THE AIRSHIP
So far in our story we have traced the origin and progress of the
balloon, showing how from small beginnings it has grown to be an
important invention, of great use to the scientific observer, the
soldier, and the explorer, and the means of teaching us much fresh
knowledge.
But in spite of the high hopes of early aeronauts, and the extravagant
prophecies made when the first balloons ascended into the sky, it has
long been evident that the balloon alone has not solved the problem
of human flight or accomplished the conquest of the air. An ordinary
balloon is, in fact, nothing more than a mere lifting machine, no more
capable of sailing the sky, in the proper sense of the word, than a
cork floating in the water is capable of sailing the sea. It has no
movement of its own, but drifts simply at the mercy of the wind, and
quite beyond control. By the discharge of ballast, or by the letting
out of gas, the aeronaut can indeed cause it to rise or sink at
pleasure, and sometimes when two currents of air are blowing aloft in
different directions at the same time he may, by passing from one to
the other, “tack” his balloon to some extent across the sky. Otherwise
he has no power of guiding or directing it in the least degree, and
should he lose sight of the earth above the clouds, has even no method
of telling in which direction he is travelling.
Early inventors thought they would be able to steer balloons by means
of sails, like a boat, but they soon found that this was impossible.
The effect of hoisting a sail at the side of a balloon was merely to
swing the balloon round until the sail was in front, while meantime it
continued its course unaltered. The use of a rudder and other means
were also tried, but without success; nor can such methods ever hope to
succeed so long as a balloon floats in the air at the same pace as the
wind that carries it forward. A balloon travelling with the wind may be
compared to a boat drifting idly with the tide. As long as she drifts
she refuses to answer her rudder, which swings idly. But presently the
boatman hoists a sail, and the wind carries the boat onwards faster
than the tide, and then immediately the rudder comes into action. Or
should there be no wind, he may accomplish the same thing by dragging
an anchor or other weight in the water, and so slowing his boat down
until it moves slower than the current; he will then again find that
his boat will answer her helm.
To steer his course in a balloon, therefore, the aeronaut must so
arrange that he is travelling faster or slower than the wind in which
he finds himself. To travel faster, he must employ some sort of engine
or motor to drive his craft onwards. To travel slower, he must trail
something along the ground beneath to act as a drag.
Part of the equipment of every balloon is a long trail-rope, which,
when the balloon is aloft, hangs some 300 feet below the car. The
object of this rope is to break the force of the fall when the balloon
comes down to the earth at the end of the voyage. In the greater number
of cases a balloon, in its final swoop to the ground, falls the last
few hundred feet with considerable, and often uncomfortable, speed. But
when provided with a trail-rope, as it descends more and more of the
heavy rope will lie along the ground, and so lighten the weight of the
balloon, and lessen the shock of falling.
If then a trail-rope were used of such length that it would sweep along
the ground while the balloon was flying in the air, the effect would
be to put a drag or brake on the balloon, and so render it capable of
being steered to some extent with a sail; and this is what has actually
been done in all attempts of the kind. But since a long rope dragging
rapidly across the country is a very dangerous object, capable of doing
great damage, and also liable to catch in trees and other obstacles,
such experiments can only be tried with safety over the sea, or, as in
the case of Andrée’s voyage, over desert or uninhabited country.
The best way of steering a balloon, therefore, is to provide it with
some mechanical power which shall urge it onwards at a greater speed
than the wind; and when this is done, it has ceased to be a balloon in
the popular sense of the word, and has become an “airship.”
There is a great deal of confusion between the terms “airship,” and
“flying machine,” and the two words are often considered as meaning
the same thing. But while, strictly speaking, neither word in itself
has any very definite meaning, it is gradually becoming more general
to apply them to two widely different objects. According to this plan,
although both names stand for an aerial vessel capable of travelling
in the sky by its own motion, an airship is a machine supported in the
air by reason of its buoyancy, while a flying machine is kept aloft
only by virtue of its onward movement.
In other words, part of the construction of an airship consists of a
bag or balloon, filled with gas or hot air, which causes the whole to
rise and maintain its position in the air. This balloon part is quite
independent of the machinery which drives the airship forward, and
indeed if the engine ceases working, the vessel becomes nothing more
than an ordinary balloon in its nature, and will behave like one. An
airship, therefore, is in principle an apparatus lighter than air.
