James Fox Wilson visited South Africa in the early eighteen-sixties. Subsequently he delivered a paper, "On the increasing desiccation of inner southern Africa", at the annual meeting of the British Association for the Advancement of Science in 1864. The paper, or a closely related one, was published as "On the progressing desiccation of the basin of the Orange River in southern Africa" in the Proceedings of the Royal Geographical Society of London (1864-1865). The next year Wilson published a paper on "Water supply in the basin of the River Orange, or Gariep, South Africa" in the Journal of the Royal Geographical Society (1865, Vol. 35, pp. 106-129) . He provided extensive qualitative evidence that southern Africa was gradually drying up, and identified veld burning, overstocking, and trekking from one waterhole to another as the main causes. To address the problem he recommended the damming of smaller streams and the encouragement of appropriate vegetation to reduce evaporation.
The belief that central southern Africa was becoming dryer persisted for many decades. For example, in an editorial review of local desertification, published in the Agricultural Journal of the Union of South Africa in 1912, Wilson's paper is cited as having proved beyond doubt that the Kalahari is drying up. The belief was gradually disproved by rainfall records. For schemes to improve the rainfall of the Kalahari see F. Gessert* and E.H.L. Schwarz*.
