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Chapter VI. Question and Answer
On the 4th of December, when the travelers awoke after
fifty-four hours’ journey, the chronometer marked five
o’clock of the terrestrial morning. In time it was just over
five hours and forty minutes, half of that assigned to their
sojourn in the projectile; but they had already accomplished nearly
seven-tenths of the way. This peculiarity was due to their
regularly decreasing speed.
Now when they observed the earth through the lower window, it
looked like nothing more than a dark spot, drowned in the solar
rays. No more crescent, no more cloudy light! The next day, at
midnight, the earth would be new, at the very moment when the moon
would be full. Above, the orb of night was nearing the line
followed by the projectile, so as to meet it at the given hour. All
around the black vault was studded with brilliant points, which
seemed to move slowly; but, at the great distance they were from
them, their relative size did not seem to change. The sun and stars
appeared exactly as they do to us upon earth. As to the moon, she
was considerably larger; but the travelers’ glasses, not very
powerful, did not allow them as yet to make any useful observations
upon her surface, or reconnoiter her topographically or
geologically.
Thus the time passed in never-ending conversations all about the
moon. Each one brought forward his own contingent of particular
facts; Barbicane and Nicholl always serious, Michel Ardan always
enthusiastic. The projectile, its situation, its direction,
incidents which might happen, the precautions necessitated by their
fall on to the moon, were inexhaustible matters of conjecture.
As they were breakfasting, a question of Michel’s,
relating to the projectile, provoked rather a curious answer from
Barbicane, which is worth repeating. Michel, supposing it to be
roughly stopped, while still under its formidable initial speed,
wished to know what the consequences of the stoppage would have
been.
“But,” said Barbicane, “I do not see how it
could have been stopped.”
“But let us suppose so,” said Michel.
“It is an impossible supposition,” said the
practical Barbicane; “unless that impulsive force had failed;
but even then its speed would diminish by degrees, and it would not
have stopped suddenly.”
“Admit that it had struck a body in space.”
“What body?”
“Why that enormous meteor which we met.”
“Then,” said Nicholl, “the projectile would
have been broken into a thousand pieces, and we with it.”
“More than that,” replied Barbicane; “we
should have been burned to death.”
“Burned?” exclaimed Michel, “by Jove! I am
sorry it did not happen, ‘just to see.’”
“And you would have seen,” replied Barbicane.
“It is known now that heat is only a modification of motion.
When water is warmed— that is to say, when heat is added to
it—its particles are set in motion.”
“Well,” said michel, “that is an ingenious
theory!”
“And a true one, my worthy friend; for it explains every
phenomenon of caloric. Heat is but the motion of atoms, a simple
oscillation of the particles of a body. When they apply the brake
to a train, the train comes to a stop; but what becomes of the
motion which it had previously possessed? It is transformed into
heat, and the brake becomes hot. Why do they grease the axles of
the wheels? To prevent their heating, because this heat would be
generated by the motion which is thus lost by
transformation.”
“Yes, I understand,” replied Michel,
“perfectly. For example, when I have run a long time, when I
am swimming, when I am perspiring in large drops, why am I obliged
to stop? Simply because my motion is changed into heat.”
Barbicane could not help smiling at Michel’s reply; then,
returning to his theory, said:
“Thus, in case of a shock, it would have been with our
projectile as with a ball which falls in a burning state after
having struck the metal plate; it is its motion which is turned
into heat. Consequently I affirm that, if our projectile had struck
the meteor, its speed thus suddenly checked would have raised a
heat great enough to turn it into vapor instantaneously.”
“Then,” asked Nicholl, “what would happen if
the earth’s motion were to stop suddenly?”
“Her temperature would be raised to such a pitch,”
said Barbicane, “that she would be at once reduced to
vapor.”
“Well,” said Michel, “that is a way of ending
the earth which will greatly simplify things.”
“And if the earth fell upon the sun?” asked
Nicholl.
