THE COURSE OF THE DHIOLIBA. 371 
Timbuctoo which flows to Funda), can run on to lake 
Tchad, three hundred and fifty leagues farther, through a 
country represented by all accounts as mountainous ? But 
this, even, is not the greatest difficulty. 
It is hardly conceivable that any geographer should 
have admitted an hypothesis, the absurdity of which must 
have been manifest upon the slightest reflection. The 
height of lake Tchad has been ascertained : it is nine 
hundred and twenty French feet above the level of the 
sea, or something less than three hundred metres ; it 
cannot, therefore, receive the waters which flow to 
Funda. 
The course of this river east of Funda must be re- 
versed, and the supposed elbow converted into a tribu- 
tary : we shall then probably approach the truth. Major 
Denham was the first to conceive this easterly turn of the 
river, running north of the great chain of mountains, and 
falling at a great distance into the central lake ; he had 
been assured that a communication existed between this 
river and lake Tchad by the Chary. How is it that the 
physical impossibility of this course did not occur to 
him ? 
A very simple consideration appears to afford a solu- 
tion of this difficulty, namely, the existence of a lake in 
an elevated point of the Mandara chain, giving rise both 
to the Chary and the river which flows by Adamowa 
2 B 2 
