by Jules Verne
CHAPTER VI.
INSTRUCTIVE CONVERSATION.
On the fourth of December, the Projectile chronometers marked fiveo'clock in the morning, just as the travellers woke up from a pleasantslumber. They had now been 54 hours on their journey. As to lapse of_time_, they had passed not much more than half of the number of hoursduring which their trip was to last; but, as to lapse of _space_, theyhad already accomplished very nearly the seven-tenths of their passage.This difference between time and distance was due to the regularretardation of their velocity.
They looked at the earth through the floor-light, but it was little morethan visible--a black spot drowned in the solar rays. No longer any signof a crescent, no longer any sign of ashy light. Next day, towardsmidnight, the Earth was to be _new_, at the precise moment when the Moonwas to be _full_. Overhead, they could see the Queen of Night comingnearer and nearer to the line followed by the Projectile, and evidentlyapproaching the point where both should meet at the appointed moment.All around, the black vault of heaven was dotted with luminous pointswhich seemed to move somewhat, though, of course, in their extremedistance their relative size underwent no change. The Sun and the starslooked exactly as they had appeared when observed from the Earth. TheMoon indeed had become considerably enlarged in size, but thetravellers' telescopes were still too weak to enable them to make anyimportant observation regarding the nature of her surface, or that mightdetermine her topographical or geological features.
Naturally, therefore, the time slipped away in endless conversation. TheMoon, of course, was the chief topic. Each one contributed his share ofpeculiar information, or peculiar ignorance, as the case might be.Barbican and M'Nicholl always treated the subject gravely, as becamelearned scientists, but Ardan preferred to look on things with the eyeof fancy. The Projectile, its situation, its direction, the incidentspossible to occur, the precautions necessary to take in order to breakthe fall on the Moon's surface--these and many other subjects furnishedendless food for constant debate and inexhaustible conjectures.
For instance, at breakfast that morning, a question of Ardan's regardingthe Projectile drew from Barbican an answer curious enough to bereported.
"Suppose, on the night that we were shot up from Stony Hill," saidArdan, "suppose the Projectile had encountered some obstacle powerfulenough to stop it--what would be the consequence of the sudden halt?"
"But," replied Barbican, "I don't understand what obstacle it could havemet powerful enough to stop it."
"Suppose some obstacle, for the sake of argument," said Ardan.
"Suppose what can't be supposed," replied the matter-of-fact Barbican,"what cannot possibly be supposed, unless indeed the original impulseproved too weak. In that case, the velocity would have decreased bydegrees, but the Projectile itself would not have suddenly stopped."
"Suppose it had struck against some body in space."
"What body, for instance?"
"Well, that enormous bolide which we met."
"Oh!" hastily observed the Captain, "the Projectile would have beendashed into a thousand pieces and we along with it."
"Better than that," observed Barbican; "we should have been burnedalive."
"Burned alive!" laughed Ardan. "What a pity we missed so interesting anexperiment! How I should have liked to find out how it felt!"
"You would not have much time to record your observations, friendMichael, I assure you," observed Barbican. "The case is plain enough.Heat and motion are convertible terms. What do we mean by heating water?Simply giving increased, in fact, violent motion to its molecules."
"Well!" exclaimed the Frenchman, "that's an ingenious theory any how!"
"Not only ingenious but correct, my dear friend, for it completelyexplains all the phenomena of caloric. Heat is nothing but molecularmovement, the violent oscillation of the particles of a body. When youapply the brakes to the train, the train stops. But what has become ofits motion? It turns into heat and makes the brakes hot. Why do peoplegrease the axles? To hinder them from getting too hot, which theyassuredly would become if friction was allowed to obstruct the motion.You understand, don't you?"
"Don't I though?" replied Ardan, apparently in earnest. "Let me show youhow thoroughly. When I have been running hard and long, I feel myselfperspiring like a bull and hot as a furnace. Why am I then forced tostop? Simply because my motion has been transformed into heat! Ofcourse, I understand all about it!"
Barbican smiled a moment at this comical illustration of his theory andthen went on:
"Accordingly, in case of a collision it would have been all overinstantly with our Projectile. You have seen what becomes of the bulletthat strikes the iron target. It is flattened out of all shape;sometimes it is even melted into a thin film. Its motion has been turnedinto heat. Therefore, I maintain that if our Projectile had struck thatbolide, its velocity, suddenly checked, would have given rise to a heatcapable of completely volatilizing it in less than a second."
