48 TRAVELS IN 
fine-grained blue sand, and it generally exceeded a hundred 
yards in width ; but the collected streamlets, creeping over 
its surface, would scarcely have furnished a quantity of water 
sufficient to turn a mill. The rivers that cross the Karroo have 
this difference, which distinguishes them from rivers in gene- 
ral, that, notwithstanding all the tributary streamlets that may 
fall into them, the greater the distance from the source the 
less water they contain. As it seldom rains on the desert, 
they have no supply but from the springs ; and the water, in 
its passage from these, is continually losing of its bulk both 
by absorption and by evaporation. Though the surrounding 
country was destitute of vegetation, a thick forest of mimosas 
covered the banks of the Dwyka, and followed it through all 
its windings. This plant grows indeed on every part of the 
desert, on which it is the inseparable companion of all the 
rivers and all the periodical streamlets. Should a traveller 
happen to be in want of water, the appearance of the mimosa 
is a sure guide to the place where it occasionally at least is 
to be found. 
On the evening of the nineteenth we encamped upon the 
banks of the Ghanika, or Lion's river. Its distance from the 
Dwyka is about twenty miles of the most beautiful road I ever 
beheld. There was neither stone nor loose sand, nor rut, to 
break the equality of the surface, which was level as that of a 
bowling-green, and consisted of a hard bed of clay bound to- 
gether, and colored brown, with iron. Not a swell of any sort 
intervened to interrupt the line of the horizon, which was as 
perfect as that viewed over the surface of the sea. Here, 
too, as on that element, the mind was as little distracted by a 