A flying machine, on the contrary, is heavier than air, and maintains
its position aloft merely by the power it obtains from its engines,
assisted by its special construction. The inventors of flying machines
take as their analogy the flight of birds. Birds are creatures
heavier than air, which yet manage to rise and fly by reason of the
strength and construction of their wings. In the same way the heavy
flying machine essays to fly by the power of its machinery. And, as
a bird aloft, if its wings became disabled, would instantly drop
towards earth, so a flying machine would immediately commence to fall
if its engine stopped or ceased to move with sufficient power. The
airship and the flying machine, therefore, may be regarded as rival
aerial vessels, and their inventors and advocates, sometimes known
as “lighter-than-air-ites” and “heavier-than-air-ites,” though both
working for the same end, are endeavouring to accomplish their aim by
widely different methods.
Up to the present day the airship--to which we will first turn our
attention--has been much more largely and successfully experimented
with than the flying machine. It is, however, the opinion of many,
including the great authority Sir Hiram Maxim, that in the future the
flying machine will become the more important invention of the two.
“In all Nature,” says Sir Hiram, “we do not find a single balloon. All
Nature’s flying machines are heavier than air.” And from this he argues
that, as Nature is ever our best guide and example, a flying machine
heavier than air will be in the end most likely to succeed.
One of the earliest airships which achieved any success was invented
by a Frenchman, M. Giffard, about the year 1852. He made his balloon
of an elongated or cigar shape, a form adopted by airship inventors
as offering less resistance to the air than the ordinary globular or
pear shape. To this balloon, which was 104 feet long and 39 feet in
diameter, he attached a steam-engine of three-horse power, weighing 462
lbs. and working a screw-propeller, which, by its rapid revolutions,
urged the balloon onwards through the air, even as the screw of a
steamship urges the vessel through the water. With this apparatus he
succeeded on one occasion, for a very short while, in obtaining a speed
of six and a half miles an hour. Twenty years later another Frenchman,
M. Dupuy de Lôme, constructed another airship; but fearing to place an
engine so near the gas of his balloon, he used the strength of eight
men to work his screw. This was a very wasteful mode of supplying
energy, for the weight of the men was very great in proportion to
their strength, and this machine, during its trial, did not attain as
great a speed as Giffard’s. Twelve years after a third Frenchman, M.
Tissandier, took up the same experiments. His elongated balloon was
smaller than the two previous, and his engine was an electric motor of
one and a half horse-power. On one occasion a speed of nearly eight
miles an hour was attained.
By this time the French Government had become interested in the work,
and provided money to continue investigations. The result of this was
that in 1885 two officers of the French army, Captains Renard and
Krebs, brought out by far the most successful airship yet constructed.
It was 165 feet long, 27 feet in diameter, and was driven by an
electric motor of nine horse-power. That this machine proved itself
perfectly capable of being guided in the air is amply shown by the
fact that it returned to its shed five times out of the seven on which
it was publicly taken out. It also attained a speed of fourteen miles
an hour, and indeed it would seem that Renard and Krebs, although their
names are now almost forgotten, accomplished nearly as great things
twenty years ago as the popular airship inventors of the present day.
One of the greatest difficulties with which early inventors had to
contend was the enormous weight of their engines. The machinery they
were obliged to use to drive their airships through the air weighed
more than their balloons, unless made of unwieldy size, had power
to lift. The same difficulty indeed exists at the present time,
though to a much less degree. Of late years, and especially since
the introduction of the motor-car, great progress has been made in
the construction of light but powerful engines, or motors, and the
employment of petrol vapour instead of coal or oil has very greatly
lessened the weight of the fuel which has to be carried.
In consequence of this improvement many airships have recently been
made which have met with varying success, and many more are at the
present moment in process of construction. Among the host of inventors,
whose names it would here be impossible even to mention, three stand
out from the rest in special prominence--Zeppelin, Santos Dumont, and
Stanley Spencer--all three the inventors of airships which have, by
actual experience, proved their power of steering a course across the
sky.
Of these rival airships, by far the largest and most elaborate was
that built by the first named, Count Zeppelin, a distinguished veteran
soldier of the German army. For many years he had spent his time and
fortune in making experiments in aerial navigation, and at length in
1900, having formed a company and collected a large sum of money for
the purpose, he produced an enormous airship, which, from its size,
has been compared to a man-of-war. In shape Count Zeppelin’s invention
resembled a gigantic cigar, 420 feet in length, pointed at both ends.
