddeck, flies 4.5 miles.

_February 24, 1909_--Moore-Brabazon, with biplane, at Issy, flies
1.2 miles, tracing two circles.

_February 28, 1909_--Moore-Brabazon made several flights at Issy.

_March 8, 1909_--McCurdy, with biplane “Silver Dart,” at Baddeck,
made five flights, the longest about 8 miles in 11 minutes and 15
seconds.

_March 10, 1909_--Santos-Dumont, with monoplane “Libellule,” at
Bagatelle, flies 1,300 feet.

_March 11, 1909_--W. J. Richardson with a new form of aeroplane,
at Dayton, O., flies for 38 minutes, rising to a height of over
300 feet.

_March 11, 1909_--McCurdy with biplane “Silver Dart,” at Baddeck,
flies 19 miles in 22 minutes.

_March 17, 1909_--Count de Lambert (pupil of Wilbur Wright) made
his first flight alone in biplane, at Pau, France. He remained in
the air 3 minutes.

_March 18, 1909_--McCurdy, with biplane “Silver Dart,” at
Baddeck, flies 16 miles, completing a record of an even 1,000
miles in the air within a period of 10 months.

_March 18, 1909_--F. W. Baldwin with biplane “Silver Dart,” at
Baddeck, made a short flight.

_March 20, 1909_--Wilbur Wright, with biplane, at Pau, succeeds
in rising from the ground without the starting device previously
used. He makes several flights.

_March 24, 1909_--Count de Lambert with biplane, at Pau, flies
15.6 miles in 27 minutes and 11 seconds.

_April 10, 1909_--Santos-Dumont with monoplane “Demoiselle,” at
St. Cyr, France, flies 1.2 miles.

_April 13, 1909_--Count de Lambert with biplane, at Pau, flies
for 1 minute and 30 seconds, with one passenger (Leon Delagrange).

_April 16, 1909_--Wilbur Wright with biplane, at Rome, Italy,
made many flights, taking up many passengers, one at a time.

_April 27, 1909_--Legagneux with Voisin biplane, at Vienna, flies
2.5 miles in 3 minutes and 26 seconds.

_April 28, 1909_--Lieutenant Mario Calderara (pupil of Wilbur
Wright) with biplane, at Rome, made his first public flight,
remaining in the air 10 minutes.

_April 30, 1909_--Moore-Brabazon with biplane, in England, flies
4.5 miles.

_May 14, 1909_--S. F. Cody, with the army biplane, at Aldershot,
flies 1 mile.

_May 19, 1909_--Hubert Latham, with Antoinette monoplane, at
Chalons, flies 1,640 feet.

_May 20, 1909_--Paul Tissandier (pupil of Wilbur Wright) with
biplane at Pau, flies 35.7 miles.

_May 23, 1909_--Delagrange, with biplane, at Juvissy, flies 3.6
miles in 10 minutes and 18 seconds, winning the Lagatineri prize.

_May 23, 1909_--Henri Rougier, with biplane, at Juvissy, flies
18.6 miles (30 kilometres).

_May 30, 1909_--Bleriot, with monoplane at Issy, flies 8.7 miles.

_June 5, 1909_--Latham, with monoplane, at Chalons, flies for 1
hour 7 minutes and 37 seconds in wind and rain.

_June 6, 1909_--Latham, with monoplane, at Juvissy, flies 10
miles across country.

_June 12, 1909_--Latham, with monoplane, at Juvissy, flies 30
miles in 39 minutes, winning the Goupy prize.

_June 12, 1909_--Delagrange, with biplane, at Juvissy, makes
cross country flight of 3.7 miles.

_June 12, 1909_--Bleriot, with monoplane, at Juvissy, flies 984
feet, with two passengers--Santos-Dumont and Fournier.

_June 13 1909_--Ferber, with Voisin biplane, at Juvissy, flies
3.1 miles in 5 minutes and 30 seconds.

_June 19, 1909_--Santos-Dumont, with monoplane, at Issy, makes
several flights.

_July 4, 1909_--Roger Sommer with biplane, at Chalons, flies 3.75
miles on Farman machine.

_July 10, 1909_--Louis Paulhan, with biplane, at Douai, France,
makes his first flight--1.25 miles.

_July 13, 1909_--Curtiss, with biplane, at Mineola, L. I., flies
1.5 miles in 3 minutes.

_July 13, 1909_--Bleriot, with monoplane, at Mondesir, makes a
flight of 26 miles across country in 44 minutes and 30 seconds.

_July 15, 1909_--Paulhan with biplane, at Douai, flies for 1
minute and 17 seconds, soaring to an altitude of 357 feet.

_July 17, 1909_--Orville Wright, with biplane, at Fort Myer,
flies 16 minutes and 40 seconds, at a speed of 40 miles an hour.

_July 17, 1909_--Curtiss, with biplane, at Mineola, makes 15
miles in 21 minutes, describing circles in both directions, as in
the figure 8.

_July 18, 1909_--Curtiss, with biplane, at Hempstead Plains,
L. I., flies 29½ miles in 52 minutes and 30 seconds, a flight
exceeded only by the Wrights, in America, and Bleriot, Latham,
and Paulhan, in Europe.

_July 18, 1909_--Farman, with biplane, at Chalons, flies for 1
hour and 23 minutes, making his first long flight.

_July 18, 1909_--Sommer, with biplane, at Chalons, makes his
longest flight--1 hour and 40 minutes.

_July 19, 1909_--Latham, with monoplane, at Calais, France, makes
his first attempt to cross the Channel to Dover. He flies 11
miles, and then his machine falls into the sea.

_July 19, 1909_--Paulhan, with biplane, at Douai, makes a
cross-country flight of 12.1 miles in 22 minutes and 53 seconds.

_July 20, 1909_--Orville Wright, with biplane, at Fort Myer,
flies 1 hour and 20 minutes.

_July 21, 1909_--Orville Wright, with biplane, at Fort Myer,
flies 1 hour and 29 minutes.

_July 21, 1909_--E. Lefebvre, with biplane, at La Haye, France,
flies 2 miles.

_July 21, 1909_--S. F. Cody, with biplane, at Aldershot, flies 4
miles.

_July 23, 1909_--Farman, with biplane, at Chalons, makes a
cross-country flight to Suippes--40 miles in 1 hour and five
minutes.

_July 23, 1909_--Paulhan, with biplane, at Douai, flies 43.5
miles in 1 hour 17 minutes and 19 seconds.

_July 24, 1909_--Curtiss in biplane, at Hempstead Plains, flies
25 miles in 52 minutes and 30 seconds, winning the _Scientific
American_ cup the second time.

_July 25, 1909_--Bleriot, with monoplane, at Calais, flies to
Dover, England, across the English Channel--32 miles in 37
minutes.

_July 27, 1909_--Orville Wright, with biplane, at Fort Myer,
flies 1 hour and 13 minutes, with one passenger, securing
acceptance of Wright machine by U. S. Government on the duration
specifications.

_July 27, 1909_--Latham, with monoplane, at Calais, flies 20
miles in a second attempt to cross the English Channel. When near
Dover the machine fell.

