by Jules Verne
CHAPTER XII.
OROGRAPHIC DETAILS.
The course taken by the projectile, as we have before remarked, wasbearing it towards the moon's northern hemisphere. The travellers werefar from the central point which they would have struck, had their coursenot been subject to an irremediable deviation. It was past midnight; andBarbicane then estimated the distance at 750 miles, which was a littlegreater than the length of the lunar radius, and which would diminishas it advanced nearer to the North Pole. The projectile was then notat the altitude of the equator; but across the tenth parallel, and fromthat latitude, carefully taken on the map to the pole, Barbicane and histwo companions were able to observe the moon under the most favourableconditions. Indeed, by means of glasses, the above named distance wasreduced to little more than fourteen miles. The telescope of the RockyMountains brought the moon much nearer; but the terrestrial atmospheresingularly lessened its power. Thus Barbicane, posted in his projectile,with the glasses to his eyes, could seize upon details which were almostimperceptible to earthly observers.
"My friends," said the president, in a serious voice, "I do not knowwhither we are going; I do not know if we shall ever see the terrestrialglobe again. Nevertheless, let us proceed as if our work would one daybe useful to our fellow-men. Let us keep our minds free from every otherconsideration. We are astronomers; and this projectile is a room in theCambridge University, carried into space. Let us make our observations!"
This said, work was begun with great exactness; and they faithfullyreproduced the different aspects of the moon, at the different distanceswhich 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, eastlongitude. We must here make one important remark with regard to the mapby which they were taking observations. In the selenographical maps where,on account of the reversing of the objects by the glasses, the southis above and the north below, it would seem natural that, on account ofthat inversion, the east should be to the left hand, and the west to theright. But it is not so. If the map were turned upside down, showing themoon 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 followingis the reason of this anomaly. Observers in the northern hemisphere(say in Europe) see the moon in the south,-- according to them. Whenthey take observations, they turn their backs to the north, the reverseposition to that which they occupy when they study a terrestrial map. Asthey turn their backs to the north, the east is on their left, and thewest to their right. To observers in the southern hemisphere (Patagoniafor example), the moon's west would be quite to their left, and the eastto their right, as the south is behind them. Such is the reason of theapparent reversing of these two cardinal points, and we must bear it inmind in order to be able to follow President Barbicane'sobservations.
With the help of Boeer and Moedler's _Mappa Selenographica_, the travellerswere able at once to recognise that portion of the disc enclosed withinthe 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. "Weare too far off to recognize its nature. Are these plains composed ofarid sand, as the first astronomer maintained? Or are they nothing butimmense forests, according to M. Warren de la Rue's opinion, who givesthe moon an atmosphere, though a very low and a very dense one? That weshall know by and by. We must affirm nothing until we are in a positionto do so."
This "Sea of Clouds" is rather doubtfully marked out upon the maps. Itis supposed that these vast plains are strewn with blocks of lava fromthe neighbouring volcanoes on its right, Ptolemy, Purbach, Arzachel.But the projectile was advancing, and sensibly nearing it. Soon thereappeared the heights which bound this sea at this northern limit. Beforethem rose a mountain radiant with beauty, the top of which seemed lostin an eruption of solar rays.
"That is--?" asked Michel.
"Copernicus," replied Barbicane.
"Let us see Copernicus."
This mount situated in 9 deg. north latitude and 20 deg. east longitude,rose to a height of 10,600 feet above the surface of the moon. It isquite visible from the earth; and astronomers can study it with ease,particularly during the phase between the last quarter and the newmoon, 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, situatedin the southern hemisphere, according to Tycho Brahe. It rises isolatedlike a gigantic lighthouse on that portion of the Sea of Clouds, which isbounded by the "Sea of Tempests," thus lighting by its splendid rays twooceans at a time. It was a sight without an equal, those long luminoustrains, so dazzling in the full moon, and which, passing the boundarychain on the north, extends to the "Sea of Rains." At one o'clock of theterrestrial morning, the projectile, like a balloon borne into space,overlooked the top of this superb mountain. Barbicane could recognizeperfectly its chief features. Copernicus is comprised in the series ofringed 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 extinctone,--like all on that side of the moon. Its circumference showed adiameter of about twenty-two leagues. The glasses discovered traces ofstratification produced by successive eruptions, and the neighbourhoodwas strewn with volcanic remains which still choked some of the craters.
