CHAPTER XII 



THE PHYSICAL GEOGRAPHY AND THE GEOLOGY OF BRITISH 



EAST AFRICA 



" Hier aber war's ! Plutonisch grimmig Feuer 

 Aeolischer Diinste knallkraft, umgeheuer, 

 Durchbrach des flachen Bodens alte Kruste, 

 Dass neu ein Berg sogleich entstehen musste." 



Goethe. 



In 1852 Sir Roderick Murchison advanced the hypothesis that 

 Africa, south of the Sahara, was a continent of great antiquity 

 and simpHcity, which had maintained the form of a great basin 

 ever since the age of the New Red Sandstone. Murchison 

 based his theory on the discoveries of Bain, the pioneer of 

 South African geology ; but he drew support for it from the 

 probabiHty that Lakes Ngami and Tchad, at the two ends of 

 the supposed basin, were connected by others reported by 

 classical traditions and modern traders. Murchison regarded 

 these lakes as the remnants of a series which had existed 

 uninterruptedly throughout two of the three great eras of the 

 earth's history.^ 



This brilliant speculation was reaffirmed after the dis- 

 coveries of Livingstone,^ Burton and Speke,^ and Speke and 

 Grant,^ and was finally summarised in 1864 in the presidential 

 address to the Geographical Society, and in a paper entitled 

 " On the Antiquity of the Physical Geography of Inner Africa." ^ 

 In these he claimed the country as of interest, because it was 



^ R. I. Murchison, President's Address, Journ. Roy. Geog. Soc. vol. xxii. (1852), 

 p. cxxiii. 2 Ibid. vol. xxvii. (1857), p. clxix. 



^ Ibid. vol. xxviii. (1858), p. ccviii. 

 * Ibid. vol. xxxiii. (1863), p. clxxxi. 

 ^ Ibid. vol. xxxiv. (1864), p. clxxxvii. and pp. 201-205. 