_July 27, 1909_--Sommer, with biplane, at Chalons, flies to
Vadenay and back--25 miles in 1 hour 23 minutes and 30 seconds.

_July 30, 1909_--Orville Wright, with biplane, at Fort Myer,
established a world record with one passenger in a cross-country
flight to Shuter’s Hill and back--about 10 miles in 14 minutes
and 40 seconds, a speed of about 42 miles an hour--winning a
bonus of $25,000 from the U. S. Government.

_August 1, 1909_--Sommer, with biplane, at Chalons, flies 1 hour
50 minutes and 30 seconds, at an average height of 80 feet, over
a distance estimated at 70 miles, surpassing all French records.

_August 2, 1909_--McCurdy, with a new type of machine, at
Petawawa, makes several flights.

_August 2, 1909_--F. W. Baldwin, with biplane, at Petawawa, makes
several short flights.

_August 2, 1909_--Sommer, with biplane, at Chalons, flies to
Suippes--9 miles, at the rate of 45 miles an hour.

_August 4, 1909_--Sommer, with biplane, at Chalons, in the effort
to beat Wilbur Wright’s record, flies for 2 hours 0 minutes and
10 seconds (Wright’s record flight was 2 hours 20 minutes and 23
seconds, made on December 31, 1908).

_August 5, 1909_--E. Bunau-Varilla, with Voisin biplane, at
Chalons, flies for 15 minutes.

_August 6, 1909_--Legagneux, with biplane, at Stockholm, flies
with one passenger, 3,280 feet.

_August 6, 1909_--Paulhan, with biplane, at Dunkerque, France,
flies for 18 minutes and 20 seconds, reaching an altitude of 200
feet.

_August 7, 1909_--Paulhan, with Voisin biplane, at Dunkerque,
flies 23 miles in 33 minutes.

_August 7, 1909_--Sommer, with Voisin biplane, at Chalons, flies
for 2 hours 27 minutes and 15 seconds, making new world record
for duration.

_August 13, 1909_--Charles F. Willard, with biplane, at Hempstead
Plains, made the longest cross-country flight on record for
America--about 12 miles in 19 minutes and 30 seconds. The
breaking of his engine caused him to come down. He landed without
mishap.

_August 22, 1909_--Sommer, with biplane, at Rheims, France, flies
1 hour 19 minutes and 30 seconds.

_August 22, 1909_--Legagneux, with biplane, at Rheims, flies 6.2
miles in 9 minutes and 56 seconds, winning third prize for speed
over course of 10 kilometres.

_August 22, 1909_--Tissandier, with biplane, at Rheims, flies
18.6 miles in 29 minutes. (He won with this record the third
prize for speed over 30 kilometres.)

_August 22, 1909_--E. Bunau-Varilla, with biplane, at Rheims,
flies 6.2 miles in 13 minutes and 30 seconds. (With this
record he won the thirteenth prize for speed over course of 10
kilometres.)

_August 23, 1909_--Delagrange, with monoplane, at Rheims, flies
6.2 miles in 11 minutes and 4 seconds. (He won the tenth prize
for speed over 10 kilometres.)

_August 23, 1909_--Curtiss, with biplane, at Rheims, flies 6.2
miles in 8 minutes and 35 seconds--a speed of 42.3 miles an
hour--beating the record for speed over course of 10 kilometres.

_August 23, 1909_--Paulhan, with biplane, at Rheims, flies 18.6
miles in 38 minutes and 12 seconds, reaching an altitude of 295
feet.

_August 23, 1909_--Paulhan, with biplane, at Rheims, flies 34.8
miles in an endurance test.

_August 25, 1909_--Paulhan, with biplane, at Rheims, flies 82
miles in 2 hours 43 minutes and 25 seconds. (With this record he
won the third prize for duration of flight.)

_August 25, 1909_--Curtiss, with biplane, at Rheims, flies 6.2
miles in 8 minutes and 44 seconds, again reducing the time for 10
kilometres.

_August 25, 1909_--Bleriot, with monoplane, at Rheims, flies 6.2
miles in 8 minutes and 4 seconds, making a new record for speed
over the course of 10 kilometres.

_August 26, 1909_--Curtiss, in biplane, at Rheims, flies 19 miles
in 29 minutes. (With this record he won the tenth prize for
duration of flight.)

_August 26, 1909_--Count de Lambert, with biplane, at Rheims,
flies 72 miles in 1 hour and 52 minutes. (With this record he won
the fourth prize for duration of flight.)

_August 26, 1909_--Latham, with monoplane, at Rheims, flies 96.5
miles in 2 hours 17 minutes and 21 seconds. (With this record he
won the second prize for duration of flight.)

_August 27, 1909_--Farman, with biplane, at Rheims, flies 112
miles in 3 hours 4 minutes and 57 seconds. (This record won for
him the first prize for duration of flight.)

[Illustration: Latham flying in his Antoinette at Rheims. To view this
properly the picture should be held overhead.]

_August 27, 1909_--Latham, with monoplane, at Rheims, flies to an
altitude of 508 feet. (With this record he won first prize for
altitude.)

_August 27, 1909_--Delagrange, with monoplane, at Rheims, flies
31 miles. (With this record he won the eighth prize for duration
of flight.)

_August 27, 1909_--Sommer, with biplane, at Rheims, flies 37
miles. He won the seventh prize for distance.

_August 27, 1909_--Tissandier, with biplane, at Rheims, flies 69
miles. (This record won for him the sixth prize for distance.)

_August 27, 1909_--Lefebvre, with biplane, at Rheims, flies 12.4
miles in 20 minutes and 47 seconds, exhibiting great daring and
skill. (He was fined for “recklessness.”)

_August 27, 1909_--Bleriot, with monoplane, at Rheims, flies 25
miles in 41 minutes. (This record won for him the ninth prize for
distance flown.)

_August 28, 1909_--Lefebvre, with biplane, at Rheims, makes a
spectacular flight for 11 minutes with one passenger.

_August 28, 1909_--Curtiss, with biplane, at Rheims, flies 12.4
miles in 15 minutes and 56 seconds, winning the Gordon Bennett
cup.

_August 28, 1909_--Bleriot, with monoplane, at Rheims, flies 6.2
miles in 7 minutes and 48 seconds. (With this record he won the
first prize for speed over course of 10 kilometres.)

_August 29, 1909_--Farman, with biplane, at Rheims, flies 6.2
miles with two passengers, in 10 minutes and 30 seconds, winning
a prize.

_August 29. 1909--Curtiss, with biplane, at Rheims, flies 18.6
miles in 23 minutes and 30 seconds. (With this record he won the
first prize for speed over course of 30 kilometres.)

_August 29, 1909_--Curtiss, with biplane, at Rheims, flies 6.2
miles in 7 minutes and 51 seconds, winning the second prize for
speed over course of 10 kilometres.

_August 29, 1909_--Rougier, with biplane, at Rheims, rises to a
height of 180 feet, winning the fourth prize for altitude.

