deg. deg. metres.
Mounts Doerfel 84 to 0 S. lat. 7,603
" Leibnitz 65 " 0 " 7,600
" Rook 20 " 30 " 1,600
" Altai 17 " 28 " 4,047
" Cordilleras 10 " 20 " 3,898
" Pyrenees 8 " 18 " 3,631
" Oural 5 " 13 " 838
" Alembert 4 " 10 " 5,847
" Hoemus 8 " 21 N. lat. 2,021
" Carpathians 15 " 19 " 1,939
" Apennines 14 " 27 " 5,501
" Taurus 21 " 28 " 2,746
" Riphees 25 " 33 " 4,171
" Hercynians 17 " 29 " 1,170
" Caucasia 32 " 41 " 5,567
" Alps 42 " 49 " 3,617
The most important of these different chains is that of the Apennines, the development of which extends 150 leagues, and is yet inferior to that of the great orographical movements of the earth. The Apennines run along the eastern border of the Sea of Rains, and are continued on the north by the Carpathians, the profile of which measures about 100 leagues.
The travellers could only catch a glimpse of the summit of these Apennines which lie between west long. 10° and east long. 16°; but the chain of the Carpathians was visible from 18° to 30° east long., and they could see how they were distributed.
One hypothesis seemed to them very justifiable. Seeing that this chain of the Carpathians was here and there circular in form and with high peaks, they concluded that it anciently formed important amphitheatres. These mountainous circles must have been broken up by the vast cataclysm to which the Sea of Rains was due. These Carpathians looked then what the amphitheatres of Purbach, Arzachel, and Ptolemy would if some cataclysm were to throw down their left ramparts and transform them into continuous chains. They present an average height of 3,200 metres, a height comparable to certain of the Pyrenees. Their southern slopes fall straight into the immense Sea of Rains.
About 2 a.m. Barbicane was at the altitude of the 20th lunar parallel, not far from that little mountain, 1,559 metres high, which bears the name of Pythias. The distance from the projectile to the moon was only 1,200 kilometres, brought by means of telescopes to two and a half leagues.
The "Mare Imbrium" lay before the eyes of the travellers like an immense depression of which the details were not very distinct. Near them on the left rose Mount Lambert, the altitude of which is estimated at 1,813 metres, and farther on, upon the borders of the Ocean of Tempests, in north lat. 23° and east long. 29°, rose the shining mountain of Euler. This mountain, which rises only 1,815 metres above the lunar surface, has been the object of an interesting work by the astronomer Schroeter. This savant, trying to find out the origin of the lunar mountains, asked himself whether the volume of the crater always looked equal to the volume of the ramparts that formed it. Now this he found to be generally the case, and he hence concluded that a single eruption of volcanic matter had sufficed to form these ramparts, for successive eruptions would have destroyed the connection. Mount Euler alone was an exception to this general law, and it must have taken several successive eruptions to form it, for the volume of its cavity is double that of its inclosure.
All these hypotheses were allowable to terrestrial observers whose instruments were incomplete; but Barbicane was no longer contented to accept them, and seeing that his projectile drew regularly nearer the lunar disc he did not despair of ultimately reaching it, or at least of finding out the secrets of its formation.
CHAPTER XIII.
LUNAR LANDSCAPES.
At half-past two in the morning the bullet was over the 30th lunar parallel at an effective distance of 1,000 kilometres, reduced by the optical instruments to ten. It still seemed impossible that it could reach any point on the disc. Its movement of translation, relatively slow, was inexplicable to President Barbicane. At that distance from the moon it ought to have been fast in order to maintain it against the power of attraction. The reason of that phenomenon was also inexplicable; besides, time was wanting to seek for the cause. The reliefs on the lunar surface flew beneath their eyes, and they did not want to lose a single detail.