66 THE NGAMI. Chap. III. 



its north-west extremity. We could detect no horizon where we 

 stood looking S.S.W. ; nor could we form any idea of the extent 

 of the lake except from the reports of the inhabitants of the dis- 

 trict ; and, as they professed to go round it in three days, allowing 

 twenty-five miles a-day would make it seventy-five, or less than 

 seventy geographical miles in circumference. Other guesses have 

 been made since as to its circumference, ranging between seventy 

 and one hundred miles. It is shallow, for I subsequently saw a 

 native punting Ins canoe over seven or eight miles of the north- 

 east end ; it can never, therefore, be of much value as a com- 

 mercial highway. In fact, during the months preceding the 

 annual supply of water from the north, the lake is so shallow that 

 it is with difficulty cattle can approach the water through the 

 boggy, reedy banks. These are low on all sides, but on the west 

 there is a space devoid of trees, showing that the waters have 

 retired thence at no very ancient date. This is another of the 

 proofs of desiccation met with so abundantly throughout the 

 whole country. A number of dead trees lie on tins space, some 

 of them embedded in the mud, right hi the water. We were 

 informed by the Bayeiye, who live on the lake, that, when the 

 annual inundation begins, not only trees of great size, but ante- 

 lopes, as the springbuck and tsessebe (Acronotus lunata), are 

 swept down by its rushing waters ; the trees are gradually 

 driven by the winds to the opposite side, and become embedded 

 in mud. 



The water of the lake is perfectly fresh when full, but brackish 

 when low ; and that coming down the Tamunak'le we found to 

 be so clear, cold, and soft, the higher we ascended, that the idea 

 of melting snow was suggested to our minds. We found this 

 region, with regard to that from which we had come, to be clearly 

 a hollow, the lowest point being Lake Kumadau ; the point of the 

 ebullition of water, as shown by one of Newman's barometric ther- 

 mometers, was only between 207|° and 206°, giving an elevation 

 of not much more than two thousand feet above the level of the 

 sea. We had descended above two thousand feet in comino- to it 

 from Kolobeng. It is the southern and lowest part of the great 

 river system beyond, in which large tracts of country are inundated 

 annually by tropical rains, hereafter to be described. A little of 

 that water, which in the countries farther north produces inunda- 