"Not a doubt of it!" said the Captain. "President," he added after amoment, "haven't they calculated what would be the result, if the Earthwere suddenly brought to a stand-still in her journey, through herorbit?"
"It has been calculated," answered Barbican, "that in such a case somuch heat would be developed as would instantly reduce her to vapor."
"Hm!" exclaimed Ardan; "a remarkably simple way for putting an end tothe world!"
"And supposing the Earth to fall into the Sun?" asked the Captain.
"Such a fall," answered Barbican, "according to the calculations ofTyndall and Thomson, would develop an amount of heat equal to thatproduced by sixteen hundred globes of burning coal, each globe equal insize to the earth itself. Furthermore such a fall would supply the Sunwith at least as much heat as he expends in a hundred years!"
"A hundred years! Good! Nothing like accuracy!" cried Ardan. "Suchinfallible calculators as Messrs. Tyndall and Thomson I can easilyexcuse for any airs they may give themselves. They must be of an ordermuch higher than that of ordinary mortals like us!"
"I would not answer myself for the accuracy of such intricate problems,"quietly observed Barbican; "but there is no doubt whatever regarding onefact: motion suddenly interrupted always develops heat. And this hasgiven rise to another theory regarding the maintenance of the Sun'stemperature at a constant point. An incessant rain of bolides falling onhis surface compensates sufficiently for the heat that he iscontinually giving forth. It has been calculated--"
"Good Lord deliver us!" cried Ardan, putting his hands to his ears:"here comes Tyndall and Thomson again!"
--"It has been calculated," continued Barbican, not heeding theinterruption, "that the shock of every bolide drawn to the Sun's surfaceby gravity, must produce there an amount of heat equal to that of thecombustion of four thousand blocks of coal, each the same size as thefalling bolide."
"I'll wager another cent that our bold savants calculated the heat ofthe Sun himself," cried Ardan, with an incredulous laugh.
"That is precisely what they have done," answered Barbican referring tohis memorandum book; "the heat emitted by the Sun," he continued, "isexactly that which would be produced by the combustion of a layer ofcoal enveloping the Sun's surface, like an atmosphere, 17 miles inthickness."
"Well done! and such heat would be capable of--?"
"Of melting in an hour a stratum of ice 2400 feet thick, or, accordingto another calculation, of raising a globe of ice-cold water, 3 timesthe size of our Earth, to the boiling point in an hour."
"Why not calculate the exact fraction of a second it would take to cooka couple of eggs?" laughed Ardan. "I should as soon believe in onecalculation as in the other.--But--by the by--why does not such extremeheat cook us all up like so many beefsteaks?"
"For two very good and sufficient reasons," answered Barbican. "In thefirst place, the terrestrial atmosphere absorbs the 4/10 of the solarheat. In the second, the quantity of solar heat intercepted by the Earthis only about the two billionth part of all that is radiated."
"Yes," said the Captain, "but unfortunately we can't say so much for theMoon."
"Oh pshaw!" cried Ardan, always full of confidence. "It's all rightthere too! The Moon is either inhabited or she is not. If she is, theinhabitants must breathe. If she is not, there must be oxygen enoughleft for we, us and co., even if we should have to go after it to thebottom of the ravines, where, by its gravity, it must have accumulated!So much the better! we shall not have to climb those thunderingmountains!"
So saying, he jumped up and began to gaze with considerable interest onthe lunar disc, which just then was glittering with dazzling brightness.
"By Jove!" he exclaimed at length; "it must be pretty hot up there!"
"I should think so," observed the Captain; "especially when you rememberthat the day up there lasts 360 hours!"
"Yes," observed Barbican, "but remember on the other hand that thenights are just as long, and, as the heat escapes by radiation, the meantemperature cannot be much greater than that of interplanetary space."
