“I have ascertained that the watershed of the Nile is a broad upland between ten degrees and twelve degrees south latitude, and from 4,000 to 5,000 feet above the level of the sea. Mountains stand on it at various points, which, though not apparently very high, are between 6,000 and 7,000 feet of actual altitude. The watershed is over 700 miles in length, from west to east. The springs that rise on it are almost innumerable--that is, it would take a large part of a man’s life to count them. A bird’s-eye view of some parts of the watershed would resemble the frost vegetation on window panes. They all begin in an ooze at the head of a slightly depressed valley. A few hundred yards down the quantity of water from oozing earthen sponge forms a brisk perennial burn or brook a few feet broad, and deep enough to require a bridge. These are the ultimate or primary sources of the great rivers that flow to the north in the great Nile valley. The primaries unite and form streams in general larger than the Isis at Oxford or Avon at Hamilton, and may be called secondary sources. They never dry, but unite again into four large lines of drainage, the head waters or mains of the river of Egypt. These four are each called by the natives Lualaba, which, if not too pedantic, may be spoken of as lacustrine rivers, extant specimens of those which, in pre-historic times, abounded in Africa, and which in the south are still called by Bechuanas ‘Melapo,’ in the north, by Arabs, ‘Wadys;’ both words meaning the same thing--river bed in which no water ever now flows. Two of the four great rivers mentioned fall into the central Lualaba, or Webb’s Lake River, and then we have but two main lines of drainage as depicted nearly by Ptolemy. “In passing over sixty miles of latitude I waded thirty-two primary sources from calf to waist deep, and requiring from twenty minutes to an hour and a quarter to cross stream and sponge. This would give about one source to every two miles. A Suaheli friend in passing along part of the Lake Bangweolo during six days counted twenty-two from thigh to waist deep. This lake is on the watershed, for the village at which I observed on its northwest shore was a few seconds into eleven degrees south. I tried to cross it in order to measure the breadth accurately. The first stage to an inhabited island was about twenty-four miles. From the highest point here the tops of the trees, evidently lifted by the mirage, could be seen on the second stage and the third stage; the mainland was said to be as far as this beyond it. But my canoe men had stolen the canoe and got a hint that the real owners were in pursuit, and got into a flurry to return home.