THE EAST AFRICAN LAKE-CHAIN 



Basso Ebor (Lakes Rudolf and Stephanie) ; and Baumann's 

 recent march past Manyara and Eiassi. 



The determination of the principal features in the topo- 

 graphy of these lakes has, however, done more to stimulate 

 than to satisfy our desire for knowledge about them. Mr. F. 

 Galton,^ in the discussion on Mr. Thomson's paper on his 

 journey through Masailand, pointed out that the great de- 

 pression or trough in which Naivasha and Baringo lie, is part 

 of one " which begins with the Dead Sea, extends down the 

 Red Sea, and ends at Tanganyika." This view has often been 

 repeated, but it remained as a hazy speculation until Professor 

 Suess of Vienna recently gave it scientific expression. To 

 understand this let us examine a map of the lake system (Fig. 

 i) of East Africa. One of the first points shown by it is that 

 the lakes are developed according to two absolutely different 

 types. Some are rounded in shape, as the Nyanza, and others 

 are long and narrow, as Tanganyika and the Nyasa. If we 

 examine views of these lakes we find that the round lakes have 

 low shelving shores, and that the long ones lie, like fiords, 

 between high precipitous cliffs. The illustrations on the first 

 plate show this contrast : the upper shows the southern shore 

 of the Nyanza, and the lower, one of the bounding walls of 

 Tanganyika. If we read descriptions of the lakes we learn the 

 same facts. Thus Thomson^ remarks that, "unlike most other 

 African lakes, the Nyanza is not bounded by ranges of moun- 

 tains. The ground descends gradually to its shores, and peace- 

 fully the water laps the muddy and marshy beach." 



The map, moreover, shows us that these two types of lakes 

 are not distributed haphazard, but on a definite plan. The 

 long fiord -like lakes occur on two lines, which pass one on 

 either side of the Nyanza and meet at Basso Narok (Lake 

 Rudolf). Thence the line continues northward as a long strip 

 of low land, dotted with lakes and old lake basins, and sinking 

 in places below the level of the sea. This extends to the 

 southern end of the Red Sea, which repeats the structure of 

 these fiord-like lakes on a larger scale : it is long and narrow 

 and, excluding some strips of coast deposits, has high pre- 

 cipitous shores. From its northern end the Gulf of Akaba 

 leads to another valley with similar characteris-tics, and from 



^ Proc, Roy. Geog. Soc. new ser. vol. vi. (1884), p. 71 r. - Ibid. p. 707. 



