The Aeroplane
by Claude Grahame-White · English · Gutenberg #45825 · 427,095 chars · public domain (US)
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Title: The Aeroplane
Author: Claude Grahame-White
Harry Harper
Release date: May 30, 2014 [eBook #45825]
Most recently updated: October 24, 2024
Language: English
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“Romance of Reality” Series
Edited by Ellison Hawks
THE AEROPLANE
* * * * * *
_VOLUMES ALREADY ISSUED_
1. THE AEROPLANE.
By GRAHAME WHITE and HARRY HARPER.
2. THE MAN-OF-WAR.
By Commander E. H. CURREY, R.N.
3. MODERN INVENTIONS. By V. E. JOHNSON, M.A.
4. ELECTRICITY. By W. H. MCCORMICK.
5. ENGINEERING. By GORDON D. KNOX.
* * * * * *
[Illustration: THE AIR LINER OF THE FUTURE.
By the use of such a machine as this, twenty years hence, we shall be
able to spend a week-end in New York, as we do now in Paris or Scotland.
Flying at immense heights, and at speeds of 200 miles an hour, these
huge aircraft--carrying hundreds of passengers in vibrationless
luxury--will pass from London to New York in less than twenty hours.]
“Romance of Reality” Series
THE AEROPLANE
by
CLAUDE GRAHAME-WHITE and HARRY HARPER
Joint Authors of
“The Aeroplane; Past, Present, and Future”
“The Aeroplane in War" “Heroes of the Air”
“With the Airmen" “The Air King's Treasure”
etc. etc.
[Illustration]
London: T. C. & E. C. Jack
67 Long Acre, W.C., & Edinburgh
Printed in Great Britain
PREFACE
Our aim in these pages is to tell a complete story of the aerial
conquest, beginning from crude experiments, made hundreds of years ago;
passing thence to the first serious experimenters, with their
difficulties and triumphs; and so carrying on the tale to present-day
achievements and the latest-type machines.
There is one aspect of this history which has an especial fascination;
and it is the personality of the men who--braving ridicule and scorn and
surmounting obstacles without number--laid the foundation-stones of
flight. Instead of being a compilation of dates, with certain
explanatory matter added, our book endeavours to make these men live: to
show what induced them to embark upon their seemingly hopeless quest; to
tell of their dreams and longings, and how they built their first frail
craft; to trace them to their boyhood and their play with kites; to
reveal them, in a word, as living beings, and not merely as names.
With this strongly human note, emphasizing the romance of the tale,
there goes also a series of explanations--made clearer by drawings and
diagrams--and tending always to show how, link by link and step by step,
data and experience were secured; how each pioneer, however humble,
played his individual and useful part; and how in the end, by sifting
all such knowledge and carrying experiment to its final stage, the
Wrights achieved the apparent miracle, and flew safely and successfully
in a power-driven machine.
The book divides itself naturally into sections. First there is the
story of the very early and haphazard tests, and of the notes and
speculations of scientists; then of the advent of the practical, patient
experimenter--the man who, taking a hint from the birds, realized that
ere he could hope to fly he must learn first to balance himself when in
the air. This stage, of course, introduces Otto Lilienthal--the German
engineer who, by his gliding flights from hilltops with outstretched,
bird-like wings, has won the honour of being styled “the father of the
aeroplane.”
From a narration of his work, so vital a link in the chain of progress,
the story passes to those two men--unflurried, reserved, and infinitely
painstaking--who at last evolved order out of chaos: Wilbur and Orville
Wright. Their diligent study is described; their perfected glider; the
building of their own motor; and, finally, that great day of triumph
which came in 1903--just eleven years ago.
The world being given thus an aeroplane which would fly, the steps which
followed were mainly those of perfection and improvement. One by one the
limitations were removed. At first men dared only to fly above a
smooth-surfaced aerodrome, in case their motors should stop and send
them gliding back to earth; but soon, gaining confidence in themselves
and in their engines, they were passing high across country. So, also,
in regard to their enemy the wind. Dreading even a gentle gust at
first, for fear it might overturn them, they have gained so rapidly in
skill that, thanks to their experience and the stability of their
machines, the airmen of to-day will do battle with a gale. In this
section of our book is a description of the greatest feats, both of
early days and of modern times--such as speed flying, altitude records,
and the touring of continents by air.
Thus logically may the tale be told: with digressions of course to cover
the risks of aviation, and to explain how they are being overcome; to
deal with aerial warfare and its many problems; to describe the advent
of the sea-plane; and to discuss the day when--a perfected passenger
craft being available--men will journey by air as they do now by land or
sea.
CLAUDE GRAHAME-WHITE.
HARRY HARPER.
LONDON, 1914.
NOTE.--_The authors thank most cordially the proprietors of_ The
Daily Mirror _for permission to reproduce certain photographs,
of an historical interest, which depict incidents from the
cross-Channel flying both of Latham and Bleriot; also F. N.
Birkett, Esq., the Topical Postcard Company, and_ The Central
News _for permission to use photographs illustrative of modern
aviation_.
CONTENTS
CHAP. PAGE
I. WHAT EARLY HISTORY TELLS 1
II. THE WORK OF SCIENTISTS 8
III. FIRST FRUITS OF STUDY 21
IV. OTTO AND GUSTAV LILIENTHAL 31
V. GLIDING FLIGHT 41
VI. “THE BIRD MAN” 53
VII. WILBUR AND ORVILLE WRIGHT 62
VIII. THE WRIGHT MOTOR-DRIVEN PLANE 71
IX. DAWN OF FLIGHT 84
X. RIVAL AIRMEN 93
XI. A YEAR OF TRIUMPH 101
XII. PERILS OF THE AIR 130
XIII. MILITARY AND CROSS-COUNTRY FLYING 149
XIV. SEA-PLANES AND AIRSHIPS 169
XV. AERIAL WARFARE 188
XVI. AT A MODERN AERODROME 209
XVII. THE FLYING SCHOOL 226
XVIII. TOURING BY AIR 247
XIX. TWENTY YEARS HENCE 270
LIST OF PLATES
THE AIR LINER OF THE FUTURE _Frontispiece_
PLATE FACING PAGE
I. THE LANGLEY MACHINE 26
II. SANTOS-DUMONT’S FIRST FLIGHTS 46
III. FARMAN’S VOISIN BIPLANE 68
IV. LATHAM’S FALL INTO THE SEA 84
V. BLERIOT LEAVING THE FRENCH COAST 96
VI. BLERIOT REACHES DOVER 110
VII. A FARMAN IN FLIGHT 116
VIII. THE GNOME MOTOR 122
IX. THE FIRST HIGH-POWERED BLERIOT 134
X. MAURICE FARMAN BIPLANE 150
XI. AN AIRMAN’S POINT OF VIEW 164
XII. THE LONDON AERODROME FROM ABOVE 188
XIII. AN AEROPLANE FACTORY 202
XIV. BIPLANE CIRCLING A PYLON 230
XV. VIEW FROM A CRAFT ASCENDING 240
XVI. THE GRAHAME-WHITE “AEROBUS” 252
THE AEROPLANE
CHAPTER I
WHAT EARLY HISTORY TELLS
Simon the magician--A monk who sprang from a
tower--The Saracen who “rose like a bird.”
In learning to fly, men have passed through five definite and
clearly-marked stages which have extended over centuries, and cost many
lives. These five stages may be summarized thus:
1. Haphazard and foolhardy tests--ending generally in
death.
2. A period of scientific research, in which the
flight of birds was studied and experiments made
with lifting planes of various shapes.
3. A phase during which engineers built large,
power-driven machines, but had not the skill to
control them when in flight.
4. A stage in which, making a simple apparatus of
wings, men glided from hilltops, and learned to
balance themselves while in the air.
5. The stage in which, perfecting the gliding machines
they had learned to control, men fitted petrol
motors to them, and achieved at last a power-driven
flight.
In dim, remote ages, watching winged creatures as they skimmed above the
earth, men longed passionately to fly; instead of scaling hills or
creeping through woods, they desired to pass high above them; to spurn
the obstructions of creatures earth-bound, and fly over mountains and
seas. This longing to fly, even at the risk of life itself, was
expressed beautifully by Otto Lilienthal, the greatest of the pioneers.
He wrote:
“With each advent of spring, when the air is alive with
innumerable happy creatures; when the storks, on their arrival at
their old northern resorts, fold up the imposing flying apparatus
which carries them thousands of miles, lay back their heads and
announce their arrival by joyfully rattling their beaks; when the
swallows have made their entry and hurry through our streets and
pass our windows in sailing flight; when the lark appears as a dot
in the ether and manifests its joy of existence by its song; then
a certain desire takes possession of man. He longs to soar upward
and to glide free as a bird over smiling fields, leafy woods, and
mirror-like lakes, and so enjoy the fairy landscape as only a bird
can do.”
But man’s first attempts to fly were ill-judged and foolish. He failed
to understand the problems involved; he forgot that, even were he able
to build a machine which would navigate the air, he must learn to
control this craft; must learn to steer and balance it, and make it ride
the gusts. One might, for example, take a bicycle and say to a man:
“Here is a machine that can be propelled along the road; mount it and
ride away.” But if the man had not learned to handle a bicycle, and
balance himself on one, he would swerve for a few yards and then fall.
So with the man who, without forethought or study, sought to navigate
the air.
Probing the recesses of history we find that, even as far back as the
reign of the Emperor Nero, there was one Simon the magician who--if
legend can be credited--sought “to rise towards Heaven.” Simon, it
would seem, actually lifted himself into the air by the use of some
apparatus; but what this device was legend does not state. The
spectators seem to have been horrified, and Simon’s ascent into the air
was attributed to “the assistance of Beelzebub.” His triumph was
short-lived, for, as the legend goes on to record, he fell to the earth
and was killed. And this fate befell many who, in those very early days,
made flimsy wings and threw themselves from towers or the tops of hills.
Simon, it is thought, may have had some method in his apparent madness.
He may, for instance, have made a lifting plane and discovered that, if
he placed himself in a rising current of air, the effect would be to
raise him from the ground; and this suggestion has a greater probability
when we remember that in warm, southern lands there are often strong
up-currents of air upon which birds will soar, with wings motionless.
But what machine Simon used, and how he made his flight--if he did--are
questions that remain unanswered.
[Illustration: FIG. 1.]
Looking back into history, one fact is striking; and this is the part
that monks played in studying flight. They had leisure to think, and
time in which to make tests; and in many a monastery, hundreds of years
ago, quaint theories were propounded and queer craft planned. In the
eleventh century, at Malmesbury in England, there was a Benedictine monk
named Elmerus, or Oliver, more ambitious than many of his brethren. He
built himself a machine with wings; then, in order to put it to the
test, he ascended a tall tower, faced the wind, and sprang into the air.
That he had studied weighting and balance to some purpose was evident,
for he glided a short distance without accident; then, struck perhaps by
a sudden gust, lost equilibrium and came crashing to the ground. He was
not killed, as were many less rash than he; but broke his legs, and
nothing more is read of him as an experimenter. Of the doings of another
of these brave but reckless men--a Saracen who tried to fly in the
twelfth century--there is fuller information. He provided himself with
wings which he stiffened with wooden rods, and held out upon either side
of his body. Wearing these, he mounted to the top of a tower in
Constantinople (Fig. 1) and stood waiting for a favourable gust of wind.
When this came and caught his wings, he “rose into the air like a bird.”
And then, of course, seeing that he had no idea of balancing himself
when actually aloft, he fell pell-mell and “broke his bones.” People who
had gathered to watch, seeing this inglorious ending to the flight,
burst into laughter: ridicule rather than praise, indeed, was the fate
of the pioneers, even to the days when the first real flights were made.
In the fifteenth century, working upon more sensible lines of thought,
Leonardo da Vinci--an Italian genius who was painter, inventor,
sculptor, writer, and musician--devised several machines by which men
might navigate the air. Success did not come to him, as he had no motive
power with which he could equip a craft; but how keen a watcher he was
of the birds is shown by a passage from one of his manuscripts:
“The kite and other birds, which beat their wings little, go
seeking the course of the wind, and when the wind prevails on high
then will they be seen at a great height, and if it prevails low
they will hold themselves low. When the wind does not prevail at
all, then the kite beats its wings several times in its flight
in such a way that it raises itself high and acquires a start,
descending afterwards a little and progressing without beating its
wings, repeating the same performance time after time.”
Da Vinci, too, had some notion as to the need for balancing a machine
while in the air, and did not seem--like most others of the early
pioneers--to imagine that once a man had launched himself from a height
he would be able to control his craft by instinct. He wrote, indeed,
suggesting the position of a pilot in a flying machine, that “he should
be free from the waist upwards, in order that he might keep himself in
equilibrium, as one does in a boat.”
He realised, too, a fact that the modern airman always bears in mind;
and that is the value of flying high. Da Vinci wrote in this regard:
“Safety lies in flying at a considerable height from the ground, so that
if equilibrium be temporarily upset there may be time and space for
regaining it.”
Among the machines Da Vinci planned was an ornithopter, or craft with
arched wings which would flap like those of a bird; and a helicopter, or
apparatus in which revolving screws are used to draw it up into the
air. He devised mechanism by which a man might move two wings, shaped
like those of the bird, and thus imitate natural fight. These wings were
planned ingeniously, so that they would contract on the up-stroke and
expand when forced downward. In one of his notebooks, too, he made a
sketch of a helicopter machine which was to have a lifting propeller 96
feet in diameter, and to be built of iron with a bamboo framework. He
made paper helicopters, or whirling screws, and sent them spinning into
the air; and to him, also, was due the first suggestion for the use of a
parachute.
[Illustration: FIG. 2.--Besnier’s Apparatus.]
From this time, until the beginning of the nineteenth century, men still
strove to fly, but all of them failed to see a vital point: that they
must learn gradually to balance themselves in the air, even as the young
birds have to do. So those who were not killed were badly injured, and
those who persisted in experiments were looked upon either as madmen or
fools. Some, however, were not so foolish as they seemed. They brought
forward schemes so as to attract the attention of kings and those in
high places; and this was particularly the case in France, during the
reigns of Louis XIV. and Louis XV. But the notoriety they won was
short-lived. The day came when they needed to make good their
claims--when they were called upon to fly; and then they met death,
disablement, or disgrace, and were forgotten quickly. Of the devices
suggested many showed ingenuity; and some were quaint, in view of what
we know of flight to-day. In the machine, for instance, designed by an
experimenter named Besnier--who was a locksmith by trade--there were
four lifting planes, closing on the up-stroke and opening on the down,
and these the operator was to flap by the use of his hands and feet
(Fig. 2). A rather similar idea was suggested as long ago as 1744, by
the inventor De Bacqueville; his plan was to fix four planes or wings to
his hands and feet, and then propel himself through the air by vigorous
motions of his arms, and kickings of his legs (Fig. 3). He made a flight
from a balcony overlooking a river, but finished his trial ingloriously
by falling into a barge. Such schemes, indeed, were doomed to failure;
and they are only interesting because they show how, even in those
far-off days, men were ready to risk their lives in attempts to conquer
the air.
[Illustration: FIG. 3.--De Bacqueville (1744).]
CHAPTER II
THE WORK OF SCIENTISTS
Sir George Cayley’s forecasts--A steam-driven model
which flew--The shape and curve of planes.
So passed the haphazard stage of flight; and now history moves to a
second and more important period, that in which men of science were
attracted to the problem. They worked upon theories, and made
experiments with models; they studied the shape which Nature has given
the birds; they sifted false notions and showed where error lay. But
they did not fly. They were merely clearers of the ground, gathering
information and classifying it, and paving the way for those daring
workers who were to follow them--men who, by putting science to the
test, were willing to risk their lives.
[Illustration: FIG. 4.--Sir George Cayley’s suggestion for an Arched
Plane.]
To England goes the distinction of the first practical attempts to solve
the problems of flight; and it is the work of Sir George Cayley, an
eminent scientist and engineer, that next merits attention. In a series
of articles, published in _Nicholson’s Journal_ during the years
1809-10, he forecasted many of the principles that go to the making of a
modern-type aeroplane. He advised the construction of machines with
fixed, outstretched wings like those of a bird; but he did more than
this, for it is admitted generally he was first to point out that, to
increase their lifting power as they were moved through the air, these
wings should not be flat, but should be curved from front to back, or
arched upward (Fig. 4). How important this suggestion was, subsequent
experimenters were to show. Sir George Cayley realised also that a
tail-plane, carried at the rear of a machine, would give it equilibrium,
and might be moved up and down to control ascent or descent; and he used
a rudder upon models, to steer them from side to side. He advised the
use of steam engines as a motive power, and of revolving propellers to
drive a craft through the air. But, like many another man, he was before
his time. He built experimental craft--one, a model glider, which would
sail down gracefully from the top of a hill; and another, a far larger
machine, which would bear a man through the air, for a distance of
several yards, if he ran forward with it against the wind. But the
difficulty of obtaining a sufficiently light and practical motor, either
of steam or other power, was an obstacle that proved insurmountable. One
light engine, which Sir George Cayley planned, was to be driven by a
series of gunpowder explosions in a cylinder; but the suggestion came to
no practical issue.
This scientist did not write or work in vain. He compiled data which was
invaluable, and interested and encouraged other men--even those, indeed,
who in due course made the conquest. One of the first to work upon Sir
George Cayley’s theories was an experimenter named Henson. He planned
an ambitious machine weighing about a ton. It was to have planes of
canvas stretched over a rigidly trussed frame of bamboo rods and hollow
wooden spars; and these planes were to contain 4500 square feet of
lifting surface, and be driven by screws operated by a steam engine of
30 h.p. (Fig. 5).
But this craft did not take practical shape, although in its appearance
and many of its details it bore a resemblance to machines which
ultimately were to fly. In the specification of the patent he took out
for his invention, Henson indicated that it was for
“Improvements in locomotive apparatus and machinery for conveying
letters, goods, and passengers from place to place through the
air.”
[Illustration: FIG. 5.--Henson’s proposed Machine.]
Explaining his theories in this same specification he wrote:
“If any light and flat or nearly flat article be projected or
thrown edgewise in a slightly inclined position, the same will
rise into the air till the force exerted is expended, when the
article so thrown or projected will descend; and it will readily
be conceived that, if the article so projected or thrown possessed
in itself a continuous power or force equal to that used in
throwing or projecting it, the article would continue to ascend so
long as the forward part of the surface was upwards in respect to
the hinder part.”
Had Henson been able to carry out his ideas, it is almost certain that
this experimental machine would have been wrecked in its tests, and
probably several more after it, seeing that he would have had to learn
to control them when in flight, and remembering also that, even with
aircraft as they are built to-day, many details have to be studied and
improved before a successful model is evolved.
All such work, of course, entails heavy expense. It was, indeed, the
cost of experiments which prevented many an early inventor from building
a full-sized machine. The designing and construction of a man-carrying
craft, and the employment of skilled workmen and mechanics, to say
nothing of repairs that may have to be made during a series of tests,
represent an expenditure that may amount to thousands of pounds. As a
rule, the inventor is not a man of wealth; and so far as flying was
concerned, at any rate in the early days,--and to a more limited extent
even at the present time,--people with money thought the difficulties so
great that they would not advance funds for the carrying out of trials.
So men with ideas had to do the best they could, and this resolved
itself generally into writing and lecturing, and endeavouring to
interest the public. But the public was not easily interested; ordinary
folk did not believe that men would ever fly, while many people declared
that it was going against Nature for us to try to imitate the birds, and
that nothing but mischief would come of so doing.
Henson, failing to make definite progress with his scheme for a
man-carrying craft--despite the fact that a company was floated to
assist him--co-operated with another enthusiast named Stringfellow in a
plan which was not so elaborate. They began to experiment with a series
of models driven by tiny and most ingenious steam engines built by
Stringfellow; and so cleverly did he construct them that the
Aeronautical Society awarded him a prize of £100. The model which won
him this recognition was a little plant which, while it weighed only 13
lbs., without water or fuel, would develop one horse-power.
What, by the way, is meant by a horse-power? The answer is as follows:
in the early days of engineering, when it was found necessary to
establish some well-recognised unit of power, a large number of
experiments were carried out with horses, which were made to raise a
weight from the ground by means of an arrangement of pulleys and ropes.
The experiments showed this: that a horse can exert sufficient power to
raise 33,000 lbs., or about 15 tons, to a height of 1 foot in the space
of one minute. This, therefore, was called “one horse-power.”
