The course taken by the projectile, as we have before remarked, was bearing it towards the moon's northern hemisphere. The travellers were far from the central point which they would have struck, had their course not been subject to an irremediable deviation. It was past midnight; and Barbicane then estimated the distance at 750 miles, which was a little greater than the length of the lunar radius, and which would diminish as it advanced nearer to the North Pole. The projectile was then not at the altitude of the equator; but across the tenth parallel, and from that latitude, carefully taken on the map to the pole, Barbicane and his two companions were able to observe the moon under the most favourable conditions. Indeed, by means of glasses, the above named distance was reduced to little more than fourteen miles. The telescope of the Rocky Mountains brought the moon much nearer; but the terrestrial atmosphere singularly lessened its power. Thus Barbicane, posted in his projectile, with the glasses to his eyes, could seize upon details which were almost imperceptible to earthly observers.

"My friends," said the president, in a serious voice, "I do not know whither we are going; I do not know if we shall ever see the terrestrial globe again. Nevertheless, let us proceed as if our work would one day be useful to our fellow-men. Let us keep our minds free from every other consideration. We are astronomers; and this projectile is a room in the Cambridge University, carried into space. Let us make our observations!"

This said, work was begun with great exactness; and they faithfully reproduced the different aspects of the moon, at the different distances which the projectile reached.

At the time that the projectile was as high as the tenth parallel, north latitude, it seemed rigidly to follow the twentieth degree, east longitude. We must here make one important remark with regard to the map by which they were taking observations. In the selenographical maps where, on account of the reversing of the objects by the glasses, the south is above and the north below, it would seem natural that, on account of that inversion, the east should be to the left hand, and the west to the right. But it is not so. If the map were turned upside down, showing the moon as we see her, the east would be to the left, and the west to the right, contrary to that which exists on terrestrial maps. The following is the reason of this anomaly. Observers in the northern hemisphere (say in Europe) see the moon in the south, – according to them. When they take observations, they turn their backs to the north, the reverse position to that which they occupy when they study a terrestrial map. As they turn their backs to the north, the east is on their left, and the west to their right. To observers in the southern hemisphere (Patagonia for example), the moon's west would be quite to their left, and the east to their right, as the south is behind them. Such is the reason of the apparent reversing of these two cardinal points, and we must bear it in mind in order to be able to follow President Barbicane's observations.

With the help of Bœer and Moedler's Mappa Selenographica, the travellers were able at once to recognise that portion of the disc enclosed within the field of their glasses.

"What are we looking at, at this moment?" asked Michel.

"At the northern part of the 'Sea of Clouds,'" answered Barbicane. "We are too far off to recognize its nature. Are these plains composed of arid sand, as the first astronomer maintained? Or are they nothing but immense forests, according to M. Warren de la Rue's opinion, who gives the moon an atmosphere, though a very low and a very dense one? That we shall know by and by. We must affirm nothing until we are in a position to do so."

This "Sea of Clouds" is rather doubtfully marked out upon the maps. It is supposed that these vast plains are strewn with blocks of lava from the neighbouring volcanoes on its right, Ptolemy, Purbach, Arzachel. But the projectile was advancing, and sensibly nearing it. Soon there appeared the heights which bound this sea at this northern limit. Before them rose a mountain radiant with beauty, the top of which seemed lost in an eruption of solar rays.

"That is – ?" asked Michel.

"Copernicus," replied Barbicane.

"Let us see Copernicus."

This mount situated in 9° north latitude and 20° east longitude, rose to a height of 10,600 feet above the surface of the moon. It is quite visible from the earth; and astronomers can study it with ease, particularly during the phase between the last quarter and the new moon, because then the shadows are thrown lengthways from east to west, allowing them to measure the heights.

This Copernicus forms the most important of the radiating system, situated in the southern hemisphere, according to Tycho Brahé. It rises isolated like a gigantic lighthouse on that portion of the Sea of Clouds, which is bounded by the "Sea of Tempests," thus lighting by its splendid rays two oceans at a time. It was a sight without an equal, those long luminous trains, so dazzling in the full moon, and which, passing the boundary chain on the north, extends to the "Sea of Rains." At one o'clock of the terrestrial morning, the projectile, like a balloon borne into space, overlooked the top of this superb mountain. Barbicane could recognize perfectly its chief features. Copernicus is comprised in the series of ringed mountains of the first order, in the division of great circles. Like Kepler and Aristarchus, which overlook the Ocean of Tempests, sometimes it appeared like a brilliant point through the cloudy light, and was taken for a volcano in activity. But it is only an extinct one, – like all on that side of the moon. Its circumference showed a diameter of about twenty-two leagues. The glasses discovered traces of stratification produced by successive eruptions, and the neighbourhood was strewn with volcanic remains which still choked some of the craters.

