Lieut. Newbold on the Geology of Egypt. 225 
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 
the recent marine sands and calcareous strata, occupying the position 
of the great harbour. Foah, which at the commencement of the 
fifteenth century was situated at the Canobic mouth of the Nile, 
though now amile from it, and the present inland position of Rosetta, 
Micopolis and Taposiris, Mr. Newbold says, must likewise be ascribed, 
in great measure, to the intervention of marine sand-banks, 
The increase of soil from the waters of the Nile is much slower in 
the Delta than in the valley of the river, being spread over a much 
greater extent ; and though a considerable quantity of the suspended 
matter is carried into the Mediterranean, yet the author does not 
think that the submarine accumulation of the Delta can be very rapid. 
10. Sand-drifts.—At a short distance from both the Red Sea and 
the Mediterranean, the shores are occasionally studded with dunes or 
hills derived chiefly from the drifting of sand-banks thrown up by the 
waves. In considering the nature of the sands of the deserts, and 
their encroachments, the author dwells upon the effects of the strong 
north-westerly and westerly winds, which blow during nine months of 
the year; and on the agency of the little whirlwinds which prevail 
chiefly in the hot season, and transport not merely the finer particles 
of sand, but seeds of plants, and marine, fluviatile and land shells. 
With respect to the effects of the sand-flood, the author alludes to the 
more considerable encroachments and to their increasing influence, 
likewise to the natural impediments to their progress presented by the 
rugged ravines and cliffs of the western desert, and by the Nile: 
and lastly, he states that the accounts of whole caravans having been 
overwhelmed by clouds of drifting desert-sands are greatly exagge- 
rated; the effects having been confined to infirm or over-fatigued tra- 
vellers and animals who were unable to keep pace with the caravan. 
Phil, Mag. S. 3. Vol. 22. No. 144. March 1843. Q 
