AIR-CRUISERS.
We trust our readers will not be wearied because it is necessary to give
them at some length an explanation concerning the aerial machines to
which reference has so often been made as air-cruisers. It need scarcely
be said that from time immemorial a great deal of attention has been
directed to the question whether aerial travelling could he made
subservient to the purposes of man. Balloons, as they were called, made
of strong fabrics filled with a gas lighter than air, were to some
extent used, but rarely for practical purposes. They were in
considerable request for military objects, and it is recorded that
Gambetta managed to get out of Paris in a balloon when that city was
beleaguered by the German army in 1871. The principle of the balloon
was the use of a vessel which, weighing, with all its contents, less
than a similar volume of the atmosphere, would consequently rise in the
air. But evidently no great progress could be made with such an
apparatus. The low specific gravity of the atmosphere forbade the hope
of its being possible to carry a heavy weight in great quantity on a
machine that depended for its buoyancy on a less specific gravity.
Besides, there was danger in using a fabric because of its liability to
irreparable destruction by the smallest puncture.
The question then was mooted, Could not an aerial machine be devised to
work although of higher specific gravity than the air? Birds, it was
argued, kept themselves afloat by the motion of their wings, although
their weight was considerably greater than a similar volume of the air
through which they travelled. This idea was pursued. The cheap
production of aluminium, a strong but light metal, gave an impulse to
the experiment; and it was at length proved quite satisfactorily that
aerial travelling was practicable in vessels considerably heavier than
the air, by the use of quickly revolving fans working in the directions
that were found to be suitable to the progress of the vessel. But great
power was required to make the fans revolve, and the machinery to yield
great power was proportionately heavy. It was especially heavy if
applied separately to a portion of the fans, whilst it was dangerous to
rely on one set of machinery, since any accident to it would mean
cessation of the movement of the whole of the fans and consequently
instant destruction. It was considered that, for safety's sake, there
should be at least three sets of fans, worked by separate machinery, and
that any one set should be able to preserve sufficient buoyancy although
the other two were disabled. But whilst it was easy to define the
conditions of safety, it was not easy to give them effect. All
applications of known engines, whether of steam, water gas, electricity,
compressed air, or petroleum, were found to be too bulky; and although
three sets of machines were considered necessary, one set only was
generally used, and many accidents occurred in consequence. The aerial
mode of travelling was much employed by the adventurous, but hundreds of
people lost their lives annually.
At length that grand association the Inventors' Institution came to the
rescue. The founders of the Inventors' Institution, though working
really with the object of benefiting humanity, were much too wise to
place the undertaking on a purely philanthropic basis. On the contrary,
they constructed it on a commercial basis. The object was to encourage
the progress of valuable inventions, and they were willing to lend sums
from trifling amounts to very large ones to aid the development of any
invention of which they approved. They might lend only a trifle to
obtain a patent or a large sum to make exhaustive experiments. The
borrower had to enter into a bond to repay the amount tenfold or to any
less extent demanded by the Institution at its own discretion. It was
clearly laid down that, when the invention proved a failure through no
fault of the inventor, he would not be asked for any repayment. In case
of moderate success, he would only be asked for moderate repayment, and
so on. The fairness of the Institution's exercise of discretion was
rarely, if ever, called into question. Once they lent nearly thirty
thousand pounds to finally develop an invention. Within four years they
called upon the inventor to repay nearly three hundred thousand, but he
was nothing loath. The invention was a great commercial success and
yielding him at the rate of nearly a million per annum. This association
offered a large reward for the best suggestion as to the nature of an
invention to render aerial travelling safe, quick, and economical. A
remarkable paper gained the prize.
The writer was an eminent chemist. He expressed the opinion that the one
possible means of success was the use of a power which, as in the case
of explosives, could be easily produced from substances of comparative
light weight. He urged, it was only of late years that any real
knowledge of the nature of explosives was obtained. It was nearly four
hundred years after the discovery of gunpowder before any possible
substitutes were invented. It was again a long time before it was
discovered that explosives partook of two distinctly separate
characters. One was the quick or shattering compound producing
instantaneous effect; the other was the slow or rending compound of more
protracted action. He dwelt on the fact that in all cases the force
yielded by explosives was through the change of a solid into a gaseous
body, and that the volume of the gaseous body was greatly increased by
the expansion consequent on the heat evolved during decomposition. The
total amount of heat evolved during decomposition did not differ, but
evidently the concentration of heat at any one time depended on the
rapidity of the decomposition. The volume of gas, independent of
expansion by heat, varied also with different substances. Blasting oil,
for instance, gave nearly thirteen hundred times its own volume of gas,
and this was increased more than eight times by the concentration of
heat; gunpowder only yielded in gas expanded by heat eight hundred times
its own volume: or, in other words, the one yielded through
decomposition thirteen times the volume of the other. He went on to
argue that what was required was the leisurely chemical decomposition of
a solid into a gas without sensible explosion, and of such a slow
character as to avoid the production of great heat. He referred, as an
example of the change resulting from the contact of two bodies, to the
effect of safety matches. The match would only ignite by contact with a
specially prepared surface. This match was as great an improvement on
the old primitive match, as would be a decomposing material the force of
which could be controlled, an improvement on the present means of
obtaining power. He expressed a positive opinion that substances could
be found whose rapidity of decomposition, and consequent heat and
strength, could be nicely regulated, so that a force could be employed
which would not be too sudden nor too strong to be used in substitution
of steam or compressed air. He was, moreover, of opinion that, instead
of the substances being mixed ready for use, with the concurrent danger,
a mode could be devised of bringing the different component parts into
contact in a not dissimilar manner to the application of the safety
match, thereby assuring absolute immunity from danger in the carriage of
the materials. This discovery could be made, he went on to say; and upon
it depended improvement in aerial travelling. Each fan could be impelled
by a separate machine of a light weight, worked with perfect safety by a
cheap material; for the probabilities were, the substance would be
cheaply producible. Each aerial vessel should carry three or four times
the number of separate fans and machinery necessary to obtain buoyancy.
