MR. HORNER ON THE ALLUVIAL LAND OF EGYPT. 
117 
When we consider, therefore, the large amount of earthy matter held suspended in 
the water, as will presently appear, and how much the volume of water is diminished 
before the Nile reaches the sea, it is evident that a vast amount of sediment must be 
annually left upon the land which the inundation overspreads, that a much larger 
proportion must be deposited in Upper Egypt than in the Delta, and, from the greater 
surface of the latter, that the depth of the annual accumulation there must be greatly 
less than in the more contracted part of the valley. 
The solid matter conveyed hy the Nile, to form its sedimentary deposits. 
When the inundations commence the Nile comes down of a reddish colour, loaded 
with sand and mud. From the small amount of the fall between the cataract at 
Wadi-Halfa (the second) and that at Assouan (the first), a distance of 214 miles, and 
the difference of height between the two places being only 157 feet*, thus making 
the average fall of the river not quite 9 inches in a mile, it is not to be expected that 
much coarse gravel can be carried forward, and that which arrives at the island of 
Philm must be much sifted and comminuted in its passage through the rocks form- 
ing the rapid of Assouan. Below that place, the fall of the land goes on diminish- 
ing, so that the transporting power of the stream is small. The greater proportion 
of the heavier detritus thus falls down in the higher parts of Upper Egypt, and from 
the very gentle slope of the Delta, it might be concluded that only a small amount of 
the solid matter suspended in the water can reach the mouths of the river. But very 
fine particles of earthy matter, as is well known, are long in subsiding, and much is 
carried out to sea-f-. Herodotus notices that during the inundation the sea is ren- 
dered turbid, and Bruce observed the same thing. Newbold states, that he found 
the sea coloured at a distance of forty miles from the shore. 
A modern traveller thus describes the appearance of the water in the Nile opposite 
to Thebes on the 7th of November: — ‘‘Ce sera curieux pour nous de revoir ce Nil 
lorsque I’eau en sera transparente, au lieu d’etre, comme maintenant, de la couleur 
de caf(6-au-lait tr^s noir and he says of it three weeks before at Cairo, “ Main- 
tenant que I’eau est a son plus haut niveau, elle est d’une ^paisseur inconcevable, 
presque comme du chocolat, et plus foncee:|:.” 
The sediment is slightly modified in character at various localities, according to 
the nature of the formation near to which the river flows. Its composition and 
texture are also subject to variation from its proximity to or distance from the main 
channel of the stream, where the coarser and heavier siliceous particles are usually 
* See a paper by the author in the Edinburgh Philosophical Journal for July 1850. 
t “ The out-pouring of the Nile during the inundation is so powerful that fresh water may be skimmed off 
the surface of the sea at the distance of two or three miles out in the offing. During the full surcharge, pot- 
able water may be baled on the surface of the Mediterranean even out of sight of land.” — The Mediterranean, 
by Admiral Smyth, p. 84 and 169. 
+ Melly, Lettres d’Egypte et de Nubie, printed for private circulation, 1852. 