In Stringfellow’s days, it must be remembered, there was no petrol
engine; an engine so extremely light for the power that it will give,
and with its liquid fuel and oil carried conveniently in tanks--an
engine which, as Sir Hiram Maxim puts it, will give one horse-power of
energy “for the weight of a barn-door fowl.”
The question of motive-power was, indeed, the great obstacle for the
pioneers. When a man builds an aeroplane he must drive it through the
air; and to drive it through the air he requires an engine. But he knows
that his planes, owing to the small density or sustaining power of the
air through which they pass, will raise only a limited load. And the
machine itself, even if it is built of wood and canvas, represents an
appreciable weight; to say nothing of that of the pilot. So, if his
engine is heavy in proportion to the power it gives, and its fuel
weighty, he may be prevented altogether from rising from the ground; or
if he does rise, he may be able only to carry sufficient fuel for a
flight of a short distance.
[Illustration: FIG. 6.--Henson and Stringfellow’s Model.]
Henson and Stringfellow built in 1845 a model which weighed about 30
lbs. (Fig. 6); and although its stability was not perfect, it was an
interesting machine--a forecast of the monoplane of the future. Here one
saw the lifting planes take shape; the body between the wings; the
tail-planes at the rear; and, above all, a suggestion of the means by
which machines would be driven through the air: the fitting to the
model, that is to say, of revolving propellers or screws. When an
inventor has fitted an engine to an aircraft, means must be devised for
using its power to drive the machine through the air; and to make the
wings flap like those of a bird, has been found so complicated, owing to
the mechanism necessary to imitate natural movements, that much of the
power is wasted. Inventors such as Henson and Stringfellow, realising
this difficulty, made wings that were outstretched and immovable, like
those of a bird when it is soaring, and relied upon screw
propellers--which they set spinning at great speed by means of their
engines--to thrust their craft forward through the air.
[Illustration: FIG. 7.]
In an early and simple form, the aerial propeller was as shown in Fig.
7. Here are two curved blades, so shaped that, when the propeller is
made to revolve quickly, these blades will act powerfully upon the air.
What the propeller does is to screw itself forward through the air, as
one might revolve a corkscrew and drive it into a cork, or force a
gimlet into a piece of wood. Each time you twist the gimlet for
instance, as you drive it inwards, it forces itself a certain distance
through the wood; and in a like manner the air-propeller, each time it
revolves, tends to bore its way through the air (Fig. 8) and so push, or
draw with it, the flying machine to which it is attached. But with air,
seeing that its density is small, it is necessary to use a large screw,
and to turn it fast, before power can be obtained.
[Illustration: FIG. 8.]
In 1845, Stringfellow, who was now working alone--Henson having
abandoned the tests and gone abroad--met with a definite success. He
obtained actual flights with a steam-driven model in the form of a
monoplane, weighing 8-1/2 lbs. These tests attracted attention among
scientists, but they led to nothing else--that is to say, no full-sized
machine was the result. But Stringfellow’s model interested many people
in the problems of flight. It showed, indeed, although in miniature,
that a flying machine could be built and driven through the air; and so
this patient experimenter did not labour in vain.
Following Stringfellow, upon the list of those who forged links in the
aerial conquest, came Francis Herbert Wenham. His interest in flying, as
with many other men, was aroused by watching the birds. Wenham, an
engineer by profession, made a voyage up the Nile; and his study of the
movement of birds, as they flew near his yacht, caused him to take up
aviation in earnest, and carry out experiments for the Aeronautical
Society. Wenham was interested largely in the lifting power of planes,
and sought efficient shapes. He recommended the building of arched
surfaces, so arranged that they had considerable span, but were narrow
from front to back; and he suggested also that they should, when fitted
to a machine, be placed one above another. Thus Wenham was the inventor
of the biplane, as we know that craft to-day.
In explaining this point he wrote:
“Having remarked how thin a stratum of air is displaced between
the wings of a bird in rapid flight, it follows that, in order to
obtain the necessary length of plane for supporting heavy weights,
the surfaces may be superposed, or placed in parallel rows with an
interval between them” (Fig. 9).
[Illustration: FIG. 9.--Superposed Lifting Planes.]
To illustrate his theory, he built a model which had six long, narrow
planes, arranged one above the other, rather like the slats of a
Venetian blind. Wenham’s experiments were highly important, because they
cleared a great deal of ground, and removed many misunderstandings. By
showing that a long, narrow plane was more efficient--would, that is to
say, carry a greater load through the air than one which was deep from
front to back, owing to the fact that it is the front section of an
inclined plane that provides the most “lift”; and by illustrating how,
in a full-sized machine, such a row of planes could be arranged one
above another, Wenham directed men’s thoughts towards a definite goal.
By his work, and chiefly by his sifting of data, an outline was obtained
of that aeroplane of the future which was actually to fly.
While Wenham was experimenting, an inventor named Penaud, in France,
testing a series of models, made one which was driven by the twisting of
elastic, and flew quite well. Penaud’s work in this respect is
interesting, because small elastic-driven machines, such as he designed,
were used afterwards in demonstration, and are flown to-day. For a
miniature aeroplane, elastic is an ideal motive force--light and yet
providing ample power, and with only one disadvantage: it unwinds itself
rapidly, and then the model must descend.
In experiments of permanent value, after the discoveries of Wenham,
important work was that of Horatio Phillips. Like Wenham, he devoted his
attention mainly to a study of lifting planes, and tested many shapes
and curves. Sir George Cayley, it may be remembered, had suggested a
curved and not a flat plane; but Phillips went one better than this, for
in 1881 he devised a plane with what has been termed a dipping front
edge.
[Illustration: FIG. 10.--The Phillips Wing-Curve.]
The shape and curve of a plane, is of vital importance. A machine may be
built, and an engine and propellers fitted, but the question is: Will
the planes support through the air the load they have been given to
carry? Phillips made many experiments, and in the end he produced a
wing-shape which he patented. He pointed out that an advantage might be
gained in lifting effect if the main curve or camber was situated near
the front edge of the plane, and not in the centre (Fig. 10). The theory
Phillips worked upon was this--and it is interesting if it can be
expressed clearly. Taking a plane curved as he recommended, with this
“hump” towards the front, and forcing it through the air as would be the
case were an aeroplane in flight, the rush of wind which meets the edge
of the plane is split into two currents--one sweeping above and one
below. The air current below the plane, following its curve, is thrust
downward, and in being so thrust down imparts a lift to the plane; while
the current thrown above the plane--rushing up and over the “hump”
which, as has been shown, is situated close to the front edge--will
sweep rearwards in such a way that there is a partial vacuum or air
space between the fast-moving wind current and the curved-down section
of the plane behind the “hump.” The value of such a vacuum is this: it
has a raising effect upon the surface of the plane, which is thus not
only pushed up from below, but drawn from above.
[Illustration: FIG. 11.--Suction above a Cambered Surface.]
How a vacuum is caused, by air passing over such an arched surface as
Phillips recommended, may be shown in a simple experiment. Take a sheet
of paper and curve it in the way shown in Fig. 11, allowing the rear
portion to hinge in such a way that it will move freely up and down.
Then, if the sheet of paper is held between the finger and thumb and one
blows across the top edge, the hinged flap at the rear will be found to
raise itself--drawn up by the influence of the vacuum, such as Phillips
describes.
Apart from his theory as to the dipping front edge of a plane, Phillips
agreed with a suggestion made by Wenham; and this was that a plane, in
order to be most effective in its “lift,” should be narrow from front to
back. This theory meant that, as a plane moved forward, it was the
curving front section which gripped and acted up the air; and that, if
the plane was carried too far towards the rear, its lifting influence
fell away, while the surface that was superfluous acted as so much
resistance to the machine’s progress through the air.
[Illustration: FIG. 12.--Phillips’s Experimental Craft.]
In furtherance of his views, Phillips built the strange-looking machine
which is seen in Fig. 12. It resembled, more than anything else, a huge
Venetian blind; and he adopted this form so as to introduce as many
narrow planes as possible. There were, as a matter of fact, fifty in the
machine, each 22 feet long and only 1-1/2 inch wide. The craft, as can
be seen, was mounted on a light carriage which, having wheels fitted to
it, ran round and round upon a railed track. A steam engine was used as
motive power, driving a two-bladed propeller at the rate of 400
revolutions a minute. The machine was so arranged on its metals that,
although the rear wheels could raise themselves and show whether the
planes exercised a lift, the front one was fixed to its track--thus
preventing the apparatus from leaping into the air, overturning, and
perhaps wrecking itself. Tests with the machine were successful. The
lifting influence of the planes, when the engine drove them forward, was
sufficient to raise the rear wheels from the track; and they did so even
when a weight of 72 lbs., in addition to that of the apparatus, had been
placed upon the carriage. In his main object, then, Phillips succeeded;
and that was to show the lifting power of his planes. But his apparatus
had not the makings of a practical aeroplane. He gained for himself,
nevertheless, a name that has lived and will live. Even to-day, in
discussing the wing-shape of some machine, draughtsmen will speak of the
“Phillips entry.” Other workers did not pin themselves exactly to his
shapes or theories, but these paved the way for a series of further
tests.
Science was forging link by link indeed the chain that would lead to an
ultimate conquest. Sir George Cayley suggested an arched plane; Wenham
devised a machine in which narrow planes should be fitted one above
another; and Phillips laid down the rule for a curve or camber of
special shape, which should exercise most “lift” when thrust through the
air. But still men lacked many things; all the links in the chain were
far from being in their place; and one of the greatest flaws was that no
man, even supposing he was able to build a machine that would fly, had
learned as yet to balance that machine when it was in the air.
CHAPTER III
FIRST FRUITS OF STUDY
The building of large machines--Sir Hiram Maxim’s
costly work--A steam-driven French craft which
flew--Professor Langley’s research in America.
Of the way research next tended, it may be said that it was the first
putting into practice of the theories science had laid down; for now,
having an idea as to the shape of planes, and knowing that these planes
could be made to carry a load through the air, there were engineers who
began to build man-carrying, power-driven machines. In so doing,
however, they may be said to have tried to run before they could walk.
What they did was to provide the world with powerful flying craft before
there were men who could handle them.
One of the most interesting and ambitious designs was that of Sir Hiram
Maxim; and it was one to which he devoted years of labour and large sums
of money. He is said, indeed, to have expended £20,000 upon aerial
research. After a number of experiments with plane shapes, following the
theories of Phillips, he began to build a very large machine, which he
set upon a miniature railway as Phillips had done, using the same
precaution of a check-rail to prevent it from rising more than a certain
distance in the air. His apparatus, when built at Baldwin’s Park, Kent,
weighed 8000 lbs.: it was, in fact, the largest machine ever built. The
span of its planes was 105 feet, and they offered a total supporting
surface of 6000 square feet.
[Illustration: FIG. 13.
A. Elevating Plane; B.B. Outriggers; C.C. Operating Wires; D.D. Position
for ascending; E.E. Position for descending.]
The inventor employed the suggestion made by Wenham, and fitted his
lifting planes one above the other; while he used a horizontal plane in
front of the machine to act as an elevator. This plane could be tilted
up and down; and the idea was that, when it was tilted upward as the
machine ran forward upon its rails, it would exercise such a lifting
influence that the front of the craft itself would be raised, and so
cause the main-planes to assume a steeper angle to the air; and the
result of the planes being inclined thus more steeply would be to give
them a greater lift, and so induce the whole machine to raise itself
from the ground. This system is explained in Fig. 13, and is important
because such lifting planes, for rising or descending, have now come
into general use.
Sir Hiram Maxim employed another controlling surface which has become a
feature of present-day aircraft, and this was an upright plane, which
could be swung from side to side, and by which his craft was to be
steered. Such a rudder-plane is illustrated in Fig. 14. By this means,
as will be shown later, practically all aeroplanes are steered to-day.
The action of the aerial rudder, when it is moved from side to side, is
like that of swinging the rudder of a ship; but for the same reason that
propellers have to be made large--owing to the small density of the
air--so an aeroplane rudder needs to be a comparatively large plane, in
proportion to the size of the craft, before it will exercise an adequate
turning influence.
[Illustration: FIG. 14.
A. Vertical steering rudder; B.B. Outriggers; C.C. Operating wires;
D.D., E.E. Positions assumed in turning.]
To drive his machine Sir Hiram used two specially-built and lightened
steam engines, which developed a total of 360 h.p., and yet weighed only
640 lbs.; that is to say, they gave one h.p. of energy for each 1-3/4
lb. of weight. But they were only suitable for purposes of experiment.
Sir Hiram himself wrote:
“The quantity of water consumed was so large that the machine
could only remain in the air for a few minutes, even if I had had
room to manœuvre and learn the knack of balancing it in the air.
It was only too evident to me that it was no use to go on with the
steam engine.”
The engines drove two canvas-covered wooden screws, each 18 feet in
length, and the general appearance of the machine is indicated by Fig.
15. In these trials, although it was always captive, the aeroplane
demonstrated much that its inventor had set himself to prove. In Sir
Hiram Maxim’s own words, it showed that it had “a lifting effect of more
than a ton, in addition to the weight of three men and 600 lbs. of
water.” He adds: “My machine demonstrated one very important fact, and
that was that very large aeroplanes had a fair degree of lifting power
for their area.”
[Illustration: FIG. 15.--The Maxim Machine.]
So unmistakably did this craft show its lifting power, that--in one
fierce effort to rise--it broke a check rail which kept it upon its
metals, with the consequence that it became unmanageable, swerved
sideways, and was wrecked. At this stage Sir Hiram, having no faith in
the future of such steam engines as he was using, and having spent a
large sum of money, was compelled to relinquish his tests. His trouble
was that he was, as the saying goes, “before his time.” The machine was
too ambitious and too large. That it would have lifted itself into the
air was proved; but there was no man living who could have controlled
it. To put in charge of such a craft a man who knew nothing of the
navigation of the air, would have been like placing a novice at the
levers of a 60-mile-an-hour express. Picture such a huge aircraft in the
hands of a man who had never flown. It would rise, it is true; but how
could one who was not an expert so adjust the angle of its lifting plane
that it would glide smoothly from the ground and not rear itself upward
and fall with a crash? A machine is struck by wind-gusts, too, when it
is aloft; and there is the delicate art of making a descent, without
damaging one’s craft by a rough contact with the ground. Besides, it
would have been unlikely that this machine, being purely experimental,
would have been perfectly balanced as it flew: it might have shown a
tendency to slip sideways when in the air, or dive steeply. All of which
goes to show this: that the inventor might have wrecked one costly
machine after another before he obtained a practical model, even were he
lucky enough to escape with his life. Sir Hiram Maxim’s machine, while
it settled problems as to weight-lifting and power, lacked the man who
could fly it; and so did others of these man-lifting craft which were
built before their time. A child must learn to walk before it can run,
and must learn to crawl before it can walk. And what had not been
realised, at this stage of the conquest, was that there must be some
stage between building a model and a full-sized, motor-driven machine:
some step, in a word, by which a man might learn, without too great a
risk of death, to balance himself when in the air.
While Sir Hiram Maxim in England was devoting time and money to the
quest, there was another skilled engineer, a Frenchman, who was working
at the problem, and also by means of large machines. This was Clement
Ader, one of the European pioneers of the telephone, and he experimented
for many years. One of his first machines had wings like those of a
bird, and these the would-be flier was to operate by his own muscular
power. But this failed, seeing that men are not provided with sufficient
power, by their unaided efforts, to wing their way through the air in a
flapping flight. As Giovanni Borelli, a seventeenth century writer,
quaintly puts it: “It is impossible that men should be able to fly
craftily by their own strength.”
[Illustration: PLATE I.--THE LANGLEY MACHINE.
This craft, a double monoplane, was launched from a platform over the
river Potomac, loaded with a weight equivalent to that of a man. The
trials were unsuccessful; but recently--after a lapse of many years--the
Langley machine has been tested again, and has proved its ability to
fly.]
Ader next turned to steam-driven craft, and built a series of queer,
bat-like machines, which he called “Avions,” one of which is illustrated
in Fig. 16. Its wings were built up lightly and with great strength by
means of hollow wooden spars, and had a span of 54 feet, being deeply
arched. The whole machine weighed 1100 lbs., and was thus far smaller
and lighter than Maxim’s mighty craft. To propel it, Ader used a couple
of horizontal, compound steam engines, which gave 20 h.p. each and drew
the machine through the air by means of two 4-bladed screws. The craft
was controlled by altering the inclination of its wings, and also by a
rudder, the pilot sitting in a carriage below the planes. In 1890, after
its inventor had spent a large sum of money, the machine--which, unlike
those of Phillips and Maxim, ran upon wheels and was free to rise--did
actually make a flight, or rather a leap into the air, covering a
distance of about fifty yards. But then, on coming into contact with the
ground again, it was wrecked. Ader’s experiments were regarded by the
French Government as being so important that he received a grant
equalling £20,000 to assist him in continuing his tests; and this goes
to show how, even from the first, the French nation was--by reason of
its enthusiasm and imagination--able to appreciate what its inventors
were striving to attain, and eager to encourage them in their quest. For
just an opposite reason--because, that is to say, it had not this
imagination nor intuition--England neglected her experimenters, or
merely regarded their efforts with an amused tolerance, as though they
were children playing with toys.
[Illustration: FIG. 16.--Ader’s “Avion.”]
Ader’s greatest success came in 1897. With an improved machine, he
obtained a flight through the air of nearly 300 yards; and this goes
down to history as being the first ascent by a power-driven aeroplane
having a man on board. Ader’s name will never be forgotten, and one of
his machines is exhibited, as a relic beyond price, at the Institute of
Arts and Science in Paris. But the flight ended in damage to the
machine, as the other had done. A wind gust threatened to overturn the
craft, its engines were shut off, and it descended so heavily that it
was wrecked. Through constant difficulties in regard to motive power,
and the heavy cost of his experimental work, Ader was unable to make a
definite success, or produce a machine which could be called a practical
craft. In his case again, as in that of Maxim, there was a great and
apparently insurmountable defect. The aeroplane would rise; its engines
and propellers would drive it through the air; but the steersman had not
his machine under control: he had not, in a word, learned to fly. The
prospect, therefore, was unpromising, because one machine after another
might share the same fate--rising into the air, flying a hundred yards
or so, and then over-balancing and crashing to earth: thus, in fact,
might thousands of pounds be squandered.
But this stage of putting into practice what science had taught,
although disheartening for those who passed through it, was still of
value; it made a stepping-stone to the next. One of the men who thus
laboured, without himself seeing his work brought to the goal of
success, was Professor S. P. Langley, an American scientist connected
with the Smithsonian Institution, and a man of original ideas and great
resource. He made a methodical investigation of the action of lifting
planes and the shape of propellers, using a large revolving table so
that he could test the latter while they were moving through the air.
Then he began building models which took a double monoplane form, as
indicated by Fig. 17, with wings set at dihedral or upturned angle. This
uptilting of the wings was to give the models stability while in flight:
and the fixing of planes at the dihedral angle was tested, by later
experimenters, in regard to full-sized machines. But while it gave an
undoubted stability when a craft was flying under fair conditions, it
was declared by some experts to be a disadvantage in gusty winds. There
seemed also a risk that a machine so built might slip sideways when upon
a turn. But in some machines to-day a modified dihedral angle is used,
and with satisfactory results.
[Illustration: FIG. 17.--Langley’s Steam-driven Model.]
Professor Langley’s models, tested over the river Potomac, flew many
times for distances of half a mile. One, weighing 25 lbs., flew for
appreciably more than half a mile, and at a speed of 20 miles an hour;
and with another, which was slightly larger and weighed 30 lbs., a
three-quarters of a mile flight was obtained. This model measured a
little more than 12 feet across its wing tips, and was about 16 feet
long. The miniature steam engine which drove it, developing 1-1/2 h.p.,
weighed about 7 lbs., and operated a couple of two-bladed propellers
which were fitted behind the main wings, and turned in opposite
directions at the rate of 1200 revolutions a minute.
So successful were Professor Langley’s models that the United States War
Department became interested; and the result was that an official grant
was made for the building, according to the Professor’s plans, of a
machine of man-carrying size. But with this craft, which weighed 830
lbs., and was driven by a 52 h.p. engine--and is shown in Plate I--there
was a record of failure: launched from the roof of a house-boat over the
Potomac, it fell several times into the water; and ultimately, and
largely owing to the heavy cost of tests with such large machines, the
trials had to be abandoned.
