About 2 a.m.
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 .