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the apex of the Delta it is eighteen feet. According to Sir G. Wil- 
kinson, the deposit has increased during the last 1700 years at Ele- 
phantine in Upper Egypt nine feet, at Thebes seven feet, and at He- 
liopolis five feet ten inches; but the amount of accumulation dimi- 
nishes in general more rapidly towards the Delta and Mediterranean. 
All calculations, however, on the progressive rate of increase through« 
out Egypt, deduced from the actual addition around the bases of 
nilometers, statues or buildings, in particular localities, are liable, 
Mr. Newbold says, to uncertainty, on account of the shifting of the 
river’s bed, and the intermingling of the drift sand of the desert. 
Moreover, the alluvium at the foot of these monuments has been 
disturbed by the plough and spade of cultivators; and in most cases 
it has not been proved at what period the Nile reached these bases ; 
but judging from the thickness of the annual layers, of which the 
author has counted upwards of 900 in the clifis of the Nile, he 
concludes that the yearly deposition has not varied in the aggregate 
for the last thousand years. It is equally difficult, he adds, to calcu- 
late the progressive superficial extension of the mud. 
Few pebbles or detritus of any size are found in Lower Egypt and 
in the Delta, and only the finest ingredients escape into the Mediter- 
ranean, but Mr. Newbold has observed the sea coloured by this 
drifted matter to the distance of forty’miles from the shore. The 
northern or Etesian winds, which commence about May, or the period 
of the inundation, retard, he says, the downward freshes, and contri- 
bute materially to the accumulation of the mud upon the land, as well 
as to the silting up of the embouchures of the river, by raising the 
level of the Mediterranean along the coast, and checking the currents 
in the estuaries. Near the mouths of the Nile the mud is inter- 
mingled with marine sand, and contains Mediterranean species of 
Mollusca, associated with terrestrial and fluviatile remains. Ac- 
cording to Ehrenberg, the river-mud contains an immense number 
of infusoria. 
The action of the Nile on its eastern bank, arising from a difference 
in the level at the base of the Arabian cliffs and the prevalence of 
westwardly winds, is shown to be considerable. Many monuments 
of Koum Ombos have been carried away, and the remainder are 
threatened ; further down, the ancient quay, and the temple at Luxor, 
are in great danger; and the ruins of Gou-el-Kebir have been in part 
destroyed by the encroachments of the river, the traditional channel 
of the Nile being nearly a mile to the westward. Other changes are 
also mentioned. 
(2.) Delta of the Nile.—On account of the absence of all marine 
remains from the mud covering the middle and upper portions of the 
Delta, Mr. Newbold infers that the present alluvium must have been 
deposited, for the most part, on a surface previously above the level 
of the Mediterranean ; and he is also of opinion that other causes 
than the deposition’ of mud have tended to the formation of the Delta. 
The coast-line, he shows, consists chiefly of banks of marine sand, 
and a recent marine limestone: ancient Alexandria also stood on the 
calcareous rock of the Libyan desert; but the modern city is built on 
