Basin-like Form of Africa. 55 



but some to the east, and will further answer the query, 

 whether they may not also shed off other streams to a great 

 lacustrine and sandy interior of this continent, will be justly 

 considered among the greatest benefactors of this age to 

 geographical science ! 



The great east and west range of the Atlas, which in a 

 similar general sense forms the northern frontier of Africa, 

 is, indeed, already known to be composed of primeval strata 

 and eruptive rocks, like those which encircle the Cape Colony 

 on the south, and is equally fissured by transverse rents. As 

 to the hills which fringe the west coast, and through aper- 

 tures of which the Niger and the Gambia escape, we have 

 yet to learn if they are representatives of similar ancient 

 rocks, and thus complete the analogy of Northern with 

 Southern Africa. But I venture to throw out the general 

 suggestion of an original basin-like arrangement of all 

 Africa, through the existence of a grand encircling girdle of 

 the older rocks, which, though exhibited at certain distances 

 from her present shores, is still external, as regards her 

 vast interior. 



Let me, therefore, impress on all travellers who may visit 

 any part of Africa, that their researches will always be much 

 increased in value, if they bring away with them (as I have 

 just learned that Mr Oswell has done) the smallest speci- 

 mens of rocks containing fossil organic remains, and will 

 note the general direction and inclination of the strata. 



"With no region of the old world have we been till very 

 lately so ill acquainted as Africa. But now the light is 

 dawning quickly upon us from all sides ; and in the genera- 

 tion which follows, I have no doubt that many of the links 

 in the chain of inductive reasoning, as to the history of the 

 successively lost races of that part of the globe, will be made 

 known, from the earliest recognisable zones of animal life, 

 through the secondary and tertiary periods of geologists. 

 Passing thence to the creation of mankind and to the subse- 

 quent accumulations of the great delta of the Nile, we have 

 recently been put in the way of learning what has been the 

 amount of wear and tear of the upland or granitic rocks, and 

 what the additions to the great alluvial plain of Lower 



