86 STEPPES AND DESERTS. 



This interruption of the mountain chain, caused by the transverse 

 intersection of the Gobi, continues for more than 9 degrees of 

 longitude ; but beyond it the mountains recommence in the somewhat 

 more southerly chain of the In*schan, or the Silver Mountains, 

 running (north of the Pe-tscheli) from west to east, almost to the 

 shores of the Pacific near Pekin, and forming a continuation of the 

 Thian-schan. As I have viewed the In-schan as an easterly pro- 

 longation (beyond the interruption of the Gobi) of the cleft above 

 which the Thian-schan stands, so one might possibly view the 

 Caucasus as a westerly prolongation of the same, beyond the great 

 basin of the Aral and Caspian Seas, or the depression of Turan. 

 The mean parallel of latitude or axis of elevation of the Thian- 

 schan oscillates between 40f and 43 N. lat.; that of the Cau- 

 casus, according to the map of the Russian Etat-Major (running 

 rather BSE. and WNW,), is between 41 and 44 north lat. 

 (Baron von Meyendorff, in the Bulletin de la Soci^te" Gologique 

 de France, t. ix. 1837-1838, p. 230.) Of the four parallel chains 

 which traverse Asia from east to west, the Thian-schan is the only 

 one in which no summits have yet had their elevation above the sea 

 determined by measurement. 



3. The mountain system of the Kuen-liin (Kurkun or Kulkun), 

 if we include it in the Hindu-Coosh and its Western prolongation in 

 the Persian Elbourz and Demavend, is, next to the American Cor- 

 dillera of the Andes, the longest line of elevation on the surface of 

 our planet. Where the north-and-south chain of Bolor intersects 

 the Kuen-liin at right angles, the latter takes the name of the 

 Thsung-ling (Onion Mountains), which is also given to a part of the 

 Bolor at the eastern angle of intersection. The Kuen-liin, forming 

 the northern boundary of Thibet, runs very regularly in an east and 

 west direction, in the latitude of 36. In the meridian of H'lassa, 

 an interruption takes place from the great mountain knot which sur- 

 rounds the alpine lake of Khuku-noor, the Sing-so-hai, or Starry Sea, 

 so celebrated in the mythical geography of the Chinese. The some- 

 what more northerly chains of Nan-schan and Kilian-schan may 

 almost be regarded as an easterly prolongation of the Thian-schan. 

 They extend to the Chinese wall near Liang-tscheu. West of the 

 intersection of the Bolor and Kufen-liin (the Thsung-ling), I think 



