598 SAND-RIVULET ZINGESI. Chap. XXIX. 



zinkwa's we came to the Zingesi, a sand rivulet in flood (lat. 15° 

 38' 34" S., long. 31° 1' E.). It was sixty or seventy yards wide, 

 and waist-deep. Like all these sand-rivers, it is for the most 

 part dry ; but by digging down a few feet, water is to be found, 

 which is percolating along the bed on a stratum of clay. This 

 is the phenomenon which is dignified by the name of " a river 

 flowing underground." In trying to ford this I felt thousands 

 of particles of coarse sand striking my legs, and the slight dis- 

 turbance of our footsteps caused deep holes to be made in the 

 bed. The water, which is almost always very rapid in them, 

 du<r out the sand beneath our feet in a second or two, and we 

 were all sinking by that means so deep, that we were glad to 

 relinquish the attempt to ford it before we got halfway over; 

 the oxen were carried away down into the Zambesi. These 

 sand-rivers remove vast masses of disintegrated rock before it is 

 fine enough to form soil. The man who preceded me was only 

 thigh-deep, but the disturbance caused by his feet made it breast- 

 deep for me. The shower of particles and gravel which struck 

 against my legs, gave me the idea that the amount of matter 

 removed by every freshet must be very great. In most rivers 

 where much wearing is going on, a person diving to the bottom 

 may hear literally thousands of stones knocking against each 

 other. This attrition, being carried on for hundreds of miles in 

 different rivers, must have an effect greater than-if all the pestles 

 and mortars and mills of the world, were grinding and wearing 

 away the rocks. The pounding to which I refer, may be heard 

 most distinctly in the Vaal River, when that is slightly in flood. 

 It was there I first heard it. In the Leeambye in the middle of 

 the country, where there is no discoloration and little carried 

 along but sand, it is not to be heard. 



While opposite the village of a head-man called Mosusa, a 

 number of elephants took refuge on an island in the river. 

 There were two males, and a third not full-grown, indeed 

 scarcely the size of a female. This was the first instance I had 

 ever seen of a comparatively young one with the males, for they 

 usually remain with the female herd till as large as their dams. 

 The inhabitants were very anxious that my men should attack 

 them, as they go into the gardens on the islands, and do much 

 damage. The men went, but the elephants ran about half a 



