G10 TRAVELS TO DISCOVER’ 
Dr Suaw, indeed *, fays, that there feems to be a defcent 
from the banks to the foot of the mountains, but this he 
confiders as an optic fallacy; 1 wifh he had told us upon 
what principle of optics ; but if it was really fo, how comes 
it that the banks are every year dry, when the foot of the 
mountains is at fame time under inundation; or, in other 
words, what is the reafon of that undifputed faét, that the 
foot of the mountains is laid under water in the begin- 
ning of the rivers rifing, while the ground which they cul- 
tivate by labour near the banks, cannot fupply itfelf from 
the river by machines, till near the height of the inunda- 
tion? thefe faéts will not be contraverted by any traveller, 
who has ever been in Upper Egypt; but if this had been ad- 
mitted as truth inftead of an optic fallacy, this queftion 
would have immediately followed. If the land of Egypt 
at the foot of the mountains, is the loweft, the firft over- — 
flowed, and the longeft covered with water, and often the 
only part overflowed at all, whence can it arife that it is 
not upon a level with the banks of the river if it is true 
that the land of Egypt receives additional height every | 
year by the mud from Abyflinia depofited by the ftream ? 
and this queftion would not have been fo eafily anfwer- 
ed. 
Tue Nile for thefe thirty years has but once fo failed as - 
to occafion dearth, but never in that period fo as to produce 
famine in Egypt. The redundance of the water fweeping 
every thing before it, has thrice been the caufe, not of 
dearth, but of famine and emigration ; but carelefinefs, I 
ee believe, 
* Shaw’s Travels, {e@. 4. p. 4ot. 
