378 



ELEMEXTS OF DIRECTION. 



CHATTF.R 

 X-WIII. 



Area of tlie 

 Altai Koly- 

 vau. 



Cuhninatlnj 

 points. 



Direction of 

 strata. 



riements of 

 direction. 



tiferous region forms only the third part of the Altai, 

 properly so called. The area of the Altai Kolyvan is 

 ahout 4400 square leagues, nearly equal to that of 

 England. The direction of its mean axis is from west 

 to east, and, with the exception of its eastern side, it is 

 surrounded by low regions, — a peculiarity the more re- 

 markable, that, at a distance of twenty-five leagues, the 

 Alps of Tigratzki and the Korgou rise rapidly to 7000 

 feet, and at the distance of fifty or sixty leagues, the 

 Alps of Bieloukha rise to the height of 10,300 feet above 

 the sea. The culminating points of this system lie in 

 the second meridional range, a little to the east of the 

 sources of the Ouimon, where, between the snowy Alps 

 of Katunia and the Tchouya, the majestic peak of Bie- 

 loukha rises to the height of 10,300 feet. This inacces- 

 sible mountain has two horns entirely covered with snow, 

 the westernmost being the highest. A glacier similar to 

 those in Switzerland, and terminated by huge and ancient 

 moraines, gives birth to the river Katunia. The two next 

 highest summits are the Alas-tou and the Irbis-tou, 

 thirty or forty leagues farther to the east. After stating 

 that in the Altai the mean direction of the schistoze 

 strata is not, as in the Ural Mountains, parallel to the 

 mean direction of the whole chain, our author discusses 

 this curious subject with his usual perspicuity and learn- 

 ing, and points out the necessity of distinguishing, what 

 have been so often confounded, the various elements of 

 direction, ^we in number, which exist in every mountain 

 chain. These elements are — 



" 1. The longitudinal axis of the entire chain, or of 

 the upheaved mass. 



"2. The line of ridge passing through its highest 

 points. 



" 3. The line which follows the fissures of stratification. 



"4. The watershed, or the line which divides the 

 waters. 



" 6. The line which separates, in horizontal sections, 

 two contiguous formations ; for example, the granite 



