783 
Pelusium are stated, on the authority of Laborde, to be twenty-four 
feet below the sea-level. 
The aspect of the valley and delta of the Nile varies with the sea- 
sons, presenting while the country is inundated a vast freshwater lake, 
studded with palm-shaded hamlets ; and after the subsidence of the 
waters, exhibiting along the course of the river a line of brilliant ver- 
dure winding through higher sterile tracts. When the grain has been 
gathered, the prospect consists of one monotonous brown, dusty plain, 
traversed by the sluggish Nile. The dip of the country from the first 
cataract to the Mediterranean is, according to Mr. Wallace, only two 
inches in a mile; but the descent a little north of Assuan is seven 
inches, lessening however on approaching the delta, and the canal 
between the Nile and Alexandria, a distance of sixty miles, has not a 
single lock. 
From the horizontal stratification of the rocks composing the greater 
part of Egypt, it is difficult, Mr. Newbold says, to trace any particu- 
lar lines of elevation. The mural cliffs which flank the valley of the 
Nile to the vicinity of Cairo, there deviate towards the east and west, 
and similar but less abrupt cliffs flank both shores of the Red Sea. 
This horizontal formation is traversed by valleys and ravines or wa- 
dis, having a north and south, and east and west direction, or which 
intersect each other at right angles, the most considerable being that 
of the Nile. 
In the eastern desert of Upper Egypt, Mr. Newbold traced these 
valleys to a north and south anticlinal line, caused by plutonic rocks 
which attain an altitude of 1000 feet above the sea-level; and their 
upheaval, he says, accounts for the intersecting systems of valleys, 
and illustrates forcibly the truth of Mr. Hopkins’s observations on the 
laws of fracture. In the vicinity of the erupted rocks the sedimentary 
strata exhibit considerable proofs of disturbance, but as the distance 
increases the inclination diminishes, proving, Mr. Newbold states, 
that the strata were elevated to their present position with no more 
force than was necessary to produce the fissures or valleys; and he 
adds, that in proportion as the horizontality is recovered, the fre- 
quency, depth, and extent of the fissures decrease. 
Some of the valleys, as that of Kossier, are considered to have 
been widened by aqueous causes no longer in operation, and that 
of the Nile by the still continued erosion of the river ; while others, 
as the Bahr-bila Maieh, or waterless river*, and that which separates 
the petrified wood formation from the Red Mountain, to have been 
formed entirely by them. The surface of these valleys is covered, 
for the greater part, with the detritus of the neighbouring rocks and 
of distantly transported rolled pebbles, which often rest on ledges 
and hills much above the general drainage-level. In the valley of 
Kossier, near the Red Sea, the gravel consists principally of pebbles 
of plutonic and hypogene rocks derived from the interior ; but near 
* Mr. Newbold objects to the opinion entertained by some travellers that 
_this valley was anciently the channel of the Nile, as it contains no rich, 
dark-coloured alluyium. 