"There exist," said Barbicane, "several kinds of circles on the surfaceof the moon, and it is easy to see that Copernicus belongs to theradiating class. If we were nearer, we should see the cones bristling onthe inside, which in former times were so many fiery mouths. A curiousarrangement, and one without an exception on the lunar disc, is thatthe 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 ofa 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 finerspectacle, I think."
"What would you say, then," replied Barbicane, "if chance should bear ustowards the southern hemisphere?"
"Well, I should say that it was still more beautiful," retorted MichelArdan.
At this moment the projectile hung perpendicularly over the circle. Thecircumference of Copernicus formed almost a perfect circle, and its steepescarpments were clearly defined. They could even distinguish a secondringed enclosure. Around spread a greyish plain, of a wild aspect, onwhich 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 threeeruptive cones, like enormous dazzling gems. Towards the north theescarpments were lowered by a depression which would probably have givenaccess to the interior of the crater.
In passing over the surrounding plains, Barbicane noticed a great numberof less important mountains; and among others a little ringed one calledGuy 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 itwas bounded by the Sea of Storms it resembled a liquid surface agitatedby a storm, of which the hills and hollows formed a succession of wavessuddenly congealed. Over the whole of this, and in all directions, laythe luminous lines, all converging to the summit of Copernicus.
The travellers discussed the origin of these strange rays; but they couldnot determine their nature any more than terrestrial observers.
"But why," said Nicholl, "should not these rays be simply spurs ofmountains which reflect more vividly the light of the sun?"
"No," replied Barbicane; "if it was so, under certain conditions of th
emoon, these ridges would cast shadows, and they do not cast any."
And indeed, these rays only appeared when the orb of day was in oppositionto the moon, and disappeared as soon as its rays became oblique.
"But how have they endeavoured to explain these lines of light?" askedMichel; "for I cannot believe that savants would ever be stranded forwant of an explanation."
"Yes," replied Barbicane; "Herschel has put forward an opinion, but hedid not venture to affirm it."
"Never mind. What was the opinion?"
"He thought that these rays might be streams of cooled lava which shonewhen the sun beat straight upon them. It may be so; but nothing canbe less certain. Besides, if we pass nearer to Tycho, we shall be in abetter position to find out the cause of this radiation."
Illustration: "THIS PLAIN WOULD THEN BE NOTHING BUT AN IMMENSE CEMETERY."
"Do you know, my friends, what that plain, seen from the height we areat, resembles?" said Michel.
"No," replied Nicholl.
"Very well; with all those pieces of lava lengthened like rockets, itresembles an immense game of spelikans thrown pell-mell. There wants butthe hook to pull them out one by one."
"Do be serious," said Barbicane.
"Well, let us be serious," replied Michel quietly; "and instead ofspelikans, let us put bones. This plain would then be nothing but animmense cemetery, on which would repose the mortal remains of thousandsof 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 mattersbut little what it _resembles_, when we do not know what it _is_."
"Well answered," exclaimed Michel. "That will teach me to reason withsavants."
But the projectile continued to advance with almost uniform speed aroundthe lunar disc. The travellers, we may easily imagine, did not dream oftaking a moment's rest. Every minute changed the landscape which fledfrom beneath their gaze. About half-past one o'clock in the morning, theycaught a glimpse of the tops of another mountain. Barbicane, consultinghis map, recognized Eratosthenes.
It was a ringed mountain 9000 feet high, and one of those circles sonumerous on this satellite. With regard to this, Barbicane relatedKepler's singular opinion on the formation of circles. According to thatcelebrated mathematician, these crater-like cavities had been dug by thehand of man.
"For what purpose?" asked Nicholl.
"For a very natural one," replied Barbicane. "The Selenites might haveundertaken these immense works and dug these enormous holes for a refugeand shield from the solar rays which beat upon them during fifteenconsecutive days."
"The Selenites are not fools," said Michel.
"A singular idea," replied Nicholl; "but it is probable that Kepler didnot know the true dimensions of these circles, for the digging of themwould 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 theearth?" 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 projectilebeing sufficiently near to allow of close observation. This mountainseparated the Apennines from the Carpathians. In the lunar orography theyhave discerned some chains of mountains, which are chiefly distributedover the northern hemisphere. Some, however, occupy certain portions ofthe southern hemisphere also.
About two o'clock in the morning Barbicane found that they were above thetwentieth lunar parallel. The distance of the projectile from the moonwas not more than 600 miles. Barbicane, now perceiving that the projectilewas steadily approaching the lunar disc, did not despair, if of reachingher, at least of discovering the secrets of her configuration.
