Eratosthenes soon disappeared from the horizon without the projectile having been sufficiently near it to allow a rigorous observation. This mountain separated the Apennines from the Carpathians. In lunar orography, several chains of mountains have been distinguished which are principally distributed over the northern hemisphere. Some, however, occupy certain portions of the southern hemisphere. The following is a list of these different chains, with their latitudes and the height of their highest summits:-- 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.