But that the Langley machine would have flown, had it been launched more
carefully, has been demonstrated recently, and in a remarkable way. On
June 28th, 1914, obtaining permission to make tests with the actual
Langley machine, which had been preserved as a relic. Mr. Glenn Curtiss
fitted the craft with floats, and drove it across the surface of the
water at Hammondsport, New York, using the same engine that had been in
the machine during its early and unsuccessful trials. After skimming the
water for a short distance the monoplane rose, flying steadily and well,
and vindicating its constructor’s theories, although he himself was
dead.
CHAPTER IV
OTTO AND GUSTAV LILIENTHAL
How two German schoolboys built wings which they
tested on moonlit nights--The beginnings of a great
and patient quest--Otto Lilienthal’s theories and
study of the birds.
Much of the ground has now been cleared, and--apart from such a story as
may be told merely from facts and figures, and is apt to prove
unsatisfying--we have striven to show the inner meaning of this great
quest: how each of these pioneers, although he may have seemed to spend
money in vain, and build models only to meet with failure, was really
playing a useful part; was in fact--although he himself did not realise
it--forging one of the links in the chain.
It has been shown how men passed from an ill-judged, haphazard stage;
how science threw upon the problem the clear, cold light of wisdom; and
then, further encouraged by the data that was to hand, how there were
engineers who were ready to build large machines and demonstrate that,
even in a crude and early form, an apparatus with curved planes would
lift itself from the ground.
But still there remained this problem: how were men to learn to balance
themselves when in the air? And, in considering the equilibrium of the
aeroplane, it must be remembered that the air in which a machine must
fly is a disturbed and turbulent sea. So, even were a man to build
himself a craft which would, without the need of a hand upon its levers,
balance itself accurately when in still air, there would still be the
problem of the wind gusts; there would, that is to say, still be the
risk of a machine being struck by an air-wave, particularly when flying
near the ground, and being thrown out of its balance and dashed to
earth.
[Illustration: FIG. 18.--Flow of the wind over hills.]
As waves roll across the surface of the sea, so in the aerial ocean are
there breakers and eddies and many dangers unknown; and men cannot see,
but only feel them. The air does not flow in regular streams over the
earth’s surface; could we follow its movements with our eyes, we should
see that it is full of whirls and eddies, with currents of warm air
flowing upward, streams of cool air moving downward; and with all the
obstructions on the face of the earth, such as hills and woods, causing
an interruption and a disturbance in the air flowing over them (Fig.
18). The face of a cliff, for instance, will deflect a current upward,
leaving a partial void at its summit; and into this void the air will
rush in the form of a whirling eddy.
The man who would learn to fly has to launch himself into a treacherous,
quickly-moving element; and one which, to add to his perils, he cannot
see. The rower in a boat, who sets out upon a stormy sea, can watch the
flow of the waves and turn the prow of his vessel to a breaker that
threatens him. But the aerial navigator moves in a medium that is
invisible; gusts that rush upon him are unseen; he is unaware of their
onslaught until his craft heels before the shock. This risk, from the
sudden sweeping up of an air-wave, was put clearly by Wilbur Wright when
he wrote:
“A gust, coming on very suddenly, will strike the front of a
machine and will throw it up before the back part is acted on at
all. Or the right wing may encounter a wind of very different
velocity and trend to the left wing.”
In the aerial sea a machine will pitch and roll as does a ship upon the
water; and the man who would fly must learn to check his craft, should
it threaten to overturn; must be ready instantly with some system of
controlling gear so as to correct the influence of each driving gust.
And his task is made the harder because his machine, when struck
suddenly by a gust, may fall towards the earth at any angle. On the
road, when one learns to ride a bicycle, the machine will topple to one
side or the other; but a craft in the air may fall forward or backward
as well as from side to side, or partly forward and partly backward--or
may slip and dive at any possible angle, either forward or backward or
upon either side. A pioneer wrote, after his first experience in
learning to fly:
“It is rather like trying to steer a motor-car along an
exceptionally greasy road; you seem to slip all ways at once; and
to slip so quickly also that, unless you make the right balancing
movements without an instant’s delay, you find your machine has
gone beyond control.”
If he were to succeed, if he were to fly like a bird, then a man had to
learn this art of balancing himself in the air. Futile it was, as has
been shown, to build some powerfully-engined machine that no one could
control; futile also, and perilous as well, to make a pair of wings and
jump from a tower. Another way must be found, or the quest abandoned and
admitted hopeless. Here was the need; and here too, as we shall tell,
came the man; a man who was not famous, who worked without reward and
struggled to find time for his experiments; who died before he could see
the final triumph; yet who won a fame that cannot die, and whom men call
“the father of the aeroplane.”
To Germany one turns in telling the story of this man’s work. He was an
engineer, Otto Lilienthal by name, and from the days of his boyhood he
and his brother Gustav, living in Anklam, a small German town, were
builders of model aeroplanes and students of the flight of birds. When
the boys were thirteen and fourteen years of age respectively, they
designed a flying machine; and in describing it afterwards, Gustav
Lilienthal wrote:
“Our wings consisted of beech veneer with straps on the under
sides through which we pushed our arms. It was our intention to
run down a hill and to rise against the wind like a stork. In
order to escape the gibes of our schoolmates, we experimented at
night-time on the drill-ground outside the town; but there being
no wind on these clear, star-lit summer nights, we met with no
success.”
But they were not discouraged, and continued to build simple,
easily-constructed machines--from each of which, although it would not
fly, they learned a useful lesson. One, for instance, they made with
wings of goose feathers, sewn upon tape and fixed to wooden spars. These
wings, when finished, they fastened upon hoops which were strapped to
the operator’s chest and hips; and he could, by means of a lever and a
stirrup arrangement, beat the wings up and down by movements of his
legs. This machine they hung from a beam in an attic in their house; but
although the wings _did_ flap, and actually showed some tendency to
lift, the apparatus was soon consigned to a lumber-room, and they were
busy with plans for another.
What impressed Otto Lilienthal was the fact that, even when provided by
Nature with a perfect flying apparatus, the birds of the air had to
learn to use it. They could not just leap upward and “ride the wind” as
men had tried to do; they needed to take their first fluttering
flights--beating their wings anxiously and often falling back to earth,
because they did not know as yet how to use these wings. Particularly
did Lilienthal study the flight of storks. He obtained young birds from
neighbouring villages, and fed them in his garden with meat and fish
while he watched their efforts to learn to fly, and studied that
marvellous piece of mechanism--the wing Nature had given them. Writing
of his observations in a book he afterwards prepared, called _Birdflight
as the Basis of Aviation_, Lilienthal describes the antics of young
storks upon the lawn behind his house:
“When the actual flying practice begins, the first attention is
devoted to the determination of the wind direction; all the
exercises are practised against the wind, but since the latter is
not so constant on the lawn as on the roofs, progress is some-what
slower. Frequently a sudden squall produces eddies in the air, and
it is most amusing to watch the birds dancing about with lifted
wings in order to catch the wind which changes from one side to
another, all round. Any successful short flight is announced by
joyful manifestations. When the wind blows uniformly from an open
direction over the clearing, the young stork meets it, hopping
and running; then turning round, he gravely walks back to the
starting-point and again tries to rise against the wind.
“Such exercises are continued daily: at first only one single
wing-beat succeeds, and before the wings can be raised for the
second beat, the long, cautiously placed legs are again touching
ground. But as soon as this stage is passed, _i.e._ when a second
wing-beat is possible without the legs touching the ground,
progress becomes very rapid, because the increased forward
velocity facilitates flight, and three, four, or more double beats
follow each other in one attempt, maybe awkward and unskilled, but
never attended by accident, because of the caution exercised by
the bird.”
Lilienthal was fascinated by the mechanism of the bird’s wing. He and
his brother built one machine after another to determine the exact
amount of lifting effort that a man could obtain by imitating the
wing-beat of a bird. One such apparatus is illustrated in Fig. 19. This
had a double set of wings; a wide pair in the centre and narrower ones
in front and at the rear. These wings beat alternately, by movements of
the operator’s legs; and the machine was suspended by a rope and pulleys
from a beam, being counterbalanced by a weight. The tests showed this:
that, after some practice in working the wings, a man could raise with
them just half the weight of himself and of the machine; but the
muscular effort proved so great that he could only maintain this rate
of wing-beating for a few seconds. Here, incidentally, a fact may be
mentioned: the energy a man can produce, at all events for a prolonged
effort, has been estimated at about a quarter of a horse-power; and
this--in tests so far made--has been insufficient for the purpose of
wing-flapping flight. Lilienthal himself thought that, with some perfect
form of apparatus, a man might fly with an expenditure of 1·5 h.p. of
energy; but other experimenters have put the minimum power necessary,
even if mechanism could be devised, at 2 h.p. And another fact must be
remembered: even had Lilienthal been able, with such a machine, actually
to raise himself in the air, he would still have had the problem of
balancing himself, in addition to the working of his wings.
[Illustration: FIG. 19.]
[Illustration: FIG. 20.--Lilienthal Kite.]
After many tests such as these, carried out over a number of years,
during which the brothers grew from boys to men, Lilienthal decided that
no good results could be obtained unless a machine was made to move
forward through the air, instead of seeking to rise straight upward. By
such forward motion if rapidly made, and with a suitably shaped wing or
surface, he calculated that a definite support might be obtained from
the air, and without any great output of energy. The value of forward
motion is seen when a large bird seeks to rise. The first few flaps are
heavy and laboured; but after this, as soon as it begins to travel
forward, the wings exercise a lifting influence apart from their beat;
and, as the bird flies faster, so its wing-beats become less violent. An
instance of the need for a bird to move forward when it begins to fly,
is provided in the case, say, of a sparrow imprisoned in a chimney: even
if the chimney is wide, and there is plenty of room for the bird to fly
straight upward and escape, it has not the power to lift itself
vertically for any appreciable distance, because it cannot obtain the
lifting assistance of a leap forward through the air; it is in fact a
prisoner within the chimney.
Lilienthal studied the gliding or soaring flight of many birds; that
form of flight in which, with its wings outstretched and held almost
motionless, a bird such as the falcon will hover in the air, using no
apparent effort and yet supporting itself with ease; diving, rising
again, and wheeling in a perfect mastery of the medium in which it
moves. Lilienthal built and flew kites, to which he gave curved wings in
imitation of those of birds (Fig. 20). With one of these he obtained,
although only for a few moments, an actual gliding flight. The incident
is described by his brother Gustav:
“It (the kite) was held by three persons, one of whom took hold
of the two lines which were fastened to the front cane and to the
tail respectively, whilst the other two persons each held the
line which was fastened to each wing. In this way it was possible
to regulate the floating kite, as regards its two axes. Once,
in the autumn of 1874, during a very strong wind, we were able
to so direct the kite that it moved against the wind. As soon
as its long axis was approximately horizontal the kite did not
come down, but moved forward at the same level. I held the cords
controlling the longitudinal axis, and my brother and my sister
each one of the cords for the adjustment of the cross-axis. As the
kite maintained its lateral equilibrium, they let go the cords;
the kite then stood almost vertically above me and I also had to
free it. After another thirty steps forward my cords got entangled
in some bushes, the kite lost its balance, and in coming down was
destroyed. Yet, having gained another experience, we easily got
over the loss.”
From kites, in quest of a curved surface which should give a maximum
lift with a minimum resistance to its own passage through the air,
Lilienthal embarked upon a series of tests with wing shapes; setting
these up in the wind upon suitable recording machines, and noting
patiently the data that could be procured. There are many problems to be
considered when planning a wing for flight. If it is given a deep curve
or camber from front to back this may, while exercising a powerful lift,
offer too high a resistance as it passes through the air, and thus waste
the energy needed to propel the craft; or, if its front edge is dipped
too sharply, this may cause the air to act upon its upper surface, and
send a machine diving headlong to the ground. The planning of a
successful wing becomes a compromise, having for its object a surface
which shall give the greatest lifting influence with the least
resistance. Lilienthal, after much experiment and the examination of the
wings of many birds, decided that the curve, camber, or upward arch of a
plane should measure, at its maximum depth, about one-twelfth of
whatever width the plane might have from front to back.
CHAPTER V
GLIDING FLIGHT
How a man may use gravity as a motor--Theory of the
“glider”--The craft Lilienthal built--A problem of
balance--The centres of gravity and pressure.
Up to this point in his research Lilienthal had moved more or less upon
the lines of other experimenters. Had he continued to follow in their
footsteps, he would have planned some large and impracticable
machine--and perhaps gone no further. But although he desired to test
the lifting power of the planes he had built, Lilienthal had always in
mind this vital fact--that a man must learn to balance himself in the
air before he can hope to fly. His own words, in summing up this
problem, were: “stability first; propulsion afterwards”; and by this he
meant a man must acquire the art of handling a craft in the air, before
he dares to fit a motor and attempt power-driven flight.
But if a man used neither wing-beats nor a motor to drive him through
the air, how was such practice to be obtained? Lilienthal solved the
problem--and made his name immortal--by devising a system in which he
used the force of gravity as his motor. His plan was this: first he
would build a pair of large, light wings--so light in fact that, even
with the woodwork that was in them and with the additional weight of a
balancing tail, he could raise them to his shoulders and run forward.
With these wings he would go to the summit of a sloping hill and face
what wind might be blowing--as he had seen the young storks do. Then he
would run forward with his wings, so as to obtain the lifting influence
necessary before they could act upon the air. And then, when the wind
was sweeping under his curved wings, he would raise his legs from the
ground and seek to soar or glide; his own weight, and that of his
machine, providing a gravity motor or downward pulling influence, while
the sustaining power of his planes, resisting this drag, would send him
gliding through the air, only a few feet from the ground, at an angle
which tended gradually earthward.
[Illustration: FIG. 21.
Paper glider, in which the cardboard weight (A.) should be 3/10 inch
wide, and 1/16 inch thick, slightly arch planes upward (B.B.). Turn up a
little flap at each end (C.C.). An eighth inch is sufficient. Hold
between finger and thumb (the cardboard weight uppermost); then allow to
dive, as indicated by the dotted line.]
This power of a weighted plane to glide, even when no motive power is
attached to it, may be demonstrated quite simply by the little paper
model seen in Fig. 21. If, when you have made this, you allow it to
flutter from your hand without any weight attached, the model plunges,
dips, and dives; it has no forward motion, therefore it has no stability
or poise. But when you gum the small cardboard weight to its fore-plane,
the action of the model is changed. By the use of this tiny strip of
cardboard you have, so to say, given it an engine; you have provided it
with means whereby it can obtain forward motion, and so glide through
the air. When you hold it as shown in the sketch, with the weighted
fore-plane tilted downward, and release it without a jerk, the tendency
for the model is to fall to the ground as it did before. But now there
is the weight to reckon with: this pulls the model forward and downward,
tending to fall more quickly, of course, than the paper by itself would
do. But there is also the plane behind the falling weight to be taken
into consideration: jerked forward and downward through the air, this
begins to exercise a sustaining influence, and so resists the falling
movement of the weight. Still the weight, actuated by the force of
gravity, pulls downward. But the plane refuses to fall sheer to the
ground; and yet the weight must have its way. So, as in most situations
of this kind, there is a compromise. The falling weight pulls; the
plane resists; and in a flash the model starts upon a graceful glide.
Its plane is fulfilling its task of bearing it through the air; and the
weight is carrying out its mission also, in causing the glide to tend
earthward. So, pulled down by its weight and yet partly sustained by its
plane, the model will pass across a room; and if its plane and its
weight are in a nice adjustment, one may see a pretty manœuvre before it
reaches the floor. As it is swept faster through the air, owing to the
increasing drag of the weight, the plane of the model acquires a greater
lifting influence; and the moment comes when this “lift,” reaching a
maximum, checks altogether the descending movement, and causes the model
actually to ascend. Up indeed it goes, for a second, in a sudden swerve.
But this ascending impulse is soon checked; gravity cannot be denied.
The model loses speed; and, as it loses speed, so does its plane lose
lift. Hence the weight is again the predominating partner; it pulls down
the fore-plane, converts the rise into a fall, and brings the model with
another dive to the floor.
But here, at all events, is a demonstration of this theory of gliding
flight--one that can be carried out without a motor. Of course such
flying has its restrictions: a man must start from the summit of a hill,
and the glide is in the form of a descent towards the ground below; but
still he is passing through the air; and above all--and this proved the
advantage of the scheme for such a pioneer as Lilienthal--there is no
need, during any such glide, to pass high above the ground. The
operator may, in fact, if the side of his hill slopes gently, skim
within only a few feet of its surface; and this means that, should he
lose his balance at first, as he may expect to do, he will not share the
fate of those who leapt from towers, but will be able to alight without
mishap.
[Illustration: FIG. 22.--Lilienthal Glider.]
This, then, was Lilienthal’s plan; he would build a machine with wings
and a tail, stand facing the wind as the storks had done, then seek to
glide through the air in the manner of a soaring bird. The idea
underlying his scheme was that he hoped, by a series of such gliding
flights, to learn the adjusting movements he knew would be necessary to
preserve his balance in the air. The gliding craft Lilienthal built, as
illustrated in Fig. 22, has become an historical machine. The framework
of its wings and the supports of its tail were of willow, and the wings
and tail, to give them their grip upon the air, were covered with a
smoothly stretched fabric. Then the whole structure was braced and
tightened; and though it weighed less than 50 lbs., it was strong enough
to bear its operator though the air. Lilienthal could raise the
apparatus upon his shoulders--passing his head through the aperture
between the planes, which will be noted in the sketch--and walk or run
forward; and to hold the machine, as he carried it thus, he gripped two
wooden rods. The tail was flexible, being allowed an automatic movement,
thus giving the craft a certain natural stability. The main wings had a
span of 24 feet, and the machine measured 18 feet from front to tail.
The wings were cambered, according to the curve Lilienthal had decided
most efficient, and contained about 180 square feet of lifting surface.
In giving them this area, Lilienthal was relying upon experiments he had
made; these showed that, as his machine glided through the air, each
square foot of its surface should bear a weight equal to about 1 lb.
Although enthusiastic, Lilienthal was not impatient: he had the
priceless gift of judgment, allied to common-sense. So, when he had his
glider built, he made no wild nor dangerous tests. He contented himself,
in fact, with a leap from a springboard no more than 3 feet high; and
this height he increased gradually to 8 feet. By such humble beginnings,
and without risking his life, he proved that his glider would sustain
his weight in the air; or, to be more precise, that its wings would
exercise a lift sufficient to permit him to glide rather than fall to
the ground. So now he began more elaborate tests, seeking hills which
had gently-sloping sides, so that he might glide down them. But with
many the difficulty was this: the winds near the surface, being broken
and disturbed, blew fitfully and in gusts, while what Lilienthal needed
was a steady, uniform wind. At length he found favourable conditions at
some gravel-pits at Südende; and here, on the brink of a pit, he built a
shed and housed his gliders.
[Illustration: PLATE II.--SANTOS-DUMONT’S FIRST FLIGHTS.
Here, actually in the air, and with its pilot clearly visible at the
controls, is seen the craft in which--at Bagatelle in 1906--the airman
flew a distance of 230 yards.]
Now, patient and assiduous, he began to teach himself the art of aerial
balance. Raising his wings to his shoulders he would face the
wind--which in his first tests he did not care to be blowing at more
than ten or fifteen miles an hour. Then, running against the wind to
increase the pressure beneath his wings, he would raise his legs and
begin to glide, moving forward and at the same time downward. How he
appeared when in flight is indicated by Fig. 23.
[Illustration: FIG. 23.--Lilienthal gliding.]
His first tests were brief, for the reason that his craft would either
dip too sharply, or incline its planes steeply and so check its forward
speed. In either event the result was the same: the glide came to an
end. But Lilienthal’s caution saved him from being injured in an
involuntary descent. It must be remembered he was always moving close to
the earth; therefore he had only a short distance to fall. To safeguard
himself still further he fitted below his machine a shock absorber,
which came into contact with the ground first and lessened the force of
any impact.
