THE DESICCATFON OF AFRICA. 189 



be indefinitely to enlarge the vast Okavango-Kwando swamp- 

 land : a region of almost indescribable dismalness, absolutely 

 useless for any purpose, and \ery unhealthy. 



Now there appears to be considerable misapprehension in 

 regard to the Northern Kalahari. Much the greater part of this 

 alleged desert is well timbered and grassed, and is, in the opinion 

 of competent judges, admirabl}- adapted to cattle-ranching. The 

 only obstacles to the settlement of t'he area, apart from its 

 inaccessibility, are the lack of surface water during the greater 

 part of the year and its iinhealthy character in the rainy season. 



In regard to the first oif these obstacles, I am convinced that 

 water could be obtained by putting down boreholes through the 

 thick mantle of sand with which the whole region is covered, 

 seeing that the average annual rainfall over the area probably 

 exceeds 20 inches, while tlie run-off is nil. It is also relevant to 

 observe that excellent supplies of artesian water have been struck 

 in the eastern part oi the Southern Kalahari in the Protectorate 

 of South-West Africa. In regard to the second obstacle, t^e 

 climate of the Northern Kalahari, except in the neighbourhood of 

 the Okavango swampland, is probably not more unhealthy than 

 that of other malarial regions in Southern and South-Western 

 Africa wbich have been successfully colonised. 



Professor Schwarz's barrage, in addition to permanently 

 destroying enormous areas of this potentially valuable ranching 

 country would render equally large areas so unhealthy as to be 

 uninhabitable by Europeans, and as the benefits to be derived, 

 judging by wdiat we have heard from Messrs. Kanthack and 

 Stewart, are very problematical, it appears to me that this boldly 

 conceived scheme, though appealing powenfully to the imagina- 

 tion, is in fact quite impracticable. 



Dr. A. L. Du ToiT, B.A., F.G.S., Government Geologist, 

 said that the course of the Proto-Orange across the Kalahari, as 

 advocated by Professor Schwarz, receives considerable geological 

 support, and there are also indications that the damming back oif 

 the drainage over the N'Gami region may have been brought 

 about by gentle unwarping along an east-west line through the 

 Central Kalahari, this action provoking the capture of the waters 

 of the S3^stem by the more active young Zambesi on the east. Such 

 a tilting movement might not yet have ceased, and its continuance 

 might be an important influence in diverting the waters of the 

 depression towards the north even at the present day. Presuming 

 that there was originally a great body of water in this hollow, 

 it does not necessarily follow that the area was any more fertile 

 in the past than to-day. for it is important to observe that in 

 almost all the continental masses there are, on their western 

 shores or just within their western interiors at about t'he Tropics, 

 extensive areas over which desert or semi-arid conditions prevail. 



A most important point is the magnitude of the evaporative 

 losses from such a large body of water. Taking evaporation at 

 about 8 feet per annum, the loss would be equivalent to about 