_August 29, 1909_--E. Bunau-Varilla, with biplane, at Rheims,
flies 18.6 miles in 38 minutes and 31 seconds. (With this record
he won the eighth prize for speed over course of 30 kilometres.)

_August 29, 1909_--Orville Wright, with biplane, at Berlin, makes
several short flights.

_August 29, 1909_--S. F. Cody, with biplane, at Aldershot, flies
10 miles with one passenger.

_September 4, 1909_--Orville Wright, with biplane, at Berlin,
flies for 55 minutes.

_September 6, 1909_--Sommer, with biplane, at Nancy, France,
flies 25 miles in 35 minutes. He takes up a number of passengers;
one at a time.

_September 7, 1909_--Lefebvre, with biplane, at Juvissy, is
killed by the breaking of his machine in the air after he had
flown 1,800 feet.

_September 8, 1909_--Orville Wright, with biplane, at Berlin,
flies 17 minutes with one passenger--Captain Hildebrandt.

_September 8, 1909_--S. F. Cody, with biplane, at Aldershot,
flies to Farnborough and back--46 miles in 1 hour and 3 minutes.
This is the first recorded cross-country flight in England.

_September 9, 1909_--Orville Wright, with biplane, at Berlin,
flies for 15 minutes with one passenger--Captain Englehardt.

_September 9, 1909_--Paulhan, with biplane, at Tournai, Belgium,
flies 12.4 miles in 17 minutes.

_September 9, 1909_--Rougier, with biplane, at Brescia, flies 12
minutes and 10 seconds, soaring to a height of 328 feet.

_September 10, 1909_--Sommer, with biplane, at Nancy, flies 18
miles, accompanying troops on review.

_September 11, 1909_--Sommer, with biplane, at Nancy, flies to
Lenoncourt--24 miles.

_September 11, 1909_--Curtiss, with biplane, at Brescia, flies 31
miles in 49 minutes and 24 seconds, winning the first prize for
speed.

_September 12, 1909_--Rougier, with biplane, at Brescia, flies 31
miles in 1 hour 10 minutes and 18 seconds, soaring to a height of
380 feet.

_September 12, 1909_--Calderara, with biplane, at Brescia, flies
6.3 miles with one passenger, winning a prize.

_September 13, 1909_--Paulhan, with biplane, at Tournai, flies to
Taintiguies and back in 1 hour and 35 minutes.

_September 13, 1909_--Santos-Dumont, with monoplane, at St. Cyr,
France, flies 5 miles in 12 minutes, to Buc, to visit Maurice
Guffroy, on a bet of $200 that each would be the first to visit
the other.

_September 15, 1909_--Ferber, with biplane, at Boulogne, France,
flies to Wimeroux--6 miles in 9 minutes.

_September 15, 1909_--Calderara, with biplane, at Brescia, flies
5.6 miles with one passenger, winning the Oldofredi prize.

_September 17, 1909_--Orville Wright, with biplane, at Berlin,
flies for 54 minutes and 26 seconds, rising to an altitude of
765 feet (estimated). He afterward flew for 47 minutes and 5
seconds with Captain Englehardt.

_September 17, 1909_--Santos-Dumont, with monoplane, at St. Cyr,
flies 10 miles in 16 minutes across country.

_September 17, 1909_--Paulhan, with biplane, at Ostend, Belgium,
flies 1.24 miles in 3 minutes and 16 seconds, along the water
front and out over the sea.

_September 18, 1909_--Orville Wright, with biplane, at Berlin,
establishes a world record by flying for 1 hour 35 minutes and 47
seconds, with one passenger--Captain Englehardt.

_September 18, 1909_--Paulhan, with biplane, at Ostend, flies for
1 hour over sea front, circling over the water; winning a prize
of $5,000.

_September 20, 1909_--Rougier, with biplane, at Brescia, broke
the record for high flying by reaching an altitude of 645 feet
(official measurement).

_September 20, 1909_--Calderara, with biplane, at Brescia, flies
31 miles in 50 minutes and 51 seconds, winning the second prize
for speed.

_September 22, 1909_--Captain Ferber, with a biplane, at
Boulogne, flies 1 mile, when, his engine breaking in the air, his
machine falls and he is killed.

_September 25, 1909_--Wilbur Wright, with biplane, at New York,
flies from Governor’s Island around the Statue of Liberty.

_September 27, 1909_--Latham, in monoplane, at Berlin, flies 6.5
miles across country in 13 minutes.

_September 28, 1909_--Rougier, with biplane, at Berlin, flies 31
miles in 54 minutes, soaring to an altitude of 518 feet.

_September 29, 1909_--Latham in monoplane, at Berlin, flies 42
miles in 1 hour and 10 minutes, winning the second prize for
distance.

_September 29, 1909_--Rougier, with biplane, at Berlin, flies 48
miles in 1 hour and 35 minutes.

_September 29, 1909_--Curtiss, with biplane, at New York, makes
flights about the harbor from Governor’s Island.

_September 30, 1909_--Orville Wright, with biplane, at Berlin,
soars to a height of 902 feet, making a world record for altitude.

_September 30, 1909_--Latham, with monoplane, at Berlin, flies 51
miles in 1 hour and 23 minutes.

_October 1, 1909_--Rougier, with biplane, at Berlin, flies 80
miles in 2 hours and 38 minutes, winning the first prize for
distance and speed.

_October 2, 1909_--Orville Wright, with biplane, at Berlin, makes
a flight of 10 minutes’ duration with the Crown Prince of Germany.

_October 3, 1909_--Farman, with biplane, at Berlin, flies 62
miles in 1 hour and 40 minutes, winning the third prize for
distance and speed.

_October 4, 1909_--Orville Wright, with biplane, at Berlin,
soared to an altitude of 1,600 feet, making a world record.

_October 4, 1909_--Wilbur Wright, with biplane, at New York,
flies from Governor’s Island to Grant’s Tomb and back--21 miles
in 33 minutes and 33 seconds.

_October 10, 1909_--Curtiss, with biplane, at St. Louis, Mo.,
makes several flights at the Centennial celebration.

_October 10, 1909_--Paulhan, with biplane, at Pt. Aviation, flies
21.5 miles in 21 minutes and 48 seconds.

_October 12, 1909_--Paulhan, with biplane, at Pt. Aviation, flies
3.6 miles in 6 minutes and 11 seconds, winning the prize for
slowest flight.

_October 16, 1909_--Curtiss, with biplane, at Chicago, makes
exhibition flights at 45 miles per hour.

_October 16, 1909_--Sommer, with biplane, at Doncaster, England,
flies 9.7 miles in 21 minutes and 45 seconds, making the record
for Great Britain.

_October 16, 1909_--Delagrange, with monoplane, at Doncaster,
flies 5.75 miles in 11 minutes and 25 seconds.

_October 16, 1909_--Cody, with biplane, at Doncaster, flies 3,000
feet, when his machine is wrecked, and he is injured.

_October 18, 1909_--Paulhan, with biplane, at Blackpool, England,
flies 14 miles in 25 minutes and 53 seconds.

_October 18, 1909_--Rougier, with biplane, at Blackpool, flies
17.7 miles in 24 minutes and 43 seconds, winning the second prize.

