xviii THE CRATERS OF THE RIFT VALJ.EY 231 



plateaus fall abruptly to the lake : some of the clifls 

 are several thousand feet high. The lake is 2,700 feet 

 above sea-level and forms an abrupt termination to the 

 southern end of the western arm of the Rift A^alley. 



Gregory has drawn attention to a point of some 

 interest in regard to Tanganyika : the natives of 

 Ujiji have a folk-love that goes back to the time when 

 the lake was formed by the flooding of a fertile 

 valley. 



In regard to the Eed Sea some curious folk-lore is 

 available, for the Somalis believe that when their 

 ancestors crossed from Arabia, to Africa, there was a 

 land connection across the Straits of Bab-el-mandeb. 



Fischer demonstrated the existence of the Rift 

 Valley in Equatorial Africa (1883). Joseph Thomson 

 explored the parts of the valley around Lake Baringo 

 (1883), and Count Teleki, accompanied by Lieutenant 

 von Plrihnel, travelling along the eastern extension of 

 the Rift in 1887-8, discovered Lakes Rudolf and 

 Stefanie (the latter has since dried up), as well as an 

 active volcano at the south end of Lake Rudolf. 

 (Iregory investigated the portion of the valley which 

 traverses the British East Africa Protectorate in 

 1892-3, especially from the geological point of view, 

 and ascended Mount Kenia. He admirably sums up 

 the matter: — From the Lebanons almost to the Cape 

 there runs a valley, unique, on account of the per- 

 sistence with which it maintains its trough-like form 

 throughout the whole of its course of 4,000 miles, and 

 on account of the fact that scattered along its floor is a 

 series of over thirty lakes, of which only one has an out- 

 let to the sea. 



The section of the Rift valley bordered by the Kikuyu 

 and the Mau escarpments has a width of about twenty 

 miles. The floor of the valley in the neighbourhood of 

 Lake Naivasha is 6,300 feet above sea-level. The edge 

 of the Kikuyu escarpment is 1,400 feet above the floor 

 of the valley and that of Mau is 8,300 feet above sea- 



