THE EARTH. 11 



The earth presents a very different appearance 

 at the equator, where the sun-beams, darting di- 

 rectly downwards, burn up the lighter soils into 

 extensive sandy deserts, or quicken all the mois- 

 ter tracts with incredible vegetation. In these 

 regions, almost all the same inconveniencies are 

 felt from the proximity of the sun, that in the 

 former were endured from its absence. The de- 

 serts are entirely barren, except where they are 

 found to produce serpents, and these in such 

 quantities, that some extensive plains seem al- 

 most entirely covered with them.* 



It not unfrequently happens, also, that this dry 

 soil, which is so parched and comminuted by the 

 force of the sun, rises with the smallest breeze of 

 wind ; and the sands being composed of parts 

 almost as small as those of water, they assume a 

 similar appearance, rolling onward in waves, like 

 those of a troubled sea, and overwhelming all they 

 meet with inevitable destruction. On the other 

 hand, those tracts which are fertile, teem with 

 vegetation even to a noxious degree. The grass 

 rises to such a height, as often to require burn- 

 ing ; the forests are impassable from underwoods, 

 and so matted above, that even the sun, fierce as 

 it is, can seldom penetrate.t These are so thick 

 as scarcely to be extirpated ; for the tops being 

 so bound together by the climbing plants that 

 grow round them, though a hundred should be 

 cut at the bottom, yet not one would fall, as they 

 mutually support each other. In these dark and 



Adanson's Description of Senegal. f Linnsi Amain, vol. vi. p. 67, 