"There exist," said Barbicane, "several kinds of circles on the surface of the moon, and it is easy to see that Copernicus belongs to the radiating class. If we were nearer, we should see the cones bristling on the inside, which in former times were so many fiery mouths. A curious arrangement, and one without an exception on the lunar disc, is that the interior surface of these circles is the reverse of the exterior, and contrary to the form taken by terrestrial craters. It follows, then, that the general curve of the bottom of these circles gives a sphere of a smaller diameter than that of the moon."

"And why this peculiar disposition?" asked Nicholl.

"We do not know," replied Barbicane.

"What splendid radiation!" said Michel. "One could hardly see a finer spectacle, I think."

"What would you say, then," replied Barbicane, "if chance should bear us towards the southern hemisphere?"

"Well, I should say that it was still more beautiful," retorted Michel Ardan.

At this moment the projectile hung perpendicularly over the circle. The circumference of Copernicus formed almost a perfect circle, and its steep escarpments were clearly defined. They could even distinguish a second ringed enclosure. Around spread a greyish plain, of a wild aspect, on which every relief was marked in yellow. At the bottom of the circle, as if enclosed in a jewel case, sparkled for one instant two or three eruptive cones, like enormous dazzling gems. Towards the north the escarpments were lowered by a depression which would probably have given access to the interior of the crater.

In passing over the surrounding plains, Barbicane noticed a great number of less important mountains; and among others a little ringed one called Guy Lussac, the breadth of which measured twelve miles.

Towards the south, the plain was very flat, without one elevation, without one projection. Towards the north, on the contrary, till where it was bounded by the Sea of Storms it resembled a liquid surface agitated by a storm, of which the hills and hollows formed a succession of waves suddenly congealed. Over the whole of this, and in all directions, lay the luminous lines, all converging to the summit of Copernicus.

The travellers discussed the origin of these strange rays; but they could not determine their nature any more than terrestrial observers.

"But why," said Nicholl, "should not these rays be simply spurs of mountains which reflect more vividly the light of the sun?"

"No," replied Barbicane; "if it was so, under certain conditions of the moon, these ridges would cast shadows, and they do not cast any."

And indeed, these rays only appeared when the orb of day was in opposition to the moon, and disappeared as soon as its rays became oblique.

"But how have they endeavoured to explain these lines of light?" asked Michel; "for I cannot believe that savants would ever be stranded for want of an explanation."

"Yes," replied Barbicane; "Herschel has put forward an opinion, but he did not venture to affirm it."

"Never mind. What was the opinion?"

"He thought that these rays might be streams of cooled lava which shone when the sun beat straight upon them. It may be so; but nothing can be less certain. Besides, if we pass nearer to Tycho, we shall be in a better position to find out the cause of this radiation."

"Do you know, my friends, what that plain, seen from the height we are at, resembles?" said Michel.

"No," replied Nicholl.

"Very well; with all those pieces of lava lengthened like rockets, it resembles an immense game of spelikans thrown pell-mell. There wants but the hook to pull them out one by one."

"Do be serious," said Barbicane.

"Well, let us be serious," replied Michel quietly; "and instead of spelikans, let us put bones. This plain would then be nothing but an immense cemetery, on which would repose the mortal remains of thousands of extinct generations. Do you prefer that high-flown comparison?"

"One is as good as the other," retorted Barbicane.

"My word, you are difficult to please," answered Michel.

"My worthy friend," continued the matter-of-fact Barbicane, "it matters but little what it resembles, when we do not know what it is."

"Well answered," exclaimed Michel. "That will teach me to reason with savants."

But the projectile continued to advance with almost uniform speed around the lunar disc. The travellers, we may easily imagine, did not dream of taking a moment's rest. Every minute changed the landscape which fled from beneath their gaze. About half-past one o'clock in the morning, they caught a glimpse of the tops of another mountain. Barbicane, consulting his map, recognized Eratosthenes.

