An Experiment with a Zeppelin
"LOOK slick!" hissed Detroit. "Don't stand there looking in the air."
The American's words roused Hamerton to action. Quickly he descended
below the level of the floor of the turntable, the flap fell with a
dull thud, and the two fugitives found themselves in darkness, save
for a faint circle of light where the exterior glare filtered through
the narrow space between the round platform and the edge of the pit
in which it stood.
Then came the tramp of many feet. Not knowing whether they had been
"spotted" by a keen-eyed sentry, Hamerton and his comrade remained on
the thorns of expectancy. Alternate hopes and fears flashed across
their minds in quick succession. Detroit was mentally bemoaning the
rashness that prompted Hamerton to suggest the exploration of the
aircrafts' subterranean shelter instead of making for the base of the
cliffs; while the latter regretted that he had not been able to
continue his nocturnal tour of investigation.
Yet, although men were running hither and thither, none came across
the floor of the turntable. Trucks were rumbling along the tram
lines, men were shouting in guttural tones, electric motors were
whizzing and buzzing. The place, hitherto practically deserted,
resembled a gigantic beehive.
"They are not looking for us," whispered the Sub. "They are evidently
getting one of the Zeppelins ready for a flight. I hope we won't be
disturbed. We may as well have a tour round our limited quarters, to
make ourselves acquainted with our hiding place."
"Go steady," cautioned Detroit.
"Trust me for that," rejoined Hamerton, "We don't want to electrocute
ourselves, or start the turntable spinning round at the rate of
knots."
"Like a new form of joy-wheel," added the American. "It would be a
bit of a joke to see the soldiers attempting to reach the traphatch
with the platform spinning round at twenty miles an hour."
Their eyes were now getting accustomed to the gloom, for there was a
fair amount of reflected light that at first was almost unnoticeable
after the powerful glare without.
The place of refuge was certainly expansive, but much of the space
was taken up with complicated machinery. The turntable itself worked
on steel rollers set in a "race", the upper bearing surface
consisting of steel skeleton trestles, which in turn supported the
revolving platform. Between the latter and the edge of the circular
concrete wall was a width of less than eight inches, insufficient to
allow a man to crawl through. The only means of gaining the machinery
chamber was by the two trapdoors.
"Shall we barricade the hatchways?" asked Detroit.
"No use," replied Hamerton. "It would only arouse suspicion. Then we
should either be starved out or run the risk of being potted, for the
floor is not proof against rifle fire. No, the best thing we can do
is to keep quiet. Should anyone come we must endeavour to dodge
behind some of this gear."
"Guess I'm getting precious hungry," remarked the American.
"Now you mention it I begin to have a sinking sensation: a kind of
famine and hunger strike rolled into one. But we can't go too strong
in the provision line."
Six half-slices of rye bread, two small pieces of cold meat, and
about a pound of fish formed the sum total of the commissariat,
barely sufficient, even with stringent economy, to last over
twenty-four hours.
The food, after reposing in their pockets, was not pleasing to the
eye, but adverse circumstances settled all qualms. Both men ate with
avidity, though sparingly.
At length daylight gained the mastery over artificial lighting, and
the arc lamps were extinguished. With the morning the rain ceased and
the wind dropped.
Peering through the gap between the turntable and the encircling
wall, Hamerton could see the sun shining upon the upper portion of
the red sandstone cliffs that enclosed the vast artificial basin. His
field of vision was limited, but he was able to come to the
conclusion that the floor of the airship sheds was nearly two hundred
feet below the surface of the tableland that comprised the major part
of the island.
Between each pair of caverns constructed for the accommodation of the
Zeppelins was an iron ladder running perpendicularly up the sheer
wall of sandstone. These were connected by an open lattice platform
just above the crown of the arch formed by the caves, and were
evidently for the purpose of facilitating the movements of the
airships when entering or leaving their bases. Curiously enough, both
Hamerton and Detroit had previously failed to notice these ladders
when making a circuit of the basin.
