94? STEPPES AND DESERTS. 



Having thus described the four great mountain systems 

 of Asia, which in their normal geognostic character are 

 chains coinciding with parallels of latitude, I have next to 

 speak of the series of elevations coinciding nearly with meri- 

 dians, (or more precisely, having a SSE.-NNW. direction), 

 M r hich, from Cape Comorin opposite to the Island of Ceylon 

 to the Icy Sea, alternate between the meridians of 66 and 

 77 E. long, from Greenwich. To this system, of which 

 the alternations remind us of faults in veins, belong the 

 Ghauts, the Soliman chain, the Paralasa, the Bolor, and the 

 Ural. The interruptions of the series of elevations are so 

 arranged that, beside their alternate position in respect to 

 longitude, each new chain begins in a degree of latitude to 

 which the preceding chain had not quite reached. The im- 

 portance which the Greeks (although probably not before 

 the second century) attached to these chains induced Aga- 

 thodemon and Ptolemy (Tab. vii. and viii.) to represent to 

 themselves the Bolor, under the name of Imaus, as an axis 

 of elevation extending as far as 62 N. lat. into the low 

 basin of the Lower Irtisch and the Obi. (Asie Centrale, 

 T. i. p. 138, 154, and 198; T. ii. p. 367.) 



As the perpendicular elevation of mountain summits 

 above the level of the sea (unimportant as in the eyes of the 

 geologist the circumstance of the greater or lesser corruga- 

 tion of the crust of the earth may be), is still, like all that is 

 difficult of attainment, an object of popular curiosity, the 

 following historical notice of the gradual progress of hypso- 

 metric knowledge may here find a suitable place. When I 

 returned to Europe in 1804 after a four years' absence, not 

 a single Asiatic snowy summit either in the Himalaya, the 



