"But don't you think, Barbican," asked the Captain, "that every force, internal or external, that might modify the Moon's shape, has ceased long ago?"
"I am rather inclined to that opinion," said Barbican; "it is not, however, a new one. Descartes maintained that as the Earth is an extinct Sun, so is the Moon an extinct Earth. My own opinion at present is that the Moon is now the image of death, but I can't say if she has ever been the abode of life."
"The abode of life!" cried Ardan, who had great repugnance in accepting the idea that the Moon was no better than a heap of cinders and ashes; "why, look there! If those are not as neat a set of the ruins of an abandoned city as ever I saw, I should like to know what they are!"
He pointed to some very remarkable rocky formations in the neighborhood of Short, a ring mountain rising to an altitude considerably higher than that of Mont Blanc. Even Barbican and M'Nicholl could detect some regularity and semblance of order in the arrangement of these rocks, but this, of course, they looked on as a mere freak of nature, like the Lurlei Rock, the Giant's Causeway, or the Old Man of the Franconia Mountains. Ardan, however, would not accept such an easy mode of getting rid of a difficulty.
"See the ruins on that bluff," he exclaimed; "those steep sides must have been washed by a great river in the prehistoric times. That was the fortress. Farther down lay the city. There are the dismantled ramparts; why, there's the very coping of a portico still intact! Don't you see three broken pillars lying beside their pedestals? There! a little to the left of those arches that evidently once bore the pipes of an aqueduct! You don't see them? Well, look a little to the right, and there is something that you can see! As I'm a living man I have no difficulty in discerning the gigantic butments of a great bridge that formerly spanned that immense river!"
Did he really see all this? To this day he affirms stoutly that he did, and even greater wonders besides. His companions, however, without denying that he had good grounds for his assertion on this subject or questioning the general accuracy of his observations, content themselves with saying that the reason why they had failed to discover the wonderful city, was that Ardan's telescope was of a strange and peculiar construction. Being somewhat short-sighted, he had had it manufactured expressly for his own use, but it was of such singular power that his companions could not use it without hurting their eyes.
But, whether the ruins were real or not, the moments were evidently too precious to be lost in idle discussion. The great city of the Selenites soon disappeared on the remote horizon, and, what was of far greater importance, the distance of the Projectile from the Moon's disc began to increase so sensibly that the smaller details of the surface were soon lost in a confused mass, and it was only the lofty heights, the wide craters, the great ring mountains, and the vast plains that still continued to give sharp, distinctive outlines.
A little to their left, the travellers could now plainly distinguish one of the most remarkable of the Moon's craters, Newton, so well known to all lunar astronomers. Its ramparts, forming a perfect circle, rise to such a height, at least 22,000 feet, as to seem insurmountable.
"You can, no doubt, notice for yourselves," said Barbican, "that the external height of this mountain is far from being equal to the depth of its crater. The enormous pit, in fact, seems to be a soundless sea of pitchy black, the bottom of which the Sun's rays have never reached. There, as Humboldt says, reigns eternal darkness, so absolute that Earth-shine or even Sunlight is never able to dispel it. Had Michael's friends the old mythologists ever known anything about it, they would doubtless have made it the entrance to the infernal regions. On the whole surface of our Earth, there is no mountain even remotely resembling it. It is a perfect type of the lunar crater. Like most of them, it shows that the peculiar formation of the Moon's surface is due, first, to the cooling of the lunar crust; secondly, to the cracking from internal pressure; and, thirdly, to the violent volcanic action in consequence. This must have been of a far fiercer nature than it has ever been with us. The matter was ejected to a vast height till great mountains were formed; and still the action went on, until at last the floor of the crater sank to a depth far lower than the level of the external plain."
"You may be right," said Ardan by way of reply; "as for me, I'm looking out for another city. But I'm sorry to say that our Projectile is increasing its distance so fast that, even if one lay at my feet at this moment, I doubt very much if I could see it a bit better than either you or the Captain."
Newton was soon passed, and the Projectile followed a course that took it directly over the ring mountain Moretus. A little to the west the travellers could easily distinguish the summits of Blancanus, 7,000 feet high, and, towards seven o'clock in the evening, they were approaching the neighborhood of Clavius.
This walled-plain, one of the most remarkable on the Moon, lies 55° S. by 15° E. Its height is estimated at 16,000 feet, but it is considered to be about a hundred and fifty miles in diameter. Of this vast crater, the travellers now at a distance of 250 miles, reduced to 2-1/2 by their telescopes, had a magnificent bird's-eye view.
"Our terrestrial volcanoes," said Barbican, "as you can now readily judge for yourselves, are no more than molehills when compared with those of the Moon. Measure the old craters formed by the early eruptions of Vesuvius and Ætna, and you will find them little more than three miles in diameter. The crater of Cantal in central France is only about six miles in width; the famous valley in Ceylon, called the Crater, though not at all due to volcanic action, is 44 miles across and is considered to be the greatest in the world. But even this is very little in comparison to the diameter of Clavius lying beneath us at the present moment."
"How much is its diameter?" asked the Captain.
"At least one hundred and forty-two miles," replied Barbican; "it is probably the greatest in the Moon, but many others measure more than a hundred miles across."
"Dear boys," said Ardan, half to himself, half to the others, "only imagine the delicious state of things on the surface of the gentle Moon when these craters, brimming over with hissing lava, were vomiting forth, all at the same time, showers of melted stones, clouds of blinding smoke, and sheets of blasting flame! What an intensely overpowering spectacle was here presented once, but now, how are the mighty fallen! Our Moon, as at present beheld, seems to be nothing more than the skinny spectre left after a brilliant display of fireworks, when the spluttering crackers, the glittering wheels, the hissing serpents, the revolving suns, and the dazzling stars, are all 'played out', and nothing remains to tell of the gorgeous spectacle but a few blackened sticks and half a dozen half burned bits of pasteboard. I should like to hear one of you trying to explain the cause, the reason, the principle, the philosophy of such tremendous cataclysms!"
Barbican's only reply was a series of nods, for in truth he had not heard a single word of Ardan's philosophic explosion. His ears were with his eyes, and these were obstinately bent on the gigantic ramparts of Clavius, formed of concentric mountain ridges, which were actually leagues in depth. On the floor of the vast cavity, could be seen hundreds of smaller craters, mottling it like a skimming dish, and pierced here and there by sharp peaks, one of which could hardly be less than 15,000 feet high.
All around, the plain was desolate in the extreme. You could not conceive how anything could be barrener than these serrated outlines, or gloomier than these shattered mountains—until you looked at the plain that encircled them. Ardan hardly exaggerated when he called it the scene of a battle fought thousands of years ago but still white with the hideous bones of overthrown peaks, slaughtered mountains and mutilated precipices!
"Hills amid the air encountered hills,
Hurled to and fro in jaculation dire,"
murmured M'Nicholl, who could quote you Milton quite as readily as the Bible.
"This must have been the spot," muttered Barbican to himself, "where the brittle shell of the cooling sphere, being thicker than usual, offered greater resistance to an eruption of the red-hot nucleus. Hence these piled up buttresses, and these orderless heaps of consolidated lava and ejected scoriæ."
The Projectile advanced, but the scene of desolation seemed to remain unchanged.