Part 311

If we take a glance back at the great valley, the form the rivers have taken imparts the idea of a lake slowly drained out, for they have cut out for themselves beds exactly like what we may see in the soft mud of a shallow pool of rain-water, when that is let off by a furrow. This idea would probably not strike a person on coming first into the country, but more extensive acquaintance with the river system certainly would convey the impression. None of the rivers in the valley of the Leeambye have slopes down to their beds. Indeed, many parts are much like the Thames at the Isle of Dogs, only the Leeambye has to rise twenty or thirty feet before it can overflow some of its meadows. The rivers have each a bed of low water--a simple furrow cut sharply out of the calcareous tufa which lined the channel of the ancient lake--and another of inundation. When the beds of inundation are filled, they assume the appearance of chains of lakes. When the Clyde fills the holms ("haughs") above Bothwell Bridge and retires again into its channel, it resembles the river we are speaking of, only here there are no high lands sloping down toward the bed of inundation, for the greater part of the region is not elevated fifty feet above them. Even the rocky banks of the Leeambye below Gonye, and the ridges bounding the Barotse valley, are not more than two or three hundred feet in altitude over the general dead level. Many of the rivers are very tortuous in their course, the Chobe and Simah particularly so; and, if we may receive the testimony of the natives, they form what anatomists call 'anastamosis', or a network of rivers. Thus, for instance, they assured me that if they go up the Simah in a canoe, they can enter the Chobe, and descend that river to the Leeambye; or they may go up the Kama and come down the Simah; and so in the case of the Kafue. It is reputed to be connected in this way with the Leeambye in the north, and to part with the Loangwa; and the Makololo went from the one into the other in canoes. And even though the interlacing may not be quite to the extent believed by the natives, the country is so level and the rivers so tortuous that I see no improbability in the conclusion that here is a network of waters of a very peculiar nature. The reason why I am disposed to place a certain amount of confidence in the native reports is this: when Mr. Oswell and I discovered the Zambesi in the centre of the continent in 1851, being unable to ascend it at the time ourselves, we employed the natives to draw a map embodying their ideas of that river. We then sent the native map home with the same view that I now mention their ideas of the river system, namely, in order to be an aid to others in farther investigations. When I was able to ascend the Leeambye to 14 Deg. south, and subsequently descend it, I found, after all the care I could bestow, that the alterations I was able to make in the original native plan were very trifling. The general idea their map gave was wonderfully accurate; and now I give, in the larger map appended, their views of the other rivers, in the hope that they may prove helpful to any traveler who may pursue the investigation farther.