Page:Africa by Élisée Reclus, Volume 4.djvu/136

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SOUTH AND EAST AFRICA.

missionaries and by passing travellers are not sufficiently accurate, nor do they cover enough ground to decide the question whether during the present century there has been really a falling off in the supply of moisture in South Africa, or whether the distribution of the rainfall has merely become more irregular, so that long periods of drought and of rains alternate with more or less regular recurrence. The latter would seem to be the more probable view of the case. The destruction of the forests which has taken place in all the districts where colonists have settled, us well as the conflagrations which have been kindled by the cattle grazers, must have had the result of rendering the running waters much more irregular in their flow, and even changing many of them into mere spruits, or wadys. The tranquil

Fig. 33. — Rainfall of South Africa.

streams winding along well-defined channels have been largely replaced by the "wild waters" rushing suddenly in impetuous freshets down to the plains, and as suddenly leaving the fluvial beds again dry or swampy. The ground, swept of its grassy carpet and hardened by the sun, no longer absorbs the rain waters, which pass rapidly away without being of much avail for irrigation purposes. But during the half-century since regular observations have been taken at the Cape and at a few other meteorological stations in Austral Africa, no facts have been recorded at all pointing to any actual diminution of the rainfall, at least throughout the coastlands. On the contrary, many farmsteads formerly suffered from an insufficient supply on the upland plateaux, where at present, thanks to a careful