"They are naval airships," announced the Sub, for men were swarming
up and down the ladders with a seeming recklessness that only seaman
dare show, and they were wearing the uniforms of the German Imperial
Navy.
"Here she comes," said Detroit, as the huge bulk of a Zeppelin
emerged slowly yet steadily from its resting place.
"What a superb target!" commented the Sub. "A dose of shrapnel would
knock the whole concern to smithereens, while one of our seaplanes
with a one-pounder automatic gun would make rings round her."
"I don't know so much about that," said Detroit. "Just look at the
aluminium body just abaft the 'midship car. It's been holed at one
time, and they've put a patch on it."
"An accident, perhaps," rejoined Hamerton. "The airship looks rather
old."
Over the heads of the two watchers passed the unwieldy craft. Now
they could hear the jar of the framework as it settled on the
turntable. Then, with hardly a sound and barely a tremor, the
platform began to move until the bows of the Zeppelin pointed in the
direction of the great incline. The six propellers began to revolve,
and the airship, gathering way, rose rapidly and steadily, keeping
almost parallel with the slope. Then, gaining an altitude of nearly
five hundred feet, she circled slowly and disappeared beyond the
limits of the vision of the two spectators in the pit.
Within a quarter of an hour of its leaving the cave the Zeppelin
returned to earth. Anchored fore and aft it strained and staggered in
the still strong wind. The officers and crew descended by means of a
rope ladder, then the holding ropes were cast off and the aircraft
bounded upwards. Hamerton could see that it was still connected with
the ground by a flexible steel rope. The propellers were revolving
and the rudders set hard over, consequently the Zeppelin was
describing circles in the air at a height of a little over five
hundred feet.
"What's the game?" asked the Sub.
The words were hardly out of his mouth when the sharp, rapid
detonations of a pom-pom were heard. Almost simultaneously with the
screech of the projectiles sinister dark marks appeared on the
aluminium cover of the Zeppelin; yet to the Sub's surprise the
one-pounder shells without exception did not burst, neither did the
airship appear to lose its reserve of buoyancy.
For nearly fifteen seconds the firing continued. Nearly four times
that number of projectiles had been fired, many of the shot-holes
overlapping each other.
Upon the conclusion of this severe test the Zeppelin was brought
down, and, controlled by about fifty men holding guide ropes, was
taken down the incline.
As it neared the turntable Hamerton was able to come to some
conclusion as to the nature of the self-closing material surrounding
the ballonettes. In one place the havoc wrought by the concentration
of several projectiles had completely torn off a strip of aluminium
measuring roughly two feet six inches by two feet. Within the cavity
could be seen the inner lining of aluminium, which had been badly
perforated, thus releasing all the hydrogen from that particular
ballonette. At the edges of the perforations a substance resembling
dirty cotton waste had been forced out. Only the width of the fissure
prevented the closing up of the textile fabric.
As the Zeppelin was being guided on to the turntable a fragment of
the plugging material fluttered to the ground. A breeze caught it and
swept it towards the edge of the turntable pit. There it stopped,
provokingly out of reach even if the Sub had dared to stretch out his
hand to grasp it.
Just then one of the sailors manning the trail ropes kicked the piece
of packing. It fell literally into Hamerton's hands.
Hamerton and his comrade exchanged glances of satisfaction. They
dared not speak. They realized that they had made a great discovery.
Directly the experimental airship was safely housed the men in
attendance were marched off, presumably to breakfast, and the
occupants of the machinery pit were able to discuss their find.
"It's cotton waste, right enough," said Hamerton.
"And asbestos fibre," said Detroit, plucking out a piece of core. "I
suppose that renders the waste non-inflammable?"
"Hardly," replied the Sub. "Besides, how do you account for the stuff
being gas-proof? It's as porous as a sponge."
Detroit put a small quantity of the stuff between his teeth.
"Ugh!" he exclaimed. "There's alum in it, and gum arabic in a viscous
state, only this piece has got slightly dry. I guess I see the trick.
