CHAPTER XIX 



PHYSIOGRAPHY, GEOLOGY, AND CLIMATE- 

 HEALTH AND DISEASE 



IT is not universally recognized that the 

 greater part of Africa is well above sea- 

 level, and usually rises from a narrow 

 low-lying coastal belt by terraces to plateaux 

 2000 to 4000 feet above the sea. 



Angola shares this conformation, and its 

 plateaux, 3000 to over 5000 feet high, form in 

 the east the Congo-Zambezi watershed, and to 

 the west that between the Coanza River in the 

 north and the Cubango and Cunene in the south. 

 From these watersheds flow many great rivers 

 which, while within a few miles of each other at 

 their source, are hundreds of miles apart at their 

 estuaries, and even enter different oceans. As 

 Mir slope of the land is abrupt to the west, and 

 gradual to north-east, the east to west flowing 

 rivers are usually small and rapid ; the excep- 

 tions are the Coanza, which is navigable for 

 steamers for only the last hundred miles of its 

 course, and the Cunene, which disappears in the 

 sand of the coastal desert before entering the sea. 



If the economic value of the rivers seems to 

 be HnyHerl, flint oi' some of the harbours is 