The same substances probably could be used to procure buoyancy in the
improbable event of all the machines breaking down. Supposing, as he
suspected would be the case, that the resultant gas of the decomposition
was lighter than air, a hollow case of a strong elastic fabric could be
fastened to the whole of the outside exposed surface of the machine; and
this could be rapidly inflated by the use of the same material. The
movement of a button should be sufficient to produce decomposition, and
as a consequence to charge the whole of this casing with gas lighter
than the air. As the heat attending the decomposition subsided the
elastic fabric would sufficiently collapse. The danger then would not be
so much of descending too rapidly through the atmosphere as of remaining
in it; a difficulty, however, which a system of valves would easily
overcome.
The Institution offered twenty-five thousand pounds for a discovery on
the lines indicated; and the Government offered seventy-five thousand
pounds more on the condition that they should have the right to purchase
the invention and preserve it as a secret, they supplying the material
for civil purposes, but retaining absolute control over it for military
purposes. This proviso was inserted because of the opinion of the writer
that the effects he looked for might not so much depend on the chemical
composition of the substances as on their molecular conditions, and that
these might defy the efforts of analysts. If he was wrong, and the
nature of the compound could be ascertained by analysis, the Government
need not buy the invention; they could leave the discoverer to enjoy its
advantages by patenting it, and share with other nations the uses that
could be made of it for purposes of warfare.
It was some time before the investigations were completely successful.
There was no lack of attention to the subject, the inducements being so
splendid. Many fatal accidents occurred through the widely spread
attention given to the properties of explosives and to the possibility
of modifying their effects. On one occasion it was thought that success
was attained. Laboratory experiments were entirely satisfactory, and at
length it was determined to have a grand trial of the substance. A large
quantity was prepared, and it was applied to the production of power in
various descriptions of machinery. Many distinguished people were
present, including a Cabinet Minister, a Lord of the Admiralty, the
Under-Secretary for Defence, the President of the Inventors'
Institution, several members of Parliament, a dozen or more
distinguished men and women of science, and the inventor himself. The
assemblage was a brilliant one; but, alas! not one of those present
lived to record an opinion of the invention. The substance discovered
was evidently not wanting in power. How far it was successful no one
ever learnt. It may have been faultily made or injudiciously employed.
But the very nature of the composition was lost, for the inventor went
with the rest. An explosion occurred; and all the men and women within
the building were scattered miles around, with fragments of the edifice
itself. The largest recognisable human remains discovered were the
well-defined joint of a little finger. A great commotion followed. The
eminent chemist who wrote the paper suggesting the discovery was covered
with obloquy. Suggestions were made that the law should restrain such
investigations. Some people went so far as to describe them as
diabolical. All things, however, come to those who wait; and at length a
discovery was made faithfully resembling the one prognosticated by the
great chemist.
Strange to say, the inventor or discoverer was a young Jewish woman not
yet thirty years of age. From childhood she had taken an intense
interest in the question, and the terrible accident above recorded
seemed to spur her on to further exertion. She had a wonderful knowledge
of ancient languages, and she searched for information concerning
chemical secrets which she believed lost to the present day. She had a
notion that the atomic structure of substances was better known to
students in the early ages. It was said that the hint she acted on was
conveyed to her by some passage in a Chaldean inscription of great
antiquity. She neither admitted nor denied it. Perhaps the
susceptibilities of an intensely Eastern nature led her to welcome the
halo of romance cast over her discovery. Be that as it may, it is
certain she discovered a substance, or rather substances which, brought
into contact with each other, faithfully fulfilled all that the chemist
had ventured to suggest. Together with unwavering efficiency there was
perfect safety; and so much of the action depended on the structure, not
the composition, that the efforts of thousands of _savants_ failed to
discover the secret of the invention. What the substances were in
composition, and what they became after decomposition was easily
determined, but how to make them in a form that fulfilled the purpose
required defied every investigation.
The inventor did not patent her invention. After making an enormous
fortune from it, she sold it to the Government, who took over the
manufactory and its secrets; and whilst they sold it in quantity for
ordinary use, they jealously guarded against its accumulation in foreign
countries for possible warlike purposes. This invention, as much almost
as its vast naval and military forces, gave to the empire of Britain the
great power it possessed. The United States alone affected to underrate
that power. It was the habit of Americans to declare that they did not
believe in standing armies or fleets. If they wanted to fight, they
could afford to spend any amount of treasure; and they could do more in
the way of organising than any nation in the world. They were not going
to spend money on keeping themselves in readiness for what might never
happen. But we have not now to consider the aerial ships from their
warlike point of view.
It should be mentioned that the inventor of this new form of power was
the aunt of Colonel Laurient. She died nearly twenty years before this
history, and left to him, her favourite nephew, so much of her gigantic
fortune as the law permitted her to devise to one inheritor.