The framework was made of the specially light metal aluminium, covered
over with silk, and though from outside it looked all in one piece,
within it was divided into seventeen compartments, each holding a
separate balloon made of oiled silk and absolutely gas-tight. The
object of this was to prevent the tendency the gas has to collect all
at one end as the ship forces its way through the air. These balloons
were filled with pure hydrogen, the cost of the inflation alone being
£500. Beneath was slung a long gangway, 346 feet in length, with two
cars, also made of aluminium, attached to it. In these cars were placed
two motor-engines of sixteen horse power each, driven by benzine, and
working a pair of screw-propellers attached to the balloon. A steering
apparatus was placed at each end, and the whole machine, with five
passengers, weighed about eleven tons.
[Illustration: ZEPPELIN’S AIRSHIP OVER LAKE CONSTANCE.]
To lessen the effects of a possible fall, the experiments were carried
out over water, and the great airship was housed in a shed built on
Lake Constance. The cost of this shed alone was enormous, for it was
elaborately constructed on pontoons, and anchored in such a way that
it could be turned round to allow the airship to be liberated from it
in the best direction to suit the wind. The trial trip was made one
evening in June 1900, when a very light wind was blowing. The great
machine rose into the air, carrying Zeppelin and four companions to a
height of 800 feet. The steering apparatus then being put into action,
it circled round and faced the wind, remained stationary for a short
while, and then sank gracefully and gently upon the water. A few days
later another and more successful trial was made. The wind at the time
was blowing at sixteen miles an hour, but in spite of this the airship
slowly steered its course against the wind for three and a half miles,
when, one of the rudders breaking, it was obliged to come down. On
one or two other occasions also it made successful voyages, proving
itself to be perfectly manageable and capable of being steered on an
absolutely calm day. The expense of the experiments was, however,
tremendous; money fell short, and the great machine, the result of many
years’ labour and thought, has since been abandoned and broken up.
[Illustration: SANTOS DUMONT’S AIRSHIP.]
A far happier fate has so far attended the efforts of the brave young
Brazilian, Albert Santos Dumont. The wealthy son of a successful
coffee-planter, he had always from his boyhood been keenly interested
in aeronautics, and, coming to Paris, he constructed in 1898 an
airship of a somewhat novel kind. His balloon was cigar-shaped, 83
feet long, and holding 6500 feet of pure hydrogen. Attached to the
balloon, and working a propeller, was a small motor like those used
for motor cycles, and astride of this Santos Dumont rode, bicycle
fashion, steering his course with a rudder. In this ingenious machine
he ascended from the Botanical Gardens in Paris and circled several
times round the large captive balloon then moored there, after which
he made a number of bold sweeps in the air, until an accident occurred
to his engine and he came precipitately to the ground. Though shaken he
was by no means discouraged, and declared his intention of continuing
his experiments until he should have invented an airship which, in his
own words, should be “not a mere plaything, but a practical invention,
capable of being applied in a thoroughly useful fashion.”
Accordingly he constructed one machine after another, gaining fresh
knowledge by each new experience, and profiting by the accidents and
failures which continually beset him in his dangerous and daring work.
Before long also he received an additional incentive to his labours.
Early in the year of 1900 it was announced by the Paris Aero Club, a
society of Frenchmen interested in aeronautical matters, that one of
its members, M. Deutsch, had offered a prize of 100,000 francs--about
£4000--to the man who, starting from the Aero Club grounds at
Longchamps in a balloon or flying machine, should steer his course
right round the Eiffel Tower and back to the starting-place--a distance
of three and a half miles--within half an hour. If the prize were not
won within a certain time, his offer was to be withdrawn, and meanwhile
he promised a certain sum of money every year for the encouragement of
aeronautical experiments.
The offer of this reward set many inventors to work upon the
construction of various aerial vessels of all kinds, but from the
beginning Santos Dumont was well to the fore. By the middle of 1901
he had completed what was his sixth airship--a cigar-shaped balloon,
100 feet long, its propeller worked by a motor-car engine of fifteen
horse-power--and with it, on July 15th, he made a splendid attempt
for the prize. Starting from the Club grounds, he reached the Eiffel
Tower in thirteen minutes, and, circling round it, started back on
his homeward journey. But this time his voyage was against the wind,
which was really too strong for the success of his experiment; part
of his engine broke down, and the balance of the vessel became upset;
and although he managed to fight his way back to the starting point,
he arrived eleven minutes behind time, and so failed to fulfil M.
Deutsch’s conditions.
