TEEN-SHAN MOUNTAINS. 



361 



India, which is lower. The plains in the neighbour- 

 hood of the lake Balkachi have not an elevation of 

 more than 1920 feet above the sea. 



Between the meridians of Oust-Kamenogorskand 

 Semipolatinsk the Altaic system is prolonged, from 

 east to west under the parallels of 49 and 50 degrees, 

 by a chain of low mountains, over an extent of 736 

 miles, as far as the steppe of the Kirghiz. This ridge 

 has been elevated through a fissure which forms the 

 line of separation of the streams of the Sara-sou and 

 Irtisch, and which regularly follows the same direc- 

 tion over an extent of 16 degrees of longitude. It 

 consists of stratified granites not intermixed with 

 gneiss, and of greenstone, porphyry, jasper, and tran- 

 sition-limestone, in which there occur various me- 

 tallic substances. This low range does not reach 

 the southern extremity of the Ural, a chain which, 

 like the Andes, presents a long wall running north 

 and south, with metallic mines on its eastern slope, 

 but terminates abruptly in the meridian of Sverino- 

 govloskoi. 



Here commences a remarkable region of lakes, 

 comprising the group of Balek-koul (lat. 51° 30'), 

 and that of Koumkoul (lat. 49° 45'), indicating an 

 ancient communication of a mass of water with the 

 lake Ak-sakal, which receives the Tourgai and the 

 Kamichloi Irghiz, as well as with the lake Aral; 

 and which would seem from Chinese accounts to 

 have formed part of a great plain extending to the 

 borders of the Frozen Sea. 



2. System of Teen-shan. — The mean latitude of 

 this system is the 42d degree. Its highest summit 

 is perhaps the mass of mountains covered with per- 

 petual snow, and celebrated under the name of 

 Bokhda-ovla, from which Pallas gave the designation 

 of Bogdo to the whole chain. From Bokhda-ovla 

 and Khatoun-bokhda, the Teen-shan mountains run 

 eastward towards Bar-koul, where they are suddenly 

 lowered so as to fall to the level of the elevated 

 Hh 



