by Jules Verne
CHAPTER VI.
QUESTION AND ANSWER.
On the 4th of December, when the travellers awoke after fifty-fourhours' journey, the chronometer marked five o'clock of the terrestrialmorning. In time it was just over five hours and forty minutes, half ofthat assigned to their sojourn in the projectile; but they had alreadyaccomplished nearly seven-tenths of the way. This peculiarity was due totheir regularly decreasing speed.
Now when they observed the earth through the lower window, it lookedlike nothing more than a dark spot, drowned in the solar rays. No morecrescent, no more cloudy light! The next day, at midnight, the earthwould 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, soas to meet it at the given hour. All around the black vault was studdedwith brilliant points, which seemed to move slowly; but, at the greatdistance 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 tothe moon, she was considerably larger; but the travellers' glasses, notvery powerful, did not allow them as yet to make any useful observationsupon her surface, or reconnoitre her topographically orgeologically.
Thus the time passed in never-ending conversations all about themoon. 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 mighthappen, the precautions necessitated by their fall on to the moon, wereinexhaustible matters of conjecture.
As they were breakfasting, a question of Michel's, relating to theprojectile, provoked rather a curious answer from Barbicane, which isworth repeating. Michel, supposing it to be roughly stopped, while stillunder its formidable initial speed, wished to know what the consequencesof 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; "unlessthe impulsive force had failed; but even then its speed would diminishby 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 athousand pieces, and we with it."
"More than that," replied Barbicane; "we should have been burnt todeath."
"Burnt?" exclaimed Michel, "by Jove! I am sorry it did not happen, 'justto see.'"
"And you would have seen," replied Barbicane. "It is known now that heatis 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 ofcaloric. Heat is but the motion of atoms, a simple oscillation of theparticles of a body. When they apply the brake to a train, the traincomes to a stop; but what becomes of the motion which it had previouslypossessed? 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 bytransformation."
"Yes, I understand," replied Michel, "perfectly. For example, when Ihave run a long time, when I am swimming, when I am perspiring in largedrops, why am I obliged to stop? Simply because my motion is changed intoheat."
Barbicane could not help smiling at Michel's reply; then, returning tohis theory, said,--
"Thus, in case of a shock, it would have been with our projectile aswith a ball which falls in a burning state after having struck the metalplate; it is its motion which is turned into heat. Consequently I affirmthat, if our projectile had struck the meteor, its speed thus suddenlychecked would have raised a heat great enough to turn it into vapourinstantaneously."
"Then," asked Nicholl, "what would happen if the earth's motion were tostop suddenly?"
"Her temperature would be raised to such a pitch," said Barbicane, "thatshe would be at once reduced to vapour."
"Well," said Michel, "that is a way of ending the earth which willgreatly simplify things."
"And if the earth fell upon the sun?" asked Nicholl.
"According to calculation," replied Barbicane, "the fall would developea heat equal to that produced by 16,000 globes of coal, each equal inbulk to our terrestrial globe."
"Good additional heat for the sun," replied Michel Ardan, "of which theinhabitants of Uranus or Neptune would doubtless not complain; they mustbe perished with cold on their planets."
"Thus, my friends," said Barbicane, "all motion suddenly stopped producesheat. And this theory allows us to infer that the heat of the solar discis fed by a hail of meteors falling incessantly on its surface. They haveeven calculated--"
"Oh, dear!" murmured Michel, "the figures are coming."
"They have even calculated," continued the imperturbable Barbicane, "thatthe shock of each meteor on the sun ought to produce a heat equal to thatof 4000 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 coalsurrounding the sun to a depth of forty-seven miles."
"And that heat--"
"Would be able to boil two billions nine hundred millions of cubicmyriameters* of water."
*The myriameter is equal to rather more than 10,936 cubic yards English.--(Ed.)
"And it does not roast us!" exclaimed Michel.
"No," replied Barbicane, "because the terrestrial atmosphere absorbsfour-tenths of the solar heat; besides, the quantity of heat interceptedby the earth is but a billionth part of the entire radiation."
"I see that all is for the best," said Michel, "and that this atmosphereis a useful invention; for it not only allows us to breathe, but itprevents us from roasting."
"Yes!" said Nicholl, "unfortunately, it will not be the same in themoon."
"Bah!" said Michel, always hopeful. "If there are inhabitants, they mustbreathe. If there are no longer any, they must have left enough oxygenfor three people, if only at the bottom of ravines, where its own weightwill cause it to accumulate, and we will not climb the mountains; thatis all." And Michel, rising, went to look at the lunar disc, which shonewith 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 samelength; and as heat is restored by radiation, their temperature can onlybe that of the planetary space."
