The
Evolution of the Airship
The
most, powerful navy that could be built, the strongest fortifications
that the wit of man could devise, or the most numerous and efficient
army in the world, would all be comparatively helpless and at the
mercy of the nation possessing a fleet of airships so designed as
to be capable of carrying quantities of high explosives, and really
under the control of those who manned them.
Is the
possibility of the construction of such an aerial fleet altogether
remote - or is it on the eve of realisation? The present article,
bracing the story of the evolution of the airship as far as it has
progressed, may be some assistance in
answering those important questions.
The possibility or otherwise
of travelling through the air, has exercised the minds of men from
time immemorial, and although it would be both curious and interesting
a very detailed description of the earlier attempts to solve the problem
would we no useful purpose, still, a short account of some of the
more noteworthy will not be out of place.
In the middle ages it was
a very perilous business for anyone to attempt anything, of the kind,
because for anyone to attempt anything of the kind, because the dangers
attending the experiments were supplemented by the additional risk
of being burnt at the stake or boiled in oil for witchcraft, for in
those days anyone who accomplished anything out of the common was
often suspected of dealing in magic, and of being able to perform
his feats of skill chiefly through the secret aid of the Evil One.
Notwithstanding this drawback, a great, many individuals devoted attention
to the subject, and some of them claimed to have succeeded, notably
one Albertus Magnus, who flourished about the first part of the 13th
century; his plan was so simple that I cannot, do better than give
it in his own words: "Take one pound of sulphur, two pounds of
willow carbon, six pounds of rock salt; grind these very fine in a
marble mortar; place the powder in a covering of papyrus: in order
to ascend and float away, the covering should be long, graceful, and
well filled with this fine powder."
Other would-be aeronauts,
having observed that the dew fell from the heavens during the night,
and was drawn up again in the day by the Sun, conceived the idea of
collecting some dew and enclosing it in a hollow sphere, and then
exposing the vessel to the rays of the sun in the expectation that
it would ascend. A gentleman named Lauretus Laurus in the 15th century
announced that he had experimented successfully in this manner, using
the shells of hens' eggs partly filled with dew and sealed up.
One of the first vessels
ever seriously designed to travel the air of which we possess any
really authentic record was that projected in 1670 by Francis Lana,
a Jesuit; it consisted of a wicker boat or basket, to be lifted into
the air by four spherical balloons, each 25 feet in diameter, made
of sheet copper 1/200 of an inch thick, each enclosing a vacuum; and
to be propelled by a sail and oars. This project never came to anything,
because it is obvious that even if if were possible to construct such
balloons, they would collapse directly an attempt was made to exhaust
the air contained in them.
Lana's
Airship by Robert Tressell
This proposition, although
impracticable, is remarkable as containing the principle of the balloon
as we know it today, and as showing the idea prevalent at that time,
that the atmosphere was of no great height, and that it covered the
earth like a shallow ocean; Lana's airship was designed to float upon
the surface of this imaginary sea.
There were innumerable
other schemes, some ingenious, some ridiculous, but, nothing was actually
accomplished until 1783, when the Brothers Montgolfler, of Annanoy
in France, constructed a linen globe 105 feet in circumference, which
they on June 5th of that year inflated over a fire made of small bundles
of straw. The balloon, when released rose at once to a great height,
and descended after 10 minutes at a distance of 1.5 miles (2,414 meters).
Such was the first balloon.
Two months afterwards,
a balloon made of varnished silk and filled with hydrogen gas, was
constructed at Paris under the direction of Professor Charles. It
ascended and remained in the air for three quarters of an hour, and
descended at a distance of 15 miles. This was thus the first hydrogen
balloon.
The first human being
to ascend in a balloon was M. Francois Pilatre de Rozier, who on October
15, 1783 went up in a fire balloon of Montgolfler principle. This
aeronaut made numerous ascents, and was finally killed in an attempt
to cross the English Channel in a balloon.