They pack the space between the outer and inner skins with the stuff
under pressure. There is not sufficient resistance to cause the shell
to explode, therefore the projectile passes completely through,
making only a small aperture that instantly closes behind. They made
a severe test, for the Zeppelin was practically a captive balloon.
Had she been travelling at from thirty to fifty knots at an uncertain
range it would have been a difficult matter to get a shot home."
"Do you know what they were firing with?" asked Hamerton.
"A pom-pom, I should imagine."
"Yes, firing a one-pound shell, almost the identical weapon we mount
on our seaplanes. Every blessed experiment these Germans make seems
directed solely against the recognized means of offence adopted by
the British Government."
"Shrapnel's the thing."
"Aye, coarse-charged with irregular pieces of metal in the place of
the bullets used in shells when directed against troops. These
Zeppelins, with their non-explosive hydrogen and their fireproof,
shot-closing envelopes will be a tough nut to crack in the next war,
I fancy. Look here, Detroit, old man, this stuff's worth keeping.
We'll divide it into four parts, and wear it in our shoes like cork
socks; then, if we are collared, we may stand a chance of keeping it
in our possession."
While the two friends were thus engaged the dull boom of a gun fired
thrice in quick succession struck their ears. This was followed by a
bugle-call that Hamerton recognized as the "Assembly" of the German
Army. This was taken up in other parts of the island till the whole
garrison was aroused.
Hamerton glanced at his watch. It was just after seven o'clock, at
which hour their jailers were wont to bring in the prisoners'
breakfasts.
"They've discovered we've broken ship," he said. "Hans and company
have found that our cells are empty. Now comes the fun."
It seemed as if the caves in the sandstone cliffs surrounding the
Zeppelin station disgorged human beings, for within a few seconds of
the alarm being given two hundred men were drawn up in divisions,
while their officers were discussing amongst themselves the probable
reason for the unexpected summons.
Up ran a portly sergeant-major. He was almost out of breath, yet he
spoke in such a loud voice that the Sub was able to interpret every
word.
"A message has just come through on the telephone, Herr Major," he
announced; "those rascally English spies have escaped. The general
orders are that all commanding officers shall post double sentries
over all confidential posts; the rest of the men are to be employed
in the search. No leave is to be granted until the spies are
recaptured."
The major shrugged his shoulders. He was not at all pleased with the
telephone message, since he had arranged to spend the following
Sunday at Flensburg.
"Why have we not turned out the bloodhounds, sir?" asked a captain.
"The scent must be hot."
"Ach, I know not!" was the reply.
"All the dogs were taken across to Sandinsel yesterday, Herr Major,"
announced another officer, a tall, fair-haired subaltern. "Colonel
Dietrich wished to try the hounds on a trail laid on the sand."
"And, as a result, we have two English spies roaming over the
island," added the major. Then, giving the order to march, he led the
four companies under his command up the steep incline. "Now the fun
commences," observed Detroit, when all seemed quiet once more. "Thank
goodness they have no suspicions that we made our way here!"
"And it's lucky for us that the bloodhounds are away," rejoined
Hamerton. "One never knows; they might be able to follow a trail in
spite of a couple of ounces of pepper."
Before Detroit could express his opinion a deep baying sound came
from the heights above.
Both men looked at each other as if to say: "We counted our chickens
before they were hatched;" then, without a word, they made their way
to a different part of their place of concealment whence they could
command a view of the summit of the artificial cliffs.
Standing out clearly against the white drifting clouds were four
large hounds. With their noses almost touching the ground they moved
deliberately and unhesitatingly, while behind them walked a number of
officers and men, the latter armed with rifles and bayonets.
The bloodhounds, keeping close to the brink of the abyss, gradually
approached the spot where the inclined plane met the level ground of
the tableland. Here they paused but for a brief instant; then they
began to trot straight towards the fugitives' hiding place.
"They've tracked us right enough," muttered the Sub dejectedly.