SAND-KIVULET ZINGESI. 641 



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

 38' 34'< S., long. 31° V 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 clown 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 

 under ground." In trying to ford this I felt thousands of particles 

 of coarse sand striking my legs, and the slight disturbance of our 

 footsteps caused deep holes to be made in the bed. The water, 

 which is almost always very rapid in them, dug out the sand be- 

 neath 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 half way 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 thou- 

 sands 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 Yaal 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 



Ss 



