SOUTHERN AFRICA. 
73 
oppofite fide of the dale, however, ftood a long range of hills 
which had every appearance of volcanic origin. Some were 
perfect cones ; others truncated at the fuminit in the manner 
of thofe on which craters are generally found. Hills like 
thefe, {landing each on its proper bafe, and fo very different 
from any that had yet been feen, were too interefting to pafs. 
They were found to be compofed of quartz, fand-ftone, and 
iron; not, however, ftratified like the great chains, but torn and 
rent into large fragments. There was no lava ; nor did it ap- 
pear that any of the flones had undergone fufion. There was 
no blue flate in their fides, which moft probably would have 
been the cafe had they been thrown up by any fubtcrranean 
impulfe, the whole bafe of the plain being compofed of it. 
Within thefe hills we came to a valley about three miles in 
length and two in width, having a furface as level as that of 
a bowling-green. By a ftrong flream paffmg from one end to 
the other, the whole might be laid under water, and converted 
into moft excellent rice grounds. This ftream was fmoking 
hot. The fprings, by which it was fupplied, iffued out of 
the ground at the foot of fome hills which formed the head of 
the valley. They threw up the water with great violence, and 
with it quantities of fmall whitifh fand mixed with minute 
chryftals of quartz. The bed of the refervoir, and the channel 
down which the water was carried acrofs the valley, in a ftream 
ftrong enough to turn the largeft mill in England, were com- 
pofed of thefe materials. The water was perfectly clear, and 
depoflted not the fmalleft degree of any kind of fediment, 
neither in the pool where the fprings were, nor by the edges 
L of 