_October 18, 1909_--Farman, with biplane, at Blackpool, flies 14
miles in 23 minutes.

_October 18, 1909_--Le Blon, with monoplane, at Doncaster, flies
22 miles in 30 minutes, in a rainstorm, winning the Bradford cup.

_October 18, 1909_--Count de Lambert, with biplane, at Juvissy,
flies 31 miles to the Eiffel Tower in Paris, and back, in 49
minutes and 39 seconds.

_October 19, 1909_--Le Blon, with monoplane, at Doncaster, flies
15 miles in a gale.

_October 19, 1909_--Paulhan, with biplane, at Blackpool, flies
15.7 miles in 32 minutes and 18 seconds, winning the third prize.

_October 20, 1909_--Farman, with biplane, at Blackpool, flies 47
miles in 1 hour, 32 minutes, and 16 seconds, winning the first
prize--$10,000.

_October 20, 1909_--Le Blon, with monoplane, at Doncaster, makes
a spectacular flight in a fierce gale.

_October 21, 1909_--Count de Lambert, with biplane, at Pt.
Aviation, flies 1.25 miles in 1 minute and 57 seconds, winning
prize of $3,000 for speed.

_October 22, 1909_--Latham, with monoplane, at Blackpool, flies
in a squally gale blowing from 30 to 50 miles an hour. When
headed into the wind the machine moved backward in relation to
points on the ground. Going before the wind, it passed points on
the ground at a speed of nearly 100 miles an hour. This flight,
twice around the course, is the most difficult feat accomplished
by any aviator up to this date.

_October 26, 1909_--Sommer, with biplane, at Doncaster, flies
29.7 miles in 44 minutes and 53 seconds, winning the Whitworth
cup.

_October 26, 1909_--Delagrange, with monoplane, at Doncaster,
flies 6 miles in 7 minutes and 36 seconds--a speed of over 50
miles an hour.

_October 30, 1909_--Moore-Brabazon, with biplane, at Shell Beach,
England, wins a prize of $5,000 for flight with a British machine.

_November 3, 1909_--Farman, with biplane, at Mourmelon, France,
flies 144 miles in 4 hours 6 minutes and 25 seconds, far
surpassing his previous best record of 112 miles in 3 hours 4
minutes and 57 seconds, made at Rheims, and winning the Michelin
cup for duration and distance.

_November 19, 1909_--Paulhan, with biplane, at Mourmelon, broke
the record for height by ascending to 1,170 feet, in a wind
blowing from 20 to 25 miles an hour.

_November 19, 1909_--Latham, with Antoinette monoplane, surpassed
Paulhan’s record by rising to an altitude of 1,333 feet.

_November 20, 1909_--Paulhan, with biplane, at Mourmelon, flies
to Chalons and back--37 miles in 55 minutes.

_December 1, 1909_--Latham, with monoplane, at Mourmelon, soars
to 1,500 feet in a 40-mile gale.

_December 30, 1909_--Delagrange, with monoplane, at Juvissy,
flies 124 miles in 2 hours and 32 minutes--an average speed of
48.9 miles per hour, surpassing all previous records.

_December 31, 1909_--Farman at Chartres, France, flies to
Orleans--42 miles in 50 minutes.

_December 31, 1909_--Maurice Farman, at Mourmelon, defending his
brother Henry’s record against competing aviators, flies 100
miles in 2 hours and 45 minutes, without a fault. The Michelin
cup remains in his brother’s possession.

_January 7, 1910_--Latham, with Antoinette monoplane, at Chalons,
rises to height of 3,281 feet (world’s record).

_January 10, 1910_--Opening of aviation meet at Los Angeles, Cal.

_January 12, 1910_--Paulhan, Farman biplane, at Los Angeles,
rises to height of 4,146 feet. (World’s record.)

_January 17, 1910_--Paulhan, Farman biplane, at Los Angeles,
flies 75 miles in 1 hour 58 minutes and 27⅖ seconds.

_February 7, 1910_--First flight in South America. Bregi, Voisin
biplane, makes two flights near Buenos Aires.

_February 7, 1910_--Duray, with Farman biplane, at Heliopolis,
Egypt, flies 5 kilometres in 4 minutes and 12⅘ seconds. (World’s
record.)

_April 8, 1910_--D. Kinet, with Farman biplane, at Mourmelon,
flies for 2 hours 19 minutes and 4⅖ seconds with passenger,
covering 102 miles. (World’s record for passenger flight.)

_April 11, 1910_--E. Jeannin, with Farman biplane, flies 2 hours
1 minute and 55 seconds, at Johannisthal. (German record.)

_April 15, 1910_--Opening of Nice meeting.

_April 17, 1910_--Paulhan, with Farman biplane, flies from
Chevilly to Arcis-sur-Aube, 118 miles. (Record cross-country
flight.)

_April 23, 1910_--Grahame-White, with Farman biplane, flies from
Park Royal, London, to Rugby (83 miles) in 2 hours and 1 minute.
Starting again in 55 minutes, flies to Whittington in 1 hour and
5 minutes.

_April 27, 1910_--Paulhan, with Farman biplane, starts from
Hendon, London, at 5.31 P. M., flies within 5 mile circle
and continues to Lichfield, arriving 8.10 P. M. (117 miles).
Grahame-White starts from Wormwood Scrubs, London, at 6.29 P.
M., flies to Roade, arriving 7.55 P. M. (60 miles).

_April 28, 1910_--Paulhan flies from Lichfield to within 5 miles
of Manchester, winning the £10,000 _Daily Mail_ prize.

_April 30, 1910_--Opening of meeting at Tours, France.

_May 1, 1910_--Opening of flying-week at Barcelona.

_May 3, 1910_--Wiencziers, with Antoinette monoplane, twice
circles the Strassburg cathedral.

_May 6, 1910_--Olieslagers, with Bleriot monoplane, makes flight
of 18 minutes and 20 seconds above the sea at Barcelona, and over
the fortress of Monjuich.

_May 13, 1910_--Engelhardt, with Wright biplane, at Berlin, flies
2 hours 21 minutes and 45 seconds. (German record.)

_May 15, 1910_--Kinet, with Farman biplane, flies 2 hours and 51
minutes with a passenger at Mourmelon, making the world’s record
for passenger flight.

_May 15, 1910_--Olieslagers, with Bleriot monoplane, flies 15
miles over the sea at Genoa.

_May 21, 1910_--M. de Lesseps, with Bleriot monoplane, flies
from Calais to Dover in 37 minutes, winning £500 prize offered by
M. M. Ruinart.

_May 28, 1910_--G. Curtiss, with Curtiss biplane, starts from
Albany at 7.03 A. M., flies to Poughkeepsie in 1 hour and 21
minutes (70 miles). Leaves Poughkeepsie at 9.24 A. M., flies to
Spuyten Duyvil in 1 hour and 11 minutes (67 miles). Rises again
at 11.45, flies over New York, landing on Governor’s Island at
12.03 P. M. Wins prize of $10,000 given by the New York _World_.

