7*0 TRAVELS TO DISCOVER
Dr Shaw, indeed % fays, that there feems to be a defcent from the banks to the foot 6f the mountains, but this he confiders as an optic fallacy; I with 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 fact, that the foot of the mountains is laid under water in the begin- ning of the rivers riling, 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 facts will not be contravened 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 longeff. 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 depoflted by the flream ? and this queftion would not have been fo eafily anfwer- ed.
The 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 careleflhefs, I 4 believe,
- Shaw's Travels, [t£t. 4. p. 401.