It was a ringed mountain 9000 feet high, and one of those circles so numerous on this satellite. With regard to this, Barbicane related Kepler's singular opinion on the formation of circles. According to that celebrated mathematician, these crater-like cavities had been dug by the hand of man.

"For what purpose?" asked Nicholl.

"For a very natural one," replied Barbicane. "The Selenites might have undertaken these immense works and dug these enormous holes for a refuge and shield from the solar rays which beat upon them during fifteen consecutive days."

"The Selenites are not fools," said Michel.

"A singular idea," replied Nicholl; "but it is probable that Kepler did not know the true dimensions of these circles, for the digging of them would have been the work of giants quite impossible for the Selenites."

"Why? if weight on the moon's surface is six times less than on the earth?" said Michel.

"But if the Selenites are six times smaller?" retorted Nicholl.

"And if there are no Selenites?" added Barbicane.

This put an end to the discussion.

Soon Eratosthenes disappeared under the horizon without the projectile being sufficiently near to allow of close observation. This mountain separated the Apennines from the Carpathians. In the lunar orography they have discerned some chains of mountains, which are chiefly distributed over the northern hemisphere. Some, however, occupy certain portions of the southern hemisphere also.

About two o'clock in the morning Barbicane found that they were above the twentieth lunar parallel. The distance of the projectile from the moon was not more than 600 miles. Barbicane, now perceiving that the projectile was steadily approaching the lunar disc, did not despair, if of reaching her, at least of discovering the secrets of her configuration.

CHAPTER XIII.
LUNAR LANDSCAPES

At half-past two in the morning, the projectile was over the thirteenth lunar parallel and at the effective distance of 500 miles, reduced by the glasses to five. It still seemed impossible, however, that it could ever touch any part of the disc. Its motive speed, comparatively so moderate, was inexplicable to President Barbicane. At that distance from the moon it must have been considerable, to enable it to bear up against her attraction. Here was a phenomenon the cause of which escaped them again. Besides, time failed them to investigate the cause. All lunar relief was defiling under the eyes of the travellers, and they would not lose a single detail.

Under the glasses the disc appeared at the distance of five miles. What would an aeronaut, borne to this distance from the earth, distinguish on its surface? We cannot say, since the greatest ascension has not been more than 25,000 feet.

This, however, is an exact description of what Barbicane and his companions saw at this height. Large patches of different colours appeared on the disc. Selenographers are not agreed upon the nature of these colours. There are several, and rather vividly marked. Julius Schmidt pretends that, if the terrestrial oceans were dried up, a Selenite observer could not distinguish on the globe a greater diversity of shades between the oceans and the continental plains than those on the moon present to a terrestrial observer. According to him, the colour common to the vast plains known by the name of "seas" is a dark grey mixed with green and brown. Some of the large craters present the same appearance. Barbicane knew this opinion of the German selenographer, an opinion shared by Bœer and Moedler. Observation has proved that right was on their side, and not on that of some astronomers who admit the existence of only grey on the moon's surface. In some parts green was very distinct, such as springs, according to Julius Schmidt, from the seas of Serenity and Humours. Barbicane also noticed large craters, without any interior cones, which shed a bluish tint similar to the reflection of a sheet of steel freshly polished. These colours belonged really to the lunar disc, and did not result, as some astronomers say, either from the imperfection in the objective of the glasses or from the interposition of the terrestrial atmosphere.

Not a doubt existed in Barbicane's mind with regard to it, as he observed it through space, and so could not commit any optical error. He considered the establishment of this fact as an acquisition to science. Now, were these shades of green, belonging to tropical vegetation, kept up by a low dense atmosphere? He could not yet say.

Farther on, he noticed a reddish tint, quite defined. The same shade had before been observed at the bottom of an isolated enclosure, known by the name of Lichtenburg's circle, which is situated near the Hercynian mountains, on the borders of the moon; but they could not tell the nature of it.

They were not more fortunate with regard to another peculiarity of the disc, for they could not decide upon the cause of it.

Michel Ardan was watching near the president, when he noticed long white lines, vividly lighted up by the direct rays of the sun. It was a succession of luminous furrows, very different from the radiation of Copernicus not long before; they ran parallel with each other.

Michel, with his usual readiness, hastened to exclaim, – "Look there! cultivated fields!"

"Cultivated fields!" replied Nicholl, shrugging his shoulders.