M.
Francois Pilatre de Rozier balloon by Robert Tressell
The first British aeronaut
was Mr. J. Tytler, who made an ascent at Edinburgh on S7 August 1784
in a fire balloon of his own construction.
From this time forward
innumerable aerial voyages were made. The valve was invented by Professor
Charles, who also originated the hoop and net from which the car is
suspended. The guide or trail rope for preventing loss of gas and
ballast was introduced by the celebrated British aeronaut Mr. Green,
and a number of other improvements were effected. On January 7, 1785
M, Blanchard, accompanied by Dr. Jeffries, accomplished the unprecedented
feat of crossing the English Channel from Dover to Calais in a balloon;
but notwithstanding the efforts of Blanchard, Lunardi and many others
who sought by means of oars and other devices to steer the aerial
vessel, the balloon remained essentially what it was at the first,
a thing to be blown whithersoever the wind listed, and no material
advance was made in this direction until 1852, when M. Giffard constructed
the first elongated or cigar-shaped
balloon, equipped with a screw or fan propeller, and driven by a steam
engine of special design; the rudder was a triangular sail at the
rear, above the car, and under the balloon.
Signor
Lunardi's balloon in 1784 by Robert Tressell
Giffard made his first
voyage on September 25th, 1852. At the time of the ascent there was
a light breeze, and the airship answered the slightest movement of
the rudder; later on the wind increased considerably but even in a
stiff breeze, M. Giffard, although unable to drive his aerial vessel
directly against the wind, was
able to 'tack" and make circular movements.
The aeronaut descended
in safety, after having demonstrated in a most unmistakable manner,
the possibility of controlling, to a certain extent, the direction
of aerial craft.
Blanchard's
balloon in 1785 by Robert Tressell
In considering the fact
that this remarkable experiment was not followed by many others, we
have to remember that at that period, as at the present time, a great
number of those who were interested in the subject of aerial navigation
were of opinion that the solution of the problem was to be found,
not in balloons of any kind, but in mechanical apparatus or flying
machines heavier than the air they displace. This circumstance may
account for the fact that we do not hear of another dirigible balloon
until 1872, when Dupoy de Lome constructed an airship very similar
to Giffard's, the chief difference being that he substituted a capstan
turned by four men, for Giffard's steam engine
Giffards's
balloon in 1852 by Robert Tressell.
In 1883-84 a series of
experiments were made by Gaston and Albert Tissandier with a balloon
of the Giffard type, the motive power this time being electricity;
the results were always distinctly encouraging; even in a strong wind
lateral deviation or "tacking" was accomplished with facility,
and on one occasion the airship "stemmed" a wind blowing
at the rate of seven miles an hour.
That the degree of success
attending these experiments did not escape the notice of the French
military authorities is evident, for In 1884-85 M.H. Renard and Krebs,
the officers in charge of the Government Balloon Park, at Meudon,
carried out a number of trials with an airship of improved design.
The balloon was 165 feet in length; the maximum diameter being 37
feet; the vessel was driven
by a 9 H.P. electric motor, and two men were required to work
the ship.
The first ascent was made
in very calm weather, and the "La France" airship realised
the most sanguine expectations, being perfectly under control, and
finally returning to the starting point without accident. The
second voyage was undertaken under different and unfavourable conditions;
a strong wind prevailed, but in order to submit the airship to a severe
test it was decided to make the ascent.
When the ship rose into
the air it immediately began to drift
before the breeze, but directly the power was transmitted to
the propeller - or in this case more properly, tractor - and the steersman
began to manipulate the rudder, the balloon turned its head to the
wind and - remained stationary. The motor was taxed to the limit of
its powers, but still the airship was unable to go forward; for ten
minutes the unequal struggle continued, and then the aeronauts observed
with alarm that the motor was becoming overheated, and to prevent
a worse calamity even than failure, the current was switched off,
and the vanquished airship again drifted before the victorious wind,
being eventually towed home by the soldiers of the Balloon Corps.