_June 2, 1910_--Rolls, with Short-Wright biplane, leaves Dover
at 6.30 P. M., crosses Channel to French coast near Calais (7.15
P. M.), without landing re-crosses Channel to Dover, flies over
harbor, circles Dover Castle, and lands at 8.10 P. M. Wins second
Ruinart prize of £80.

_June 14, 1910_--Brookins, with Wright biplane, at Indianapolis,
reaches height of 4,380 feet. (World’s record.)

_June 25, 1910_--In Italian Parliament 25 million lire (about
$5,000,000) voted for aviation in the extraordinary estimates of
the Ministry of War.

_June 26, 1910_--Dickson, with Farman biplane, at Rouen, wins
total distance prize of £2,000 and the £400 for longest unbroken
flight. Distance flown, 466 miles.

_June 27, 1910_--M. de Lesseps, with Bleriot monoplane, flies
over Montreal for 49 minutes, covering about 30 miles at height
generally of 2,000 feet.

_July 6, 1910_--First German military aeroplane makes maiden
cross-country flight over Doeberitz.

_July 26, 1910_--M. de Lesseps, with Bleriot monoplane, starting
from Ile de Gros Bois in the St. Lawrence, makes trip of 40 miles
in 37 minutes.

_August 1, 1910_--Henry Farman takes up three passengers at
Mourmelon for 1 hour and 4 minutes.

_August 5, 1910_--Chavez, with Bleriot monoplane, attains height
of 5,750 feet. World’s record.

_August 7, 1910_--Lieutenants Cammerman and Villerme fly together
from Mourmelon to Nancy, 125 miles in 2½ hours, with a Farman
biplane.

_August 11, 1910_--Drexel, with Bleriot monoplane, at Lanark,
beats the world’s record for height, rising 6,600 feet.

_August 27, 1910_--First wireless telegram from a flying
aeroplane, sent by McCurdy from a Curtiss machine in the air,
at Atlantic City, N. J. The sending key was attached to the
steering wheel.

_August 28, 1910_--Dufaux, with biplane constructed by himself,
flies over Lake Geneva, wins prize of £200 offered by Swiss Aero
Club.

_August 29, 1910_--Breguet, with Breguet monoplane, makes a
flight at Lille, France, carrying five passengers, establishing
world’s record for passenger flight.

_August 29, 1910_--Morane, with Bleriot monoplane, at Havre,
beats world’s altitude record, reaches height of 7,166 feet.

_September 2, 1910_--Mlle. Hélène Dutrieux flies with a passenger
from Ostend to Bruges, Belgium, and back to Ostend. At Bruges she
circled around the famous belfry at a height of 1,300 feet, the
chimes pealing in honor of the feat--the most wonderful flight so
far accomplished by a woman.

_September 3, 1910_--M. Bielovucci lands at Bordeaux, France,
having made the trip from Paris, 366 miles, inside of 48 hours.
The actual time in the air was 7 hours 6 minutes. Strong head
winds blew him backward, forcing a landing three times on the
way. This is the fourth longest cross-country flight on record,
and makes the world’s record for sustained speed over a long
distance.

[Illustration: Mlle. Hélène Dutrieux.]

_September 4, 1910_--Morane, at Havre, rises to height of 8,469
feet.

_September 7, 1910_--Weyman, with Farman biplane, flies from Buc
in attempt to reach the top of the Puy-de-Dôme, lands at Volvic,
5 miles from his destination. Establishes world’s record for
flight with passenger, having covered 139 miles without landing.

_September 28, 1910_--Chavez crosses the Alps on a Bleriot
monoplane from Brigue, in Switzerland, to Domodossola, in Italy,
flying over the Simplon Pass.

_October 1, 1910_--Henri Wynmalen, of Holland, with a biplane at
Mourmelon, France, rises to a height of 9,121 feet, making a new
world’s record for altitude.

_October 4, 1910_--Maurice Tabuteau recrossed the Pyrenees, in
his return trip from San Sebastian to Biarritz, without accident
or marked incident.

_October 5, 1910_--Leon Morane, the winner of nearly all the
contests in the English meets for 1910, fell with his monoplane
at Boissy St. Leger, during a contest for the Michelin cup, and
was seriously injured.

_October 8, 1910_--Archibald Hoxsey, with a biplane, makes the
longest continuous aeroplane flight recorded in America, between
Springfield, Ill., and St. Louis, Mo.--104 miles.

_October 12, 1910_--Alfred Leblanc, with monoplane, at St. Louis,
flies 13 miles in 10 minutes, a speed of 78 miles per hour.
It was not officially recorded, as a part of the distance was
outside of the prescribed course.

_October 14, 1910_--Grahame-White flies from the Bennings
Race Track 6 miles across the Potomac River to the Capitol at
Washington, circles the dome, and then circles the Washington
Monument, and finally alights with precision in Executive Street,
between the Executive Offices and the building of the State,
Army, and Navy Departments. After a brief call, he rose from the
narrow street--but 20 feet wider than his biplane--and returned
to the race track without untoward incident.

_October 16, 1910_--Wynmalen flies from Paris to Brussels, and
returns, with one passenger, within the elapsed time of 27 hours
50 minutes, winning two prizes amounting to $35,000. The distance
is 350 miles, and the actual time in the air was 15 hours 38
minutes.

_October 25, 1910_--J. Armstrong Drexel, with monoplane, at
Belmont Park, L. I., rises to height of 7,105 feet, breaking
previous records, and surpassing his own record of 6,600 feet,
made at Lanark, Scotland.

_October 26, 1910_--Ralph Johnstone, in biplane, at Belmont
Park, rises to the height of 7,313 feet, through sleet and snow,
breaking the new American record made by Drexel the day before.

_October 27, 1910_--Johnstone, with biplane, at Belmont Park,
rises to height of 8,471 feet, surpassing his own record of the
day before and establishing a new American record. The feat was
performed in a gale blowing nearly 60 miles per hour, and the
aviator was carried 55 miles away from his starting point before
he landed.

_October 28, 1910_--Tabuteau, with biplane, at Etampes, France,
makes a new world’s endurance record of 6 hours’ continuous
flight, covering a distance of 289 miles.

_October 29, 1910_--Grahame-White, with monoplane, at Belmont
Park, wins the International speed race over the distance of 62.1
miles, in 1 hour 1 minute 4⅗ seconds.

_October 29, 1910_--Leblanc, with monoplane, at Belmont Park,
makes a new world’s record for speed, reaching 70 miles per hour
during the International speed race. Through a lack of fuel he
lost the race to Grahame-White, after covering 59 miles in 52
minutes.

_October 30, 1910_--John B. Moisant, with monoplane, wins the
race from Belmont Park around the Statue of Liberty in New York
harbor, and the prize of $10,000. The distance is about 34 miles,
and Moisant covered it in 34 minutes 39 seconds.

_October 30, 1910_--James Radley, with monoplane, at Belmont
Park, wins the cross-country flight of 20 miles in 20 minutes 5
seconds.

_October 31, 1910_--Johnstone, with biplane, at Belmont Park,
rises to a height of 9,714 feet, breaking the previous world’s
record, made by Wynmalen on October 1.