But the difficulties of preserving his balance were great, as he had
foreseen; for not only did his glider dip down, or rear itself up, but
also--under the influence of wind-gusts--threatened to slip sideways. It
was Wilbur Wright, lecturing afterwards upon problems of aerial
equilibrium, who said crisply:
“The balancing of a gliding or flying machine is very simple in
theory; it merely consists in causing the centre of pressure to
coincide with the centre of gravity; but in actual practice there
seems to be an almost boundless incompatibility of temperament
between the two, which prevents their remaining peaceably together
for a single instant.”
[Illustration: FIG. 24.--Centres of gravity and pressure.]
Here, in a sentence, is the problem. As a cambered plane is moved in
flight, the air-pressure upon it is not disposed equally over the
surface, but tends to locate itself at a spot to the front of the middle
line of the plane. When a plane is at a normal inclination to the air,
indeed, this centre of pressure, as it is called, is at a point upon the
surface about one-third of the distance between the front and rear
edges. As to the centre of gravity, the second factor in the problem,
this may be explained best, perhaps, by a practical illustration. Take a
small sheet of cartridge paper, cut to represent the plane of a flying
machine, and lay this along the blade of a knife. By moving it to and
fro and adjusting its equilibrium, you will be able to make it rest upon
the knife-edge without falling forward or backward; this point at which
it balances itself represents its centre of gravity. Here, then, are the
forces: the centre of pressure, which is the thrust of the air, and the
centre of gravity, which is the pull of the earth seeking to drag down a
machine when in flight. These two forces must, as we have been told, be
made to coincide. In the next illustration (Fig. 24) the problem is made
clearer. In diagram A is seen a plane A.B. which is moving through the
air in the direction indicated by the arrow. The two forces--that is to
say, the centre of pressure (C.P.) and the centre of gravity
(C.G.)--coincide with each other: therefore the plane is in equilibrium.
But now suppose a gust of wind strikes the plane. This tends to tilt it
upward; and the result is that the centres of pressure and gravity show
that “boundless incompatibility of temperament” of which Wilbur Wright
complained. The impact of the gust, making the plane rear up, throws the
centre of pressure farther back along its surface, as is shown in
diagram B. The plane is at once out of balance. Or it may be argued
that, as it passes through the air, the wind pressure under the plane is
suddenly lessened. This would cause its front edge to drop; whereupon
the centre of pressure would, as is seen in diagram C, move immediately
forward upon the plane--and so throw it out of balance again.
This is the problem of the man who would navigate the air. He launches
himself in a treacherous, unstable element: constantly, beneath his
wings, the air pressure changes and varies in its strength; constantly
is he losing his balance--and as constantly must he regain it. Imagine a
man walking a tight-rope, and seeking incessantly to keep himself in
equilibrium, and you have a notion of what the first man faced when he
strove to fly. And his case, really, was worse than that of the
tight-rope walker. The latter is concerned mainly with the danger of
falling to one side or the other; he need not trouble himself unduly
with the problem of his fore and aft stability. But the aerial acrobat
may fall forward or backward, or from side to side. Hence his trick,
once he masters it, is the more skilful.
The art, as has been shown, is to bring together these centres of
gravity and pressure; and it can be done in either of two ways. One is
to alter the centre of gravity should the machine begin to fall, and the
other to move the centre of pressure. Lilienthal, and others of the
early gliders, adopted the plan first mentioned; they shifted the centre
of gravity. But others who followed them, and notably the Wright
brothers, finding that they needed to build larger craft, made use of
movable planes by which they could shift the centre of pressure; but
this, of course, will be dealt with in its place.
To alter the centre of gravity of a machine it is necessary to move in
some way the weight it carries--to shift the load forward or backward,
say, or from side to side. In Lilienthal’s glider the load was the
weight of his own body, and he learned to move this when wind-gusts
struck his craft. His body, as he passed through the air in flight, hung
free from the shoulders below the wings of his machine; he was therefore
able to swing himself forward or backward, or from side to side. And
this he did, counteracting the rolling movements of his machine, and
seeking always to prolong the glide. Should his craft be struck by a
sudden gust, for example, and heel to one side, he swung the weight of
his body towards the rising wing; should he dive abruptly, or threaten
to rise at an acute angle, he was ready with a movement of his body to
check the falling tendency and restore the machine to an even keel. But
the point to be considered is this: all these movements, when a craft is
in flight, have to be made with a lightning rapidity. There is not an
instant to lose; not a fraction of a second to be wasted while a man
thinks what he is to do. His balancing, if he would glide through the
air with wings, must be instinctive--instantaneous; as, indeed, is the
balancing of the birds. Here, then, is the difficulty: to learn to make
these balancing movements with sufficient quickness; and this Lilienthal
found to be the stumbling-block. Time after time, while gliding close to
the ground, his machine lost its balance and, before he could correct
the slip or dive, had come to earth. But these falls did not hurt him,
nor did they damage his machine; so he was able, like the storks, to try
again and again.
It is not easy to realise this difficulty of learning to fly. The first
airmen found their rate of thinking too slow. For all earthly actions
they could think quickly enough; but when they came to pass through the
air they found the sending of a command from their brains to their limbs
was not done fast enough. They found they could not rely upon _thinking_
what to do when a craft threatened to fall. They had to practise until
they acquired the power of making a balancing movement without thinking
at all; they learned, that is to say, to keep their equilibrium by
sub-conscious movements--or, to use a simpler word, by “instinct”; to
balance themselves as they passed through the air, like a man balances
himself when he rides a bicycle, without giving the action a thought.
Lilienthal probed all these difficulties, and saw that--as with other
problems--it was not so much brilliant daring that would bring him
success, as a painstaking course of practice, along right and sensible
lines. So, whenever the weather was favourable and the wind not too
high, he made his running leaps down the sides of hills, being content
as a rule, in all his early trials, if he remained only a second or so
in the air. Here, indeed, was another difficulty of learning to fly. No
experience was possible unless a machine was in flight; and yet, in
making his first tests, Lilienthal had to be content with a second’s
practice here and a second there; to be glad in fact if, after a whole
month’s work, he had been for one clear minute in the air.
CHAPTER VI
“THE BIRD MAN”
Construction of an artificial hill--The building of
larger craft--Peril of gusty winds--The accident
which caused Lilienthal’s death.
So determined was Lilienthal to obtain the best conditions for his
gliding that, finding no natural slope to meet his purpose, he ordered
the construction of an artificial hill. This was built at
Gross-Lichterfelde, near Berlin, and was 50 feet high and had gently
sloping sides from which, at any direction of the wind, he could make a
soaring flight. On the top of the hill, which is illustrated in Fig. 25,
Lilienthal had a roomy chamber, and in it he stored his craft. In this
illustration, also, the airman may be observed standing upon the
hilltop, ready for a trial. By means of dotted lines, and
representations of machines in flight, it is possible to show how he
glided through the air.
In the upper of the two flights shown, profiting by a day when there
were rising currents in the wind, Lilienthal had allowed himself to be
lifted, for a moment or so, to a point in the air actually higher than
that from which he started. Then, in order to obtain forward speed, he
dived, only to incline his wings more steeply again, and allow the wind
to bear him upward. In this way, by exercising skill in the balancing
of his machine, he was able to prolong a glide, and under favourable
conditions to traverse, before touching ground, a distance through the
air of nearly 1000 feet.
[Illustration: FIG. 25.--Lilienthal’s artificial hill.]
In the second of the glides shown in Fig. 25, Lilienthal is making a
swift, low flight--one of those during which he was never far from the
ground, and with which he contented himself in early tests. On glancing
again at this sketch it will be noted that the upper of the craft shown
has two main sustaining wings, placed one over the other in the girder
construction already described. It is in fact a biplane, whereas the
lower machine is a monoplane--such a craft as was illustrated in Fig.
22. It was when Lilienthal became expert at balancing himself in the air
that he built a machine on the biplane principle. His reason for doing
so was that he required more surface in the sustaining wings, so that
they might carry him farther through the air. What he wanted to do in
each of his glides was to remain in the air as long as possible, and
thus gain a maximum of experience. The difficulty, as explained, was to
obtain enough practice. In five years, for instance, although assiduous
in his experiments, Lilienthal was not more than five hours in the air.
[Illustration: FIG. 26.--Lilienthal’s Biplane Glider.]
Thus it was that he built a biplane, each of the wings being 18 feet in
span, and containing 100 square feet of surface. The craft is shown in
Fig. 26. Lilienthal did with it what he expected he would be able to do;
he increased materially the length of his glides. But there were
drawbacks in the use of this machine, and one introduced an element of
danger. With the monoplane, so soon as he made balancing movements by
instinct, Lilienthal found he could control his craft quite well; it was
small, and responded quickly when he threw the weight of his body from
side to side. But the biplane, being considerably larger, and having
more surface upon which the wind could act, was sluggish in its response
to his controlling movements. In the case of both monoplane and biplane,
Lilienthal relied merely upon the weight of his body to counteract
falling movements. In the biplane, therefore, although it required a
greater leverage to restore its balance, he was unable to increase the
correcting influence. This difficulty, in the use of a large machine,
was faced subsequently by the Wrights, and how they solved it will be
shown.
Lilienthal recognised the position, of course, and saw there might be
peril in the use of a biplane; but he was content, none the less, to
rely upon his skill. In each glide he made he became more expert;
instead of allowing his machine to slip to the ground when struck by a
gust, he restored its equilibrium by an instantaneous movement of his
body: he was, in fact, like a man who had learned to ride a
bicycle--balancing himself without pausing to think what he should do.
But Lilienthal, in his navigation of the air, was facing a danger the
cyclist has not to fear. He was braving dangerous wind-gusts; and he did
not know, and had no means of knowing, with just what strength these
gusts would strike his craft. Also--and this too was a danger no man on
earth need fear--he had empty air below him should he fall. The peril
grew greater as his skill increased, because he soared higher, and left
greater distances between him and the ground below. In another way,
also, he courted greater risk; and this was through gliding in stronger
winds. At first, when he was unskilled, he had cared only to brave a
wind of a velocity, say, of 10 or 15 miles an hour. But soon, feeling
his balancing power grow greater, he ventured into the air when there
was a wind of from 20 to 25 miles an hour.
In regard to this question of the strength of the wind, uncertainty
often exists. What, for example, is a “stiff breeze”? What is a “strong
wind”? And at what velocity must the wind blow before it is called a
gale? Such questions are often asked, and the table below should prove
instructive:
Velocity of wind Description given
(miles per hour). such strength.
0-5 Calm.
6-10 Light air.
11-15 Light breeze.
16-20 Gentle breeze.
21-25 Moderate breeze.
26-30 Fresh breeze.
31-36 Strong breeze.
37-44 Moderate gale.
45-53 Fresh gale.
54-60 Strong gale.
61-69 Whole gale.
70-80 Storm.
80 upwards Hurricane.
[Illustration: FIG. 27.--Lilienthal combating a wind-gust.]
In gliding in a breeze, say of 25 miles an hour, Lilienthal had to face
this danger, and it is one all airmen meet: whereas the average strength
of a wind may be maintained at 25 miles an hour, there is no assurance
that there will not be a sudden and heavy gust of a greater force than
this. Sometimes, when the wind is uncertain, there will come a gust
which has double the force of the normal pressure; and such a gust,
sweeping unexpectedly against an aircraft, threatens to blow it over and
send it headlong to the ground. Thus Lilienthal, having no more control
over his machine than could be brought to bear by movements of his
body, was running a considerable risk when he soared in gusty
winds--particularly if using the biplane form of craft. Sometimes, when
struck by a gust, his glider would heel and assume a dangerous position
in the air such as is illustrated in Fig. 27. Here the craft threatens
to fall backwards and partly sideways; and the operator can be seen
throwing his body and legs forward, in a quick effort to check this
overturning impulse.
One incident, indicating the risks Lilienthal ran, should be mentioned:
he was gliding 50 feet high one day, in a fresh wind, when one of the
wooden arm supports, which he gripped while in flight, broke suddenly
and threw his craft out of balance. The machine, before he could right
it, fell heavily to the ground; but, thanks to the shock-absorber below
the wings, Lilienthal escaped with nothing worse than bruises.
He had set himself to master this art of balance, and master it he did,
and was ready to risk his life in so doing. In the year 1896 he was bold
enough to glide from hills 250 feet high; and from such a height he
would come sweeping through the air, often traversing before alighting a
distance of 750 feet. Sometimes, too, on a day when the wind was high,
he would stand upon the hilltop and allow the wind pressure under his
wings to raise him in the air; then, throwing his weight forward, he
would start his craft on a downward glide. Frequently, when
experimenting in strong winds, he would find himself higher than his
starting-point, and would hang almost motionless for a moment or so,
soaring in the air. But such hovering flight, though he practised
assiduously, he found difficult to maintain. He could not keep his
machine poised in an ascending current of wind; he had not that instinct
of the birds which enables them to profit instantly by each rising gust,
and hold themselves in it as they allow it to bear them upward. Soaring
flight has a fascination for those who study the navigation of the air;
but no man, as yet, has been able to indulge in it for more than the
briefest space of time. It is only possible to hover thus, without
effort or the use of a motor, when the forces that govern a machine are
exactly in balance; that is to say, the power of gravity which is
pulling downwards must be balanced perfectly by the strength of the
wind, which is blowing under the planes of the machine and tending to
force it upward. Should the wind fail in its thrust, then the craft will
move forward and downward; should the wind blow more strongly, then it
will drive the machine backward, and tend to throw it out of
equilibrium. Some birds, profiting by the skill they have in the minute
adjustment of their wings, are able to hover over a given spot at will,
remaining motionless in the air, without flap or visible effort.
But Lilienthal, although he never attained such proficiency as might
enable him to soar indefinitely above the hill from which he sprang, was
always confident that some perfect glider would be invented, and men
thus be able to imitate the birds. It was when writing upon this problem
of soaring flight that he expressed the thought:
“It is not to be wondered at that birds are able to perceive the
slightest variations in the movements of the air, because the
whole of their body surface acts as an organ for this sensation;
the long and widely extended wings constitute a sensitive feeling
lever, and minute sensibility will be particularly concentrated in
the follicles from which the feathers issue, just as is the case
with our finger-tips.... Should it ever become possible for man
to imitate the splendid sailing movements of birds, he will not
require to use steam engines or electro-motors for the purpose;
a light, properly shaped, and sufficiently moveable wing, and
the necessary practice in its manipulation is all that will be
required of him. He should, unconsciously, be able to draw the
greatest advantages from whatever wind may be blowing, by properly
presenting the wings.”
When three years of gliding lay behind him, Lilienthal thought he could
go little farther in this research. He was able to balance himself in
the air; he could glide in high winds; but always, seeing that he had no
motive power with which to drive his craft, he must start from a hilltop
and descend to the ground. Now he sought longer and bolder flight; and
so he and his brother discussed the building of an engine which might
propel a glider through the air. No petrol motor, unfortunately for
Lilienthal, was then available; so he planned to construct a carbonic
acid motor, and make this drive his craft by flapping the ends of its
wings.
During the summer of 1896 he was busy with plans for this motor, while
still continuing his flights; but in August he decided to cease gliding
for a while, and await a test of the power-driven craft. So on Sunday,
August 9th, he said he would travel out to Stollen, make one or two
final flights, and pack up his machine. His brother Gustav was to have
accompanied him as usual, but had a mishap with his bicycle, and so
remained behind. What happened is described, in few but expressive
words, by Gustav Lilienthal:
“Our families, whom we had intended to take with us, remained
at home, and my brother drove out, accompanied by a servant.
He intended to make some change on the rudder, but at the very
first glide, the wind being uncertain, the apparatus, when at a
considerable height, lost its balance. Unfortunately my brother
had not fitted the shock-absorber, and the full shock of the fall
took effect, so that the apprehension of our uncle was fulfilled.
My brother fell, a victim to the great idea which--although at
that time so little recognised--is now acknowledged in its full
bearing by the whole civilised world.”
At the moment his machine lost balance, Lilienthal was more than 100
feet in the air. Striking the ground with great violence, he sustained
injuries which were almost immediately fatal. In his work, to which he
sacrificed his life, he had met with no encouragement or recognition. He
suffered the fate of pioneers; his theories were so far ahead of his
time that folk did not grasp their significance. Little interest seems
to have been taken in his glides; there was no sensation; there were no
crowds. Nobody, in fact, realised what he was doing, or appreciated the
vast importance of these seemingly simple tests. But in the years that
followed, when other men came to grips with the problem as Lilienthal
had done, when they were able to use the data he had compiled and to
profit by his experiences in actual flight, then this pioneer came into
his own.
His work, summarised, may be said to lie in this: he provided a
stepping-stone to power-driven flight. He showed men that they should
learn to balance themselves in the air _before_, and not _after_, they
had built themselves costly craft. How his example acted as a spur upon
others, and how the work he had begun was carried to its triumph, will
be the purpose of our next chapters to show.[1]
[1] In addition to the work of the Wright brothers, which was carried to
the triumph of actual flight--and with which we shall concern
ourselves--valuable gliding tests were made in England by Filcher, and
in America by Chanute.
CHAPTER VII
WILBUR AND ORVILLE WRIGHT
How two American engineers followed up Lilienthal’s
work--Their biplane glider and its ingenious
control--First experiments and successes.
For those who might care to study them, Lilienthal had written papers
and essays as explanations of his work, and when the news of his death
was flashed round the world, inventors were induced to turn to these
teachings and read for themselves what he had done. Among those who were
interested were two young Americans, unknown then, but now
world-famous--Wilbur and Orville Wright. Living in Dayton, Ohio, they
were the sons of Milton Wright, a prominent church worker of that city,
and they carried on a bicycle store and engineer’s shop. Both were born
engineers--keen, clever, patient, and enthusiastic in their work; and
they had discussed many times--before they read of Lilienthal’s
death--the problem of building an aeroplane. Now this interest was
re-awakened; and as Wilbur Wright himself said:
“The brief notice of his (Lilienthal’s) death which appeared in
the telegraphic news at that time, aroused a passive interest
which had existed from my childhood, and led me to take down from
the shelves of our home library a book on “Animal Mechanism” by
Professor Marey, which I had already read several times. From this
I was led to read more modern works, and as my brother soon became
equally interested with myself, we passed from the reading to the
thinking, and finally to the working stage.”
What the Wrights first set themselves to do was to investigate previous
data. They wanted to prove, if they could, whether this data was sound
or badly reasoned: they needed a firm and definite basis of their own
before they would build any large machine. So they tested the theories
of their predecessors and made experiments, particularly as to the
sustaining power of surfaces of various shapes and curves. To this end
they built and flew kites, studying the lift they exercised; then they
decided to build a light gliding machine, such as Lilienthal had used.
But there was a drawback to be faced in all such practical work, and the
Wrights saw it clearly; this was to get a sufficient amount of actual
flying. It was Wilbur who wrote:
“It seemed to us that the main reason why the problem had remained
so long unsolved was that no one had been able to obtain any
adequate practice. It would not be considered at all safe for a
bicycle rider to attempt to ride through a crowded city street
after only five hours’ practice, spread out in bits of 10 seconds
each over a period of five years; yet Lilienthal, with this brief
practice, was remarkably successful in meeting the fluctuations
and eddies of the wind gusts.”
They made up their minds to build a glider with ample wing-surface, so
that it would be sustained in light breezes, and to take the machine to
where they might be sure of a steady wind, and there fly it as a kite;
allow it, that is to say, to ascend into the air at the end of a rope,
and hold it steady against the wind while the operator practised his
balancing movements.
[Illustration: FIG. 28.--The 1900 Wright Glider (operator’s position).]
Their first glider was a biplane, with 165 square feet of lifting
surface, as illustrated in Fig. 28; several of its features need
explanation. First there is the position of the operator; he can be seen
lying prone across the centre of the lower plane. This attitude was
adopted by the Wrights to minimise wind-pressure. Should a man be
upright in his machine, they calculated that his body would, as the
glider passed through the air, offer an appreciable resistance; while,
in lying flat, he would offer scarcely any resistance at all.
