But the projectile had passed the enceinte of Tycho, and
Barbicane and his two companions watched with scrupulous
attention the brilliant rays which the celebrated mountain shed
so curiously over the horizon.
What was this radiant glory?  What geological phenomenon had
designed these ardent beams?  This question occupied Barbicane's mind.
Under his eyes ran in all directions luminous furrows, raised at
the edges and concave in the center, some twelve miles, others
thirty miles broad.  These brilliant trains extended in some
places to within 600 miles of Tycho, and seemed to cover,
particularly toward the east, the northeast and the north, the
half of the southern hemisphere.  One of these jets extended as
far as the circle of Neander, situated on the 40th meridian.
Another, by a slight curve, furrowed the "Sea of Nectar," breaking
against the chain of Pyrenees, after a circuit of 800 miles.
Others, toward the west, covered the "Sea of Clouds" and
the "Sea of Humors" with a luminous network.  What was the
origin of these sparkling rays, which shone on the plains as
well as on the reliefs, at whatever height they might be?
All started from a common center, the crater of Tycho.
They sprang from him.  Herschel attributed their brilliancy to
currents of lava congealed by the cold; an opinion, however,
which has not been generally adopted.  Other astronomers have
seen in these inexplicable rays a kind of moraines, rows of
erratic blocks, which had been thrown up at the period of
Tycho's formation.
"And why not?" asked Nicholl of Barbicane, who was relating and
rejecting these different opinions.
"Because the regularity of these luminous lines, and the
violence necessary to carry volcanic matter to such distances,
is inexplicable."
"Eh! by Jove!" replied Michel Ardan, "it seems easy enough to me
to explain the origin of these rays."
"Indeed?" said Barbicane.
"Indeed," continued Michel.  "It is enough to say that it is a
vast star, similar to that produced by a ball or a stone thrown
at a square of glass!"
"Well!" replied Barbicane, smiling.  "And what hand would be
powerful enough to throw a ball to give such a shock as that?"
"The hand is not necessary," answered Nicholl, not at all
confounded; "and as to the stone, let us suppose it to be a comet."
"Ah! those much-abused comets!" exclaimed Barbicane.  "My brave
Michel, your explanation is not bad; but your comet is useless.
The shock which produced that rent must have some from the
inside of the star.  A violent contraction of the lunar crust,
while cooling, might suffice to imprint this gigantic star."
"A contraction! something like a lunar stomach-ache." said
Michel Ardan.
"Besides," added Barbicane, "this opinion is that of an English
savant, Nasmyth, and it seems to me to sufficiently explain the
radiation of these mountains."
"That Nasmyth was no fool!" replied Michel.
Long did the travelers, whom such a sight could never weary,
admire the splendors of Tycho.  Their projectile, saturated with
luminous gleams in the double irradiation of sun and moon, must
have appeared like an incandescent globe.  They had passed
suddenly from excessive cold to intense heat.  Nature was thus
preparing them to become Selenites.  Become Selenites!  That idea
brought up once more the question of the habitability of the moon.
After what they had seen, could the travelers solve it?  Would they
decide for or against it?  Michel Ardan persuaded his two friends
to form an opinion, and asked them directly if they thought that
men and animals were represented in the lunar world.
"I think that we can answer," said Barbicane; "but according to
my idea the question ought not to be put in that form.  I ask it
to be put differently."
"Put it your own way," replied Michel.
"Here it is," continued Barbicane.  "The problem is a double one,
and requires a double solution.  Is the moon habitable?  Has the
moon ever been inhabitable?"
"Good!" replied Nicholl.  "First let us see whether the moon
is habitable."
"To tell the truth, I know nothing about it," answered Michel.
"And I answer in the negative," continued Barbicane.  "In her
actual state, with her surrounding atmosphere certainly very
much reduced, her seas for the most part dried up, her
insufficient supply of water restricted, vegetation, sudden
alternations of cold and heat, her days and nights of 354
hours-- the moon does not seem habitable to me, nor does she
seem propitious to animal development, nor sufficient for the
wants of existence as we understand it."
"Agreed," replied Nicholl.  "But is not the moon habitable for
creatures differently organized from ourselves?"
"That question is more difficult to answer, but I will try; and
I ask Nicholl if motion appears to him to be a necessary
result of life, whatever be its organization?"
"Without a doubt!" answered Nicholl.
"Then, my worthy companion, I would answer that we have observed
the lunar continent at a distance of 500 yards at most, and that
nothing seemed to us to move on the moon's surface.  The presence
of any kind of life would have been betrayed by its attendant marks,
such as divers buildings, and even by ruins.  And what have
we seen?  Everywhere and always the geological works of nature,
never the work of man.  If, then, there exist representatives
of the animal kingdom on the moon, they must have fled to those
unfathomable cavities which the eye cannot reach; which I cannot
admit, for they must have left traces of their passage on those
plains which the atmosphere must cover, however slightly raised
it may be.  These traces are nowhere visible.  There remains but
one hypothesis, that of a living race to which motion, which is
life, is foreign."
"One might as well say, living creatures which do not live,"
replied Michel.
"Just so," said Barbicane, "which for us has no meaning."
"Then we may form our opinion?" said Michel.
"Yes," replied Nicholl.
"Very well," continued Michel Ardan, "the Scientific Commission
assembled in the projectile of the Gun Club, after having
founded their argument on facts recently observed, decide
unanimously upon the question of the habitability of the moon--
`No! the moon is not habitable.'"
This decision was consigned by President Barbicane to his
notebook, where the process of the sitting of the 6th of
December may be seen.
