It is not difficult to detect the pitfalls after one's attention has been called to them; but in places where they are careful to carry the earth off to a distance, and a person is not thinking of such things, a sudden descent of nine feet is an experience not easily forgotten by the traveller.

The sensations of one thus instantaneously swallowed up by the earth are peculiar.

A momentary suspension of consciousness is followed by the rustling sound of a shower of sand and dry grass, and the half-bewildered thought of where he is, and how he came into darkness.

Reason awakes to assure him that he must have come down through that small opening of daylight overhead, and that he is now where a hippopotamus ought to have been.

The descent of a hippopotamus pitfall is easy, but to get out again into the upper air is a work of labour.