_October 31, 1910_--Drexel, with monoplane, racing for altitude
with Johnstone, reaches a height of 8,370 feet.

_October 31, 1910_--Moisant, with monoplane, at Belmont Park,
wins the two-hour distance race with a record of 84 miles. His
next nearest competitor covered but 57 miles.

_November 14, 1910_--Eugene Ely, with biplane, flew from a
staging on the deck of the U. S. Cruiser _Birmingham_ 8 miles
to the shore near the mouth of Chesapeake Bay. The flight was
intended to end at the Norfolk Navy Yard, but an accident to the
propeller at starting forced Ely to make directly for the shore.

_November 17, 1910_--Ralph Johnstone, holder of the world’s
altitude record of 9,714 feet, was killed at Denver, Col., by a
fall with his biplane.

_November 23, 1910_--Drexel, at Philadelphia, reaches an altitude
of 9,970 feet, passing all other altitude records. Coming down he
made a straight glide of seven miles.

_December 2, 1910_--Charles K. Hamilton, at Memphis, Tenn., flies
4 miles in 3 minutes 1 second, a speed of 79.2 miles per hour.
This is a new world’s record.

Chapter XX.

EXPLANATION OF AERONAUTICAL TERMS.

Every development in human progress is marked by a concurrent
development in language. To express the new ideas, new words appear, or
new meanings are given to words already in use.

As yet, the vocabulary of aeronautics is in the same constructive and
incomplete state as is the science to which it attempts to give voice,
and the utmost that can be done at this time is to record such words
and special meanings as are in use in the immediate present.

_Adjusting Plane_--A small plane, or surface, at the outer end of
a wing, by which the lateral (from side to side) balance of an
aeroplane is adjusted. It is not connected with the controlling
mechanism, as are the ailerons--nor with any automatic device.

_Aerodrome_--A term used by Professor Langley as a better
name for the aeroplane; but latterly it has been applied to
the buildings in which airships are housed, and also in a few
instances, as a name for the course laid out for aeronautical
contests.

_Aerofoil_--Another name for the aeroplane, suggested as more
accurate, considering that the surfaces are not true planes.

_Aeronef_--Another name for an aeroplane.

_Aeroplane_--The type of flying machine which is supported
in the air by a spread of surfaces or planes, formerly flat,
and therefore truly “plane,” but of late more or less curved.
Even though not absolutely accurate, this term has resisted
displacement by any other.

_Aerostat_--A free balloon afloat in the air.

_Aeronate_--A captive balloon.

_Aileron_--A small movable plane at the wing-tips, or hinged
between the main planes, usually at their outer ends, operated by
the aviator to restore the lateral balance of the machine when
disturbed.

_Air-speed_--The speed of aircraft as related to the air in which
they are moving; as distinguished from land-speed (which see).

_Alighting Gear_--Devices on the under side of the aeroplane to
take up the jar of landing after flight, and at the same time to
check the forward motion at that moment.

_Angle of Entry_--The angle made by the tangent to the curve of
the aeroplane surface at its forward edge, with the direction, or
line, of travel.

_Angle of Incidence_--The angle made by the chord of the arc of a
curved “plane,” or by the line of a flat plane, with the line of
travel.

[Illustration]

_Angle of Trail_--The angle made by the tangent to the rear edge
of a curved plane with the line of travel.

_Apteroid_--A form resembling the “short and broad” type of the
wings of certain birds--as distinguished from the pterygoid
(which see).

_Arc_--Any part of a circle, or other curved line.

_Arch_--The curve formed by bending the wings downward at the
tips, leaving them higher at the centre of the machine.

_Aspect_--The view of the top of an aeroplane as it appears when
looked down upon from above.

_Aspiration_--The (hitherto) unexplained tendency of a curved
surface--convex side upward--to rise and advance when a stream of
air blows against its forward edge and across the top.

_Attitude_--The position of a plane as related to the line of its
travel; usually expressed by the angle of incidence.

_Automatic Stability_--That stability which is preserved by
self-acting, or self-adjusting, devices which are not under the
control of the operator, nor a fixed part of the machine, as are
the adjusting planes.

_Aviation_--Flying by means of power-propelled machines which are
not buoyed up in the air, as with gas bags.

_Aviator_--The operator, driver, or pilot of an aeroplane.

_Balance_--Equilibrium maintained by the controlling mechanism,
or by the automatic action of balancing-surfaces--as
distinguished from the equilibrium preserved by stabilizing
surfaces.

_Balancing Plane_--The surface which is employed either
intentionally, or automatically, to restore a disturbed balance.

_Biplane_--The type of aeroplane which has two main supporting
surfaces or planes, placed one above the other.

_Body_--The central structure of an aeroplane, containing the
machinery and the passenger space--as distinguished from the
wings, or planes, and the tail.

_Brace_--A construction member of the framing of aircraft
which resists a compression strain in a diagonal direction--as
distinguished from a “stay,” or “diagonal,” which supports a
pulling strain; also from a strut which supports a compression
strain in a vertical direction.

_Camber_--The distance from the chord of the curve of a surface
to the highest point of that curve, measured at right angles to
the chord.

_Caster_, or _Castor_, _Wheel_--A wheel mounted on an upright
pivoted shaft placed forward of its axle, so that it swivels
automatically to assume the line of travel of an aeroplane when
landing: used in the alighting gear. To be distinguished from a
fixed wheel, which does not swivel.

_Cell_--A structure with enclosing sides--similar to a box
without top or bottom stood upon one side. The vertical walls
of the cell give lateral stability, and its horizontal walls
fore-and-aft stability.

[Illustration: The first Santos-Dumont biplane, constructed of cells.]

_Centre of Gravity_--That point of a body where its weight
centres. If this point is supported, the body rests in exact
balance.

_Centre of Lift_--The one point at which the lifting forces of
the flying planes might be concentrated, and produce the same
effect.

_Centre of Resistance_--The one point at which the forces
opposing the flight of an air-craft might be concentrated, and
produce the same result.

_Centre of Thrust_--The one point at which the forces generated
by the revolving propellers might be concentrated, and produce
the same effect.

_Chassis_--The under-structure or “running-gear” of an aeroplane.

_Chord_--The straight line between the two ends of an arc of a
circle or other curved line.

_Compound Control_--A mechanical system by which several distinct
controls are operated through different manipulations of the same
lever or steering-wheel.

_Compression Side_--That side of a plane or propeller blade
against which the air is compressed--the under surface of a
flying plane, and the rear surface of a revolving propeller.

_Curtain_--The vertical surface of a cell--the wall which stands
upright.

_Deck_--A main aeroplane surface. The term is used generally in
describing biplanes; as the upper deck, and the lower deck; or
with aeroplanes of many decks.

_Demountable_--A type of construction which permits a machine to
be easily taken apart for transportation.

_Derrick_--A tower-shaped structure in which a weight is raised
and allowed to fall to give starting impetus to an aeroplane.

_Dihedral_--That form of construction in which the wings of an
aeroplane start with an upward incline at their junction with the
body of the machine, instead of stretching out on a level.

