CHAPTER XVIII
GRAVE QUESTIONS
But the projectile had passed the _enceinte_ of Tycho, andBarbicane and his two companions watched with scrupulousattention the brilliant rays which the celebrated mountain shedso curiously over the horizon.
What was this radiant glory? What geological phenomenon haddesigned these ardent beams? This question occupied Barbicane's mind.
Under his eyes ran in all directions luminous furrows, raised atthe edges and concave in the center, some twelve miles, othersthirty miles broad. These brilliant trains extended in someplaces to within 600 miles of Tycho, and seemed to cover,particularly toward the east, the northeast and the north, thehalf of the southern hemisphere. One of these jets extended asfar as the circle of Neander, situated on the 40th meridian.Another, by a slight curve, furrowed the "Sea of Nectar," breakingagainst the chain of Pyrenees, after a circuit of 800 miles.Others, toward the west, covered the "Sea of Clouds" andthe "Sea of Humors" with a luminous network. What was theorigin of these sparkling rays, which shone on the plains aswell 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 tocurrents of lava congealed by the cold; an opinion, however,which has not been generally adopted. Other astronomers haveseen in these inexplicable rays a kind of moraines, rows oferratic blocks, which had been thrown up at the period ofTycho's formation.
"And why not?" asked Nicholl of Barbicane, who was relating andrejecting these different opinions.
"Because the regularity of these luminous lines, and theviolence necessary to carry volcanic matter to such distances,is inexplicable."
"Eh! by Jove!" replied Michel Ardan, "it seems easy enough to meto explain the origin of these rays."
"Indeed?" said Barbicane.
"Indeed," continued Michel. "It is enough to say that it is avast star, similar to that produced by a ball or a stone thrownat a square of glass!"
"Well!" replied Barbicane, smiling. "And what hand would bepowerful enough to throw a ball to give such a shock as that?"
"The hand is not necessary," answered Nicholl, not at allconfounded; "and as to the stone, let us suppose it to be a comet."
"Ah! those much-abused comets!" exclaimed Barbicane. "My braveMichel, your explanation is not bad; but your comet is useless.The shock which produced that rent must have some from theinside 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." saidMichel Ardan.
"Besides," added Barbicane, "this opinion is that of an Englishsavant, Nasmyth, and it seems to me to sufficiently explain theradiation 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 withluminous gleams in the double irradiation of sun and moon, musthave appeared like an incandescent globe. They had passedsuddenly from excessive cold to intense heat. Nature was thuspreparing them to become Selenites. Become Selenites! That ideabrought up once more the question of the habitability of the moon.After what they had seen, could the travelers solve it? Would theydecide for or against it? Michel Ardan persuaded his two friendsto form an opinion, and asked them directly if they thought thatmen and animals were represented in the lunar world.
"I think that we can answer," said Barbicane; "but according tomy idea the question ought not to be put in that form. I ask itto 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 themoon ever been _inhabitable_?"
"Good!" replied Nicholl. "First let us see whether the moonis habitable."
"To tell the truth, I know nothing about it," answered Michel.
"And I answer in the negative," continued Barbicane. "In heractual state, with her surrounding atmosphere certainly verymuch reduced, her seas for the most part dried up, herinsufficient supply of water restricted, vegetation, suddenalternations of cold and heat, her days and nights of 354hours-- the moon does not seem habitable to me, nor does sheseem propitious to animal development, nor sufficient for thewants of existence as we understand it."
"Agreed," replied Nicholl. "But is not the moon habitable forcreatures differently organized from ourselves?"
"That question is more difficult to answer, but I will try; andI ask Nicholl if _motion_ appears to him to be a necessaryresult of _life_, whatever be its organization?"
"Without a doubt!" answered Nicholl.
"Then, my worthy companion, I would answer that we have observedthe lunar continent at a distance of 500 yards at most, and thatnothing seemed to us to move on the moon's surface. The presenceof any kind of life would have been betrayed by its attendant marks,such as divers buildings, and even by ruins. And what havewe seen? Everywhere and always the geological works of nature,never the work of man. If, then, there exist representativesof the animal kingdom on the moon, they must have fled to thoseunfathomable cavities which the eye cannot reach; which I cannotadmit, for they must have left traces of their passage on thoseplains which the atmosphere must cover, however slightly raisedit may be. These traces are nowhere visible. There remains butone hypothesis, that of a living race to which motion, which islife, 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 Commissionassembled in the projectile of the Gun Club, after havingfounded their argument on facts recently observed, decideunanimously upon the question of the habitability of the moon--`_No!_ the moon is not habitable.'"
