APPENDIX. 
permanent lakes, apparently form receptacles for its waters, during the dry 
season also. The country of Wangara alone, is said by Edrisi and Ibn Al 
Wardi to have an extent of 300 miles by 150 (i. e. Arabic miles, of 56^ to 
a degree) ; and Edrisi's statement of the distances through it, proves that its 
length lies in the same direction with the course of the Niger 3 that is, from 
west to east* Now I have no kind of difficulty in supposing that any river 
may be evaporated, provided it is spread out to a sufficient extent of surface : 
and it may be that the level, or hollow, of Wangara and part of Ghana, may 
present an extent of surface sufficient to produce this effect.t And hence 
these countries must be regarded as the sink of North Africa, at all seasons. 
No doubt the inhabitants are amply repaid by the fertility produced by the 
deposition of the waters : but besides this, in the southern quarter of Wan- 
gara, they collect an incredible quantity of gold sand, after the waters are 
gone off, which is carefully sought after, as soon as the rivers regain their 
beds.J 
It may be proper to oberve, that, according to the estimation which we 
ought to make, of the quantity of water collected into the Niger, it ought not 
to bear a proportion to that, collected into the great tropical rivers of Asia; 
since it receives no branches, but on one side. Of course, it does not drain 
so great a surface of country, as those which receive them on, both sides. 
Moreover it drains only the tract situated to leeward of the great chain of 
mountains, which opposes the main body of the clouds ; so that more water 
is discharged by the south, by the rivers of the Coast of Guinea, than by 
the inland rivers j or by those of Senegal and Gambia. 
• Refer to Edrisi, p. 12, and 13 ; and to page Ix above, 
f There are many instances of this kind. In particular the Hindmetid, or Heermund, 
a very considerable river of Sigistan, terminates in the lake of Zurrah (Aria Palus). 
The lake is about 100 miles long, and 20 broad, at the widest part ; and is said to he fresh. 
The country it flows through, has all the characteristics of the alluvial tracts, at the 
mouths of great rivers ; as Egypt, Bengal, &c . and is environed by mountains. This was 
the celebrated tract which is said to have formed the appanage of Rustum ; and whose in- 
habitants, from the relief they afForded to Cyrus, were named Euergtta by Alexander. 
I Edrisi, p. 12. D'Herbelot, article Vankara. 