_Dirigible_--The condition of being directable, or steerable:
applied generally to the balloons fitted with propelling power,
or airships.

_Double Rudder_--A rudder composed of two intersecting planes,
one vertical and the other horizontal, thus enabling the operator
to steer in any direction with the one rudder.

[Illustration]

_Double-Surfaced_--Planes which are covered with fabric on both
their upper and lower surfaces, thus completely inclosing their
frames.

_Down-Wind_--Along with the wind; in the direction in which the
wind is blowing.

_Drift_--The recoil of an aeroplane surface forced through the
air: also the tendency to float in the same direction as the wind.

_Elevator_--A shorter name for the elevating planes or elevating
rudder, used for directing the aeroplane upward or downward.

_Ellipse_--An oval figure outlined by cutting a cone through from
side to side on a plane not parallel to its base. Some inventors
use the curves of the ellipse in forming the wings of aeroplanes.
See Hyperbola and Parabola.

_Entry_--The penetration of the air by the forward edge of
aircraft surfaces. See Angle of Entry.

_Equivalent Head Area_--Such an area of flat surface as will
encounter head resistance equal to the total of that of the
construction members of the framework--struts, braces, spars,
diagonals, etc., of the aerial craft.

_Feathering_--A form of construction in which mounting on hinges,
or pivots, permits the surfaces to engage the air flatwise in one
direction and to pass edgewise through it in other directions.

_Fin_--A fixed vertical stabilizing surface, similar in form to
the fin on the back of a fish.

_Fish Section_--A term applied to the lengthwise section of
an aircraft when the outline resembles the general shape of a
fish--blunted in front and tapering toward the rear. This form is
believed to encounter less resistance than any other, in passing
through the air.

_Fixed Wheel_--A wheel in a fixed mounting, so that it does not
swivel as does a caster wheel.

_Flapping Flight_--Flight by the up-and-down beating of wings,
similar to the common flight of pigeons.

_Flexible Propeller_--A propeller in which the blades are frames
covered more or less loosely with a fabric which is in a measure
free to adjust its form to the compression of the air behind it
as it revolves.

_Flying Angle_--The angle of incidence of the main surface of an
aeroplane when in flight. See Ground Angle.

_Footpound_--The amount of force required to raise one pound to
a height of one foot.

_Fore-and-aft_--From front to rear: lengthwise: longitudinal.

_Fuselage_--The framework of the body of an aeroplane.

_Glider_--A structure similar to an aeroplane, but without motive
power.

_Gliding_--Flying down a slope of air with a glider, or with an
aeroplane in which the propelling power is cut off.

_Gliding Angle_--The flattest angle at which a given machine will
make a perfect glide. This angle differs with different machines.
The flatter the gliding angle the safer the machine.

_Ground Angle_--The angle of incidence of an aeroplane surface
when the machine is standing on the ground.

_Guy_--A wire attached to a more or less distant part of the
structure of any aircraft to prevent spreading. Also used to
denote controlling wires which transmit the movements of the
levers.

_Gyroscopic Action_--The resistance which a rotating wheel, or
wheel-like construction, exhibits when a disturbing force tends
to change its plane of rotation.

_Hangar_--A structure for the housing of aeroplanes.

_Head Resistance_--The resistance encountered by a surface moving
through the air.

_Heavier-than-air_--A term applied to flying machines whose
weight is not counterbalanced or buoyed up by the lifting power
of some gas lighter than air; and which weigh more than the
volume of air displaced.

_Helicopater_--A type of flying machine in which propellers
revolving horizontally lift and sustain its weight in the air.

_Horizontal Rudder_--The rudder surface which is used to steer an
aircraft upward or downward: so-called because it lies normally
in a position parallel to the horizon; that is, level.

_Horse-power_--An amount of work equivalent to the lifting of
33,000 footpounds in one minute. See Footpound.

_Hyperbola_--The outline formed by the cutting of a cone by a
plane passing one side of its axis at such an angle that it would
also intersect another cone placed apex to apex on the same axis.

_Keel_--A framework extending lengthwise under an aircraft to
stiffen the construction: usually employed on airships with
elongated gas-bags.

_Lateral_--From side to side; that is, crossing the length
fore-and-aft, and generally at right angles to it.

_Land-speed_--The speed of aircraft as related to objects on the
ground. See Air-speed.

_Landing Area_--A piece of land specially prepared for the
alighting of aeroplanes without risk of injury.

_Leeway_--Movement of a machine aside from the intended course,
due to the lateral drift of the whole body of air; measured
usually at right angles to the course.

_Lift_--The raising, or sustaining effect of an aeroplane
surface. It is expressed in the weight thus overcome.

_Lighter-than-air_--A term used to designate aircraft which,
owing to the buoyancy of the gas attached, weigh less than the
volume of air which they displace.

_Longitudinal_--In a lengthwise, or fore-and-aft direction.

_Main Plane_--The principal supporting surface of an aeroplane.
In the biplane, or the multiplane type, it denotes the lowest
surface, unless some other is decidedly larger.

_Main Landing Wheels_--Those wheels on the alighting gear which
take the shock in landing.

_Mast_--A vertical post or strut giving angular altitude to
guys or long stays. Also used (erroneously) to designate a spar
reaching out laterally or longitudinally in a horizontal position.

_Monoplane_--An aeroplane with one main supporting surface. A
Double Monoplane has two of such surfaces set one behind the
other (tandem) but on the same level.

_Multiplane_--An aeroplane having several main planes, at least
more than three (for which there is the special name of triplane).

_Nacelle_--The framework, or body, of a dirigible balloon or
airship.

_Negative Angle of Incidence_--An angle of incidence below the
line of travel, and therefore expressed with a minus sign.
Surfaces bent to certain curves fly successfully at negative
angles of incidence, and exhibit a comparatively large lift.

_Ornithopter_--A type of flying machine with wing surfaces which
are designed to raise and sustain the machine in the air by
flapping.

_Panel_--Another name for Curtain--which see.

_Parabola_--The form outlined when a cone is cut by a plane
parallel to a line drawn on its surface from its apex to its
base. Declared to be the correct scientific curve for aeroplane
surfaces, but not so proven, as yet.

_Pilot_--A term widely used for an operator, or driver, of any
form of aircraft.

_Pitch_--The distance which a propeller would progress during one
revolution, if free to move in a medium which permitted no slip
(which see); just as the thread of a bolt travels in the groove
of its nut.

_Plane_--Speaking with exactness, a flat spread of surface; but
in aeronautics it includes also the curved sustaining surfaces of
aeroplanes.

_Polyplane_--Another term for Multiplane.

_Port_--The left-hand side of an aircraft, as one faces forward.
See Starboard.

_Projected Area_--The total area of an irregular structure as
projected upon a flat surface; like the total area of the shadow
of an object cast by the sun upon a plane fixed at right angles
to its rays.

_Propeller Reaction_--A force produced by a single revolving
propeller, which tends to revolve the machine which it is
driving, in the contrary direction. This is neutralized in
various ways in the machines driven by single propellers. Where
two propellers are used it is escaped by arranging them to move
in opposite directions.

[Illustration: A pterygoid plane.]

