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, 
dug out the sand beneath our feet in a second or two, and we 
were aU 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 gvavel 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 poundmg to which I refer, may be heard 
most distinctly in the Yaal Eiver, when that is sHghtly 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 vfllage of a head-man called Mosusa, a 
number of elephants took refuge on an island in the river. 
There were two males, and a thhd 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 tiU 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 
