<h2 id="sigil_toc_id_89">CHAPTER XV.</h2>
<h3 id="sigil_toc_id_90">HYPERBOLA OR PARABOLA.</h3>
<p>We may, perhaps, be astonished to find Barbicane and his
companions so little occupied with the future reserved for them in
their metal prison which was bearing them through the infinity of
space. Instead of asking where they were going, they passed their
time making experiments, as if they had been quietly installed in
their own study.</p>
<p>We might answer that men so strong-minded were above such
anxieties—that they did not trouble themselves about such trifles—and
that they had something else to do than to occupy their minds with
the future.</p>
<p>The truth was that they were not masters of their projectile; they
could neither check its course, nor alter its direction.</p>
<p>A sailor can change the head of his ship as he pleases; an
aeronaut can give a vertical motion to his balloon. They, on the
contrary, had no power over their vehicle. Every maneuver was
forbidden. Hence the inclination to let things alone, or as the
sailors say, "let her run."</p>
<p>Where did they find themselves at this moment, at eight o'clock in
the morning of the day called upon the earth the 6th of December?
Very certainly in the neighbourhood of the moon, and even near enough
for her to look to them like an enormous black screen upon the
firmament. As to the distance which separated them, it was impossible
to estimate it. The projectile, held by some unaccountable force, had
been within four miles of grazing the satellite's north pole.</p>
<div class="illus"><ANTIMG alt="Illustration: A DISCUSSION AROSE." id="discussion" src="images/discussion.jpg" /></div>
<div class="caption">A DISCUSSION AROSE.</div>
<p>But since entering the cone of shadow these last two hours, had
the distance increased or diminished? Every point of mark was wanting
by which to estimate both the direction and the speed of the
projectile.</p>
<p>Perhaps it was rapidly leaving the disc, so that it would soon
quit the pure shadow. Perhaps, again, on the other hand, it might be
nearing it so much that in a short time it might strike some high
point on the invisible hemisphere, which would doubtlessly have ended
the journey much to the detriment of the travellers.</p>
<p>A discussion arose on this subject, and Michel Ardan, always ready
with an explanation, gave it as his opinion that the projectile, held
by the lunar attraction, would end by falling on the surface of the
terrestrial globe like an aërolite.</p>
<p>"First of all, my friend," answered Barbicane, "every aërolite
does not fall to the earth; it is only a small proportion which do
so; and if we had passed into an aërolite, it does not necessarily
follow that we should ever reach the surface of the moon."</p>
<p>"But how if we get near enough?" replied Michel.</p>
<p>"Pure mistake," replied Barbicane. "Have you not seen shooting
stars rush through the sky by thousands at certain seasons?"</p>
<p>"Yes."</p>
<p>"Well, these stars, or rather corpuscules, only shine when they
are heated by gliding over the atmospheric layers. Now, if they enter
the atmosphere, they pass at least within forty miles of the earth,
but they seldom fall upon it. The same with our projectile. It may
approach very near to the moon, and yet not fall upon it."</p>
<p>"But then," asked Michel, "I shall be curious to know how our
erring vehicle will act in space?"</p>
<p>"I see but two hypotheses," replied Barbicane, after some moments'
reflection.</p>
<p>"What are they?"</p>
<p>"The projectile has the choice between two mathematical curves,
and it will follow one or the other according to the speed with which
it is animated, and which at this moment I cannot estimate."</p>
<p>"Yes," said Nicholl, "it will follow either a parabola or a
hyperbola."</p>
<p>"Just so," replied Barbicane. "With a certain speed it will assume
the parabola, and with a greater the hyperbola."</p>
<p>"I like those grand words," exclaimed Michel Ardan; "one knows
directly what they mean. And pray what is your parabola, if you
please?"</p>
<p>"My friend," answered the captain, "the parabola is a curve of the
second order, the result of the section of a cone intersected by a
plane parallel to one of its sides."</p>
<p>"Ah! ah!" said Michel, in a satisfied tone.</p>
<p>"It is very nearly," continued Nicholl, "the course described by a
bomb launched from a mortar."</p>
<p>"Perfect! And the hyperbola?"</p>
<p>"The hyperbola, Michel, is a curve of the second order, produced
by the intersection of a conic surface and a plane parallel to its
axis, and constitutes two branches separated one from the other, both