"Ploughed, at all events," retorted Michel Ardan; "but what labourers those Selenites must be, and what giant oxen they must harness to their plough to cut such furrows!"

"They are not furrows," said Barbicane; "they are rifts."

"Rifts? stuff!" replied Michel mildly; "but what do you mean by 'rifts' in the scientific world?"

Barbicane immediately enlightened his companion as to what he knew about lunar rifts. He knew that they were a kind of furrow found on every part of the disc which was not mountainous; that these furrows, generally isolated, measured from 400 to 500 leagues in length; that their breadth varied from 1000 to 1500 yards, and that their borders were strictly parallel; but he knew nothing more either of their formation or their nature.

Barbicane, through his glasses, observed these rifts with great attention. He noticed that their borders were formed of steep declivities; they were long parallel ramparts, and with some small amount of imagination he might have admitted the existence of long lines of fortifications, raised by Selenite engineers. Of these different rifts some were perfectly straight, as if cut by a line; others were slightly curved, though still keeping their borders parallel; some crossed each other, some cut through craters; here they wound through ordinary cavities, such as Posidonius or Petavius; there they wound through the seas, such as the Sea of Serenity.

These natural accidents naturally excited the imaginations of these terrestrial astronomers. The first observations had not discovered these rifts. Neither Hevelius, Cassim, La Hire, nor Herschel seemed to have known them. It was Schroeter who in 1789 first drew attention to them. Others followed who studied them, as Pastorff, Gruithuysen, Bœer, and Moedler. At this time their number amounts to seventy; but, if they have been counted, their nature has not yet been determined; they are certainly not fortifications, any more than they are the ancient beds of dried-up rivers; for, on one side, the waters, so slight on the moon's surface, could never have worn such drains for themselves; and, on the other, they often cross craters of great elevation.

We must, however, allow that Michel Ardan had "an idea," and that, without knowing it, he coincided in that respect with Julius Schmidt.

"Why," said he, "should not these unaccountable appearances be simply phenomena of vegetation?"

"What do you mean?" asked Barbicane quickly.

"Do not excite yourself, my worthy president," replied Michel; "might it not be possible that the dark lines forming that bastion were rows of trees regularly placed?"

"You stick to your vegetation, then?" said Barbicane.

"I like," retorted Michel Ardan, "to explain what you savants cannot explain; at least my hypothesis has the advantage of indicating why these rifts disappear, or seem to disappear, at certain seasons."

"And for what reason?"

"For the reason that the trees become invisible when they lose their leaves, and visible when they regain them."

"Your explanation is ingenious, my dear companion," replied Barbicane, "but inadmissible."

"Why?"

"Because, so to speak, there are no seasons on the moon's surface, and that, consequently, the phenomena of vegetation of which you speak cannot occur."

Indeed, the slight obliquity of the lunar axis keeps the sun at an almost equal height in every latitude. Above the equatorial regions the radiant orb almost invariably occupies the zenith, and does not pass the limits of the horizon in the polar regions; thus, according to each region, there reigns a perpetual winter, spring, summer, or autumn, as in the planet Jupiter, whose axis is but little inclined upon its orbit.

What origin do they attribute to these rifts? That is a question difficult to solve. They are certainly anterior to the formation of craters and circles, for several have introduced themselves by breaking through their circular ramparts. Thus it may be that, contemporary with the latter geological epochs, they are due to the expansion of natural forces.

But the projectile had now attained the 40° of lunar lat., at a distance not exceeding 400 miles. Through the glasses objects appeared to be only four miles distant.

At this point, under their feet, rose Mount Helicon, 1520 feet high, and round about the left rose moderate elevations, enclosing a small portion of the "Sea of Rains," under the name of the Gulf of Iris. The terrestrial atmosphere would have to be one hundred and seventy times more transparent than it is, to allow astronomers to make perfect observations on the moon's surface; but in the void in which the projectile floated no fluid interposed itself between the eye of the observer and the object observed. And more, Barbicane found himself carried to a greater distance than the most powerful telescopes had ever done before, either that of Lord Rosse or that of the Rocky Mountains. He was, therefore, under extremely favourable conditions for solving that great question of the habitability of the moon; but the solution still escaped him; he could distinguish nothing but desert beds, immense plains, and towards the north, arid mountains. Not a work betrayed the hand of man; not a ruin marked his course; not a group of animals was to be seen indicating life, even in an inferior degree. In no part was there life, in no part was there an appearance of vegetation. Of the three kingdoms which share the terrestrial globe between them, one alone was represented on the lunar and that the mineral.