A small horizontal plane will be noted in front of the main-planes; this
was to govern the rising and descending of the machine. The Wrights came
to the conclusion that any body-moving method for controlling their
craft, such as Lilienthal had adopted, would not be sufficiently
powerful in a wind. Lilienthal, it will be remembered, had found his
control weaken when he used a machine of large surface. So the Wrights
decided that, instead of altering the centre of gravity of their machine
when gusts struck it, they would leave the centre of gravity immovable
and shift the centre of pressure upon their planes. This was done partly
by the elevating plane, as it came to be called. Tilted upward, this had
the effect of raising the front of the glider, and causing the centre of
pressure to travel backward upon the planes. Tilted down, it made the
planes dip forward, and brought the centre of pressure nearer their
front edge. When he wanted to rise, the pilot raised the elevator; when
he wished to glide earthward, he inclined it down. Here, indeed, was the
method such as was described in Fig. 13, when dealing with the machine
Sir Hiram Maxim built; and this system of the lifting plane is worthy of
special mention. In one way or another, fitted in front of the planes or
behind them, it is the recognised method for controlling the rise or
descent of an aeroplane.
Apart from governing the ascending or descending movement, there was the
question of preventing a machine from slipping sideways; and this the
Wrights solved ingeniously. They saw, of course, that when their glider
lurched to one side or the other, they would need some power to tilt it
back again. So they devised a system by which the plane-ends of their
machine--being made flexible--might be warped, or caused to shift up and
down. This action the operator controlled, as he lay across the lower
plane, by a movement of cords, and its operation is shown in Fig. 29.
The effect upon the machine may be described thus: should a wind-gust
tilt down one plane-end, the “warp” upon that side of the machine was
drawn down also, and the effect of this--seeing that it caused the plane
to assume a steeper angle to the air and exercise a greater lift--was to
raise the plane-ends that had been driven down by the gust. By a system
of connecting the control cords, this balancing influence was made to
act with double force; when one wing warped down, the other moved up;
and, in this way, while the side of the machine tilted down was made to
rise, the other plane-ends, which had been lifted, were made to descend.
A dual righting influence was thus obtained. This system, which imitates
the flexing movements made by a bird, was an important device; the
Wrights patented it--combining the movement with an action of the
rudder--and brought cases at law to enforce their rights.
[Illustration: FIG. 29.--The Wright Wing-warp.]
In the summer of 1900, with their first machine, the brothers went for
experiments to Kitty Hawk, North Carolina. They had chosen this lonely
settlement, located on a strip of land that divides Albemarle Sound from
the Atlantic Ocean, because they hoped it would provide them with a
strong, steady wind; there were also, fairly close to the settlement,
suitable sand-hills for gliding.
Upon the first day of their trials the wind was blowing at nearly 30
miles an hour, and they allowed the glider to rise as a kite. Flown in
this way, it bore the weight of a man; but they were disappointed at
the position it assumed when in the air. Its planes set themselves at
an angle which was too steep, and it seemed to give less lifting power
than they had expected. They tested their system of control, and found
that the wing-warping for sideway balance acted extremely well, proving
quicker and more certain than would the shifting from side to side of
the operator’s body. The elevating plane was also efficient.
[Illustration: FIG. 30.--Launching the Wright Glider.]
Then they took the glider to the sand-hills. At first the wind was too
high, but after waiting a day it dropped to 14 miles an hour, and they
were able to make nearly a dozen glides down the side of a slope which
had a drop of 1 foot in 6. It had been their idea, in building the
machine, that the operator should run before gliding, as Lilienthal had
done, and only lie upon the plane when the speed was sufficient to give
the surfaces their lift. But in practice they found a better method than
this. Two assistants, as illustrated in Fig. 30, took the machine by its
plane-ends and ran forward with it, the pilot assuming beforehand his
position upon the plane; then, when they had gained a pace sufficient
for the machine to soar, they released their hold and it glided forward.
Beneath the glider, under the centre of the lower plane, there were two
wooden skates or runners, and these took the weight of the machine when
it alighted, and allowed it to slide forward across the ground before
coming to rest. By the use of these landing skids, and by steering at as
fine an angle as possible, the Wrights found they could touch ground,
even at 20 miles an hour and lying across the machine, without injury
either to themselves or the craft.
The first glides were short, and all close to the ground; but they bore
out the tests when the machine had been flown as a kite, and showed that
the elevating plane and wing-warp would do their work. The Wrights were,
indeed, astonished at the celerity with which the glider responded to
the fore-plane.
Writing afterwards of this first visit to Kitty Hawk, Wilbur summarised
the experiments thus:
“Although the hours and hours of practice we had hoped to obtain
finally dwindled down to about two minutes, we were very much
pleased with the general results of the trip, for setting out as
we did with almost revolutionary theories on many points and an
entirely untried form of machine, we considered it quite a point
to be able to return without having our pet theories completely
knocked on the head by the hard logic of experience, and our own
brains dashed out into the bargain.”
[Illustration: PLATE III.--FARMAN’S VOISIN BIPLANE.
The airman is seen making one of his first flights over the
parade-ground at Issy-les-Moulineaux, the machine flying low as it was
its wont, and a scattered crowd of spectators watching from afar.]
When they came to plan a new craft for the summer of 1901, they agreed
they could not better either the theory or the manipulation of their
first machine; but they decided to make one nearly double the size.
Their reason for doing this was that, having a greater lifting surface,
they hoped to fly in quite light breezes and also prolong their glides;
and they were encouraged to build a larger machine by the readiness with
which the first had responded to its controls. They therefore
constructed a biplane which had 308 instead of 165 square feet of
surface, and was the largest machine of its kind that had been built.
In July they went into camp on their remote sand-hills, housing the new
machine in a wooden shed. The first tests were made in a 13-mile-an-hour
wind, but proved disappointing. The machine dived, in spite of a quick
movement of the elevator, and landed after gliding only a short
distance. The cause was found to be this: the centre of gravity was too
far forward. Therefore the pilot took his place some few inches farther
back. But in the next glide the craft behaved alarmingly. It reared
almost vertically in the air, and would have slipped backwards had not
the operator turned down the elevator to its limit, and moved his body
forward as well. The machine, when he did this, recovered its balance
and settled without injury.
Further tests were made and the curve of the planes reduced--a change
which could be effected by altering the trussing of the ribs. Then they
obtained striking success. One glide, for instance, measured a distance
of 366 feet; and this was bettered by one of 389 feet; while the
operator found that he had perfect control over his machine in a wind
of 14 miles an hour. A day or so later an attempt was made in a wind of
22 miles an hour, and was successful. Then, in subsequent tests, they
glided in a wind as strong as 27 miles an hour.
The success of these trials led them to think of fitting a motor to
their machine; and they calculated at first that a petrol engine of
about 6 h.p., weighing 100 lbs., would be sufficient to drive a craft
through the air; but they hoped to obtain one more powerful than this.
Here it should be pointed out that, owing to the experiments of
motor-car builders, and the spending of many thousands of pounds, there
was now available a petrol motor which might be adapted to aviation.
Such engines were heavily built--when considered, that is, from the
point of view of fitting to aeroplanes; and the brothers agreed that, as
they wanted such a motor for aerial use, and not for placing in a car,
they would probably need to build one, specially lightened, in their own
workshops.
CHAPTER VIII
THE WRIGHT MOTOR-DRIVEN PLANE
Final gliding tests--Building of the motor--How
a petrol engine works--Driving, control, and
launching of the Wright machine.
Although everything induced them to hasten--for they feared another
inventor might forestall them with a power-driven craft--the Wrights
still went methodically to work, refusing to use a motor until they had
gained a fuller knowledge of the air. So they built more gliders, and
with one of them--that used in 1902--they were able to make over a
thousand flights. Only once, in all their practice, did they come near
disaster; and this was one day when Orville was testing a machine. The
accident was described by Wilbur Wright:
“My brother Orville started on a flight with one wing slightly
higher than the other. This caused the machine to veer to the
left. He waited a moment to see whether it would right itself,
but finding that it did not, then decided to apply the control.
At the very instant he did this, however, the right wing most
unexpectedly rose much higher than before, and led him to think
that possibly he had made a mistake. A moment of thought was
required to assure himself that he had made the right motion, and
another to increase the movement. Meanwhile he had neglected the
front rudder, by which the fore-and-aft balance was maintained.
The machine turned up in front more and more till it assumed a
most dangerous attitude. We who were on the ground noticed this in
advance of the aviator, who was thoroughly absorbed in the attempt
to restore the lateral balance, but our shouts of alarm were
drowned by the howling of the wind. It was only when the machine
came to a stop and started backward that he at length realised
the true situation. From the height of nearly 30 feet the machine
sailed diagonally backward till it struck the ground. The unlucky
aeronaut had time for one hasty glance behind him, and the next
instant found himself the centre of a mass of fluttering wreckage.
How he escaped injury I do not know, but afterwards he was unable
to show a scratch or bruise anywhere, though his clothes were torn
in one place.”
The amount of practice the brothers obtained began to tell its tale, and
they became sufficiently experienced to glide in winds of 37 miles an
hour. It was Wilbur who, emphasising this need for constant flying,
declared: “By long practice, the management of a machine should become
as instinctive as the balancing movements a man unconsciously employs
with every step in walking.”
After the experience with the 1902 machine, and not before, did the
brothers feel encouraged to build a craft with a motor. They decided to
construct the engine themselves, so that they might have it ready for
use in 1903. They were capable engineers, they had their own workshops,
and above all they knew just what they wanted. So they made a petrol
engine with four cylinders, developing about 25 horse-power. It was
water-cooled, and followed upon the lines of a motor-car engine--save
that it was lightened where they considered weight could be spared. As a
matter of fact, when compared with the light and ingenious motors
afterwards made in France, this engine was a heavy and clumsy piece of
work, weighing as it did about 200 lbs. But they had calculated what
load their machine would bear; and they wanted to ensure that the motor
should run reliably. They attempted, therefore, no drastic cutting down
of weight.
[Illustration: FIG. 31.--Man lifting a 100 horse-power aeroplane motor.]
An explanation may well be interposed as to the working of the petrol
motor, seeing that it plays so large a part in aviation. First should be
remembered the steam engine and its disadvantages--its boiler, weight of
water, and need for a heating agent to make this water boil. In the
petrol-motor none of these are required--none, at least, save a tank
with liquid fuel and another, a smaller tank, containing lubricating
oil. Beyond these tanks and their contents, the weight of the engine is
no more than the weight of metal which composes it; and so it is
possible, with a specially-lightened motor, to deliver one horse-power
of energy for a weight of less than 3 lbs. How lightly a petrol engine
can be made was demonstrated by the firm constructing the Antoinette
motor, with which many of the pioneers fitted their craft. A 16-cylinder
engine was made so that a man could raise it upon his shoulders--as
shown in Fig. 31--and carry it without much difficulty; and yet this
same motor, which one man could lift from the ground, developed 100
horse-power.
The principle of the petrol engine is simple. From the tank containing
petrol runs a pipe, and the liquid passes through this into the
carburettor,--a small chamber in which the petrol is vapourised and made
to mix with air and so become explosive. Petrol is a liquid which, when
in contact with air, evaporates in the form of vapour, and this forms a
powerful explosive, only needing a spark to ignite it. In the
carburettor, therefore, the petrol and air are mingled until they form
an explosive mixture, then they pass through another pipe to the engine
itself.
[Illustration: FIG. 32.--The working of a petrol motor.]
The petrol engine resembles a steam engine in these respects: it has a
cylinder in which the driving force is compressed, a piston-rod this
driving power pushes down, and a fly-wheel the piston actuates, and
which carries round the piston-rod by its momentum, pushing it towards
the top of the cylinder again after one down stroke, so that it may
obtain another thrust. What the fly-wheel does, in a word, is to store
up energy between each thrust upon the piston, and thus keep the motor
in regular motion.
In starting an engine, the petrol tap is turned on, and some of the
spirit allowed to run into the carburettor. Then, usually with a handle,
the engine is made to revolve so that the piston-rod moves down inside
the cylinder and sucks in the explosive mixture. As the piston sinks in
the cylinder, it draws in a charge of the gas; then rising again, it
compresses this charge between the head of the piston and the top of the
cylinder. Now comes the moment when, if the most forcible thrust is to
obtained from the air and gas, it should be ignited, and this is done by
causing an electric spark to jump between two metal points on what is
called the sparking-plug. This plug is screwed into the head of the
cylinder; the sparking end is inside the cylinder where the gas charge
is compressed, and to the outside are fixed wires which run to the
magneto--a small electrical machine which, driven by the motor, makes
sparks in the plug each time the gas is to be fired. Just at the right
instant, therefore, the spark flashes in the cylinder, and the gas is
exploded. Being compressed within the walls and top of the cylinder, the
explosion can only exert its force in one way--upon the head of the
piston, to which it gives a sudden downward thrust. The power is
transmitted to the fly-wheel, which is set in motion, and thus the
engine runs, driven by the series of explosions which takes place in the
cylinder.
The majority of petrol engines operate upon what is known as the
four-stroke principle. This action is as follows: First the pistons are
driven down by a charge of gas, then they ascend in the cylinders so
that the spent and useless gas fumes may be forced out through valve
ports; then the pistons descend again so that a fresh charge may be
drawn into the cylinders, and then, for a fourth time, the pistons move
so that the gas may be compressed and fired. During the period the
engine is not driven by the explosions, the fly-wheel has to do its
work, carrying the piston up and down while it expels waste gas and
obtains a new supply. In Fig. 32 is a diagram to illustrate the
principle of the petrol engine and it amplifies this explanation.
An additional point is needed to explain how motors were lightened for
aviation work. The fly-wheel has been described as vital to the engine,
and so it is, unless a number of cylinders are used. But if a maker
builds a motor with, say, eight cylinders, the driving impulses are so
frequent that there is no danger of the engine ceasing to revolve
between explosions, even if no fly-wheel is fitted. It can be so
arranged, indeed, by the timing of the explosions, that there is a
smooth, even thrust upon the crank-shaft, and by omitting the fly-wheel
there is a perceptible lessening in the weight of the motor.
When the Wrights had built an engine, there was still the question how
they should make it drive their aeroplane. They inclined naturally to
the idea of an aerial propeller such as that illustrated in Fig. 7. Two
courses lay open to them; they could fit one propeller running at high
speed and coupled directly to the motor, or they could use two
propellers, revolving at slower speed and geared in some way to the
engine. They decided upon the latter course, placing two propellers
behind the main planes of their machine and driving them from the engine
by means of light chains, these running in guiding tubes. This system
of propulsion is shown in Fig. 33.
[Illustration: FIG. 33.--Wright Motor and Propellers.
A. Motor; B. Gear-wheels upon motor crank-shaft; C.C. Tubes carrying
driving chains; D.D. Sprocket-wheels over which chains pass; E.E.
Propellers.]
The propellers revolved in opposite directions, and in order to gain
this effect one chain, as will be seen from the sketch, had to be
crossed in its tube. The Wrights preferred the use of two propellers,
even though this necessitated gearing such as might have been avoided
had a single propeller been coupled directly to the motor. They
considered the thrust upon the aeroplane would be smoother with two
screws. By using a couple of large propellers also, and running them
rather slowly, they reckoned to obtain more efficiency than with a
single high-speed screw. In illustration of this it may be mentioned
that, whereas the single propellers upon some of the French machines
made 1000 or 1500 revolutions a minute, the Wrights’ two screws made
only 450 a minute. That their system was extremely efficient they were
able to prove beyond question. Many critics condemned as clumsy the use
of gearing chains, and pointed out the danger that existed should a
chain break--causing one propeller to stop, while the other, by
continuing its thrust, tended to throw the machine out of equilibrium.
Such a system, indeed, never came into general use, but in fairness to
the Wrights it should be said that very few accidents were ever
attributed to the breaking of a chain.
[Illustration: FIG. 34.--The Wright Biplane.
A.A.--Main-planes; B. Double front elevator; C. Rudder (two narrow
vertical planes); D. Motor; E. Propellers; F. Pilot’s lever; G. Skids
upon which machine landed.]
It is now possible to describe, as a completed craft, the Wright
power-driven plane; Fig. 34 shows its appearance; and in looking at it
one is struck by the fact that, save for one or two modifications, and
the fitting of motor and propellers, the machine is practically a
glider, such as the Wrights used for soaring tests. Of the changes to be
observed, the most interesting concern the elevator and rear-rudder.
The former, it will be seen, has a double plane; it is, in fact, a
smaller biplane on the principle of the main-planes. Needing to increase
the surface of the elevator, the brothers fixed one plane above another
so as to make the construction stronger and occupy less space. The
rear-rudder, acting like that of a ship, worked upon the system
described in Fig. 14. With this, as with the elevator, in order to
economise space and obtain rigidity, two narrow planes were fitted side
by side.
So now the practical aircraft stood complete--each part adapted and
perfected; and, having traced its development step by step, we see how
the pioneers had helped the Wrights to their conquest. Sustaining
planes, propellers, controlling surfaces--all had been foreshadowed, all
hinted at and sketched crudely; but what had been lacking was the skill
which should put these theories into shape; and this skill, and also
this patience, Wilbur and Orville Wright provided to the full.
Having discussed the construction of the machine, the method by which it
was controlled when in the air may be described. In Fig. 35 the operator
is seen in the driving seat; and near him will be observed the motor
which drives the craft. In his left hand--that is to say in the one
nearest us--he grasps the lever which operates the elevating planes. The
rod from lever to plane can be seen, and the motions the pilot makes are
these: should he wish to rise, he draws the lever towards him and tilts
up the elevating planes in the manner already described, increasing the
lifting power of the main-planes and so causing the machine to ascend;
by a reverse movement of the lever--by pushing it away from him, that
is to say--he makes the craft glide downward.
[Illustration: FIG. 35.--Driving seat of Wright Biplane.
A. Motor; B. Lever operating elevating planes; C. Lever working rudder
and wing-warp.]
In the pilot’s right hand is another lever; this combines two actions in
an ingenious way. It actuates not only the rear-rudder of the machine,
but also the wing-warping for the control of sideway balance. How the
one rod combines these operations is shown by Fig. 36. Here, looking
from behind, one sees the lever which the aviator holds. Towards the
lower end is a rod projecting rearwards, and this is coupled to the
extremity of another rod set at right angles to it, and pivoted in its
centre; while from this pivoted rod run the wires which operate the
rudder-planes. If the pilot swings his hand-lever either forward or
backward, it moves to and fro the rod which is connected with it, and
this imparts a forward or backward movement to the pivoted rod, with the
result that one or other of the rudder wires is drawn forward--thus
turning the rudder-planes from side to side.
The hand-lever is free also to move from side to side; and if it is so
moved it will draw with it the swinging rod which projects from the end
of it--below that operating the rudders--and to the upright section of
which the wing-warping wires are fixed. A movement either side upon the
hand-level will pull over the wing-warping wires, therefore, and bring
the flexible plane-ends into operation. Thus the dual movement of the
lever is obtained--forward and backward for the rudder, from side to
side for the warp.
[Illustration: FIG. 36.--Rudder and wing-warp control (Wright Biplane).
A. Controlling handle; B. Pivoted rod carrying wires to rudder; C.C.
Rudder wires; D. Sideway swinging rod carrying wing-warp wires; E.E.
Wing-warp wires.]
The Wrights did not use their feet in any controlling movement, although
in practically all modern aeroplanes, as will be explained later, the
airman’s feet are utilized for pushing upon a bar and operating the
rudder of the machine; but the Wrights preferred to make all actions
with their hands.
[Illustration: FIG. 37.--Wright Launching Rail.
A. Biplane; B. Rail; C. Rope passing from the aeroplane round the
pulley-wheel (D.) and thence to the derrick (E.); (F.) Falling weight.]
Details of propulsion and control being arranged, there remained the
question of how the machine should be launched into the air. In their
gliding tests, it will be remembered, the Wrights employed assistants,
who held the machine by the wing-tips and ran forward with it. But the
weight of the power-driven machine, and its greater size, prevented such
a plan as this. They decided, therefore, to launch it from a rail, and
to aid its forward speed, at the moment of taking the air, by a derrick
and a falling weight. This method is illustrated in Fig. 37. The biplane
is seen mounted upon a truck, or under-carriage, which runs upon wheels
along a rail. To the front of the aeroplane is fixed a rope, which
passes round a pulley some distance ahead of it, and is then carried
back to the derrick, from which can be seen hanging a heavy weight.
Before making a flight the engine was set in motion, whirling the two
propellers; then, at a given signal, the weight upon the derrick was
released. Drawn forward by the pull of this weight, and aided by the
thrust of its propellers, the biplane moved rapidly along the rail, and
soon attained a speed of more than thirty miles an hour. Then, just
before the end of the rail was reached, the pilot released a catch which
freed the aeroplane from its trolley, tilted up his elevating plane and
the machine, now moving fast enough for its planes to sustain it in
flight, glided from earth to air, flying low at first but gradually
increasing his altitude.
