All Around the Moon Part 21

After _Tycho_, which is situated in the southern hemisphere, _Copernicus_ forms the most important radiating mountain in the lunar disc. It looms up, single and isolated, like a gigantic light-house, on the peninsula separating _Mare Nubium_ from _Ocea.n.u.s Procellarum_ on one side and from _Mare Imbrium_ on the other; thus illuminating with its splendid radiation three "Seas" at a time. The wonderful complexity of its bright streaks diverging on all sides from its centre presented a scene alike splendid and unique. These streaks, the travellers thought, could be traced further north than in any other direction: they fancied they could detect them even in the _Mare Imbrium_, but this of course might be owing to the point from which they made their observations. At one o'clock in the morning, the Projectile, flying through s.p.a.ce, was exactly over this magnificent mountain.

In spite of the brilliant sunlight that was blazing around them, the travellers could easily recognize the peculiar features of _Copernicus_.

It belongs to those ring mountains of the first cla.s.s called Circuses.

Like _Kepler_ and _Aristarchus_, who rule over _Ocea.n.u.s Procellarum_, _Copernicus_, when viewed through our telescopes, sometimes glistens so brightly through the ashy light of the Moon that it has been frequently taken for a volcano in full activity. Whatever it may have been once, however, it is certainly nothing more now than, like all the other mountains on the visible side of the Moon, an extinct volcano, only with a crater of such exceeding grandeur and sublimity as to throw utterly into the shade everything like it on our Earth. The crater of Etna is at most little more than a mile across. The crater of _Copernicus_ has a diameter of at least 50 miles. Within it, the travellers could easily discover by their gla.s.ses an immense number of terraced ridges, probably landslips, alternating with stratifications resulting from successive eruptions. Here and there, but particularly in the southern side, they caught glimpses of shadows of such intense blackness, projected across the plateau and lying there like pitch spots, that they could not tell them from yawning chasms of incalculable depth. Outside the crater the shadows were almost as deep, whilst on the plains all around, particularly in the west, so many small craters could be detected that the eye in vain attempted to count them.

"Many circular mountains of this kind," observed Barbican, "can be seen on the lunar surface, but _Copernicus_, though not one of the greatest, is one of the most remarkable on account of those diverging streaks of bright light that you see radiating from its summit. By looking steadily into its crater, you can see more cones than mortal eye ever lit on before. They are so numerous as to render the interior plateau quite rugged, and were formerly so many openings giving vent to fire and volcanic matter. A curious and very common arrangement of this internal plateau of lunar craters is its lying at a lower level than the external plains, quite the contrary to a terrestrial crater, which generally has its bottom much higher than the level of the surrounding country. It follows therefore that the deep lying curve of the bottom of these ring mountains would give a sphere with a diameter somewhat smaller than the Moon's."

"What can be the cause of this peculiarity?" asked M'Nicholl.

"I can't tell;" answered Barbican, "but, as a conjecture, I should say that it is probably to the comparatively smaller area of the Moon and the more violent character of her volcanic action that the extremely rugged character of her surface is mainly due."

"Why, it's the _Campi Phlegraei_ or the Fire Fields of Naples over again!" cried Ardan suddenly. "There's _Monte Barbaro_, there's the _Solfatara_, there is the crater of _Astroni_, and there is the _Monte Nuovo_, as plain as the hand on my body!"

"The great resemblance between the region you speak of and the general surface of the Moon has been often remarked;" observed Barbican, "but it is even still more striking in the neighborhood of _Theophilus_ on the borders of _Mare Nectaris_."

"That's _Mare Nectaris_, the gray spot over there on the southwest, isn't it?" asked M'Nicholl; "is there any likelihood of our getting a better view of it?"

"Not the slightest," answered Barbican, "unless we go round the Moon and return this way, like a satellite describing its...o...b..t."

By this time they had arrived at a point vertical to the mountain centre. _Copernicus's_ vast ramparts formed a perfect circle or rather a pair of concentric circles. All around the mountain extended a dark grayish plain of savage aspect, on which the peak shadows projected themselves in sharp relief. In the gloomy bottom of the crater, whose dimensions are vast enough to swallow Mont Blanc body and bones, could be distinguished a magnificent group of cones, at least half a mile in height and glittering like piles of crystal. Towards the north several breaches could be seen in the ramparts, due probably to a caving in of immense ma.s.ses acc.u.mulated on the summit of the precipitous walls.

As already observed, the surrounding plains were dotted with numberless craters mostly of small dimensions, except _Gay Lussac_ on the north, whose crater was about 12 miles in diameter. Towards the southwest and the immediate east, the plain appeared to be very flat, no protuberance, no prominence of any kind lifting itself above the general dead level.

Towards the north, on the contrary, as far as where the peninsula jutted on _Ocea.n.u.s Procellarum_, the plain looked like a sea of lava wildly lashed for a while by a furious hurricane and then, when its waves and breakers and driving ridges were at their wildest, suddenly frozen into solidity. Over this rugged, rumpled, wrinkled surface and in all directions, ran the wonderful streaks whose radiating point appeared to be the summit of _Copernicus_. Many of them appeared to be ten miles wide and hundreds of miles in length.

The travellers disputed for some time on the origin of these strange radii, but could hardly be said to have arrived at any conclusion more satisfactory than that already reached by some terrestrial observers.

To M'Nicholl's question:

"Why can't these streaks be simply prolonged mountain crests reflecting the sun's rays more vividly by their superior alt.i.tude and comparative smoothness?"

