David Livingstone,
A Popular Account of Dr Livingstone's Expedition to the Zambesi and its Tributaries…
(1894)
“ 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. The sides are smooth and treacherous, and the cross reeds, which support the covering, break in the attempt to get out by clutching them. A cry from the depths is unheard by those around, and it is only by repeated and most desperate efforts that the buried alive can regain the upper world. ”