"A pretty country, that!" exclaimed Michel. "Never mind! I wish I wasthere! Ah! my dear comrades, it will be rather curious to have the earthfor our moon, to see it rise on the horizon, to recognize the shapeof its continents, and to say to oneself, 'There is America, there isEurope;' then to follow it when it is about to lose itself in the sun'srays! By-the-bye, Barbicane, have the Selenites eclipses?"
"Yes, eclipses of the sun," replied Barbicane, "when the centres of thethree orbs are on a line, the earth being in the middle. But they areonly partial, during which the earth, cast like a screen upon the solardisc, allows the greater portion to be seen."
"And why," asked Nicholl, "is there no total eclipse? Does not the coneof the shadow cast by the earth extend beyond the moon?"
"Yes, if we do not take into consideration the refraction produced by theterrestrial atmosphere. No, if we take that refraction into consideration.Thus delta be the horizontal parallel, and _p_ the apparentsemidiameter--"
"Oh!" said Michel. "Do speak plainly, you man of algebra!"
"Very well;" replied Barbicane, "in popular language the mean distancefrom the moon to the earth being sixty terrestrial radii, the length ofthe cone of the shadow, on account of the refraction, is reduced to lessthan forty-two radii. The result
is that when there are eclipses, themoon finds itself beyond the cone of pure shadow, and that the sun sendsher its rays, not only from its edges, but also from its centre."
"Then," said Michel, in a merry tone, "why are there eclipses, when thereought not to be any?"
"Simply because the solar rays are weakened by this refraction, andthe atmosphere through which they pass extinguishes the greater part ofthem!"
"That reason satisfies me," replied Michel. "Besides we shall see whenwe get there. Now, tell me, Barbicane, do you believe that the moon isan old comet?"
"There's an idea!"
"Yes," replied Michel, with an amiable swagger, "I have a few ideas ofthat 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 pretendthat their ancestors inhabited the earth before the moon became hersatellite. Starting from this fact, some scientific men have seen in themoon a comet whose orbit will one day bring it so near to the earth thatit 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 haspreserved no trace of the gaseous envelope which always accompaniescomets."
"But," continued Nicholl, "before becoming the earth's satellite,could not the moon, when in her perihelion, pass so near the sun as byevaporation 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 hundreds of volumes we might make of allthat 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 suchas we are! Certainly, I feel I know too much! I feel that I am becominga well!"
Saying which, Michel hoisted himself to the roof of the projectile, "toobserve the moon better," he pretended. During this time his companionswere watching through the lower glass. Nothing new to note!
When Michel Ardan came down, he went to the side scuttle; and suddenlythey heard an exclamation of surprise!
"What is it?" asked Barbicane.
The president approached the window, and saw a sort of flattened sackfloating some yards from the projectile. This object seemed as motionlessas the projectile, and was consequently animated with the same ascendingmovement.
"What is that machine?" continued Michel Ardan. "Is it one of the bodiesof space which our projectile keeps within its attraction, and which willaccompany it to the moon?"
"What astonishes me," said Nicholl, "is that the specific weight of thebody, which is certainly less than that of the projectile, allows it tokeep so perfectly on a level with it."
"Nicholl," replied Barbicane, after a moment's reflection, "I do not knowwhat the object is, but I do know why it maintains our level."
"And why?"
"Because we are floating in space, my dear captain, and in space bodiesfall or move (which is the same thing) with equal speed whatever be theirweight or form; it is the air, which by its resistance creates thesedifferences in weight. When you create a vacuum in a tube, the objectsyou send through it, grains of dust or grains of lead, fall with the samerapidity. Here in space is the same cause and the same effect."
"Just so," said Nicholl, "and everything we throw out of the projectilewill 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, &c. We could have thrown them all out, and all wouldhave followed in our train. But happy thought! Why cannot we walk outsidelike the meteor? Why cannot we launch into space through the scuttle?What enjoyment it would be to feel oneself thus suspended in ether, morefavoured than the birds who must use their wings to keep themselves up!"
Illustration: IT WAS THE BODY OF SATELLITE.
"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 ofthe projectile, you would soon be left behind."
"Then we must remain in our car?"
"We must!"
"Ah!" exclaimed Michel, in a loud voice.
"What is the matter," asked Nicholl.
"I know, I guess, what this pretended meteor is! It is no asteroid whichis 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, wasthe body of Satellite, flattened like a bagpipe without wind, and evermounting, mounting!