M.
Nadar's Giant in 1863 by Robert Tressell
Some of those who had been
extravagantly elated over the performance of the "La France"
on the occasion of her first trial, were also excessively disappointed
with the result of the second: to the aeronauts it merely proved that
with the very limited driving power then at their command, it was
impossible to travel directly against a strong wind; their subsequent
experiments proved that if they had tried to reach their objective
by means of lateral or or tacking movements they would have succeeded.
Altogether the "La
France" made seven voyages, and on five of those occasions succeeded
in returning to the starting point.
La
France in 1884 by Robert Tressell
Since that time there is
no doubt that the French Government has given this important matter
the attention it deserves;
what they have actually accomplished it is of course impossible to
say, the secrets of the design of the latest French war balloons being
jealously guarded, but it is believed that they possess steerable
airships capable of travelling at from 22 to 30 miles an hour.
That Germany takes a keen
interest in aerial navigation is shown by the experiments which were
made in 1897 and subsequently with airships of various types. In that
year Dr. Wolfert ascended in an airship of his own design; the balloon,
which was cigar shaped,
exploded in the air, and Dr. Wolfert and his assistant were killed.
In the same year an aluminum
balloon (which was not completed until after the death of the inventor)
was constructed by the German government and made its first and only
voyage, for owing to the slipping of a driving belt the trial came
to a sudden and almost tragic conclusion. The inexperienced aeronaut,
finding himself unable to right the disordered machinery, opened the
valve, the balloon descended with a rush and was damaged beyond repair,
while the aeronaut narrowly escaped with his life. The balloon was
only seven minutes in the air.
More successful was the
monster airship constructed by Count Zeppelin, which made its trial
trip in June l900. This is the largest elongated balloon ever built,
being 420 ft. long and 39 ft. in diameter, containing 400,000 cubic
ft. of hydrogen. There are two boats or cars suspended from the balloon,
and the crew consists of five men.
Count
Zeppelin's Airship in 1990 by Robert Tressell
On the occasion of the
trial trip the airship developed a speed
of eighteen miles an hour, but owing to an accident to some part of
the machinery, the journey came to an abrupt end, after a run of only
three and a half miles; the airship descended safely, and the results
of later ascents have not been made public.
The recent experiments
of Santos Dumont, Severe, Spencer, and others, are familiar to all,
and need not be described here, but this article would be incomplete
without some reference to the dirigible balloon which Dr. Barton is
building for the British Government. This airship is similar to some
of its continental predecessors to the extent that it consists of
a car suspended from an elongated balloon, but there the resemblance
ceases, for the oar is of an altogether different shape, and there
are six propellers of original design. Dr. Barton has also added three
sets of air planes, designed to prevent the loss of gas and ballast
which has hitherto been such a serious obstacle to successful aerial
navigation. This vessel is not yet completed, and its capabilities
have yet to be tested, but it is safe to say that Dr. Barton's ship
is a distinct advance on any of its predecessors known to the general
public.
To conclude this necessarily
brief and restricted enquiry into the present state of the art of
aerial navigation it may be said that it has been demonstrated beyond
question that it is possible to construct dirigible balloons which
can be driven in any desired
direction on calm days or on days when only moderate winds prevail;
and it should be remembered that these favourable conditions exist
on a very large proportion of the days of the year.
Further, even under unfavourable
conditions it is possible to control an airship to the extent of considerable
lateral deviation from the direction of a strong wind, and to make
circular movements.
That an airship which can
be controlled to this extent is undoubtedly better than an ordinary
spherical balloon which cannot be controlled at all except as regards
its vertical direction.
Robert Tressell (c.1902)
Robert
Tressell Family Papers
Reg
Johnson custodian of The Robert Tressell Family Papers,
6 Arkendale, Whittington College, Felbridge, East Grinstead, West
Sussex, RH19 2QU
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