4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I42 



tude 1,000 to 1,500 meters, and still farther east is the Yellow River at 

 an altitude of 500 meters. In the central west is Sikang, with an alti- 

 tude of 4,000 meters. Crossing the "Szechwan Alps" to the east, we 

 arrive at the Chengtu plain and the Red Basin, with an altitude of 

 300 to 600 meters. Across the Tapa Shan range, in the lower Yangtse 

 Valley, the altitude is only a little above sea level. On the southwest 

 we begin with the plain west of Talifu, where the altitude is 4,000 

 meters. East of this is the Yunnan plateau, with an altitude of 2,000 

 to 2,500 meters. This plateau includes several lake basins, some 

 dry and some full of water, and several river valleys. Crossing the 

 mountains on the Yunnan-Kweichow border, we reach the Kweichow 

 plain, varying in altitude from 750 to 2,000 meters. Farther east are 

 Hunan and Kuangsi, with an average altitude of 500 meters. 



The climate of West China is strongly influenced by the altitude, 

 the latitude, the oceans, and the mountain ranges. Szechwan is 

 bounded by mountain ranges on all sides. On the west the "Szech- 

 wan Alps" act as rainsheds, so that the land farther west is much 

 dryer than that of Szechwan Province. In the winter it is very cold 

 and very dry, and but little snow falls. What does fall is evaporated 

 by the dry air and never causes floods by melting, even in Tibet. 

 The floods of the Yangtse River are caused by the summer monsoon 

 rains in the Red Basin and the Chengtu plain and on the east side 

 of the "Szechwan Alps." 



The two ranges of mountains to the north of Szechwan, the Ching- 

 ling Shan and the Tapa Shan, completely shut off the cold winter 

 winds from Kansu and Shensi. That part of the Tapa Shan range on 

 the east and the mountains on the borders of Kweichow and Yunnan 

 Provinces on the south completely shut out the strong, tempestuous 

 winds from the east and the south, so that Szechwan has no cyclones 

 and no severe windstorms. On the other hand, these mountains are 

 not high enough to shut out the moisture-bearing air and clouds, so 

 that Szechwan enjoys a comparatively abundant rainfall. Further- 

 more, enough moisture enters Szechwan from the outside so that, 

 with the natural evaporation of the moisture from the soil, the skies 

 are cloudy nearly every day. The clouds prevent too rapid evaporation 

 of the moisture from the soil and hold in the heat so that the winters 

 are not so cold as to the north, the south, and the east. There are few 

 severe frosts and little snow, and ice seldom forms on the surface of 

 the water. 



The soil of the Chengtu plain is rich alluvium deposited by the 

 Min River — rich soil carried down in the summer from the moun- 