"Ah, indeed!" said Michel Ardan, a little out of countenance; "then you see no one?"

"No," answered Nicholl; "up to this time not a man, not an animal, not a tree! After all, whether the atmosphere has taken refuge at the bottom of cavities, in the midst of the circles, or even on the opposite face of the moon, we cannot decide."

"Besides," added Barbicane, "even to the most piercing eye a man cannot be distinguished farther than three miles and a half off; so that, if there are any Selenites, they can see our projectile, but we cannot see them."

Towards four in the morning, at the height of the fiftieth parallel, the distance was reduced to 300 miles. To the left ran a line of mountains capriciously shaped, lying in the full light. To the right, on the contrary, lay a black hollow resembling a vast well, unfathomable and gloomy, drilled into the lunar soil.

This hole was the "Black Lake;" it was Pluto, a deep circle which can be conveniently studied from the earth, between the last quarter and the new moon, when the shadows fall from west to east.

This black colour is rarely met with on the surface of the satellite. As yet it has only been recognized in the depths of the circle of Endymion, to the east of the Cold Sea, in the northern hemisphere, and at the bottom of Grimaldi's circle, on the equator, towards the eastern border of the orb.

Pluto is an annular mountain, situated in 51° north latitude, and 9° east longitude. Its circuit is forty-seven miles long and thirty-two broad.

Barbicane regretted that they were not passing directly above this vast opening. There was an abyss to fathom, perhaps some mysterious phenomenon to surprise; but the projectile's course could not be altered. They must rigidly submit. They could not guide a balloon, still less a projectile, when once enclosed within its walls. Towards five in the morning the northern limits of the Sea of Rains was at length passed. The mounts of Condamine and Fontenelle remained – one on the right, the other on the left. That part of the disc beginning with 60° was becoming quite mountainous. The glasses brought them to within two miles, less than that separating the summit of Mont Blanc from the level of the sea. The whole region was bristling with spikes and circles. Towards the 60° Philolaus stood predominant at a height of 5550 feet with its elliptical crater, and seen from this distance, the disc showed a very fantastical appearance. Landscapes were presented to the eye under very different conditions from those on the earth, and also very inferior to them.

The moon having no atmosphere, the consequences arising from the absence of this gaseous envelope have already been shown. No twilight on her surface; night following day and day following night with the suddenness of a lamp which is extinguished or lighted amidst profound darkness, – no transition from cold to heat, the temperature falling in an instant from boiling point to the cold of space.

Another consequence of this want of air is that absolute darkness reigns where the sun's rays do not penetrate. That which on earth is called diffusion of light, that luminous matter which the air holds in suspension, which creates the twilight and the daybreak, which produces the umbræ and the penumbræ, and all the magic of chiaro-oscuro, does not exist on the moon. Hence the harshness of contrasts, which only admit of two colours, black and white. If a Selenite were to shade his eyes from the sun's rays, the sky would seem absolutely black, and the stars would shine to him as on the darkest night. Judge of the impression produced on Barbicane and his three friends by this strange scene! Their eyes were confused. They could no longer grasp the respective distances of the different plains. A lunar landscape without the softening of the phenomena of chiaro-oscuro could not be rendered by an earthly landscape painter: it would be spots of ink on a white page – nothing more.

This aspect was not altered even when the projectile, at the height of 80°, was only separated from the moon by a distance of fifty miles; nor even when, at five in the morning, it passed at less than twenty-five miles from the mountain of Gioja, a distance reduced by the glasses to a quarter of a mile. It seemed as if the moon might be touched by the hand! It seemed impossible that, before long, the projectile would not strike her, if only at the north pole, the brilliant arch of which was so distinctly visible on the black sky.

Michel Ardan wanted to open one of the scuttles and throw himself on to the moon's surface! A very useless attempt; for if the projectile could not attain any point whatever of the satellite, Michel, carried along by its motion, could not attain it either.

At that moment, at six o'clock, the lunar pole appeared. The disc only presented to the travellers' gaze one half brilliantly lit up, whilst the other disappeared in the darkness. Suddenly the projectile passed the line of demarcation between intense light and absolute darkness, and was plunged in profound night!