"A high old place for living in!" cried Ardan. "No matter! I wish wewere there now! Wouldn't it be jolly, dear boys, to have old MotherEarth for our Moon, to see her always on our sky, never rising, neversetting, never undergoing any change except from New Earth to LastQuarter! Would not it be fun to trace the shape of our great Oceans andContinents, and to say: 'there is the Mediterranean! there is China!there is the gulf of Mexico! there is the white line of the RockyMountains where old Marston is watching for us with his big telescope!'Then we should see every line, and brightness, and shadow fade away bydegrees, as she came nearer and nearer to the Sun, until at last she satcompletely lost in his dazzling rays! But--by the way--Barbican, arethere any eclipses in the Moon?"
"O yes; solar eclipses" replied Barbican, "must always occur wheneverthe centres of the three heavenly bodies are in the same line, the Earthoccupying the middle place. However, such eclipses must always beannular, as the Earth, projected like a screen on the solar disc, allowsmore than half of the Sun to be still visible."
"How is that?" asked M'Nicholl, "no total eclipses in the Moon? Surelythe cone of the Earth's shadow must extend far enough to envelop hersurface?"
"It does reach her, in one sense," replied Barbican, "but it does not inanother. Remember the great refraction of the solar rays that must beproduced by the Earth's atmosphere. It is easy to show that thisrefraction prevents the Sun from ever being totally invisible. Seehere!" he continued, pulling out his tablets, "Let _a_ represent thehorizontal parallax, and _b_ the half of the Sun's apparent diameter--"
"Ouch!" cried the Frenchman, making a wry face, "here comes Mr. _x_square riding to the mischief on a pair of double zeros again! TalkEnglish, or Yankee, or Dutch, or Greek, and I'm your man! Even a littleArabic I can digest! But hang me, if I can endure your Algebra!"
"Well then, talking Yankee," replied Barbican with a smile, "the meandistance of the Moon from the Earth being sixty terrestrial radii, thelength of the conic shadow, in consequence of atmospheric refraction, isreduced to less than forty-two radii. Consequently, at the moment of aneclipse, the Moon is far beyond the reach of the real shadow, so thatshe can see not only the border rays of the Sun, but even thoseproceeding from his very centre."
"Oh then," cried Ardan with a loud laugh, "we have an eclipse of the Sunat the moment when the Sun is quite visible! Isn't that very like abull, Mr. Philosopher Barbican?"
"Yet it is perfectly true notwithstanding," answered Barbican. "At sucha moment the Sun is not eclipsed, because we can see him: and then againhe is eclipsed because we see him only by means of a few of his rays,and even these have lost nearly all their brightness in their passagethrough the terrestrial atmosphere!"
"Barbican is right, friend Michael," observed the Captain slowly: "thesame phenomenon occurs on earth every morning at sunrise, whenrefraction shows us
'_the Sun new ris'n Looking through the horizontal misty air, Shorn of his beams._'"
"He must be right," said Ardan, who, to do him justice, though quick atseeing a reason, was quicker to acknowledge its justice: "yes, he mustbe right, because I begin to understand at last very clearly what hereally meant. However, we can judge for ourselves when we getthere.--But, apropos of nothing, tell me, Barbican, what do you think ofthe Moon being an ancient comet, which had come so far within the sphereof the Earth's attraction as to be kept there and turned into asatellite?"
"Well, that _is_ an original idea!" said Barbican with a smile.
"My ideas generally are of that category," observed Ardan with anaffectation of dry pomposity.
"Not this time, however, friend Michael," observed M'Nicholl.
"Oh! I'm a plagiarist, am I?" asked the Frenchman, pretending to beirritated.
"Well, something very like it," observed M'Nicholl quietly. "ApolloniusRhodius, as I read one evening in the Philadelphia Library, speaks ofthe Arcadians of Greece having a tradition that their ancestors were soancient that they inhabited the Earth long before the Moon had everbecome our satellite. They therefore called them [Greek: _Proselenoi_]or _Ante-lunarians_. Now starting with some such wild notion as this,certain scientists have looked on the Moon as an ancient comet broughtclose enough to the Earth to be retained in its orbit by terrestrialattraction."
"Why may not there be something plausible in such a hypothesis?" askedArdan with some curiosity.
"There is nothing whatever in it," replied Barbican decidedly: "a simpleproof is the fact that the Moon does not retain the slightest trace ofthe vaporous envelope by which comets are always surrounded."