“According to calculation,” replied Barbicane,
“the fall would develop a heat equal to that produced by
16,000 globes of coal, each equal in bulk to our terrestrial
globe.”
“Good additional heat for the sun,” replied Michel
Ardan, “of which the inhabitants of Uranus or Neptune would
doubtless not complain; they must be perished with cold on their
planets.”
“Thus, my friends,” said Barbicane, “all
motion suddenly stopped produces heat. And this theory allows us to
infer that the heat of the solar disc is fed by a hail of meteors
falling incessantly on its surface. They have even
calculated——”
“Oh, dear!” murmured Michel, “the figures are
coming.”
“They have even calculated,” continued the
imperturbable Barbicane, “that the shock of each meteor on
the sun ought to produce a heat equal to that of 4,000 masses of
coal of an equal bulk.”
“And what is the solar heat?” asked Michel.
“It is equal to that produced by the combustion of a
stratum of coal surrounding the sun to a depth of forty-seven
miles.”
“And that heat——”
“Would be able to boil two billions nine hundred millions
of cubic myriameters 2 of water.”
2 The myriameter is equal to rather more than 10,936 cubic
yards English.
“And it does not roast us!” exclaimed Michel.
“No,” replied Barbicane, “because the
terrestrial atmosphere absorbs four-tenths of the solar heat;
besides, the quantity of heat intercepted by the earth is but a
billionth part of the entire radiation.”
“I see that all is for the best,” said Michel,
“and that this atmosphere is a useful invention; for it not
only allows us to breathe, but it prevents us from
roasting.”
“Yes!” said Nicholl, “unfortunately, it will
not be the same in the moon.”
“Bah!” said Michel, always hopeful. “If there
are inhabitants, they must breathe. If there are no longer any,
they must have left enough oxygen for three people, if only at the
bottom of ravines, where its own weight will cause it to
accumulate, and we will not climb the mountains; that is
all.” And Michel, rising, went to look at the lunar disc,
which shone with intolerable brilliancy.
“By Jove!” said he, “it must be hot up
there!”
“Without considering,” replied Nicholl, “that
the day lasts 360 hours!”
“And to compensate that,” said Barbicane, “the
nights have the same length; and as heat is restored by radiation,
their temperature can only be that of the planetary
space.”
“A pretty country, that!” exclaimed Michel.
“Never mind! I wish I was there! Ah! my dear comrades, it
will be rather curious to have the earth for our moon, to see it
rise on the horizon, to recognize the shape of its continents, and
to say to oneself, ‘There is America, there is Europe;’
then to follow it when it is about to lose itself in the
sun’s rays! By the bye, Barbicane, have the Selenites
eclipses?”
“Yes, eclipses of the sun,” replied Barbicane,
“when the centers of the three orbs are on a line, the earth
being in the middle. But they are only partial, during which the
earth, cast like a screen upon the solar disc, allows the greater
portion to be seen.”
“And why,” asked Nicholl, “is there no total
eclipse? Does not the cone of the shadow cast by the earth extend
beyond the moon?”
“Yes, if we do not take into consideration the refraction
produced by the terrestrial atmosphere. No, if we take that
refraction into consideration. Thus let <lower case delta> be
the horizontal parallel, and p the apparent
semidiameter——”
“Oh!” said Michel. “Do speak plainly, you man
of algebra!”
“Very well, replied Barbicane; “in popular language
the mean distance from the moon to the earth being sixty
terrestrial radii, the length of the cone of the shadow, on account
of refraction, is reduced to less than forty-two radii. The result
is that when there are eclipses, the moon finds itself beyond the
cone of pure shadow, and that the sun sends her its rays, not only
from its edges, but also from its center.”
“Then,” said Michel, in a merry tone, “why are
there eclipses, when there ought not to be any?”
“Simply because the solar rays are weakened by this
refraction, and the atmosphere through which they pass extinguished
the greater part of them!”
“That reason satisfies me,” replied Michel.
“Besides we shall see when we get there. Now, tell me,
Barbicane, do you believe that the moon is an old comet?”
