138 THE LAKE EEGIONS OF CENTRAL AFKICA. 



Ukerewe, a vast reservoir formed by the drainage of 

 mountains. Judging from the eye, the walls of this 

 basin rise in an almost continuous curtain, rarely 

 waving and infracted to 2,000 or 3,000 feet above the 

 water-level. The lower slopes are well wooded : upon 

 the higher summits large trees are said not to grow ; 

 the deficiency of soil, and the prevalence of high fierce 

 winds would account for the phenomena. The lay is 

 almost due north and south, and the form a long oval, 

 widening in the central portions and contracting sys- 

 tematically at both extremities. The length of the bed 

 was thus calculated : From Ujiji (in S. lat. 4° 55') to 

 Uvira (in S. lat. 3° 25'), where the narrowing of the 

 breadth evidences approach to the northern head, was 

 found by exploration a direct distance of 1° 30' = 90 

 miles, which, allowing for the interval between Uvira 

 and the river Rusizi, that forms the northernmost limit, 

 may be increased to 100 rectilinear geographical miles. 

 According to the Arab voyagers, who have frequently 

 rounded the lake Ujiji in eight stages from the northern, 

 and twelve from the southern, end of the lake, the ex- 

 tent from Ujiji to the Marungu River, therefore, is 

 roughly computed at 150 miles. The total of length, 

 from Uvira, in S. lat. 30° 25', to Marungu, inS. lat, 7° 20', 

 would then be somewhat less than 250 rectilinear 

 geographical miles. About Ujiji the water appears to 

 vary in breadth from 30 to 35 miles, but the serpentine 

 form of the banks, with a succession of serrations and 

 indentations of salient and re-entering angles — some 

 jutting far and irregularly into the bed — render the 

 estimate of average difficult. The Arabs agree in cor- 

 rectly stating, that opposite Ujiji the shortest breadth 

 of the lake is about equal to the channel which divides 

 Zanzibar from the mainland, or between 23 and 24 



