5 6 THE TANGANYIKA PROBLEM. 



journeys, and only afterwards to attempt to bring them 

 into relation with the more fragmentary observations made 

 by several other investigators, more especially to the east 

 and to the west of the Great Central Range along which 

 I led the expeditions of 1896 and 1900. 



In bringing the results of these investigations before the 

 reader, it will further be convenient to consider the area 

 with which we have to deal from south to north. 



In the first place we shall have the Zambesi and Nyassa 

 districts as far as the high country which bounds Lake 

 Nyassa immediately to the north. The second will include 

 the territory northward as far as Ujiji on Tanganyika; 

 and the third the regions north of this as far as the Albert 

 Nyanza, in the first parallel of north latitude. But before 

 proceeding, it should be pointed out that the area with 

 which it is necessary to deal is immense, that it is in 

 nearly all parts a terrible country to geologise in, or 

 even to get through at all, and that it is to a very large 

 extent still wholly unexplored. It has been traversed this 

 way and that, but the wide spaces between these narrow 

 lines are unknown wildernesses still. It is therefore 

 extremely probable that surprises of all sorts await us in 

 the way of geological discovery, and it is practically 

 certain that whatever conclusions it may now be legitimate 

 to arrive at from a contemplation of the known facts of 

 the geology of the interior, will have to be considerably 

 modified as time goes on. 



In the more southern section of the African interior, 

 which includes the Shiri highlands, and the province of 

 Mozambique, part of Northern Charterland, the Marotse 

 country, and the little known districts of the far west, 

 the superficial geology is by no means always simple. It 

 is, indeed, far more complex than has been generally 



