May 6, 1920] 



NATURE 



299 



70,000 square miles from the condition of a 

 tropical swamp, similar to the Bahr-el-Ghazal, into 

 a wilderness of dead trees and withered grass has 

 had a very bad effect on the climate of South 

 Africa, and the consequences are noticeable north 

 as well as south of the Zambezi; the completion 

 of the process is a matter of a few years only. 

 What has happened in Ovamboland occurred in 

 the Makarikari a hundred years ago, and in the 

 central Kalahari not so very long before that ; so, 

 section by section, this great area has lost its 

 water-supply, and between 300,000 and 400,000 

 square miles of country have become desert within 

 comparatively recent times. 



The spillways from the Cunene on one side, and 

 those from the Okavango on the other, connect in 

 the great depression to the south, the Etosha Pan. 

 This is a "floor," like the Soa and Ntwetwe Pans, 

 only here there is no trace of brak, the level pan being 



Fi(i. 3. - Cambele Ca aract, I'unene Kiver. 



covered with a dark green film due to microscopic 

 plants which turn a yellowish-green when moist- 

 ' ned with water from a thunderstorm. Very little 

 water finds its way into the pan down the river 

 channels nowadays. The grass flats round the 

 pan are some 5 ft. above the level of the floor, 

 and are often black with zebras, wildebeests, 

 gemsbok, koodoos, and springbok, with the at- 

 tendant lions. The late Mr. J. W. F. Breijer was 

 game ranger at the time of my visit, and it is 

 due to his tireless efforts to suppress poaching 

 that the game has returned to the district ; to him 

 also I owe the tracing of the Lion River, a spill- 

 way from the Okavango to the Etosha, thus 

 completing the through connection of the Cunene 

 and Okavango rivers. 



The restoration of the Kalahari and Ovambo- 

 land plains by weiring up the outlets on the north 

 and turning the waters of the Cunene on one hand, 

 and of the Okavango and Chobe rivers on the 

 NO. 2636, VOL. 105] 



other, would convert these countries into habitable 

 regions once more. Both rivers are necessary, for 

 the one reinforces the other. Ovamboland would 

 be converted into a swamp, a condition of affairs 

 which the natives are accustomed to and thrive on ; 

 as it is, they are always on the verge of starvation, 

 and in 191 5-1 6 thousands did die of starvation, and 

 their bones are strewn for 200 miles along the 

 road from Ondongua to Tsumeb, the terminus of 

 the railway, where they had expected to get food 

 and work. Ovamboland is not suitable for white 

 settlement, but from the evaporation from this 

 vast swamp the rivers, like the Zambezi and Oka- 

 vango, would be reinforced at their sources, and 

 their diminishing volume converted into an in- 

 creasing one. The Kalahari, on the other hand, 

 is eminently suited for white settlement; with 

 water anything will grow ; cotton is indigenous 

 and would form the summer crop as in Egypt; 

 wheat grows as a winter crop, 

 and mealies (maize) as an autumn 

 one. Away from the actual irri- 

 gation furrows the ranching pos- 

 sibilities are enormous. The 

 country is now nominally under 

 Beehuana chiefs ; but, while every 

 consideration can be paid to their 

 wants, a meagre population of 

 150,000 natives cannot indefin- 

 itely hold up a country of 300,000 

 square miles. White settlement 

 could proceed without interfering 

 in any way with the natives, as 

 there is room enough for all. 



The effect on the climate of 

 South Africa is another matter. 

 We know that hippopotamus 

 swarmed all over the Karroo 

 in not very distant times, for 

 their bones are dug up all 

 over it in the dry river-beds. 

 Before the Makarikari went 

 dry in 1820, Barrow, Lichten- 

 stein, and Le Vaillant described 

 finding hippopotamus in enormous quantities 

 in typical Karroo country like Cookhouse, and 

 the banks of the rivers were clothed with sub- 

 tropical forest, in which roamed rhinoceros, ele- 

 phant, eland, etc. The Karroo within the last 

 120 years, in the eastern portion, was a country 

 similar in flora and fauna to British East Africa. 

 Would the restoration of the Kalahari affect the 

 Karroo? The lost lakes formed the end of the 

 series of great lakes in Central Africa, and the 

 function of these latter is to provide moisture for 

 the inland regions. The central areas of Africa 

 lie so high that moisture blown in from the sea is 

 dropped on the edge by the diminution of pressure, 

 and very little is left for the centre from these 

 sources. With the Kalahari lakes restored and the 

 vegetation once more established, it seems reason- 

 able to suppose that the effect will be the same as 

 that produced by the great northern lakes on their 

 neighbouring regions. 