Again, on the 9th of August, having in the meantime made further
trials with his machine, he embarked on another attempt to carry off
the prize. He chose the early hours of the morning, starting shortly
after six from the Club grounds, where only a few friends, among them
the keenly interested M. Deutsch, were present. The day was apparently
perfect, and when, after the lapse of five minutes only, he had reached
the Tower and swung gracefully round it, every one was convinced that
this time the prize was certain to be won. But the homeward journey
was all against the wind, which was blowing more powerfully aloft than
on the ground, and suddenly the onlookers were horrified to see the
fore part of the balloon double right back. By so doing the silken
envelope became torn and the gas began escaping. Rapidly the balloon
appeared to wither up and shrink together. The engine was seen still
to be working, though no progress was now being made. Then the whole
apparatus collapsed utterly, and fell with sickening speed upon the
house-tops.
Deutsch and his companions watched the fall horror-struck, and jumping
into their motorcars hurried to the spot, convinced that a fatal
accident must have occurred. But they found that, although the airship
was smashed to pieces, its plucky inventor had almost miraculously
escaped unhurt. The wrecked machine had fallen upon the roof of a house
in such a way that the keel had caught upon a corner, and the car,
which was fastened to it, hung at a perilous angle down the side of
a wall. Fortunately Dumont was secured to his car by a leather belt,
and he managed to hold on, though in considerable danger lest the keel
should break and let him fall, until rescued by a fireman with a rope.
His machine was hopelessly ruined; but when asked what he intended to
do next he merely answered: “Begin again. Only a little patience is
necessary.”
A new machine, “Santos Dumont VII.,” was ready in less than a month,
and tested on the 6th of September. It behaved beautifully, and all
went well until the trail-rope caught in a tree. In liberating it the
framework became bent, and the airship was being towed back to its
shed when a sudden gust of wind tore it away from those who held it.
It immediately rose into the air, and on Dumont opening the valve the
whole collapsed and fell to earth with a great shock. Again the lucky
inventor escaped unhurt, though owning this time that he had “felt
really frightened.” Ten days later, in another trial, the airship came
in contact with some trees, which pierced the silk and let out the gas,
so that it fell precipitately twenty feet. But the aeronaut appeared to
bear a charmed life, for once more he was none the worse for the fall.
Several other unsuccessful trials followed, and then, on the 19th of
October, Santos Dumont made another grand attempt for the prize.
Starting with the wind in his favour, his machine travelled at the
rate of thirty miles an hour, and rounded the Eiffel Tower in nine
minutes. But in the journey homewards the airship had to struggle with
a wind blowing at thirteen miles an hour. In endeavouring to “tack”
the machinery became upset, and Dumont, leaving his car, crawled
along the framework to the motor, which he succeeded in putting in
order again. But this naturally occasioned some delay, and though he
accomplished the rest of his journey in eight minutes, the Committee at
first decided he had exceeded the allotted time by forty seconds, and
so had lost the prize. Great popular indignation was excited by this
decision, for public sympathy was all with the daring and persistent
young Brazilian, and M. Deutsch himself was most anxious he should
receive the award. Finally, he was considered to have fairly won it,
and the money, which he afterwards divided among the poor, was formally
presented to him.
Early in the next year Santos Dumont continued his experiments at
Monaco, and on one occasion came down in the sea, and had to be rescued
in the Prince of Monaco’s own steam yacht. After this there was a talk
of further voyages being made in England, but the project came to
nothing, and although Dumont made other ascents in Paris in the summer
of 1903, he does not appear to have eclipsed his previous record.
But although Santos Dumont came through all his accidents and perils
so happily, his example led to terrible disaster on the part of a
luckless imitator. In 1902 M. Severo, also a Brazilian, was fired with
a desire to share his fellow-countryman’s fame, and he also constructed
an airship with which he proposed to do great things. But while Dumont
was a skilled aeronaut of large experience, as well as a mechanician,
Severo knew scarcely anything about the subject, and had only been
aloft once or twice. Proof of his ignorance is shown by the fact that
his motor-engine was placed only a few feet away from the valve through
which the gas from the balloon would escape.
The ascent took place in Paris early in the morning of the 12th of May,
and was witnessed, unhappily, by Severo’s wife and son. Bidding them
good-bye, he stepped into the car, and, accompanied by an assistant,
rose above the town. The balloon rose steadily, and appeared to steer
well. Then Severo commenced to throw out ballast, and when the airship
had risen 2000 feet it was suddenly seen to burst into a sheet of
flame. A terrible explosion followed, and then the whole fell to the
ground a hopeless wreck, and the two men were dashed to pieces in
the fall. It is believed that this dreadful disaster, which recalls
the fate of Pilâtre de Rozier, was caused by the hydrogen gas, which
escaped from the valve during the rapid rise, becoming ignited by the
engine, which, as has been said, was placed dangerously close.