"Now," said Nicholl, "let us attack the second question, an
indispensable complement of the first.  I ask the honorable
commission, if the moon is not habitable, has she ever been
inhabited, Citizen Barbicane?"
"My friends," replied Barbicane, "I did not undertake this
journey in order to form an opinion on the past habitability of
our satellite; but I will add that our personal observations
only confirm me in this opinion.  I believe, indeed I affirm,
that the moon has been inhabited by a human race organized like
our own; that she has produced animals anatomically formed like
the terrestrial animals:  but I add that these races, human and
animal, have had their day, and are now forever extinct!"
"Then," asked Michel, "the moon must be older than the earth?"
"No!" said Barbicane decidedly, "but a world which has grown old
quicker, and whose formation and deformation have been more rapid.
Relatively, the organizing force of matter has been much more
violent in the interior of the moon than in the interior of the
terrestrial globe.  The actual state of this cracked, twisted,
and burst disc abundantly proves this.  The moon and the earth
were nothing but gaseous masses originally.  These gases have
passed into a liquid state under different influences, and the
solid masses have been formed later. But most certainly our
sphere was still gaseous or liquid, when the moon was solidified
by cooling, and had become habitable."
"I believe it," said Nicholl.
"Then," continued Barbicane, "an atmosphere surrounded it, the
waters contained within this gaseous envelope could not evaporate.
Under the influence of air, water, light, solar heat, and central
heat, vegetation took possession of the continents prepared to
receive it, and certainly life showed itself about this period,
for nature does not expend herself in vain; and a world so
wonderfully formed for habitation must necessarily be inhabited."
"But," said Nicholl, "many phenomena inherent in our satellite
might cramp the expansion of the animal and vegetable kingdom.
For example, its days and nights of 354 hours?"
"At the terrestrial poles they last six months," said Michel.
"An argument of little value, since the poles are not inhabited."
"Let us observe, my friends," continued Barbicane, "that if in
the actual state of the moon its long nights and long days
created differences of temperature insupportable to
organization, it was not so at the historical period of time.
The atmosphere enveloped the disc with a fluid mantle; vapor
deposited itself in the shape of clouds; this natural screen
tempered the ardor of the solar rays, and retained the
nocturnal radiation.  Light, like heat, can diffuse itself in
the air; hence an equality between the influences which no longer
exists, now that atmosphere has almost entirely disappeared.
And now I am going to astonish you."
"Astonish us?" said Michel Ardan.
"I firmly believe that at the period when the moon was inhabited,
the nights and days did not last 354 hours!"
"And why?" asked Nicholl quickly.
"Because most probably then the rotary motion of the moon upon
her axis was not equal to her revolution, an equality which
presents each part of her disc during fifteen days to the action
of the solar rays."
"Granted," replied Nicholl, "but why should not these two
motions have been equal, as they are really so?"
"Because that equality has only been determined by
terrestrial attraction.  And who can say that this attraction
was powerful enough to alter the motion of the moon at that
period when the earth was still fluid?"
"Just so," replied Nicholl; "and who can say that the moon has
always been a satellite of the earth?"
"And who can say," exclaimed Michel Ardan, "that the moon did
not exist before the earth?"
Their imaginations carried them away into an indefinite field
of hypothesis.  Barbicane sought to restrain them.
"Those speculations are too high," said he; "problems
utterly insoluble.  Do not let us enter upon them.  Let us only
admit the insufficiency of the primordial attraction; and then
by the inequality of the two motions of rotation and revolution,
the days and nights could have succeeded each other on the moon
as they succeed each other on the earth.  Besides, even without
these conditions, life was possible."
"And so," asked Michel Ardan, "humanity has disappeared from
the moon?"
"Yes," replied Barbicane, "after having doubtless remained
persistently for millions of centuries; by degrees the
atmosphere becoming rarefied, the disc became uninhabitable, as
the terrestrial globe will one day become by cooling."
"By cooling?"
"Certainly," replied Barbicane; "as the internal fires became
extinguished, and the incandescent matter concentrated itself,
the lunar crust cooled.  By degrees the consequences of these
phenomena showed themselves in the disappearance of organized
beings, and by the disappearance of vegetation.  Soon the
atmosphere was rarefied, probably withdrawn by terrestrial
attraction; then aerial departure of respirable air, and
disappearance of water by means of evaporation.  At this period
the moon becoming uninhabitable, was no longer inhabited.
It was a dead world, such as we see it to-day."
"And you say that the same fate is in store for the earth?"
"Most probably."
"But when?"
"When the cooling of its crust shall have made it uninhabitable."
"And have they calculated the time which our unfortunate sphere
will take to cool?"
"Certainly."
"And you know these calculations?"
"Perfectly."
"But speak, then, my clumsy savant," exclaimed Michel Ardan,
"for you make me boil with impatience!"
"Very well, my good Michel," replied Barbicane quietly; "we know
what diminution of temperature the earth undergoes in the lapse
of a century.  And according to certain calculations, this mean
temperature will after a period of 400,000 years, be brought
down to zero!"
"Four hundred thousand years!" exclaimed Michel.  "Ah!  I
breathe again.  Really I was frightened to hear you; I imagined
that we had not more than 50,000 years to live."
Barbicane and Nicholl could not help laughing at their
companion's uneasiness.  Then Nicholl, who wished to end the
discussion, put the second question, which had just been
considered again.
"Has the moon been inhabited?" he asked.
The answer was unanimously in the affirmative.  But during this
discussion, fruitful in somewhat hazardous theories, the
projectile was rapidly leaving the moon: the lineaments faded
away from the travelers' eyes, mountains were confused in the
distance; and of all the wonderful, strange, and fantastical
form of the earth's satellite, there soon remained nothing but
the imperishable remembrance.