402 



LUNAR MOUNTAIN KANGES. 



CHAPTEP. 

 XXVIIL 



Mountain, 

 lauges. 



Forms of 

 mountaiu 

 lidges. 



Mure 

 lUibiium. 



for notice ; although, if I mistake not, hy their very con- 

 trariety with what surrounds us, these will, in some in- 

 stances, throw light on problems regarding the structure 

 of our globe, which have hitherto baffled inquirers. 



" IMountain ranges, or chains, are by no means want- 

 ing in the moon, although a glance at the map will show 

 that they are not a chief feature among the elevations of 

 that body. Their general position is a sort of circular 

 but broken skirt of the greater flats or plains. For in- 

 stance, the Apennines, the Caucasus, and the Alps, form- 

 ing, in fragments of a ring, one edge of the Mare Im- 

 brium. Some of these reach a great elevation ; the 

 Apennines rising from eighteen to twenty thousand feet 

 — much higher than Mont Blanc ; and there is another 

 ridge, on the very rim of the moon, which appears to 

 rival the gigantic Andes or Himalaya. There are two 

 sets of phenomena connected with these lunar ranges, 

 bearing so closely on some theories regarding similar 

 terrestrial forms, that I am induced to specify them. 



" We find here, as on the earth, that the ridge is uni- 

 formly extremely steep on one side, — descending to the 

 plain through abrupt precipices, or a succession of abrupt 

 terraces, while thej' slope away, as ours do also, on the 

 other side, through an extensive and gently declining 

 highland. The Lunar Apennines and the Asiatic Hima- 

 laya are illustrations of this singular fact, of about equal 

 force. But the moon unfolds something more : the 

 aljrupt face of the mountain chain is uniformly towards 

 the plain. This is very distinct in the case of the Mare 

 Jmbriuni ; and we find the same with regard to every 

 other plain, such as the Mare Serenitatis. Turn now to 

 the earth. Suppose the vast Pacific drained of its 

 waters, and that the Indian and Southern Oceans had 

 become dry land ; that would be a mighty flat or low 

 land, broken only as the lunar plains are broken — here 

 and there by a ridge — a crater, and group of mountains ; 

 but observe its edge ! Skirted on one side by the preci- 

 pitous faces of the Andes and Rocky Mountains ; and on 



