David Livingstone,
A Popular Account of Dr Livingstone's Expedition to the Zambesi and its Tributaries…
(1894)
“ The natives regarded the Upper Shire as a prolongation of Lake Nyassa; for where what we called the river approaches Lake Shirwa, a little north of the mountains, they said that the hippopotami, "which are great night travellers," pass from _one lake into the other_. There the land is flat, and only a short land journey would be necessary. Seldom does the current here exceed a knot an hour, while that of the Lower Shire is from two to two-and-a-half knots. ”