Barbican readily replied:

"These streaks _can't_ be mountain crests, because, if they were, under certain conditions of solar illumination they should project _shadows_--a thing which they have never been known to do under any circ.u.mstances whatever. In fact, it is only during the period of the full Moon that these streaks are seen at all; as soon as the sun's rays become oblique, they disappear altogether--a proof that their appearance is due altogether to peculiar advantages in their surface for the reflection of light."

"Dear boys, will you allow me to give my little guess on the subject?"

asked Ardan.

His companions were profuse in expressing their desire to hear it.

"Well then," he resumed, "seeing that these bright streaks invariably start from a certain point to radiate in all directions, why not suppose them to be streams of lava issuing from the crater and flowing down the mountain side until they cooled?"

"Such a supposition or something like it has been put forth by Herschel," replied Barbican; "but your own sense will convince you that it is quite untenable when you consider that lava, however hot and liquid it may be at the commencement of its journey, cannot flow on for hundreds of miles, up hills, across ravines, and over plains, all the time in streams of almost exactly equal width."

"That theory of yours holds no more water than mine, Ardan," observed M'Nicholl.

"Correct, Captain," replied the Frenchman; "Barbican has a trick of knocking the bottom out of every weaker vessel. But let us hear what he has to say on the subject himself. What is your theory. Barbican?"

"My theory," said Barbican, "is pretty much the same as that lately presented by an English astronomer, Nasmyth, who has devoted much study and reflection to lunar matters. Of course, I only formulate my theory, I don't affirm it. These streaks are cracks, made in the Moon's surface by cooling or by shrinkage, through which volcanic matter has been forced up by internal pressure. The sinking ice of a frozen lake, when meeting with some sharp pointed rock, cracks in a radiating manner: every one of its fissures then admits the water, which immediately spreads laterally over the ice pretty much as the lava spreads itself over the lunar surface. This theory accounts for the radiating nature of the streaks, their great and nearly equal thickness, their immense length, their inability to cast a shadow, and their invisibility at any time except at or near the Full Moon. Still it is nothing but a theory, and I don't deny that serious objections may be brought against it."

"Do you know, dear boys," cried Ardan, led off as usual by the slightest fancy, "do you know what I am thinking of when I look down on the great rugged plains spread out beneath us?"

"I can't say, I'm sure," replied Barbican, somewhat piqued at the little attention he had secured for his theory.

"Well, what are you thinking of?" asked M'Nicholl.

"Spillikins!" answered Ardan triumphantly.

"Spillikins?" cried his companions, somewhat surprised.

"Yes, Spillikins! These rocks, these blocks, these peaks, these streaks, these cones, these cracks, these ramparts, these escarpments,--what are they but a set of spillikins, though I acknowledge on a grand scale? I wish I had a little hook to pull them one by one!"

[Ill.u.s.tration: AN IMMENSE BATTLEFIELD.]

"Oh, do be serious, Ardan!" cried Barbican, a little impatiently.

"Certainly," replied Ardan. "Let us be serious, Captain, since seriousness best befits the subject in hand. What do you think of another comparison? Does not this plain look like an immense battle field piled with the bleaching bones of myriads who had slaughtered each other to a man at the bidding of some mighty Caesar? What do you think of that lofty comparison, hey?"

"It is quite on a par with the other," muttered Barbican.

"He's hard to please, Captain," continued Ardan, "but let us try him again! Does not this plain look like--?"

"My worthy friend," interrupted Barbican, quietly, but in a tone to discourage further discussion, "what you think the plain _looks like_ is of very slight import, as long as you know no more than a child what it really _is_!"

"Bravo, Barbican! well put!" cried the irrepressible Frenchman. "Shall I ever realize the absurdity of my entering into an argument with a scientist!"

But this time the Projectile, though advancing northward with a pretty uniform velocity, had neither gained nor lost in its nearness to the lunar disc. Each moment altering the character of the fleeting landscape beneath them, the travellers, as may well be imagined, never thought of taking an instant's repose. At about half past one, looking to their right on the west, they saw the summits of another mountain; Barbican, consulting his map, recognized _Eratosthenes_.

This was a ring mountain, about 33 miles in diameter, having, like _Copernicus_, a crater of immense profundity containing central cones.

Whilst they were directing their gla.s.ses towards its gloomy depths, Barbican mentioned to his friends Kepler's strange idea regarding the formation of these ring mountains. "They must have been constructed," he said, "by mortal hands."

"With what object?" asked the Captain.

"A very natural one," answered Barbican. "The Selenites must have undertaken the immense labor of digging these enormous pits at places of refuge in which they could protect themselves against the fierce solar rays that beat against them for 15 days in succession!"

"Not a bad idea, that of the Selenites!" exclaimed Ardan.

"An absurd idea!" cried M'Nicholl. "But probably Kepler never knew the real dimensions of these craters. Barbican knows the trouble and time required to dig a well in Stony Hill only nine hundred feet deep. To dig out a single lunar crater would take hundreds and hundreds of years, and even then they should be giants who would attempt it!"

"Why so?" asked Ardan. "In the Moon, where gravity is six times less than on the Earth, the labor of the Selenites can't be compared with that of men like us."

"But suppose a Selenite to be six times smaller than a man like us!"

urged M'Nicholl.

"And suppose a Selenite never had an existence at all!" interposed Barbican with his usual success in putting an end to the argument. "But never mind the Selenites now. Observe _Eratosthenes_ as long as you have the opportunity."

"Which will not be very long," said M'Nicholl. "He is already sinking out of view too far to the right to be carefully observed."

"What are those peaks beyond him?" asked Ardan.