puksidext's address. 31 



as it flows on ; till at last, after a course of a few days' journey, it is 

 lost in the sands and entirely disappears." In 1907 the open water 

 disappeared near Tsenin, about 40 miles from Kurunian, but the water 

 was being used for irrigation at many places on the way. A very good 

 description of the conditions in 1907 will be found in a paper, " Bechuana- 

 land from the Irrigation Standpoint," by Mr. F. E. Kanthack, in the 

 Agricultural Journal, Capetown, for the last four months of 1909. This 

 paper contains many interesting observations on subjects other than the 

 general water resources, such as the effect of the nature of the soil on 

 run-off, and a critical account of the popular impressions of the behaviour 

 of the Molopo. 



(77) Mr. T. G. Trevor, who has a wider personal experience of the 

 Transvaal, extending over 30 years, than any other friend of mine, is 

 sure of this general decrease in water. He writes : "I have gone into 

 the matter very carefully and am satisfied that the loss of available water 

 has gone on not only in the inhabited districts but everywhere, and is 

 not entirely due to surface erosion, as it is relatively as well marked in 

 wilderness and uninhaliited districts as in the occupied areas." 



Mr. W. H. Gilfillan, a former Surveyor General in the Transvaal, 

 tells me tliat the Waterberg, which he has known since 1886, has not, in his 

 opinion, had its water resources diminished during that period, but that 

 drainage and cuttings to fountains have lowered the water level at places. 



The practice of irrigation must have altered the normal conditions of 

 many rivers in the country by withdrawing water from the upper valleys 

 systematically The use at Pretoria of some 5 million gallons a day from 

 the springs which once fed Aapies River is another instance of the same 

 kind. 



A description of the Sand River, O.F.S. , by Zeyher, the botanist, is 

 of interest : " The Sand River which we found exceedingly difficult in 

 fording, on account of its steep banks and the great masses of shifting 

 sand. . . . Although there was only a small stream of water running in 

 its channel, the high and abruptly steep banks of that river showed 

 evidently that it had been a formidable gulf and a barrier." Hooker's 

 London Journal of Botany, vol. VII, p. 327, and on p. 328, " The channel 

 of tlie Falsrivier lies more than 100 feet deep, between banks." It is 

 hardly necessary to note that deep channels do not imply that permanently 

 deep rivers occupied them at any period. I have to thank Dr. Schonland 

 for telling me of Zeyher's narrative, and Dr. Haughton for looking it 

 up and abstracting paragraphs in Capetown. 



Arbrousset, " Relation d'un Voyage au Nord-Est de la Colonic du 

 Cap," etc., Paris, 1842, p. 149, writing of Basutoland in 1836, says : 

 " The Orange River is, like the Caledon, subject to periodical floods which 

 happen three or four times between the end of November and the middle 

 of April, the first flood usually lasting ten or twelve days, the two or 

 three others five or six weeks.'" 



(78) Passarge, " Suedafrika," p. 153. Chapters XV and XVI of that 

 book have an excellent summary of the topography of the region and a 

 discussion of change of climate; see also "Die Kalahari," p. 490. 



(79) E. H. L. Schwarz, " The Kalahari- and Ovamboland," Nature, 

 May 16th, 1920. The sudden opening of the gorge is entirely at variance 

 with the description of the bevelling and of the increasing length of the 

 tributaries and their adjustment to the water level in the gorge written 

 by Mr. G. W. Lamplugh'; Geol. Mag., Dec. 1905; Rep. Brit. Assoc, 1905; 

 Geographical Journal, Feb. and March, 1908. 



(80) Griffith Taylor, "Climatic Cycles and Evolution," The Geographic 

 Review. Dec, 1919." 