tending indefinitely in the two directions."</p>
<p>"Is it possible!" exclaimed Michel Ardan in a serious tone, as if
they had told him of some serious event. "What I particularly like in
your definition of the hyperbola (I was going to say hyperblague) is
that it is still more obscure than the word you pretend to
define."</p>
<p>Nicholl and Barbicane cared little for Michel Ardan's fun. They
were deep in a scientific discussion. What curve would the projectile
follow? was their hobby. One maintained the hyperbola, the other the
parabola. They gave each other reasons bristling with <i>x</i>. Their
arguments were couched in language which made Michel jump. The
discussion was hot, and neither would give up his chosen curve to his
adversary.</p>
<p>This scientific dispute lasted so long that it made Michel very
impatient.</p>
<p>"Now, gentlemen cosines, will you cease to throw parabolas and
hyperbolas at each other's heads? I want to understand the only
interesting question in the whole affair. We shall follow one or
other of these curves? Good. But where will they lead us to?"</p>
<p>"Nowhere," replied Nicholl.</p>
<p>"How, nowhere?"</p>
<p>"Evidently," said Barbicane, "they are open curves, which may be
prolonged indefinitely."</p>
<p>"Ah, savants!" cried Michel; "and what are either the one or the
other to us from the moment we know that they equally lead us into
infinite space?"</p>
<p>Barbicane and Nicholl could not forbear smiling. They had just
been creating "art for art's sake." Never had so idle a question been
raised at such an inopportune moment. The sinister truth remained
that, whether hyperbolically or parabolically borne away, the
projectile would never again meet either the earth or the moon.</p>
<p>What would become of these bold travellers in the immediate
future? If they did not die of hunger, if they did not die of thirst,
in some days, when the gas failed, they would die from want of air,
unless the cold had killed them first. Still, important as it was to
economize the gas, the excessive lowness of the surrounding
temperature obliged them to consume a certain quantity. Strictly
speaking, they could do without its <i>light</i>, but not without its
<i>heat</i>. Fortunately the caloric generated by Reiset's and
Regnaut's apparatus raised the temperature of the interior of the
projectile a little, and without much expenditure they were able to
keep it bearable.</p>
<p>But observations had now become very difficult. The dampness of
the projectile was condensed on the windows and congealed
immediately. This cloudiness had to be dispersed continually. In any
case they might hope to be able to discover some phenomena of the
highest interest.</p>
<p>But up to this time the disc remained dumb and dark. It did not
answer the multiplicity of questions put by these ardent minds; a
matter which drew this reflection from Michel, apparently a just
one,—</p>
<p>"If ever we begin this journey over again, we shall do well to
choose the time when the moon is at the full."</p>
<p>"Certainly," said Nicholl, "that circumstance will be more
favourable. I allow that the moon, immersed in the sun's rays, will
not be visible during the transit, but instead we should see the
earth, which would be full. And what is more, if we were drawn round
the moon, as at this moment, we should at least have the advantage of
seeing the invisible part of her disc magnificently lit."</p>
<p>"Well said, Nicholl," replied Michel Ardan. "What do you think,
Barbicane?"</p>
<p>"I think this," answered the grave president: "If ever we begin
this journey again, we shall start at the same time and under the
same conditions. Suppose we had attained our end, would it not have
been better to have found continents in broad daylight than a country
plunged in utter darkness? Would not our first installation have been
made under better circumstances? Yes, evidently. As to the
<i>invisible</i> side, we could have visited it in our exploring
expeditions on the lunar globe. So that the time of the full moon was
well chosen. But we ought to have arrived at the end; and in order to
have so arrived, we ought to have suffered no deviation on the
road."</p>
<p>"I have nothing to say to that," answered Michel Ardan. "Here is,
however, a good opportunity lost of observing the other side of the
moon."</p>
<p>But the projectile was now describing in the shadow that
incalculable course which no sight-mark would allow them to
ascertain. Had its direction been altered, either by the influence of
the lunar attraction, or by the action of some unknown star?
