428 THEORIES RESPECTING THE NIGEIt. 
at Tombuctoo, by whom he was assured, that the 
Nile Abid, in flowing eastward from that city, 
spread into an inland sea of great extent. A 
great lake, therefore, in this situation, capable of 
forming a receptacle for both the streams which 
have been supposed to flow from the opposite 
sides of Africa, appeared not only possible, but 
supported by very strong and positive testimonies. 
Some farther notices respecting the interior of 
Africa have been obtained from Adams and Ri- 
ley ; but as these appear still somewhat doubt- 
ful,* and at best vague, it would be premature to 
rest upon them any great weight of reasoning. 
The information of Riley evidently favours the 
Congo hypothesis, leaving still room for the sup- 
position, that two rivers from opposite quarters 
may have united before the stream took its final 
direction southwards. It wdll now be proper to 
consider, how far the question is affected by the 
information which Captain Tuckey collected in 
his voyage up the Congo. 
It has already been observed, that the members 
of the expedition, on their first entrance into the 
* Since the first edition of this work, and even since re- 
printing the narrative of Adams in the preceding volume, I 
have seen some strong grounds for doubting the authenticity 
of that part of his narrative which relates to Tombuctoo. See 
Edinburgh Magazine for October 1818. 