"Lost her tail you mean," said Ardan. "Pooh! Easy to account for that!It might have got cut off by coming too close to the Sun!"
"It might, friend Michael, but an amputation by such means is not verylikely."
"No? Why not?"
"Because--because--By Jove, I can't say, because I don't know," criedBarbican with a quiet smile on his countenance.
"Oh what a lot of volumes," cried Ardan, "could be made out of what wedon't know!"
"At present, for instance," observed M'Nicholl, "I don't know whato'clock it is."
"Three o'clock!" said Barbican, glancing at his chronometer.
"No!" cried Ardan in surprise. "Bless us! How rapidly the time passeswhen we are engaged in scientific conversation! Ouf! I'm gettingdecidedly too learned! I feel as if I had swallowed a library!"
"I feel," observed M'Nicholl, "as if I had been listening to a lectureon Astronomy in the _Star_ course."
"Better stir around a little more," said the Frenchman; "fatigue of bodyis the best antidote to such severe mental labor as ours. I'll run upthe ladder a bit." So saying, he paid another visit to the upper portionof the Projectile and remained there awhile whistling _Malbrouk_, whilsthis companions amused themselves in looking through the floor window.
Ardan was coming down the ladder, when his whistling was cut short by asudden exclamation of surprise.
"What's the matter?" asked Barbican quickly, as he looked up and saw theFrenchman pointing to something outside the Projectile.
Approaching the window, Barbican saw with much surprise a sort offlattened bag floating in space and only a few yards off. It seemedperfectly motionless, and, consequently, the travellers knew that itmust be animated by the same ascensional movement as themselves.
"What on earth can such a consarn be, Barbican?" asked Ardan, who everynow and then liked to ventilate his stock of American slang. "Is it oneof those particles of meteoric matter you were speaking of just now,caught within the sphere of our Projectile's attraction and accompanyingus to the Moon?"
"What I am surprised at," observed the Captain, "is that though thespecific gravity of that body is far inferior to that of our Projectile,it moves with exactly the same velocity."
"Capt
ain," said Barbican, after a moment's reflection, "I know no morewhat that object is than you do, but I can understand very well why itkeeps abreast with the Projectile."
"Very well then, why?"
"Because, my dear Captain, we are moving through a vacuum, and becauseall bodies fall or move--the same thing--with equal velocity through avacuum, no matter what may be their shape or their specific gravity. Itis the air alone that makes a difference of weight. Produce anartificial vacuum in a glass tube and you will see that all objectswhatever falling through, whether bits of feather or grains of shot,move with precisely the same rapidity. Up here, in space, like cause andlike effect."
"Correct," assented M'Nicholl. "Everything therefore that we shall throwout of the Projectile is bound to accompany us to the Moon."
"Well, we _were_ smart!" cried Ardan suddenly.
"How so, friend Michael?" asked Barbican.
"Why not have packed the Projectile with ever so many useful objects,books, instruments, tools, et cetera, and fling them out into space oncewe were fairly started! They would have all followed us safely! Nothingwould have been lost! And--now I think on it--why not fling ourselvesout through the window? Shouldn't we be as safe out there as thatbolide? What fun it would be to feel ourselves sustained and upborne inthe ether, more highly favored even than the birds, who must keep onflapping their wings continually to prevent themselves from falling!"
"Very true, my dear boy," observed Barbican; "but how could we breathe?"
"It's a fact," exclaimed the Frenchman. "Hang the air for spoiling ourfun! So we must remain shut up in our Projectile?"
"Not a doubt of it!"
--"Oh Thunder!" roared Ardan, suddenly striking his forehead.
"What ails you?" asked the Captain, somewhat surprised.
"Now I know what that bolide of ours is! Why didn't we think of itbefore? It is no asteroid! It is no particle of meteoric matter! Nor isit a piece of a shattered planet!"
"What is it then?" asked both of his companions in one voice.
SATELLITE'S BODY FLYING THROUGH SPACE.]
"It is nothing more or less than the body of the dog that we threw outyesterday!"
So in fact it was. That shapeless, unrecognizable mass, melted,expunged, flat as a bladder under an unexhausted receiver, drained ofits air, was poor Satellite's body, flying like a rocket through space,and rising higher and higher in close company with the rapidly ascendingProjectile!