Barbicane could not say. But a change had taken place in the relative
position of the vehicle; and Barbicane verified it about four in the
morning.</p>
<p>The change consisted in this, that the base of the projectile had
turned towards the moon's surface, and was so held by a perpendicular
passing through its axis. The attraction, that is to say the
<i>weight</i>, had brought about this alteration. The heaviest part
of the projectile inclined towards the invisible disc as if it would
fall upon it.</p>
<p>Was it falling? Were the travellers attaining that much desired
end? No. And the observation of a sign-point, quite inexplicable in
itself, showed Barbicane that his projectile was not nearing the
moon, and that it had shifted by following an almost concentric
curve.</p>
<p>This point of mark was a luminous brightness, which Nicholl
sighted suddenly, on the limit of the horizon formed by the black
disc. This point could not be confounded with a star. It was a
reddish incandescence which increased by degrees, a decided proof
that the projectile was shifting towards it and not falling normally
on the surface of the moon.</p>
<p>"A volcano! it is a volcano in action!" cried Nicholl; "a
disembowelling of the interior fires of the moon! That world is not
quite extinguished."</p>
<p>"Yes, an eruption," replied Barbicane, who was carefully studying
the phenomenon through his night glass. "What should it be, if not a
volcano?"</p>
<p>"But, then," said Michel Ardan, "in order to maintain that
combustion, there must be air. So an atmosphere <i>does</i> surround
that part of the moon."</p>
<p>"<i>Perhaps</i> so," replied Barbicane, "but not necessarily. The
volcano, by the decomposition of certain substances, can provide its
own oxygen, and thus throw flames into space. It seems to me that the
deflagration, by the intense brilliancy of the substances in
combustion, is produced in pure oxygen. We must not be in a hurry to
proclaim the existence of a lunar atmosphere."</p>
<p>The fiery mountain must have been situated about the 45° south
latitude on the invisible part of the disc; but, to Barbicane's great
displeasure, the curve which the projectile was describing was taking
it far from the point indicated by the eruption. Thus he could not
determine its nature exactly. Half an hour after being sighted, this
luminous point had disappeared behind the dark horizon; but the
verification of this phenomenon was of considerable consequence in
their selenographic studies. It proved that all heat had not yet
disappeared from the bowels of this globe; and where heat exists, who
can affirm that the vegetable kingdom, nay, even the animal kingdom
itself, has not up to this time resisted all destructive influences?
The existence of this volcano in eruption, unmistakably seen by these
earthly savants, would doubtless give rise to many theories
favourable to the grave question of the habitability of the moon.</p>
<p>Barbicane allowed himself to be carried away by these reflections.
