THE DRYING UP 209 



We passed over some broken country and 

 then reached a more or less level plateau, 

 which seemed to extend almost to the river. 

 Anon we crossed the ancient bed of what had 

 once been a tributary river. It was as dry as 

 the Bone-Valley of Ezekiel. Yet undoubtedly 

 water had flowed therein, continuously, and 

 that not so very long before. The course was 

 full of deep, water-rounded drift. It was this 

 kind of thing that brought home to one the 

 circumstance that a great change in the 

 direction of aridity must have taken place in 

 South Africa within a comparatively short 

 period. It was clear that not long previously 

 this valley had carried a constantly-flowing 

 stream, one that took its source from the 

 great T'Oums range. The latter, not more 

 than ten miles away, was now arid as a heap 

 of cinders. 



As we approached the river the naked and 

 enormous ramparts of the Great Namaqua- 

 land Mountains came more and more into 

 evidence. They seemed to spring sheer from 

 the narrow strip of forest at the water side. 

 From a distance the upper strata appeared to 

 be of black basalt. The purple mystery which 

 so richly filled their vast chasms was a feast 

 to the eye. 



N 



