THE TANGANYIKA PEON LEM. 
5 6 
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 
