Karl was the only one of the three who knew anything about a balloon, or
the mode of inflating it. Had it been their intention of navigating the
air, an apparatus would have been required to carry up a fire. This
Karl could easily have contrived. A basket of wicker-work, as he had
said, well lined with clay, would have answered the purpose after a
fashion; but as they did not intend to use the balloon for any purpose
beyond making the single ascent to lift them over the cliffs, a
continuous fire would not be required. The first inflation would answer
that end well enough; and therefore a grate or fire-basket was not
thought of.
The car to carry the passengers--or boat, as it is sometimes styled:
since, for reasons easily understood, it is usually a boat--was quite
another affair; and had it been designed for more than a mere temporary
use, would have taken a considerable time in the making; but for what
they wanted almost anything would serve; and all that they intended
employing was a sort of wicker basket, or deep hamper, suspended by
stout ropes. This had been already prepared; and only needed to be
attached to the bottom of the air-bag.
In the present case, the "bottom of the bag" is quite a figure of
speech--_lucus a non lucendo_. Strictly speaking, it had no bottom;
but, where this should have been, there was a round aperture, formed by
a stout hoop of ringall bamboo, to which the skin covering was lashed,
and to which, also, the cords intended to sustain the afore-mentioned
basket, as also the stay-ropes, were to be attached.
The object of this aperture will be easily understood. It was by it
that the hot air was to be admitted inside the balloon, for the purpose
of inflating it.
And how was this hot air to be obtained? That was a question which Karl
alone could answer. Of course, fire was to be the agent for producing
it: but how was it to be got into the bag? Karl could tell that, and
Karl only; and, now that the time had arrived for trying the experiment,
he condescended to explain to his coadjutors how he meant to proceed.
The bag was to be propped up between tall stakes set in the ground; its
bottomless bottom turned towards the earth, so that the aperture would
be below. Under this a fire was to be kindled--not, however, until
everything else should be ready; and the hot air rising up into the
aperture would enter the balloon, and cause it to swell out to its full
globular dimensions. More hot air being admitted, the cooler atmosphere
within would be expelled, the balloon would become lighter than the
surrounding air, and by the simple principle of atmospheric pressure it
would ascend into the air. It was expected it would do so--it was hoped
it would.
To say the truth, the hopes of the engineer were far from being high--
his expectations anything but sanguine. He had observed all along,
that, notwithstanding the process employed for lightening the eel-skins,
they were still far heavier than silk; and perhaps, after all, the
experiment might not succeed. There was another circumstance that had
as much _weight_ on the mind of Karl as the eel-skins; and that was
quite as likely to have a _bearing_ upon the balloon. He had not
overlooked the fact, that the spot, from which they proposed making the
ascent, was nearly ten thousand feet above the level of the sea. He
knew that the atmosphere in such a situation would be extremely
rarefied, and that a balloon, which might easily ascend many thousand
feet into the air starting from the level of the sea, would not stir
from the ground if carried to the top of a mountain ten thousand feet
high. This was the circumstance which preyed upon the spirit of the
young philosopher, and hindered him from entertaining any very sanguine
hopes of success in the experiment they were making.
The philosophical truth had been before his mind from the first, and at
times had almost determined him to abandon the project. But as he was
not sufficiently acquainted with the laws of aerostation as to be
certain of failure, he had worked on with the determination to seek
success, though it must be acknowledged with but faint hopes of finding
it.
Thus stood matters on the morning when it was finally arranged to launch
their great aerial ship, and ascertain whether it would swim.
All things were made ready at an early hour. The huge bag was set up
between the supporting stakes the _car_ was attached to it, as also
several ropes to keep the balloon from being carried away; and these
were fastened at their other ends to stout pegs, driven firmly into the
ground; while a little furnace of stones was built underneath to hold
the fire, whose ascending caloric was to expand the balloon, and raise
it into the air.
The fuel out of which this fire was to be made had been already
collected near the spot. It was not wood, nor faggots of any kind; for
although these might have served after a fashion, Karl was acquainted
with a better material. He remembered that the Montgolfiers, and other
early aerostats--previous to the introduction of the inflammable gas--
had used chopped straw and wool, and regarded these materials to be the
best substances for inflating their balloons. Karl had adopted their
idea; and had provided chopped grass as a substitute for the chopped
straw, and in lieu of sheep's wool he had procured a quantity of the
_poshm_ of the ibex, and other animals, that had been killed--the rich
shawl-wool of Cashmere!
The car, which has already been described as a sort of deep hamper, was
not over three feet in diameter. It was evidently not equal to the
holding of three persons--to say nothing of a large dog--for it is
hardly necessary to say that Fritz was not going to be left behind. The
faithful creature had too long followed the fortunes of our adventurers
to be abandoned by them now.
But there was not the slightest danger of that. The dimensions of the
car were large enough for what the "vehicle" was intended to carry,
which was only _one_.
Karl believed that there would be little chance of the balloon having
sufficient power to take up all three of them, their united weight being
over four hundred pounds. He would be but too contented if one should
be carried aloft; and if that one should succeed in effecting a landing
on the summit of the cliff, it was of no importance what afterwards
became of the aerial ship. Having completed that one voyage, it might
make another on its own account--either south to Calcutta or eastward to
Hong Kong, if it liked China better.
Of course, if any one of them should succeed in surmounting the cliff,
it would be an easy matter to get over the mountain; and as they had
passed native villages on their way upward, these could be reached in a
day or two, and a party of men, with a proper rope-ladder, brought to
the rescue of the others.
Even had there been no prospect of assistance from any one outside, it
would not matter very much. If only one of them could get to the top of
the cliffs, they could construct a rope-ladder of themselves--by which
the other two would be able to make the ascent.
It is hardly necessary to say who was to make the attempt--Ossaroo was
to be the aeronaut. Ossaroo had voluntarily offered himself for this
perilous performance; and his offer had been accepted.
Not that either of the others were at all afraid to have run the risk.
It was from no desire to shirk the danger that they had appointed
Ossaroo to undertake it; but simply because, once outside, the shikaree
would be far better able to find his way down the mountains: and in his
native language could readily communicate with the villagers, and give a
correct account of their situation.