From Cairo, at the top of the Delta, to the Cataracts, where the river ceascs to be navigable, the distance is about 600 miles, up a narrow valley, of which about 360 miles above Cairo the mountains are calcareous, and those to the southward of that place are granitic.
The inundations of the Nile arise from heavy rains and melting of snows in Abyssinia, and other mountain ous regions situated adjacent to the upper part of its source. Heroclotus, in his book Euterpe, states, that in the reign of Mceris, or 500 years before the Trojan War, a rise of eight cubits inundated the Delta, so as to be navigable for boats, excepting the small artificial eminences where the towns stood. In the time of Hero dotus 15 or 16 cubits were required ; this was also the case in the time of the Roman empire ; at present 18 are reckoned the standard of abundance ; sometimes the in crease is 22 cubits. The increase commences at the summer solstice, and continues to the end of August or September. At the end of November, the river has returned within its natural channels. The greatest breadth of the river is about 2000 feet, its motion three miles per hour ; its colour is a dirty red, even in April, May and June, when lowest. The perpendicular rise is one-sixth more at Assouan or Syene, than at Cairo, 360 miles below ; and, when the inundation is 27 feet at this latter place, it is only about four feet at Rosetta and Damietta ; because in Upper Egypt it is confined between high banks, and in the Delta it spleads over the whole country ; at Cairo, the banks, at low Nile, are from 12 to 15 feet high, at Rosetta they are from four to five only.
From the debased state in which Egypt has continued for upwards of two thousand years, we can form but a very indistinct notion of its ancient perfection, when under the management of a powerful and well regulated governmint ; but from the best modern authorities, (es pecially Nlajor Bryee,) it appears that during. the greatest part of the year there is in the Nile a fl ee channel for vessels of 40 tons burthen; and it is only during the lowest state of the river, in May and June, that the na vigation is confined to small boats. In Upper Egypt, as far as Siout, the ancient Lycopolis) the channel is clear of rocks. From this place to the Cataracts, the intricacy of the channel, and rapidity of the currents, require the experienced pilots of the country. Norden, in a boat
drawing three feet water, made a voyage from Cairo to the Cataracts and back, including various short stop pages, and seven days detention zit Assouan, in 97 days; that is, from 18th November to the 23c1 of February.
Of the canal of Joseph, or father Jussef, which runs parallel to, and on the western side of the Nile, the con struction and purpose seem alike uncertain. For in the map ol 'M. cl'Anville, that constructed by the engineers attached to the French army, and the excellent one com posed by Arrowsmith, front the information furnished by Major Bryce ancl other English officers, there arc con siderable differences as to the extent ancl direction of this canal, and also in regard to its connections with the river Nile and the lake Berket Keroun, (formerly the lalce Mceris). It appears to have been drawn along the skirts of the Ik7sert opposite Memphis, and thence continued along, the eastern side of the pyramids of Ghize, and terminated in the westelu branch of the Nile, towards the eastcfn extremity of the lake Mareotis, ancl from thence northward to the ancient Nimbus, or Abouscor, found the Mout gharn Point, where the head or a canal ancl sluice still exists.
With legarcl to the question, whether in upper Egypt this canal is not the channel or the ancient Nile, which :nay have formerly passed through the valley of Fai own and River without Water, into the Lyhian desert : It is not improbable, that this may have been the case with the whole or a part of the river, and that its north crn extremity may have been barred by sands drifting from the westward, thereby turning the whole stream into the eastern or present valley, but leaving for many centuries a part of the ancient course an immense lake, which has itself in course of time been filled up by sands. And the canal Jussef may be the remaining lowest parts of the ancient channel. Thus the great features may have been formed by natural operations; but many of the inferior have no doubt been, in the course of ages, accomplished by human at t and industry ; for Dioclorus Siculus informs us, that Nilus, one of the ancient kings, so much improved the economy of the river, as to have his name given to it, instead of Egyptus, its former ap pellation.