“There’s an idea!”
“Yes,” replied Michel, with an amiable swagger,
“I have a few ideas of that sort.”
“But that idea does not spring from Michel,”
answered Nicholl.
“Well, then, I am a plagiarist.”
“No doubt about it. According to the ancients, the
Arcadians pretend that their ancestors inhabited the earth before
the moon became her satellite. Starting from this fact, some
scientific men have seen in the moon a comet whose orbit will one
day bring it so near to the earth that it will be held there by its
attraction.”
“Is there any truth in this hypothesis?” asked
Michel.
“None whatever,” said Barbicane, “and the
proof is, that the moon has preserved no trace of the gaseous
envelope which always accompanies comets.”
“But,” continued Nicholl, “Before becoming the
earth’s satellite, could not the moon, when in her
perihelion, pass so near the sun as by evaporation to get rid of
all those gaseous substances?”
“It is possible, friend Nicholl, but not
probable.”
“Why not?”
“Because— Faith I do not know.”
“Ah!” exclaimed Michel, “what hundred of
volumes we might make of all that we do not know!”
“Ah! indeed. What time is it?” asked Barbicane.
“Three o’clock,” answered Nicholl.
“How time goes,” said Michel, “in the
conversation of scientific men such as we are! Certainly, I feel I
know too much! I feel that I am becoming a well!”
Saying which, Michel hoisted himself to the roof of the
projectile, “to observe the moon better,” he pretended.
During this time his companions were watching through the lower
glass. Nothing new to note!
When Michel Ardan came down, he went to the side scuttle; and
suddenly they heard an exclamation of surprise!
“What is it?” asked Barbicane.
The president approached the window, and saw a sort of flattened
sack floating some yards from the projectile. This object seemed as
motionless as the projectile, and was consequently animated with
the same ascending movement.
“What is that machine?” continued Michel Ardan.
“Is it one of the bodies which our projectile keeps within
its attraction, and which will accompany it to the moon?”
“What astonishes me,” said Nicholl, “is that
the specific weight of the body, which is certainly less than that
of the projectile, allows it to keep so perfectly on a level with
it.”
“Nicholl,” replied Barbicane, after a moment’s
reflection, “I do not know what the object it, but I do know
why it maintains our level.”
“And why?”
“Because we are floating in space, my dear captain, and in
space bodies fall or move (which is the same thing) with equal
speed whatever be their weight or form; it is the air, which by its
resistance creates these differences in weight. When you create a
vacuum in a tube, the objects you send through it, grains of dust
or grains of lead, fall with the same rapidity. Here in space is
the same cause and the same effect.”
“Just so,” said Nicholl, “and everything we
throw out of the projectile will accompany it until it reaches the
moon.”
“Ah! fools that we are!” exclaimed Michel.
“Why that expletive?” asked Barbicane.
“Because we might have filled the projectile with useful
objects, books, instruments, tools, etc. We could have thrown them
all out, and all would have followed in our train. But happy
thought! Why cannot we walk outside like the meteor? Why cannot we
launch into space through the scuttle? What enjoyment it would be
to feel oneself thus suspended in ether, more favored than the
birds who must use their wings to keep themselves up!”
“Granted,” said Barbicane, “but how to
breathe?”
“Hang the air, to fail so inopportunely!”
“But if it did not fail, Michel, your density being less
than that of the projectile, you would soon be left
behind.”
“Then we must remain in our car?”
“We must!”
“Ah!” exclaimed Michel, in a load voice.
“What is the matter,” asked Nicholl.
“I know, I guess, what this pretended meteor is! It is no
asteroid which is accompanying us! It is not a piece of a
planet.”
“What is it then?” asked Barbicane.
“It is our unfortunate dog! It is Diana’s
husband!”
Indeed, this deformed, unrecognizable object, reduced to
nothing, was the body of Satellite, flattened like a bagpipe
without wind, and ever mounting, mounting!
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