CHAPTER IX
DAWN OF FLIGHT
The Wrights complete their conquest--First trials
of the power-driven machine--Their negotiations
with Governments--How these hung fire and caused
delay--Activity in France--Santos-Dumont, Farman,
and Delagrange.
Now, as they stood upon the threshold of success, the method and
patience of the Wrights came strikingly to their aid. Their machine was
not strange to them--not a monster they had no notion of controlling, as
the first of the large machines had been to those who built them. They
had flown almost precisely similar craft in their gliding tests; they
knew the system of control; knew how to make a landing after flight. All
this experience they had gained before attempting to drive a machine
with a motor; and herein lay the secret of their success. They were not
superhuman; they were instead talented, patient, assiduously-careful
men; and their triumph goes to prove what can be done if a man will work
in the right way, is quietly and persistently enthusiastic, and ignores
all disappointments and rebuffs.
It was in December 1903 that the power-driven machine was piloted in its
first flights, the longest of which lasted for one second less than a
minute. But the ascents from the earth were made without mishap, the
machine was under control while it flew, and it landed without injury.
[Illustration: _Photo, “Daily Mirror.”_
PLATE IV.--LATHAM’S FALL INTO THE SEA.
The _Antoinette_ is seen above, just after its descent upon the water.
The torpedo-boat which followed its flight is standing by, and efforts
are being made to prevent the aircraft from sinking, and to draw it on
board.]
And this was the beginning. Here was a machine that would not merely
glide from a hilltop; it would sweep in any direction, and sustain its
flight without falter or flag, so long as its engine drove it through
the air. The craft was crude; its motor awkward to “tune” for a spell of
running; and the brothers were novices in the element they invaded. They
did not proclaim their triumph, therefore, or declare themselves
conquerors. They said nothing. In their gliding tests, and even with the
power-driven machine, they had attracted little public attention. Mild
interest had been taken; but the scene of their work was remote and
lonely; and what news leaked to the cities was disbelieved or treated
with unconcern. The world did not know what had been accomplished.
At the end of 1903, as stated, they first flew with the motor-driven
machine; and during the next two years they did nothing to exploit the
invention, being content to increase their skill and lengthen their
flights: even with the problem solved, they refused to hurry. The best
performance in 1904 was a flight of 5 minutes 4 seconds. Circles in the
air were now effected, and the aeroplane was instantly responsive to its
controls. Then in 1905 a great stride was made, Wilbur remaining in the
air for 38 minutes--wheeling, circling, rising, and falling; showing, in
fact, that he had perfect mastery over his machine.
But now rumours of the Wrights’ triumph began to reach the world; and at
a meeting of the Aeronautical Society in England a sensation was caused
one evening when Mr. Patrick Alexander, reading a letter he had received
from the Wrights, was able to announce that their aeroplane had flown
for 24 miles. Interest was aroused everywhere, and newspaper
correspondents hastened to interview the Wrights and photograph their
machine. But they were disappointed. Having proved to their own
satisfaction that their biplane was a success, the Wrights dismantled it
and packed it away, doing no more flying. Thus the reports that were
telegraphed round the world were mainly hearsay, and people refused to
believe that the Wrights had done what was claimed. They themselves said
little, but were busy with plans; and what they sought was to sell the
secret of their aeroplane to a Government. They foresaw the future of
the aeroplane as a weapon of war, and reckoned that some country would
pay handsomely for the sole rights to their machine.
Upon coming into touch with Governments, they found the French most
interested. The French War Department, in fact, sent an agent to America
to see the brothers; and this agent, on his return to France, reported
favourably upon the invention. But experimenters were now nearing
success in France, and the Wrights would consider nothing but a large
cash payment; so negotiations fell through.
During the next two years, practically nothing was heard of the Wrights.
They were, as a matter of fact, still perfecting their machine, still
negotiating for its sale; but they declined to come into the open and
show what their craft would do. There was method, of course, in this
attitude; they aimed for one definite goal--that being a large sum as a
reward for their labours. But there is no doubt that precious time was
lost. Had the Wrights been able to place confidence in some agent or
manager, he would have acted for them and advised them; their position
would have been strengthened and vital years would not have slipped
away. They were ready, as we have seen, to fly long distances in 1905;
and yet it was not until 1908 that, persuaded at last to emerge from
their seclusion, they demonstrated effectually what their machine could
do. But others had been busy during those wasted years; and, when the
Wrights did appear, their triumph was not so sweeping as it might have
been. Other men, in fact, could fly; and though neither they, nor their
machines, represented the skill and progress of the Wrights, still they
had flown; and this, at anyrate in the public mind, depreciated the
performance of the two Americans. Had the Wrights come forward when no
one else could fly, they would have been hailed as unchallenged
conquerors of the air; but as it was, they were recognised only as being
a certain distance ahead of their French rivals.
Progress in France, though many inventors were at work, had been slow.
The Wrights, in fact, by the sureness of their methods, had far
outstripped those Frenchmen who had followed up the problem at
Lilienthal’s death. Yet French experiments moved along the same path as
had those of the Wrights. First there had come tests to find
wing-curves; then the flying of gliders.
[Illustration: FIG. 38.--Voisin Glider towed by a motor-car.]
[Illustration: FIG. 39.--Voisin Glider on the river Seine.]
In the launching of gliders, some French experimenters showed ingenuity.
The brothers Voisin, for instance, who played a prominent part in the
early tests in France, adopted the plan illustrated in Fig. 38. The
gilder was towed by a motor-car across an open stretch of ground; then,
when its speed was sufficient for the planes to lift, it rose and flew
behind the car like a kite. Another form of glider, seen in Fig. 39, was
mounted upon hollow wooden floats--anticipating the sea-plane of
to-day--and towed upon the river Seine by a motor-boat. This gilder
also, when its speed became sufficient, rose into the air. In the
construction of the machine, a biplane, one notes resemblances to the
method of the Wrights; and yet generally the craft is dissimilar. There
are, of course, the two main-planes--characteristic of all machines of
this type. Projecting in front of the planes, also, there is an elevator
on the same principle as that of the Wrights. But between the
main-planes are fixed four upright planes, or curtains as they were
called. These were to preserve sideway balance, and prevent the machine
from rolling when in flight. Should the craft tend to heel over, the
surfaces of these planes--acting sideways upon the air--resisted such a
movement. No wing-warping, such as the Wrights used, was fitted to this
glider; the vertical planes alone were relied upon for sideway balance.
The tail of the machine was a reproduction of the main-planes on a
smaller scale, having two horizontal and three vertical surfaces. The
theory of these rear-planes was that of the balancing tail such as is
fitted to a kite; they steadied the machine automatically when in the
air, and checked any tendency to dive.
In 1905 a glider of this type was tested on the Seine; but it was not
until 1906, at a time when the Wright aeroplane was capable of long
flights, that a real French success was obtained; and then the flights
made were brief, and carried out with a craft that was admittedly crude.
It was a biplane of curious construction, built by the Voisin brothers
for M. Santos-Dumont--a rich Brazilian who had spent money freely upon
airships, and had been occupied, for some time before the Voisins made
him this machine, with a craft having propellers to lift it vertically
from the ground. Abandoning this idea, he devoted himself to the machine
the Voisins built, which is seen in Fig. 40. Here are the same box-kite
main-planes, with vertical curtains between them, as shown in the
illustration of the Voisin glider. But now, to give the machine more
sideway stability, these main-planes are tilted up at a pronounced
dihedral angle.
[Illustration: FIG. 40.--Santos-Dumont’s Biplane which flew at
Bagetelle.]
A curious feature of the machine was the large box-kite elevator, set in
front of the main-planes. This, as can be seen in the figure is tilted
down--the position it would occupy were the craft descending from a
flight. The machine, it should be mentioned, flew with its elevator
forward, there being no tail behind the main-planes. This elevator
played a double part; it was intended not only to make the machine rise
and descend, but also--by means of its side surfaces--to increase its
stability when in flight.
Following on lines upon which French inventors had worked, the craft was
fitted with light bicycle wheels, and upon these it was intended it
should run, until its speed was sufficient for the planes to lift. This
plan, of course, had an advantage over the starting-rail of the Wrights,
seeing that a craft so equipped could re-ascend from a spot at which it
might alight without having to be transported on a trolley to its
rail--as was the case with the Wright machine. But there was this
disadvantage of the wheel system of launching; in order to obtain a
running speed, sufficient for the planes to lift, the craft had to be
fitted with a powerful motor. In the Santos-Dumont biplane, an engine of
50 h.p. was used, and even then the machine appeared under-powered. But
this was not so much the fault of the engine as of the machine; it was
heavy, and inefficient.
From July to October 1906, Santos-Dumont was experimenting with this
biplane, using a stretch of grass-land at Bagetelle. Then, having the
motor well tuned, he gave notice to the French Aero Club that he would
make a flight on 23rd October. The Club’s officials came together, and
after some hours delay, owing to unexpected trouble with the engine, the
pilot said he would attempt a flight. At 4.45 p.m. his machine ran
forward across the ground, driven by its two-bladed propeller; then rose
gradually, foot by foot, and flew very low for a distance of about 80
yards. Almost immediately it left ground the craft began to roll from
side to side, showing that its equilibrium was faulty; and this roll
became so pronounced that the pilot switched off his motor and made
rather a heavy landing, breaking the gear beneath his planes. How the
biplane appeared when in flight is shown on Plate II.
The damage, however, was soon repaired, and some alterations made to the
machine; and on 12th November Santos-Dumont flew 160 yards, and then 230
yards. These flights made a sensation, particularly in view of the fact
that, although the Wrights had surpassed them, the stories of their
trials were thought exaggerated. But Santos-Dumont did not follow up his
success with sufficient patience. Instead of seeking to perfect his
machine, he soon abandoned it, and turned his attention to a craft that
should move upon the water before rising into the air.
But the Voisins, not discouraged by the failure of an experimental
craft, soon had another in hand. It was a biplane, with a front
elevating-plane and a box-kite balancing tail, and ran on wheels as the
other machine had done, being driven also by a 50-h.p. motor. This
craft, early in 1907, was acquired by M. Leon Delagrange, a sculptor who
had taken interest in aviation. Transported to Vincennes, it was tested
on 28th February, M. Charles Voisin being the pilot. But the
under-carriage proved too light, collapsing while the machine was
running upon the ground. At Bagatelle, later, having in the meantime
been improved, the craft was again upon trial; but this time its sideway
stability was found to be faulty, and there was another delay. Then on
30th March the machine flew for a distance of 60 yards. But Delagrange,
like Santos-Dumont, did nor persevere; he abandoned this machine in
order to carry out a new series of tests. While he was so engaged M.
Henri Farman came into touch with the Voisins, and acquired a biplane
which was practically identical with that Delagrange had used. Farman
was a man of the same mould as the Wrights--quiet, persevering,
determined to succeed; and succeed he did.
CHAPTER X
RIVAL AIRMEN
Henri Farman flies, and wins £2000--Delagrange
and Bleriot--The Wrights emerge from their
obscurity--Wilbur’s triumph in France--The flights
of December 1908.
Henri Farman, who was to achieve fame as a pilot, was in many respects
an ideal man for the task he had in hand. Small, light, quick, with a
sure eye for distances and speed, and a sound knowledge of engines, he
had won renown as a driver of racing motor-cars before turning to
aviation. As soon as he obtained delivery of his Voisin, he had it taken
to the military parade ground at Issy-les-Moulineaux, near Paris; and
here he built a shed to house it, and began systematically to learn to
fly.
For a month he was content to run the biplane up and down the ground,
accustoming himself to its controls and tuning up the motor--which in
early machines was so apt to prove refractory. Exceedingly light, and
running at very high speeds, these first aviation motors tended to
become over-heated or break some working part. But Farman, although he
had more than his share of engine trouble, was persevering; and on 30th
September 1907 he was rewarded by a flight of 90 yards. This he
increased to 100 and then 150 yards; but now he found his
elevating-plane was not in adjustment, and this caused delay. By the
middle of October, however, he had flown a distance of 311
yards--beating Santos-Dumont’s record of the year before; and on 27th
October, still improving, he flew 843 yards.
Now all eyes turned to Issy, and crowds came to watch the airman in his
tests. Progressing steadily, and with uninterrupted success, Farman was
ready at the beginning of 1908 to bid for a £2000 prize which had been
offered under the following conditions: The aeroplane was to fly across
a line 50 yards in length, marked out across the ground; to fly straight
ahead for 540 yards; to circle a flagstaff without touching ground; and
then to fly back again to its starting-point, and pass above the line.
This flight, it will be seen, necessitated a half-circle in the air; and
the making of such a turn was for some time Farman’s difficulty. His
biplane was heavy, and its engine would only just keep it in the air;
and when he came to turn, the machine lost speed a little and--seeing
that it flew low--showed a tendency to touch ground. But Farman was
always successful in tuning up his engine, and on 13th January 1908 he
made the out-and-home flight without difficulty, and won the £2000
prize. A photograph of him in flight in his biplane is seen on Plate
III.
Here was one definite rival for the Wrights, and soon they had another.
Delagrange, coming again to the Voisins after Farman had won this prize,
obtained another biplane, and flew with it on 14th March for a distance
of 328 yards. Then on 11th April, having become more proficient, he
made a circular flight of 2-1/2 miles, following this by a flight in
which he remained aloft for 18 minutes 30 seconds. Farman, gaining skill
from day to day, managed to fly for 19 minutes without descending, and
then took up a passenger for short flights.
[Illustration: FIG. 41.--The Bleriot Double Monoplane.
A.A. Sustaining-planes; B. Pilot’s seat; C. Balancing side flaps; D.
Rudder; E. Landing wheels.]
Yet another aviator, soon to become well known, had now begun to fly;
this was M. Louis Bleriot, a maker of motor-car head-lights, who spent
money and risked his life in the testing of monoplane machines. Some of
these experimental craft had two main wings; others four--one of the
latter being illustrated in Fig. 41. An interesting feature of this
machine was the use of narrow, pivoted planes at the extremities of the
front main-planes, which could be swung up and down to control sideway
balance. With a craft of this type, after many failures, Bleriot began
to make short flights. Then the machine was wrecked; but Bleriot,
indomitable as Farman and the Wrights, soon built another; and with this
he flew for 8 minutes 24 seconds.
Meanwhile--what of the Wrights? Their interests had, at last, been
placed in the hands of a syndicate; and to this syndicate it became
obvious, as one after another of the French successes was chronicled,
that some definite display should be made. The Wrights possessed an
aeroplane at this time which, in controllability and efficiency, was far
in advance of any French machine; but the need was to demonstrate this.
So it was arranged that, while Orville Wright remained in America, and
flew in a series of tests before the military authorities, Wilbur should
take a biplane to France and challenge the Frenchmen on their own
ground--or rather in their own air.
Wilbur’s first experiences in France were not pleasant. His machine, to
begin with, made an unfavourable impression. In comparison with the
ingenious, scrupulously-neat construction of the French engineers, it
appeared clumsy and amateurish. The brothers had not, in fact, wasted
any time upon the finish of their machines. They were sufficiently
strong, and they knew that they would fly. Beyond this they did not
concern themselves, disdaining all perfections of woodwork or of detail.
The Wright engine, when contrasted with the specially-lighted,
beautifully-constructed French motors, was a heavy piece of machinery
which could have been rendered more efficient in several ways. But the
Wrights understood their motor, and would use no other.
Wilbur Wright said little; made no boasts or idle claims. Putting his
machine together at Le Mans, where he had come to make his trials, he
flew on 8th August 1908 for 1 minute 45 seconds, during which he rose
about 40 feet high and made two circles in the air. He would have flown
longer, but his motor was not working well. On 13th August he was in the
air for 8 minutes 13 seconds. This he improved upon by a flight, on 5th
September, of 19 minutes 48 seconds; and on 21st September, feeling
greater confidence in his machine, he flew for 1 hour 31 minutes 25
seconds.
[Illustration: _Photo, “Daily Mirror.”_
PLATE V.--BLERIOT LEAVING THE FRENCH COAST.
Rising from Les Baraques, near Calais, on the memorable flight to Dover,
Bleriot passed over the sand-hills at the brink of the Channel, and
steered out boldly across the water, his monoplane receding quickly
until it was a speck in the sky.]
He had now rendered of small account the successes of his rivals. But it
was not so much the length of time he remained in the air, as the
control he had over his machine, which impressed those who saw his
tests. The French aeroplanes had, up to this time, flown sluggishly and
with no certainty in their movement. They rose, and that was all; they
were barely controllable; they flew falteringly, and caused anxiety in
the minds of those who saw them aloft. But with Wilbur Wright there was
none of this. His biplane rose smoothly from its rail and soared here
and there, absolutely under control, and responsive instantly to its
pilot’s levers--climbing, sinking, wheeling, and diving, with a swift
ease and precision that won the admiration of all.
After his hour’s flight in September, Wilbur undertook the teaching of
two pupils to fly--the Comte de Lambert and M. Tissandier. With the
former as a passenger he flew for seven minutes, and then took up M.
Tissandier for eleven minutes. These flights, however, he eclipsed on
3rd October, when he flew with a newspaper correspondent for fifty-five
minutes; and on the next day, seeking to improve upon this, he remained
in the air with another passenger for 1 hour 4 minutes 26 seconds.
Such flights were, at the time, quite beyond the capacity of French
machines, and Wilbur Wright--appearing so unassumingly upon the
scene--had everything in his hands. Farman, however, was not inactive
Practising now at Chalons, and having his motor well in tune, he
decided to attempt a cross-country flight--the first in aerial history.
Rising from his test-ground at Chalons, he attained a height of 130
feet, and flew a distance of 17 miles to Rheims, passing above rows of
poplar trees and being twenty minutes on his journey. This feat, as
showing the reliability of the aeroplane, was greeted with acclamation.
A point against the Wright machine--which was criticised by experts in
spite of its success--was the fact that it could ascend only from its
starting-rail. This, it was said, made it less practicable than the
machines of the French builders--which were, as explained, constructed
so that they would run on wheels. Point was lent to this criticism on
31st October 1908, by a feat of M. Bleriot. Using a new monoplane--the
eighth he had built--he said he would fly from Toury to Arteney and
back, a distance of about 19 miles, alighting when he reached Arteney
and then ascending again. This programme he carried out. Eleven minutes
after leaving Toury he reached Arteney, and then had to descend rather
hurriedly owing to a defect in his magneto. This took an hour and a half
to repair; then the airman set off on his return flight to Toury. But he
had flown only 3 miles when his magneto again gave trouble, and he had
to glide to the ground, alighting safely upon an open stretch of land.
After a few minutes delay he rose again, and this time reached his
starting-point without mishap. Such a cross-country journey as this,
with two halts, would not have been practicable with the Wright machine;
that is to say, had it descended in a field owing to engine trouble, and
at some distance from its starting-point, it would have been necessary
either to take it back by road to its launching apparatus or bring this
gear to the field in which it lay. The starting system of the Wrights,
although excellent in its way, and making for efficiency and low
engine-power, had the drawback of limiting the use of the machine to an
aerodrome; or, should the pilot attempt a cross-country flight, he knew
he must return to his starting-point without alighting, or run the risk
of being stranded at some distant point, and having to dismantle his
machine. It is not surprising, therefore, that the launching rail fell
into disfavour. No one used it except the Wrights, and in later models
of their machine even they abandoned the system, and fitted craft with
running wheels and more powerful motors.
Wilbur Wright, although he made no effort to compete with Farman or
Bleriot in cross-country flying, achieved remarkable flights in the last
month of 1908. Two prizes were on offer--one for the longest flight of
the year, the other for the greatest height attained. Making an attempt
to win the former on 18th December, he flew for 99 kilometres (61 miles)
round a triangular course, his time in the air being 1 hour 53 minutes
59 seconds. This feat dwarfed all those of his rivals; and, in another
flight on the same day, he showed still further the superiority of his
machine. Ascending in an attempt for the height prize, he reached an
altitude of 377 feet.
Not content with these flights, and fearing some opponent might beat him
at the eleventh hour, Wilbur ascended again on 31st December. Flying
steadily round a course marked by flags, he remained in the air from
early in the afternoon until sunset, having covered a distance of
76-1/2 miles and being aloft for 2 hours 20 minutes 23 seconds.