_Pterygoid_--That type of the wings of birds which is long and
narrow--as distinguished from the apteroid type.

_Pylon_--A tower-shaped structure used as a derrick (which see);
also for displaying signals to aeronauts.

_Radial Spoke_--A wire spoke extending from the hub of an
alighting wheel straight outward from the centre to the rim of
the wheel. See Tangent Spoke.

_Rarefaction Side_--A correct term for the incorrect “vacuum
side,” so-called. The side opposite the compression side: the
forward side of a revolving propeller blade, or the upper side
of a flying surface, or the side of a rudder-surface turned away
from the wind.

_Reactive Stratum_--The layer of compressed air beneath a moving
aeroplane surface, or behind a moving propeller blade.

_Rib_--The smaller construction members used in building up
surfaces. Generally they run fore-and-aft, crossing the spars or
wing-bars at right angles, and they are bent to form the curve of
the wings or planes.

_Rising Angle_--Technically, the steepest angle at which any
given aeroplane will rise into the air.

_Rudder_--A movable surface by which the aeronaut is enabled to
steer his craft in a desired direction. See Horizontal Rudder and
Vertical Rudder.

_Runner_--A construction similar to the runners of a sleigh, used
for alighting on some machines, instead of the wheel alighting
gear; a skid.

_Screw_--Another term for propeller; properly, screw-propeller.

_Single-surfaced_--A term used to designate wings or planes
whose frames are covered with fabric only on the upper side. See
Double-surfaced.

_Skid_--Another name for runner.

_Skin Friction_--The retarding effect of the adherence of the
air to surfaces moving rapidly through it. It is very slight
with polished surfaces, and in case of slow speeds is entirely
negligible.

_Slip_--The difference between the actual progress of a moving
propeller, and the theoretical progress expressed by its pitch.
It is much greater in some propellers than in others, due to the
“churning” of the air by blades of faulty design and construction.

_Soaring Flight_--The sailing motion in the air achieved by some
of the larger birds without the flapping of their wings. It is
to be distinguished from gliding in that it is in an upward
direction. Soaring has never been satisfactorily explained, and
is considered to be the secret whose discovery will bring about
the largest advance in the navigation of the air.

_Spar_--A stick of considerable length used in the framing of the
body of aeroplanes, or as the long members in wing structures.

_Stabilize_--To maintain balance by the automatic action
of adjunct surfaces, as distinguished from the intentional
manipulation of controlling devices.

_Stabilizer_--Any surface whose automatic action tends to the
maintaining of balance in the air.

_Stable Equilibrium_--That equilibrium which is inherent in the
construction of the machine, and does not depend upon automatic
or controlling balancing devices.

_Starboard_--The right-hand side of an aircraft as one faces
forward. See Port.

_Starting Area_--An area of ground specially prepared to
facilitate the starting of aeroplanes into flight.

_Starting Device_--Any contrivance for giving an aeroplane a
powerful impulse or thrust into the air. See Derrick.

_Starting Impulse_--The thrust with which an aeroplane is started
into the air for a flight. Most machines depend upon the thrust
of their own propellers, the machine being held back by force
until the engines have worked up to flying speed, when it is
suddenly released.

_Starting Rail_--The rail upon which the starting truck runs
before the aeroplane rises into the air.

_Starting Truck_--A small vehicle upon which the aeroplane rests
while it is gaining sufficient impulse to take flight.

_Stay_--A construction member of an aeroplane sustaining a
pulling strain. It is usually of wire.

_Straight Pitch_--That type of pitch (which see) in a propeller
blade in which every cross-section of the blade makes the same
angle with its axis of revolution.

_Strainer_--Another term for Turnbuckle--which see.

_Strut_--An upright, or vertical, construction member of an
aeroplane sustaining a compression strain; as distinguished from
a brace which sustains a diagonal compression strain.

_Supplementary Surface_--A comparatively small surface used as an
adjunct to the large surfaces for some special purpose; as, for
instance, the preserving of balance, or for steering.

_Sustaining Surface_--The large surfaces of the aeroplane
whose rapid movement through the air at a slight angle to the
horizontal sustains the weight of the machine.

_Tail_--A rear surface on an aeroplane designed to assist in
maintaining longitudinal stability. It is in use principally on
monoplanes, and is often so arranged as to serve as a rudder.

_Tail Wheel_--A wheel mounted under the rear end of an aeroplane
as a part of the alighting gear.

_Tangent_--A straight line passing the convex side of a curved
line, and touching it at one point only. The straight line is
said to be tangent to the curve at the point of contact.

_Tangential_--In the position or direction of a tangent.

_Tangent Spoke_--A wire spoke extending from the outer edge of
the hub of a wheel along the line of a tangent until it touches
the rim. Its position is at right angles to the course of a
radial spoke (which see) from the same point on the hub.

_Tie_--A construction member connecting two points with a pulling
strain.

_Tightener_--A device for taking up the slack of a stay, or tie;
as the turnbuckle.

_Tractor Propeller_--A propeller placed in front, so that it
pulls the machine through the air, instead of pushing, or
thrusting, it from behind.

_Triplane_--An aeroplane with three main surfaces, or decks,
placed in a tier, one above another.

_Turnbuckle_--A device with a nut at each end, of contrary pitch,
so as to take a right-hand screw at one end, and a left-hand
screw at the other; used for drawing together, or toward each
other the open ends of a stay, or tie.

_Uniform Pitch_--That varying pitch in a propeller blade which
causes each point in the blade to move forward in its own circle
the same distance in one revolution.

_Up-wind_--In a direction opposite to the current of the wind;
against the wind; in the teeth of the wind.

_Vertical Rudder_--A rudder for steering toward right or left; so
called because its surface occupies normally a vertical position.

_Wake_--The stream of disturbed air left in the rear of a moving
aircraft, due mainly to the slip of the propeller.

_Wash_--The air-currents flowing out diagonally from the sides of
a moving aeroplane.

_Wing Bar_--The larger construction members of a wing, running
from the body outward to the tips. The ribs are attached to the
wing bars, usually at right angles.

_Wing Plan_--The outline of the wing or main plane surface as
viewed from above.

_Wing Section_--The outline of the wing structure of an aeroplane
as it would appear if cut by a plane passing through it parallel
to the longitudinal centre of the machine.

_Wing Skid_--A small skid, or runner, placed under the tip of
the wings of an aeroplane, to prevent damage in case of violent
contact with the ground.

_Wing Tip_--The extreme outer end of a wing or main plane.

_Wing Warping_--A controlling device for restoring disturbed
lateral balance by the forcible pulling down or pulling up of the
tips of the wings, or of the outer ends of the main surface of
the aeroplane.

_Wing Wheel_--A small wheel placed under the outer end of a wing
or main plane to prevent contact with the ground. An improvement
on the wing skid.

THE END

[Transcriber’s Note:

Inconsistent spelling and hyphenation are as in the original.]

*** End of this LibraryBlog Digital Book "How it Flies or, Conquest of the Air - The Story of Man's Endeavors to Fly and of the Inventions - by which He Has Succeeded" ***

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