4 
Central Africa.—Ezxpeditions of Burton and Roscher. 235 
themselves to our predecessors; and yet the ready abandonin 
of expectations, prematurely indulged in respecting earlier an 
more recent expeditions, 1s a source of greater surprise than the 
fact that so large a portion of Africa remains unex ( 
All the accounts of travels, which have aided us in the con- 
struction of the map of Africa, do not give us any information 
relative to the central and northern portions of the interior of 
Africa, although these regions contain the solution of the most 
= ers have existed since the : 
‘mmedans, and here it was that the Arabian geographers, in 
structions, he directed his course westward so that the original 
: : 
two expeditions would be at all likely to meet. Dr. 
time has certainly come helt merely fruitless attempts 
must be done away with, and when travellers into Southern 
ake T'sad was impossible, and hence, contrary to all in-« 
/ 