So the year ended. The Wrights, coming late upon the scene, had proved
that their machine, save for the limitation of its starting rail, was
the most efficient in existence, and far ahead of those of the
Frenchmen. One serious accident, however, marred the Wrights’ triumph.
Orville, after excellent flights in America, was carrying a military
officer as passenger when a chain driving a propeller broke in mid-air.
The biplane passed beyond control and fell, and the officer, Lieutenant
Selfridge, was killed--the first victim of an aeroplane disaster.
Orville sustained a broken thigh.
CHAPTER XI
A YEAR OF TRIUMPH
Crossing the Channel by air--Contest of three
rivals--Bleriot’s triumph--Latham and the
Antoinette--The first flying carnival--Farman’s
success with a new machine and motor--The British
pioneers.
Up to this time the public, reading of the flights of the first airmen,
had not realised what these flights meant. They had not grasped the
significance of the aeroplane; its possibilities as a weapon of war; its
use as a vehicle for passing from place to place--high in the air, at
great speed, and with an ability to soar above land or sea, mountains or
woods, hills or valleys. But they were no longer to remain in doubt. The
year 1908, as shown, closed in rivalry between several airmen, and with
a flight lasting more than two hours. In 1909, the most memorable year
in the history of the conquest, these feats sank into insignificance,
and the world began to understand what was being done, and what flying
would mean in peace and war.
[Illustration: MACHINE SEEN FROM ABOVE,
showing the wing-spread and the box-kite tail.
FIG. 42.--The Voisin Biplane.
A. Elevating plane; B. Pilot’s seat; C.C. Main-planes; D. Engine and
propeller; E. Landing chassis; F. Balancing tail; G. Rudder.]
At the beginning of 1909 there were two types of successful
aeroplane--the Wright and the Voisin. Bleriot had flown with his
monoplane and flown well; but he was still in the process of evolving a
practical machine, and several other inventors were in a similar stage.
It was the Wright and the Voisin which had proved their worth; and the
Wright, as has been said, was the better of the two. Of the Voisin, as
flown in 1909, a reproduction is given in Fig. 42. It was a heavier
aeroplane than the Wrights’, owing largely to the weight of its
alighting gear (250 lbs.) and of its big balancing tail (more than 100
lbs.); hence the necessity for using a 50-h.p. motor, which drove a
two-bladed metal propeller at the rate of 1200 revolutions a minute. The
Voisin brothers, and other French makers, did not approve of the
two-propeller system of the Wrights: they preferred one screw, revolving
at high speed. But there was no doubt--at any rate in this stage of
aviation--that the Wright method was more efficient than that of the
Frenchmen. It was calculated, indeed, that the Wright biplane, when
actually in the air, could be driven at an expenditure of only 15 h.p.;
whereas the Voisin, even with its 50-h.p. motor running at full speed,
had only just enough power to fly.
There were in 1909 two memorable events, and both impressed the public
with the progress of aviation. One was the crossing of the English
Channel by aeroplane; the other the flying meeting--the first of its
kind in the world--which was held upon the plain of Betheny, near
Rheims. To be first to cross the channel by air was the ambition of more
than one of the rivals; and the flight was rendered attractive by a
prize of £1000, offered by the London _Daily Mail_. Preparing to attempt
the feat, early in the summer of 1909, were three competitors, the names
of two of whom are familiar. One was the Comte de Lambert; he, it will
be remembered, was Wilbur Wright’s pupil. Now an accomplished airman, he
had a Wright biplane at Wissant on the French coast. Another competitor
was M. Bleriot, whose early exploits have been chronicled. The monoplane
he had now evolved was an ingenious craft, and merits careful
description. Its main features may be seen in Fig. 43. The machine was
remarkable chiefly for its smallness and lightness. While the Voisin
biplane weighed just upon 1000 lbs., the weight of Bleriot’s monoplane
was only 484 lbs. The span of its main wings was not more than 28 feet,
and they contained only 150 square feet of lifting surface. Driving the
machine was a motor of 25 horse-power; and the propeller, being placed
at the bow, was what is known as a “tractor.” Instead of pushing the
machine, as in the case of the Wright and the Voisin, this propeller
drew the monoplane through the air.
[Illustration: MACHINE SEEN FROM ABOVE,
showing its bird-like shape and the position of the pilot.
FIG. 43.--The Bleriot Monoplane.
A. Propeller; B. Motor; C. Sustaining-plane; D. Pilot’s seat; E. Landing
chassis; F. Combined tail and elevating-planes; G. Rudder.]
Sitting within the body of his machine, at a point between the main
wings and level with their rear edges, Bleriot controlled his craft by a
simple mechanism. His feet rested upon a pivoted bar; this, by a
movement of either foot, operated the rudder at the rear of the
machine. In front of the pilot was an upright lever, which he grasped
with both hands. At the bottom of it, attached to a bell-shaped piece of
metal, were four controlling wires, two running to the wings and two
towards the tail. Those fixed to the wings caused the rear edges of the
planes, which were flexible, to move up and down. A side-to-side action
of the lever, which drew upon the wires and caused the wings to warp,
prevented the monoplane from rolling while in flight. The Wrights, it
may be recalled, adopted a similar method, although their system of
leverage was different. A forward or backward movement of this same
lever controlled the rising or descending of the monoplane. Its
elevating-planes, instead of being at the front of the machine, as in a
biplane, formed part of the tail. This tail was one narrow, horizontal
plane, with a section at either end working up or down upon a pivoted
rod. When the hand-lever was drawn back, the elevating-planes were
tilted, and the monoplane rose. A reverse movement was used for descent.
Chief interest, at the early stages of the race to be first across the
Channel, was centred in a newcomer--Mr. Hubert Latham. He was a young
man of leisure, whose family, formerly an English one, had settled in
France. Being fond of sport, and particularly of the shooting of big
game, he had been attracted to flying through the medium of some balloon
ascents.
At the beginning of 1909 a new monoplane made its appearance in
France--a powerful, finely constructed, and very stable machine. It was
the Antoinette, designed by a famous engineer, and it was this craft
which interested Latham. M. Levavasseur was the designer of it and of a
specially lightened motor, first applied to motor-boats, and afterwards
to the experimental biplane of M. Santos-Dumont and also to the
aeroplane with which Farman first flew. The Antoinette, which M.
Levavasseur also fitted with one of his motors, was a large
monoplane--far larger than the Bleriot; and built not with the idea of
being a fair-weather machine, but to fly in winds. The craft is
illustrated in Fig. 44. The span of its wings was 46 feet, and they
contained 365 square feet of sustaining surface, while the total weight
was 1040 lbs.
The monoplane, in its method of control, differed from other machines.
Upon either side of the pilot, as he sat in the tapering, boat-shaped
body, was a hand-wheel. One operated the elevating plane; the other
controlled the warping of the wings; while to steer from side to side
the airman pushed pedals at his feet, and so swung the rudder at the
stern.
Driven by its 50-h.p. Antoinette motor, the monoplane showed itself
capable of flying well; but it found no successful pilot until Latham
took it in hand. He associated himself financially with its
constructors, and went to Mourmelon in France to learn to fly the
machine, and his skill became evident. On 5th June he flew for 1 hour 7
minutes without alighting, and afterwards made flights in wind and rain.
Latham was slight of figure and deft in movement, had a cool, quiet
judgment, and was courageous sometimes to the point of being reckless.
After his success at Mourmelon, it was decided to attempt the
cross-Channel flight; and the monoplane was transferred to a temporary
shed at Sangatte, a few miles from Calais. First on the scene, Latham
was ready for flight early in July; but the weather proved unfavourable.
There was fog in the Channel and he had to wait. In the meantime--on
13th July--Bleriot made a cross-country flight of 25 miles; then he,
too, packed up his monoplane and dispatched it to Calais.
[Illustration: A. Propeller; B. Motor; C. Sustaining-plane; D. Pilot’s
seat and controlling wheel; E.E. Vertical rudders; F. Elevating-plane;
G. Landing gear.
MACHINE SEEN FROM ABOVE,
showing the spread of the planes and tail, and the delicate taper of the
long, canoe-shaped body.
THE CRAFT IN FLIGHT.
FIG. 44.--The Antoinette Monoplane.]
On the morning of 19th July, there being little wind and practically no
fog, Latham said he would attempt the crossing. Rising from the slope of
a hill a little way inland, he passed out over the cliffs and steered
for Dover--a torpedo-boat destroyer, placed at his disposal by the
French Government, following him across Channel, so as to be ready to
pick him up should he make an involuntary descent into the water. It was
fortunate this vessel did steam upon his track. When he had reached a
point not quite half-way between the French and English coasts, flying
1000 feet high, Latham’s motor began to miss-fire; then, without further
warning, it stopped altogether. There was only one thing to do, and the
airman did it. Piloting his machine in a slanting glide, he alighted
upon the surface of the water. Fortunately there was no high sea, and
the monoplane floated with its wings flat upon the water. Tucking up his
feet to avoid getting them wet, Latham lit a cigarette and waited for
the destroyer, the captain of which had seen his fall and came steaming
at full speed. How the machine appeared, as it lay in the water, is
shown in the photograph on Plate IV.
So much damage was done to the monoplane in retrieving it from the sea,
that it was practically destroyed, and Latham was left without a
machine, with his rival Bleriot now upon the scene. But the Antoinette
Company, having a craft in reserve at Rheims, decided that this should
be hurried to the coast, and Latham given the opportunity of making
another attempt. This second machine was telegraphed for, accordingly,
and assembled with all speed, and on the morning of 25th July both
Latham and Bleriot were ready for flight. Farther down the coast at
Wissant was the Comte de Lambert; he had met with an accident, however.
In testing his biplane he side-slipped near the ground and the machine
was wrecked; this spelt delay while he was procuring and tuning another
craft.
On 25th July, a Sunday, there was a stiff breeze soon after it became
light, and nobody imagined that flying would take place. Bleriot,
however, motored from Calais to the spot where his monoplane was housed,
and after a short trial flight, during which his motor ran well, said he
should attempt the Channel crossing. Latham had not then left his hotel.
There was a dramatic moment before Bleriot started his engine. Standing
up in his machine and peering over the Channel, he asked:
“Where _is_ Dover?”
A friend stretched out an arm, pointing across the water, and the airman
nodded and sat back in his machine.
Rising in a half-circle to pass above some telegraph wires, Bleriot sped
out across the water--as shown on Plate V--and his machine receded until
it was a speck. He flew low and the wind was strong enough to bring
white crests to the waves. This wind, furthermore, was seen momentarily
to be rising, and anxiety was expressed. In a few minutes, to those
watching from the French coast, the monoplane and its pursuing destroyer
passed out of sight. And then came a period of waiting, crowds gathering
about the wireless telegraph station which, installed temporarily on the
cliffs, was in touch with Dover. And while his friends waited thus in
suspense, the lonely airman fought a rising wind--poised perilously
above the waves, and with no sign of land either before him or behind.
Those on the torpedo-destroyer, although she was steaming fast, lost
sight of the airman before mid-Channel was reached. He had said that,
should he out-distance this vessel, he would circle in the air and wait
till she overtook him, so as to have the certainty of being picked up
should his engine fail. But when in actual flight, although he saw his
escort left far behind, Bleriot did not swing round and wait, but
instead bore swiftly on; and his reason for so doing was this: the wind
was rising steadily and he reckoned his only hope of reaching the
English shore was to fly straight on, and seek to make a landing before
the gusts became too violent.
For ten minutes, in this historic flight, Bleriot flew through a
sea-fog, seeing nothing above or below him, and with instinct only to
guide him upon his course. Had his motor stopped then, causing him to
plane into the sea, his position would have been almost hopeless. It is
true that in the body of his monoplane had been placed an air-bag, to
help it float should he alight upon the water; but even with such
buoyancy it is doubtful whether the machine would have withstood the
buffetings of the waves for more than a few minutes; and Bleriot himself
was handicapped by the fact that, as the result of the igniting of some
petrol a week or so before, he had a burned foot which made him limp
painfully. But his motor did not falter--although, in this
cross-Channel flight, the airman was asking it to run longer than it had
done before.
[Illustration: _Photo, “Daily Mirror.”_
PLATE VI.--BLERIOT REACHES DOVER.
Wind-tossed and exhausted, after his flight from Calais, the airman
planed down near Dover Castle; descending so abruptly, owing to the
gusts, that he broke his running-gear and propeller. He is seen above
in his overalls, a few minutes after landing--a crowd having already
gathered on the scene.]
Passing from sea-mist into open sky, Bleriot saw the English coast-line;
but it was not Dover that lay before him, but a point considerably
north-east of it; and he realised that, as he had flown across the water
with no landmark to guide his eye, he had been borne off his course by
the pressure of a south-westerly wind. Holding on till he came within
planing distance of the shore, he turned his craft towards Dover; but
the wind, which he was now facing, seemed to gain in strength. The
monoplane pitched and swayed and made little headway, and the pilot
became anxious as to his landing. It had been arranged that he should
alight upon the Shakespeare Cliff; but now, approaching Dover upon the
side opposite to this cliff, he decided to land somewhere without a
moment’s delay, and not wait until he gained the farther point. So he
turned suddenly towards an opening in the cliffs which lay below Dover
Castle. Descending in passing above the land, he met the full brunt of
the gusts as they played over the cliff. The monoplane was caught and
twirled completely round; and the airman straightened it only to be
tossed again like a leaf before the wind. A second time he regained
control, and once more his machine was flung from its course. But now,
being well over the land, and with an open stretch of grass below him,
he planed steeply down. The landing was abrupt--in fact, made with
desperate haste; and the chassis of the machine was broken by the shock
and the propeller splintered. But Bleriot was not concerned at this. He
clambered stiffly from his seat, the great flight done; and soon
motor-cars came, and he was carried in triumph to the town. The scene
upon the cliff, showing the monoplane a few minutes after it had landed,
with Bleriot being interviewed by a journalist, is seen on Plate VI. The
course the airman flew in crossing the Channel is indicated by Fig. 45.
[Illustration: FIG. 45.--Bleriot’s course when flying the Channel.]
Meanwhile, on the French shore, the news was received by wireless; and
so overjoyed was M. Anzani, the builder of Bleriot’s motor, that he
suddenly burst into tears. One of those who stood waiting for a message
was Latham; and when the word came that Bleriot had made the flight and
won the prize, he took off his cap and cried, “Bravo!” Then he ordered
his mechanics to bring out his machine, saying that, although there was
nothing to be won, he intended to make the crossing to show what his
machine could do. But when he reached the starting-point the wind had
risen and was blowing in heavy gusts; whereupon, although he seemed
determined to fly, M. Levavasseur and others persuaded him that the idea
was hopeless.
In two days’ time, however, his chance came. Upon a fine, perfectly calm
evening he started upon a second crossing, and this time flew fast and
well. The watchers at Dover saw him approach--saw him reach a point
within little more than a mile of the Admiralty pier. And then, just as
it had done before, his motor broke down and he had to plane into the
sea. But this time, failing to make a smooth contact with the water, he
was thrown forward from his seat against a wooden upright, cutting his
head badly and sustaining shock. Picked up by a motor-boat he was
brought into Dover; then, after a doctor had attended him, he returned
to France. Again his monoplane was wrecked in its recovery from the
water. The Antoinette Company had fared badly in this contest, losing
two machines and having their chief pilot injured. The Comte de Lambert,
after hearing of Bleriot’s success, did not attempt a flight.
Henri Farman had played no part in this cross-Channel flying; he was
busy with the tests of a biplane of his own construction. In July, at
Rheims, there was to be the great flying meeting; and Farman had made up
his mind to wait for this. Aided by the experience he had gained with
the Voisin machine, he had designed a craft which should be generally
more efficient and faster in flight, and more quickly responsive to its
controls. The biplane he produced, marking as it did a step forward in
construction, is a machine that needs description. The general
appearance of the craft is indicated by Fig. 46, while an illustration
of this type of machine in flight will be found on Plate VII. A feature
of the Voisin that Farman discarded was the vertical panel fitted
between the main-planes to give sideway stability. An objection to these
planes was that they added to the weight of the machine and checked its
speed, tending also to drive it from its course should there be a side
wind. But in taking away such fixed balancing-planes, Farman had to
substitute another device; and what he did was to work upon the same
theory as the Wrights had done, and obtain a similar result in a
different way. They, it will be remembered, had warped the rear portions
of their main-planes. Farman kept his planes rigid, but fitted to their
rear extremities four narrow, hinged planes, or flaps, which could be
moved up and down and were called ailerons. Their effect was the same as
with the Wright wing-warp. When a gust tilted the machine, the pilot
drew down the ailerons upon the side that was inclined downward;
whereupon the air-pressure, acting upon the drawn-down surfaces,
restored the machine to an even keel.
[Illustration: A. Elevating-plane; B.B. Main-planes; C. Pilot’s seat; D.
Motor and propeller; E. Petrol tank; F.F. Hinged balancing-planes, or
ailerons; G.G. Tail-planes; H.H. Twin vertical rudders; I. Landing
wheels and skids.
MACHINE SEEN FROM ABOVE,
showing the span of main-planes, elevator, and tail, also the positions
of landing gear and pilot’s seat.
FIG. 46.--The Farman Biplane.]
The control was simple. At the pilot’s right hand there was a lever;
this, when moved forward or backward, operated the elevating-plane; and
a sideway action controlled the ailerons. At the pilot’s feet was a
pivoted rod, and this, as he pressed upon it with one foot or the other,
swung the twin rudders at the tail.
Such a system of hand-and-foot control has become general in aeroplanes.
The pilot uses as a rule a hand-lever or wheel for governing the ascent
or descent of his craft, and for sideway balancing, and employs his
feet for operating the rudder. This leaves him a hand free for the
manipulation of his engine throttle and switch.
A feature of Farman’s biplane was the landing gear, as shown in Fig. 46.
It comprised two long skids, which projected in front of the main-planes
beneath the machine, and continued some distance rearward; while mounted
upon each of these skids, at a point below the front edge of the lower
main-plane, was a short metal axle which bore two small bicycle wheels,
fitted with pneumatic tyres. Holding the axle to the skid were thick
india-rubber bands, and the working of this apparatus was as follows:
when the machine moved across the ground, the bicycle wheels bore its
weight, and the skids were prevented from making contact with the
surface. But when alighting from a flight, should the biplane strike
ground heavily, then the wheels were pushed up by the yielding of the
elastic bands, and the skids took the shock of the impact. Light, and
with no complications, this form of gear proved remarkably efficient;
and by degrees it came to be used, not only in the Farman, but upon
other types as well. The necessity in any such device was lightness;
when the machine was in the air, and until it landed from its flight,
the alighting gear was so much dead weight--and not only this, but the
air-pressure on struts and stays acted as a check upon the speed of the
machine. Any landing gear to be useful and efficient, therefore, must
be light and yet strong, and have few parts which can offer resistance
to the air.
[Illustration: PLATE VII.--A FARMAN IN FLIGHT.
Here, using the biplane with which he first flew in England, Mr.
Grahame-White is seen ascending from a field near Rugby during his
attempts to win the £10,000 London-Manchester prize.]
Farman planned to win prizes at the Rheims flying meeting, and he
succeeded. But the flights he made would hardly have been possible had
not he obtained the use of a new motor--one destined to play a vital
part in the development of flying. This was the Gnome; and to understand
its triumph an explanation is necessary. Before Farman fitted the first
of these motors to his biplane, engines in aeroplanes had been
troublesome and unreliable. The difficulty was that they must be very
light, and yet capable of running at high speeds and under heavy loads.
Working, say, at 1000 revolutions a minute or even more, they drove the
propeller of an aeroplane at full speed for the whole of the time it was
in the air, and enjoyed no occasional rest, or slackening of power, as
was the case with motor-car engines on the road. The result was that,
being light and experimental--and at the same time so heavily
worked--they either broke small but vital parts, such as a valve or
connecting-rod, or became over-heated and failed to deliver their power.
To prevent overheating, there were two cooling systems available. In
one, known as water-cooling, a stream of water flowed through metal
chambers round the cylinders, and tended to reduce their heat. But this
implied extra weight, and the carrying also of a radiator, or framework
of thin pipes exposed to the air, through which the water was pumped, so
as to cool it after it had passed round the heated cylinders. The second
system, which obviated the use of water or radiators, was known as
air-cooling. In this the tops of the cylinders were ringed with metal
flanges, or fins, upon which the air impinged as the machine flew. This
method is adopted in most motor-cycle engines, and answers admirably.
