THESOURCEOFTHENILE. 6y s 



floods; and therefore, on the firft confideration, this annual 

 and equal increafe mull be impoflible. 



At Bafboch, before the Nile enters Sennaar, I made feve- 

 ral hundred trials upon its fediment, as it then came down, 

 from the cultivated country of Abyflinia ; I thereby found 

 this fediment furpriiingly fmall, being a mixture of fat 

 earth, and a fmall quantity of fand. At the junction of the 

 Nile and Aftaboras I did the fame, taking up the water 

 from the middle of the ftream, and, having evaporated it 

 afterwards, I found little more fediment than at Sennaar; 

 the water was indeed whiter, and the greateft part of the 

 fediment was fand. I repeated this experiment at Syene 

 with the utmoft attention, where the Nile leaves Nubia, and 

 enters Egypt, and I found the quantity of fediment fully 

 nine times increafed from what it was at Sennaar, and in 

 it only a trifle of black earth, all the rett being fand. The 

 experiment at Rofetto was not fo often repeated as the 

 others ; but the refult was, that, in the ftrength of the in- 

 undation, the fediment confided moftly of fand, and, to- 

 wards the end, was much the greater part of earth. I think 

 thefe experiments conclufive, as neither the Nile coming 

 frefh from Abyffinia, nor the Atbara, though joined by the 

 Mareb, likewife from the fame country, brought any great 

 quantity of foil from thence. 



It was at Syene that the water fhould have been moil 

 charged with mud, for all the acceflion it was to bring to 

 Egypt was then in its itream ; but there the chief part of the 

 fediment was fand, fanned and ventilated with perpetual 

 hot winds, and fpread on the furface of the burning defert, 

 never refrefhed with the dew of heaven. In that dreary 



4 Qji defert, 