This decision was consigned by President Barbicane to hisnotebook, where the process of the sitting of the 6th ofDecember may be seen.
"Now," said Nicholl, "let us attack the second question, anindispensable complement of the first. I ask the honorablecommission, if the moon is not habitable, has she ever beeninhabited, Citizen Barbicane?"
"My friends," replied Barbicane, "I did not undertake thisjourney in order to form an opinion on the past habitability ofour satellite; but I will add that our personal observationsonly confirm me in this opinion. I believe, indeed I affirm,that the moon has been inhabited by a human race organized likeour own; that she has produced animals anatomically formed likethe terrestrial animals: but I add that these races, human andanimal, 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 oldquicker, and whose formation and deformation have been more rapid.Relatively, the organizing force of matter has been much moreviolent in the interior of the moon than in the interior of theterrestrial globe. The actual state of this cracked, twisted,and burst disc abundantly proves this. The moon and the earthwere nothing but gaseous masses originally. These gases havepassed into a liquid state under different influences, and thesolid masses have been formed later. But most certainly oursphere was still gaseous or liquid, when the moon was solidifiedby cooling, and had become habitable."
"I believe it," said Nicholl.
"Then," continued Barbicane, "an atmosphere surrounded it, thewaters contained within this gaseous envelope could not evaporate.Under the influence of air, water, light, solar heat, and centralheat, vegetation took possession of the continents prepared toreceive it, and certainly life showed itself about this period,for nature does not expend herself in vain; and a world sowonderfully formed for habitation must necessarily be inhabited."
"But," said Nicholl, "many phenomena inherent in our satellitemight 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 inthe actual state of the moon its long nights and long dayscreated differences of temperature insupportable toorganization, it was not so at the historical period of time.The atmosphere enveloped the disc with a fluid mantle; vapordeposited itself in the shape of clouds; this natural screentempered the ardor of the solar rays, and retained thenocturnal radiation. Light, like heat, can diffuse itself inthe air; hence an equality between the influences which no longerexists, 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 uponher axis was not equal to her revolution, an equality whichpresents each part of her disc during fifteen days to the actionof the solar rays."
"Granted," replied Nicholl, "but why should not these twomotions have been equal, as they are really so?"
"Because that equality has only been determined byterrestrial attraction. And who can say that this attractionwas powerful enough to alter the motion of the moon at thatperiod when the earth was still fluid?"
"Just so," replied Nicholl; "and who can say that the moon hasalways been a satellite of the earth?"
"And who can say," exclaimed Michel Ardan, "that the moon didnot exist before the earth?"
Their imaginations carried them away into an indefinite fieldof hypothesis. Barbicane sought to restrain them.
"Those speculations are too high," said he; "problemsutterly insoluble. Do not let us enter upon them. Let us onlyadmit the insufficiency of the primordial attraction; and thenby the inequality of the two motions of rotation and revolution,the days and nights could have succeeded each other on the moonas they succeed each other on the earth. Besides, even withoutthese conditions, life was possible."
"And so," asked Michel Ardan, "humanity has disappeared fromthe moon?"
"Yes," replied Barbicane, "after having doubtless remainedpersistently for millions of centuries; by degrees theatmosphere becoming rarefied, the disc became uninhabitable, asthe terrestrial globe will one day become by cooling."
"By cooling?"
"Certainly," replied Barbicane; "as the internal fires becameextinguished, and the incandescent matter concentrated itself,the lunar crust cooled. By degrees the consequences of thesephenomena showed themselves in the disappearance of organizedbeings, and by the disappearance of vegetation. Soon theatmosphere was rarefied, probably withdrawn by terrestrialattraction; then aerial departure of respirable air, anddisappearance of water by means of evaporation. At this periodthe 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 spherewill 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 knowwhat diminution of temperature the earth undergoes in the lapseof a century. And according to certain calculations, this meantemperature will after a period of 400,000 years, be broughtdown to zero!"
"Four hundred thousand years!" exclaimed Michel. "Ah! Ibreathe again. Really I was frightened to hear you; I imaginedthat we had not more than 50,000 years to live."
Barbicane and Nicholl could not help laughing at theircompanion's uneasiness. Then Nicholl, who wished to end thediscussion, put the second question, which had just beenconsidered again.
"Has the moon been inhabited?" he asked.
The answer was unanimously in the affirmative. But during thisdiscussion, fruitful in somewhat hazardous theories, theprojectile was rapidly leaving the moon: the lineaments fadedaway from the travelers' eyes, mountains were confused in thedistance; and of all the wonderful, strange, and fantasticalform of the earth's satellite, there soon remained nothing butthe imperishable remembrance.