He forgot himself in a deep reverie in which the mysterious destiny
of the lunar world was uppermost. He was seeking to combine together
the facts observed up to that time, when a new incident recalled him
briskly to reality. This incident was more than a cosmical
phenomenon; it was a threatened danger, the consequences of which
might be disastrous in the extreme.</p>
<p>Suddenly, in the midst of the ether, in the profound darkness, an
enormous mass appeared. It was like a moon, but an incandescent moon
whose brilliancy was all the more intolerable as it cut sharply on
the frightful darkness of space. This mass, of a circular form, threw
a light which filled the projectile. The forms of Barbicane, Nicholl,
and Michel Ardan, bathed in its white sheets, assumed that livid
spectral appearance which physicians produce with the fictitious
light of alcohol impregnated with salt.</p>
<div class="illus"><ANTIMG alt="Illustration: A PREY TO FRIGHTFUL TERROR." id="terror" src=
"images/terror.jpg" /></div>
<div class="caption">A PREY TO FRIGHTFUL TERROR.</div>
<p>"By Jove!" cried Michel Ardan, "we are hideous. What is that
ill-conditioned moon?"</p>
<p>"A meteor," replied Barbicane.</p>
<p>"A meteor burning in space?"</p>
<p>"Yes."</p>
<p>This shooting globe suddenly appearing in shadow at a distance of
at most 200 miles, ought, according to Barbicane, to have a diameter
of 2000 yards. It advanced at a speed of about one mile and a half
per second. It cut the projectile's path and must reach it in some
minutes. As it approached it grew to enormous proportions.</p>
<p>Imagine, if possible, the situation of the travellers! It is
impossible to describe it. In spite of their courage, their
<i>sang-froid</i>, their carelessness of danger, they were mute,
motionless with stiffened limbs, a prey to frightful terror. Their
projectile, the course of which they could not alter, was rushing
straight on this ignited mass, more intense than the open mouth of an
oven. It seemed as though they were being precipitated towards an
abyss of fire.</p>
<p>Barbicane had seized the hands of his two companions, and all
three looked through their half-open eyelids upon that asteroid
heated to a white heat. If thought was not destroyed within them, if
their brains still worked amidst all this awe, they must have given
themselves up for lost.</p>
<p>Two minutes after the sudden appearance of the meteor (to them two
centuries of anguish) the projectile seemed almost about to strike
it, when the globe of fire burst like a bomb, but without making any
noise in that void where sound, which is but the agitation of the
layers of air, could not be generated.</p>
<p>Nicholl uttered a cry, and he and his companions rushed to the
scuttle. What a sight! What pen can describe it? What palette is rich
enough in colours to reproduce so magnificent a spectacle?</p>
<p>It was like the opening of a crater, like the scattering of an
immense conflagration. Thousands of luminous fragments lit up and
irradiated space with their fires. Every size, every colour, was
there intermingled. There were rays of yellow and pale yellow, red,
green, grey—a crown of fireworks of all colours. Of the enormous and
much-dreaded globe there remained nothing but these fragments carried
in all directions, now become asteroids in their turn, some flaming
like a sword, some surrounded by a whitish cloud, and others leaving
behind them trains of brilliant cosmical dust.</p>
<p>These incandescent blocks crossed and struck each other,
scattering still smaller fragments, some of which struck the
projectile. Its left scuttle was even cracked by a violent shock. It
seemed to be floating amidst a hail of howitzer shells, the smallest
of which might destroy it instantly.</p>
<p>The light which saturated the ether was so wonderfully intense,
that Michel, drawing Barbicane and Nicholl to his window, exclaimed,
"The invisible moon, visible at last!"</p>
<p>And through a luminous emanation, which lasted some seconds, the
whole three caught a glimpse of that mysterious disc which the eye of
man now saw for the first time. What could they distinguish at a
distance which they could not estimate? Some lengthened bands along
the disc, real clouds formed in the midst of a very confined
atmosphere, from which emerged not only all the mountains, but also
projections of less importance; its circles, its yawning craters, as
capriciously placed as on the visible surface. Then immense spaces,
no longer arid plains, but real seas, oceans, widely distributed,
reflecting on their liquid surface all the dazzling magic of the
fires of space; and, lastly, on the surface of the continents, large
dark masses, looking like immense forests under the rapid
illumination of a brilliance.</p>
<p>Was it an illusion, a mistake, an optical illusion? Could they
give a scientific assent to an observation so superficially obtained?
Dared they pronounce upon the question of its habitability after so
slight a glimpse of the invisible disc?</p>
<div class="illus"><ANTIMG alt="Illustration: WHAT A SIGHT." id="sight"
src="images/sight.jpg" /></div>
<div class="caption">WHAT A SIGHT.</div>
<p>But the lightnings in space subsided by degrees; its accidental
brilliancy died away; the asteroids dispersed in different directions
and were extinguished in the distance. The ether returned to its
accustomed darkness; the stars, eclipsed for a moment, again twinkled
in the firmament, and the disc, so hastily discerned, was again
buried in impenetrable night.</p>
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