But with aeroplane motors, in the early days, the high speed at which
they worked, and the fact that they obtained no rest in flight, or
slackening in the number of their revolutions, made them overheat very
often, in spite of their cooling fins. One might liken their work to
taking a motor-cycle and running it at top speed up a hill without end.
[Illustration: FIG. 47.--The seven-cylinder 50-h.p. Gnome motor.]
The difficulty with air-cooling--although it had obvious advantages over
water-cooling--was to bring enough air to play upon the surfaces of the
cylinders; and it was here that the Gnome won so complete a success. In
other engines the cylinders were stationary, and their pistons, moving
up and down in the cylinders, turned a crank-shaft to the end of which
the propeller was fixed. Therefore the only air the cylinders obtained
was what rushed upon them through the speed of the machine in flight.
But in the Gnome, instead of the cylinders remaining stationary and the
crank-shaft revolving, the cylinders themselves spun round, and the
crank-shaft did not move. An illustration of this motor with one end of
the crank-chamber removed, so that the piston-rods can be seen, is given
in Fig. 47. It will be noted that there are seven cylinders, set in the
form of a star, and that the seven piston-rods projecting from them come
together upon a single crank-pin, which is attached to the stationary
crank-shaft and turns round it. The propeller, instead of being fitted
to the crank-shaft, as was the case with other motors, was bolted to a
plate upon the engine itself, so that when this turned around its
crank-shaft, it carried the propeller with it.
A difficulty in this engine lay in feeding its cylinders with their
petrol and air. We showed, in Fig. 32, how this mixture is delivered to
an ordinary motor, which has its cylinder stationary. But with the Gnome
the mixture could not be supplied from a pipe to the cylinder-head, for
the reason that the cylinder was revolving. The problem was solved by
making the stationary crank-shaft hollow, and by delivering the mixture
through this to the interior in the engine; thence it was sucked into
the cylinder-heads through a valve in the pistons. There were other
complications, inevitable to this ingenious motor, which led critics to
declare it would prove unreliable. But their judgment was wrong, for by
making every working part with scrupulous care, and sparing no expense
in the quality of the materials used, the builders of the Gnome did
render it reliable. They achieved another triumph as well; they
eliminated overheating. Revolving more than 1000 times a minute, the
cylinders of the Gnome cooled themselves automatically, and the engine
proved that it would run for hours without becoming too hot, or the
pistons seizing in the cylinders. Furthermore, seeing that the weight of
water and of radiators was avoided, the Gnome was remarkably light. The
50-h.p. engine weighed no more than 165 lbs., which meant that it gave
one h.p. of energy for each 3.3 lbs. of its weight. A photograph of the
Gnome, as fitted to a Farman biplane, is seen on Plate VIII.
The Gnome, when first built, was regarded with scepticism. Farman,
however, showed the acuteness of his judgment. He obtained a Gnome and
fitted it to the biplane which he flew at Rheims; and the wisdom of this
choice was soon made clear. The chief prize at Rheims was for the
longest flight, and this Farman won easily, remaining in the air for 3
hrs. 4 mins. and covering a distance of about 112 miles. The flight
represented a world’s record; and by this feat alone Farman made his
biplane famous, and demonstrated the reliability of the Gnome. Those who
watched the flight will not forget it. Farman started rather late in the
afternoon and flew low round the great aerodrome, his landing-wheels
appearing sometimes to be a few feet only above the grass. He sat
leaning forward in his seat and circled close to the wooden towers
marking the course, losing no ground and steering his machine with
perfect accuracy. So he flew for lap after lap, never rising higher or
flying lower, and with the Gnome behind him emitting a booming hum as
it whirled the propeller without falter or flag. Only the approach of
darkness, in fact, caused the airman to descend.
[Illustration: A. Elevating-planes; B. Pilot’s seat and control-wheel;
C.C. Main-planes; D. Ailerons; E. Motor and propeller; F. Tail-plane and
rudder.
MACHINE SEEN FROM IN FRONT,
showing the chassis and the position between the planes of the two
ailerons (A.A.).
THE CRAFT IN FLIGHT
MAKING A TURN.
FIG. 48.--The Curtiss Biplane.]
[Illustration: FIG. 49.--The Curtiss aileron control.
A. Pilot’s seat; B. Wheel for operating elevator; C. Shoulder-pieces and
vertical rod for aileron control.]
Of famous aeroplanes at Rheims, five types stood out by themselves--the
Farman, the Voisin, the Wright, the Bleriot, and the Antoinette, all of
which have been described. But there was one other, which few people had
heard of before it appeared here. This was the Curtiss biplane, built by
an American named Glenn H. Curtiss, and engined with a motor which also
bore his name. Curtiss had experimented with many power-driven
machines--motor-cycles, motor-cars, airships, and aeroplanes--and had
won a prize in America with a small, light biplane, and it was a craft
of this type--as seen in Fig. 48--that he brought with him to Rheims,
his idea being to compete for the speed prize. The machine had a front
elevator and tail-planes, according to the practice in biplane
construction; but an innovation was the setting of the ailerons midway
between the main-planes--a position that will be noted in the sketch;
another novelty was the way these ailerons operated. At the pilot’s
back, as he sat in his driving seat, was an upright rod with two
shoulder-pieces--by means of which, should he shift his body, he could
swing the rod from side to side. Wires ran from the rod to the ailerons;
and if the pilot leaned over, say, to the right, he drew down the
ailerons on the left side of the machine. The merit of such a control
was that it was instinctive; that is to say, should the biplane tip down
on one side, it was natural for the pilot to lean away from the
plane-ends that were sinking; and he operated the ailerons
automatically, as he did this, and so brought the machine level again.
This ingenious system is illustrated in Fig. 49.
[Illustration: _Photo, F. N. Birkett._
PLATE VIII.--THE GNOME MOTOR.
This engine--of which Mr. Grahame-White is testing an exhaust
valve--is here seen fitted to a Farman biplane, the three tanks above it
containing petrol and oil.]
Features of the Curtiss biplane were its smallness and lightness. The
span of its main-planes was only 28 feet 9 inches--no more than the span
of the Bleriot; and it weighed, with its pilot on board, a total of only
710 lbs. Driving the machine was an 8-cylindered 30-h.p. motor;
therefore it was expected to be fast in flight. The speed contest, as a
matter of fact, became a duel between Curtiss--who flew his machine
himself--and Bleriot, who piloted his fastest monoplane; and in the end
Curtiss won, attaining a speed of a little more than 47 miles an hour.
Bleriot had built for the contest a new racing monoplane, which had a
motor of 80 h.p., and in which the pilot sat below the wings. The
photograph on Plate IX shows the appearance of this type of craft.
Latham, in his Antoinette, won the height prize at Rheims, rising to an
altitude of 500 feet. Others who distinguished themselves were Paulhan
and Rougier, on Voisin biplanes--the former to become famous afterwards
as the winner of the _Daily Mail_ £10,000 prize for the flight from
London to Manchester. But the Voisins, although they flew steadily,
seemed slow, clumsy machines in comparison with the Farman. The Wright
biplanes, of which there were three in competition, did not distinguish
themselves particularly. The pilots who had charge of them, and had been
taught to fly by Wilbur Wright, were the Comte de Lambert and M.
Tissandier, who have been mentioned already, and M. Lefevre--a pilot who
was the first to make trick flights, wheeling, diving, and swinging in
circles, and astonishing people who watched him from the stands. Not
long after the Rheims meeting, while testing a new machine, this airman
met with an accident that proved fatal, his craft diving suddenly and
being wrecked.
The Wright machines, to tell the truth, were not regarded favourably in
France. Many men were attracted by the speed and simplicity of the
monoplane; many others, again, championed the Farman with its Gnome. The
chain-drive of the Wright propellers was said to be a source of danger,
and their need to start from a rail was, in view of the wheeled
under-carriages of the French machines, declared a clumsy makeshift. So,
although the machine was the first power-driven craft to fly
successfully, and despite the feats of Wilbur in 1908, the Wright
biplane did not conquer France. Although they had lagged behind the
Wrights in the building of practicable machines, the enthusiasm of
French makers soon carried them ahead of their rivals. The Wrights
handicapped themselves; they would not, for a long time, discard the
starting-rail; they would not adopt the Gnome motor; they were averse
from making alterations in the construction of their machine. So their
biplane, although its efficiency was always granted, never took the
place to which it seemed entitled.
It was after the Rheims meeting that the building of aeroplanes
commenced as an industry. Farman established a factory and began to
produce biplanes in considerable numbers; Bleriot had received orders
for monoplanes after the cross-Channel flight; and the Voisins were
building too. There were French firms, also, who had been given
permission to manufacture the Wright biplane; and in England, at a
factory in the Isle of Sheppey, Messrs. Short Brothers were building
Wright machines.
[Illustration: FIG. 50.--The Roe Triplane.
A.A.A. Three main-planes; B. Motor; C. Four-bladed propeller; D.D.D.
Triplane tail; E. Rudder; F. Landing gear.]
It is necessary now to consider the growth of flying in England. While
mighty deeds were done in America and France, there had been pioneers at
work here--painstaking and enthusiastic, but handicapped sadly by the
public indifference that prevailed. They met with no encouragement--no
financial help; they had to build their machines as best they could, and
whether they succeeded or failed seemed the concern of none. An
experimenter who braved this apathy and won his way until he became a
constructor of aircraft, was Mr. A. V. Roe. For some time he was an
advocate of the triplane form of machine--a craft, that is to say, with
three main-planes fitted one above another. The machine with which he
obtained flights, although they were very brief, is seen in Fig. 50.
Subsequently, however, Mr. Roe adopted the biplane form. His
distinction in the pioneer days was that he managed to make his triplane
lift into the air and fly a short distance, with the aid of a
motor-cycle engine developing no more than 9 h.p.
Another ardent worker in England, and one destined to become famous, was
Mr. S. F. Cody. After developing a system of man-lifting kites which the
British War Office acquired, he joined the military aircraft factory
that had been established at Farnborough. Here, after tests with
dirigible balloons, he began the construction of experimental
biplanes--all machines of large size. Early in 1909 he made brief
flights--the longest being one of about 250 yards. Then, after
alterations to his machine, he managed in July to fly a distance of 4
miles. This he increased afterwards to 8 miles; and then on 1st
September flew for 1 hour 3 minutes, rising to a height of 300 feet.
Cody’s biplane was a very large machine, having 1000 square feet of
lifting surface--twice that of the Farman or Voisin. Driving it was an
80-h.p. engine, which operated two propellers on the system used by the
Wrights. With its pilot on board the machine weighed 2170 lbs. It is
illustrated in Fig. 51.
[Illustration: A. Elevating-planes and vertical-plane; B. Pilot’s
control lever; C.C. Main-planes; D. Motor; E. Propellers; F. Rudder; G.
Landing gear; H. Rear skid.
MACHINE SEEN FROM ABOVE,
showing the large size of the elevators, the position of the pilot, and
the placing of the propellers.
FIG. 51.--The Cody Biplane.]
In the control of the machine Cody introduced original devices, notably
as to sideway balance. Instead of using ailerons or wing-warping, he
arranged his two elevating-planes so that they would move up and down
independently of each other. In this way, by making one tilt up and the
other down, he was able to obtain the same effect as with ailerons. When
raised or lowered in unison, these planes acted as elevators. Cody
managed also to combine all controlling movements in one lever, and did
not use his feet for steering. Before him, as he sat in his driving
seat, he had a rod which ended in a hand-wheel. Pushed forward or
backward, this rod moved the elevating-planes; swung over from side to
side, it altered the angle of one or other of the elevating-planes and
so controlled sideway balance; while by turning the wheel at the top of
the rod, the pilot could operate the rudder at the rear of the machine.
Cody made little progress until he obtained a powerful motor, his
machine being too large and heavy for the engines fitted to other craft.
Acquiring a motor of 120 h.p. in 1912, he won the War Office competition
on Salisbury Plain, his biplane showing its superiority--as a purely
military craft--even over those of the famous French builders. It was in
the summer of 1913, while flying a new machine, that the airman and a
passenger fell to their death--expert evidence showing that the craft
collapsed in the air.
Two other Englishmen prominent in the early days of aviation were the
Hon. C. S. Rolls and Mr. J. T. C. Moore-Brabazon. The former, having
learned to glide as the Wrights had done, obtained a British-built
Wright biplane and made excellent flights at Shellbeach, Isle of
Sheppey. During the season of 1912, still piloting a Wright, he took
part in several aviation meetings; and it was at Bournemouth, owing to
the collapse of a tail-plane, that he fell 90 feet and was almost
instantly killed. Towards the end of 1909, Mr. Moore-Brabazon, after
buying and learning to pilot a Voisin, ordered a British-built biplane
from Messrs. Short Brothers, and with this machine on 30th October 1909
he won a £1000 prize offered by _The Daily Mail_ for the first circular
mile flight by a British aviator upon an all-British machine.
Now indeed, once the first obstacles had been overcome, the building of
aeroplanes and the training of men progressed astonishingly. New
champions appeared almost every day; many aviation meetings were held;
and Henri Farman, to complete the triumphs of a wonderful year, flew in
November for 4 hours 17 minutes 35 seconds, covering a distance of 150
miles through the air, and breaking all records for duration of flight.
CHAPTER XII
PERILS OF THE AIR
How pilots fought the wind--Military demands
for an “airworthy” machine--Value of the
air-scout--Dangers in wind-flying--The
“side-slip”--Aeroplanes that are automatically
stable.
It has been shown how aeroplanes were built and made to fly, and not
machines of one particular make, but biplanes and monoplanes of various
types of construction; also how, granted he had a reliable motor, a man
might fly for hours without alighting. These were the lessons of 1909;
these, and the fact that flying was proved an art that could be learned
by any man who was active and had sound nerves. After Wilbur Wright had
taught his first pupils, and Bleriot and Farman had established training
schools, men in rapidly increasing numbers came to learn to fly; so
that, quite early in 1910, it was possible to list the names of more
than 200 pilots.
Progress was now revealed in two directions: firstly, encouraged by
engine reliability, airmen made cross-country flights; and secondly,
becoming more used to being in the air, and gaining confidence in the
handling of their machines, they began to fly in gusty winds. This was
shown by the fact that, fearing any breeze at first that was higher than
10 or 15 miles an hour, pilots soon combated winds of 20 and 25 miles an
hour.
Flights of 100 miles were made across country; one historic example, of
course, was M. Paulhan’s 183-mile journey from London to Manchester,
made in 242 minutes and with but one halt, by which he won _The Daily
Mail_ £10,000 prize, and in which--meeting him in keen but friendly
rivalry as the representative of England--he had the joint author of
this book, Mr. Claude Grahame-White.
The confidence of pilots in the reliability of their machines was
demonstrated conclusively by the Comte de Lambert. Rising from the
aerodrome at Juvisy, near Paris, he flew over the city and circled the
Eiffel Tower, returning afterwards without accident to his
starting-point.
Several more airmen had, by this time, succeeded in crossing the
Channel, and a notable feat was that of the Hon. C. S. Rolls, who flew
from Dover till he reached the French coast near Calais; then, circling
without a descent, he returned to his starting-point--a flight over-sea
that lasted an hour and a half. In high flying, too, the confidence of
airmen was displayed. At Rheims in 1909, it may be remembered, Latham
rose 500 feet, and this was considered remarkable. But the record,
during 1910, was beaten and beaten again, until it stood at nearly
10,000 feet. In speed also, using monoplanes with 50-h.p. motors, pilots
made records day by day; and an English airman, Mr. Radley, flying over
a measured course in August 1910, in a Bleriot monoplane, attained a
speed of more than 70 miles an hour.
In the duration of flight, which proved the reliability of engines,
great strides also were made. From Farman’s 4-hour record at the end of
1909, the figure was carried till it stood at 6 hours 1 minute 35
seconds. This flight was made by Tabuteau, an airman flying a Maurice
Farman biplane. Maurice was a brother of the famous Henri, and he built
a biplane which, while resembling the Henri Farman in general aspect,
was different in detail. In the first machines he built,--and it is one
of these the sketch (Fig. 52) shows,--Maurice Farman used, in addition
to ailerons, two side curtains or panels, as the Voisins had done; but
these he afterwards abandoned, retaining ailerons alone. A feature of
this machine was the way in which the landing skids were continued
upward, so as to form the supports for the elevating-plane. The Maurice
Farman developed into a stable and remarkably successful craft, greatly
used for cross-country flying and by military pilots.
[Illustration: FIG. 52.--Maurice Farman Biplane (early type).
A. Elevating-plane; B. Seats for pilot and passenger; C.C. Main-planes;
D. Motor with two-bladed propeller; E. Vertical panel; F. Aileron; G.
Tail-planes; H.H. Rudders; I. Landing chassis.]
The chief triumph of 1910 was the fight airmen waged against the wind.
This was their enemy--an enemy which sought to chain them to the
ground, and prevent their craft from becoming of practical use. One
point, indeed, became clear: it was of little value to fly high or for
long distances, if one could only do so in favourable weather. The
aeroplane, if it was to play a practical part in the affairs of the
world, must ascend in high winds as well as in calms. This being
recognised, there was strenuous effort to produce an “all-weather”
machine. Particularly was wind-flying of value in the military use of
aeroplanes; and it is here that we reach a vital aspect of aviation.
Immediately craft could fly across country, and ascend high enough for a
view of the land to be obtained from them, it was seen they would have a
great value as scouts in time of war.
There has, from the earliest days of battle, been a need for scouting--a
need for news as to what the enemy is doing. Picture two armies about to
engage. They approach each other cautiously, troops spread out and
dotted here and there; while in front of each force is thrown a screen
of outposts. These form a protective fence, through which the scouts of
the enemy find it difficult to penetrate. What the scouts seek to
discover is how many men there are in the army moving forward, how many
guns, and how these men and guns are being massed and drawn up for the
battle that impends. But the outposts head them off and shoot them down;
and as both armies have outposts, and as both sets of scouts find the
same difficulty in obtaining news, the two forces may grope and blunder
into battle without knowing such facts as to numbers and positions as
might spell the difference between victory and defeat. Of course, the
scouts do their best, some on foot, some horsed; but it was Napoleon who
wrote:
“Nothing is more contradictory, nothing more bewildering, than
the multitude reports of spies or of officers sent out to
reconnoitre. Some locate army corps where they have seen only
detachments; others see only detachments where they ought to have
seen army corps.”
But now came the aeroplane, and strategists seized the opportunities it
offered. Outposts could do nothing against such a scout as this; instead
of seeking to dodge them through a wood, or round a hill, it could pass
thousands of feet above their heads; and the earth below, as viewed by
the spy sitting in his machine, would be spread out like a panorama; he
would see the troops of the enemy in motion, and note their strength and
the positions to which they moved. No wonder the War Departments of
Europe were ready to buy aeroplanes. Buy them they did, indeed, in
growing numbers; but the drawback of the early machines was that they
were fair-weather craft; they would not fly in winds. Imagine that a
battle impends, and that the Commander-in-Chief of one army seeks news
as to the movements of some division of his enemy; so he orders the
air-scouts to ascend. But the wind may be blowing hard; and if it is,
and the aeroplanes are only fair-weather machines, they will have to
remain on the ground till the wind drops, and perhaps miss their
greatest chance during a whole campaign.
But it was astonishing how, feeling greater confidence in the handling
of their machines, airmen began to join issue with this enemy the wind.
They were helped, too, by a growing efficiency in the construction of
their craft. Machines were built more strongly, engines were more
staunchly made; in all details that spelt reliability, were aircraft
improved. But the wind, none the less, took its toll. It was not
combated without loss of life; and we find that, before the end of 1910,
nearly thirty men had been killed while flying. In many cases, struck by
a heavy gust, a machine collapsed in flight; in others, beaten over by
the force of the wind, but with his craft intact, the pilot had fallen
to earth, powerless to regain the control of his machine.
[Illustration: PLATE IX.--THE FIRST HIGH-POWERED BLERIOT.
This type of monoplane, in which Mr. Grahame-White learned to fly--being
seen with a passenger above--was built by Bleriot for the speed contests
at Rheims in 1909. It had an 80-h.p. motor, as compared with the
25-h.p. engine which was then fitted to ordinary
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