In the hardening process the silica was sometimes sweated out of this rock, and it exists now as pretty efflorescences of well-shaped crystals.

But not only does this range, which stands eight or ten miles north of Kolobeng, exhibit the effects of igneous action, it shows on its eastern slope the effects of flowing water, in a large pot-hole called Loee, which has the reputation of having given exit to all the animals in South Africa, and also to the first progenitors of the whole Bechuana race.

Their footsteps attest the truth of this belief.

I was profane enough to be sceptical, because the large footstep of the first man Matsieng was directed as if going into instead of out of this famous pot-hole.

Other huge pot-holes are met with all over the country, and at heights on the slopes of the mountains far above the levels of the ancient rivers.
Many fountains rose in the courses of the ancient river beds, and the outflow was always in the direction of the current of the parent stream.
Many of these ancient fountains still contain water, and form the stages on a journey, but the primitive waters seem generally to have been laden with lime in solution: this lime was deposited in vast lakes, which are now covered with calcareous tufa.