38o DZUNGARIA 



enced, at the end of May, heavy rain-storms. It rained 

 continuously for twenty hours on one occasion, making 

 the country almost impossible for travelling, the rain- 

 storms creeping up from the west, and breaking across 

 the plains to the north, as frequently as they did on the 

 ranges to the south. 



Curiously enough, the north-western border-range — 

 the Altai — has reversed climatic conditions, the slopes 

 facing south-west, and not those facing north-east, 

 having the greater precipitation. Prof. Sapoznikoff, — 

 the most recent as well as the most trustworthy writer on 

 the Mongolian Altai, — says that, if the volumes of water 

 flowing off the two sides of the range be compared, it is 

 found that the flow of water from the south-west is by far 

 the greater, this proving to be an exception to the rule 

 generally accepted in regard to mountain-ranges in Inner 

 Asia, where the north side has usually the greater precipi- 

 tation. This contradiction is explained by the fact that 

 the spurs on the south-western slopes are longer and 

 higher than those on the north-east, and on this account 

 become the better condensers of the moisture. The cur- 

 rents of air from the west and north-west encounter these 

 outlying spurs and are relieved of their moisture ; thus 

 the precipitation on the farther side of the range is 

 greatly minimized. The result is that the forests and 

 pastures of the Dzungarian slopes of the Altai make 

 very favourable conditions for a nomadic life, while 

 the river-valleys grant facilities for future colonization. 

 The northern border-ranges of Dzungaria are, in 

 like manner, clothed with forests and grass, the lower 

 portions of the southern flanks alone being covered with 

 desert flora. 



It is this special factor in the climatic conditions of 