Nor was this, unhappily, the only accident of the kind in Paris during
the year. Only five months later, on the 13th of October, Baron Bradsky
ascended with an assistant in a large airship of his own invention.
Through faulty construction, the steel wires which fastened the car to
the balloon broke, the two became separated, the car fell, and its
occupants were killed on the spot.
So far, the credit of the only English airship which has yet flown
rests with Mr. Stanley Spencer, the well-known aeronaut. Mr. Spencer
comes of a race of aeronauts. His grandfather, Edward Spencer, was the
great friend and colleague of Charles Green, and shared with him some
of his chief ballooning adventures, notably the terrible voyage when
Cocking lost his life. Green stood godfather to Edward Spencer’s son,
who was christened Charles Green after him. He also grew up to be an
aeronaut, and made several inventions and improvements relating to
balloons and flying machines. His love of ballooning, inherited from
his father, has been passed on to his children, and his three eldest
sons, Percival, Arthur, and Stanley, are chief among British aeronauts,
and indeed have practically the monopoly of professional ballooning
and balloon manufacture in Great Britain. Nor have they confined
themselves to this country. All three have taken their balloons and
parachutes to distant parts of the world, and among their many hundreds
of ascents, both abroad and at home, have met with all manner of
exciting and perilous adventures, though never yet with serious mishap.
Their knowledge of practical aeronautics, then, is unrivalled, and Mr.
Stanley Spencer had the experience of three generations to guide him
when, in 1902, he set to work to build an airship which he had long
been devising.
His first machine was a comparatively small one, capable only of
lifting a light man. It took the usual form of a cigar-shaped balloon,
the framework of which was built of bamboo, driven forward by a
screw-propeller worked by a small petrol engine. Warned by the fate of
the unfortunate Severo, Mr. Spencer placed his engine far away from the
valve. Profiting also by Santos Dumont’s experience, he constructed
his balloon in such a manner that, should it become torn and the gas
escape, the empty silk would collapse into the form of a parachute and
break the fall. Furthermore, there was an arrangement by which, while
aloft, ordinary air could be forced into the balloon to replace any
loss of gas, and so keep the silk always fully inflated and “taut”--a
very important factor in a machine that has to be driven forward
through the atmosphere.
With this airship Mr. Spencer, as also his equally daring wife, made
several highly successful trials at the Crystal Palace, when it was
found to steer well and answer its helm most satisfactorily. Mr.
Spencer also made two long voyages, from London and from Blackpool, on
both of which occasions he found he could manœuvre his airship with
considerable success, make circular flights, and sail against the
wind, provided it was blowing only at moderate speed.
Encouraged by his success, he next built a similar but much larger
machine, nearly a hundred feet long, holding 30,000 cubic feet of gas,
and driven by a petrol motor of twenty-four horse-power. In this case
the propeller, instead of being placed at the rear, as in general, is
at the front of the airship, thereby pulling it forward through the
air instead of pushing it from behind. By this arrangement Mr. Spencer
thinks his balloon would have less tendency to double up when urged
against a strong wind. The steering is done by a rudder sail at the
stern, and to cause his machine to sail higher or lower, the aeronaut
points its head up or down by means of a heavy balance-rope.
This new airship was ready by the summer of 1903, but the unfavourable
weather of that stormy season again and again interfered with the
experiments. On the 17th of September Mr. Spencer announced his
intention of sailing from the Crystal Palace round the dome of St.
Paul’s, and returning to his starting-place. The Cathedral was indeed
safely reached, but the increasing breeze, now blowing half a gale,
baffled all his attempts to circle round. Again and again, till his
hands were cut and bleeding with the strain of the ropes, he brought
his machine up, quivering, to the wind, but all to no purpose, until at
length, abandoning the attempt, he sailed with the current to Barnet.
More favourable results may doubtless be looked for with better weather
conditions.
In France during 1903 the brothers Lebaudy made some successful trips
with an airship of their own construction. Many other airships are
now being built in all parts of the world, in preparation for the
aeronautical competitions to take place in America on the occasion of
the St. Louis Exhibition of this year.