F. Kingdon Ward — "Land of Deep Corrosions." 149 



Before passing on to a description of the country it will be first 

 necessary, for the sake of clearness, to say a few words about the 

 distribution of rainfall and wind over this region, for wliile the main 

 mountain ranges and valleys are clearly the result of crust movement, 

 other minor topographical features are us clearly the direct result of 

 local peculiarities in tlie distribution of these meteorological lactors. 



The prevailing wind is the south-west monsoon, which drenches 

 the many parallel mountain ridges between Assam and China from 



Fig. 1. The Yangtze in the arid region 

 looking south, from near Batang, 

 3,000 miles from its mouth. 



Fig. 2. The Salween Eiver in the arid region, 

 below La-kor-ah. 



May to October. In about latitude 28°, however, the three main 

 divides with which we are concerned receive such a considerable 

 uplift that the westernmost acts as a partial rain-screen to the next, 

 and so on. Thus there is, first, a high snowy range between the 

 head-waters of the Irrawaddy and the Salween, a second between 

 the Salween and the Mekong, and finally two isolated snow peaks 

 between the Mekong and the Yangtze, all in about the same latitude. 

 This sudden uplift of the Salween-Irrawaddy divide is sufficient 



