348 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 
Egypt I have seen trees apparently growing in the sandy desert, but 
which have been found to have their roots imbedded in the alluvium / / 
of the Nile below the drifted sand (fig. 6). 
Fig. 6. 
Ailuvium. Kk Desert sand. 
; ase aes 
eee = See Se See 
ZZ AZZ ng 
Many of the ruins of ancient Egypt, more especially those on the 
west bank of the Nile, have been covered with mounds of blown 
sand: the great temple of Abusambel was discovered by Burckhardt 
almost buried under a sand- drift, 31 feet of which were removed by 
Belzoni* before he could arrive at the entrance. The sites of Abydus, 
Memphis, Oxyrinchus, Bahnasat, and the tract from Saecara to Abu 
Rehe, are now covered with sand ; and its advance near Koum Ombos, 
Benisuef and Tapta is very evident. It has drifted so mucht on 
the steep ridge on the western side of the Faioom, as to cover exten- 
sive ranges of desert mountains to such a depth that their rocky 
summits are the only objects perceptible in the undulating waste ; 
and the plains and mountains near the ancient town of Dimay have 
been overwhelmed with this vast body of sand. At El Kerib, the 
supposed site of Hieracon, the mouths of the mummy-pits are com- 
pletely closed with sand. 
It has invaded the oases, and we are told by Henniker§ that the 
temple in that of Khargeh is nearly overwhelmed. The great Sphinx, 
which not thirty years s back was disinterred from the drifted sand in 
which it lay buried up to the neck, is again covered to the shoulders. 
It appears clear that so long as the prevailing winds continue to 
blow from the same quarter, or until the supply of sand from the 
great western desert becomes exhausted, the valley of Egypt must 
continue to suffer in an increasing ratio from the sand-floods, since 
the escarpments on its eastern limit present almost insurmountable 
natural obstacles to the further easterly progress of sand once lodged 
in it; and it would seem, from the rare mention of these sandy in- — 
vasions in the old records of Egypt, that it anciently experienced — 
less inconvenience from them than at present. i 
Many causes tend to retard this encroachment.. Among these 
may be mentioned—the surface of the western desert, often rugged 
with ravines and cliffs, in and around which the sand collects and 
lingers for indefinite periods, forming a barrier against its further 
progress ; the stream of the Nile, which carries off the lighter par-~ 
ticles that are blown into it or within its reach ;—and the slowly in- 
creasing extension of the alluvium, as already noticed. 
The numerous little whirlwinds that prevail, chiefly during the hot 
season, in the heated tracts bordering the Red Sea and the Nile have ~ 
a considerable share in the transport of the finer superficial sands of 
the desert and the dusty alluvium of the river; they even carry up 
small. marine, land and fluviatile shells, and ddeda of plants, distri- tt} 
. * Belzoni, p. 213. + Denon, English sgt vol. i. p. 155, 
t Vyse, vol. i. pp. 110, 168. § Travels, p. 187. . 
