568 DRAINAGE OF THE GREAT VALLEY. 



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 mead- 

 ows. 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 Both- 

 well Bridge and retires again into its channel, it resembles the 

 river we are speaking of, only here there are no high lands slop- 

 ing 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 cer- 

 tain amount of confidence in the native reports is this : when Mr. 

 Oswell and I discovered the Zambesi in the centre of the con- 

 tinent in 1851, being unable to ascend it at the time ourselves, 

 we employed the natives to draw a map imbodying 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, name- 

 ly, in order to be an aid to others in farther investigations. 

 When I was able to ascend the Leeambye to 14° south, and sub- 



