Between the Sudan and the Mediterranean the only perennial stream is the Nile, a word probably derived from the Semitic root nahal, meaning a valley or a river-valley, and subsequently a “river,” in a pre-eminent and exclusive sense. The ancient Egyptians called it the Ar or Aur (Koptic, Iaro), or “black”; hence the Greek word [...] allusion to the colour, not of the water, but of the sediment which it precipitated during the floods. In contrast to the yellow sands of the surrounding desert, the Nile mud is black enough to have given the land itself its oldest name, Kem, or Kemi, which has the same meaning of “black.” At Khartum, where the White Nile joins the Blue Nile, the main branch has a fall from its upper level in the region of the tropical lakes, four thousand feet above the sea, to twelve hundred feet, while traversing a distance of twenty-three hundred miles. From Khartum to the sea the distance through which the waters of the Nile wend their way is about eighteen hundred and forty miles. During the greater part of this course the flow is level, the average descent being about eight inches per mile. If it were not, therefore, for the obstruction met with in the Nubian section, the course of the Nile would be everywhere navigable. Although no perennial affluents enter the main stream lower down than Khartum, the volume of the Nile remains with little diminution throughout the entire distance to the Mediterranean. During the period of low water the amount of water in different localities is still uniform, notwithstanding all the irrigation, infiltration, and evaporation constantly taking place. The only explanation which has been given to this phenomenon is that there are hidden wells in the bed of the Nile, and from their flow the waste is ever renewed.
As the earth revolves from west to east, the waters of the Nile tend to be driven upon the right bank on the west, where the current is constantly eating away the sandstone and limestone cliffs. For this reason the left side of the river is far more fertile and well cultivated than the right bank. Below Ombos the valley is narrowly constructed, being but thirteen hundred yards in width, the cliffs overhanging the river on either side, but at Thebes it broadens out to nine or ten miles, and farther up, in the Keneh district, the valley is twelve or fifteen miles in width. The river here approaches within sixty miles of the Red Sea, and it is believed that a branch of the Nile once flowed out into the sea in this direction.
Seventy miles below Keneh the Nile throws from its left bank the Bahr Yusef branch, a small current of 350 feet in breadth, which flows for hundreds of miles through the broader strip of alluvial land between the main stream and the Libyan escarpments. In the Beni-Suef district this stream again bifurcates, the chief branch continuing to wind along the Nile Valley to a point above the Delta, where it joins the main stream. The left branch penetrates westward through a gap in the Libyan escarpments into the Fayum depression, ramifying into a thousand irrigating rills, and pouring its overflow into the Birket-el-Qarum, or “Lake of Horns,” which still floods the lowest cavity and is a remnant of the famous ancient Lake Moris. The Fayum, which is the territory reclaimed from the former lake, is now an exceedingly productive district, a sort of inland delta, fed like the marine delta by the fertilising flood-waters of the Nile.
The traveller Junker wrote of this district in 1875: “I found myself surrounded by a garden tract of unsurpassed fertility, where there was scarcely room for a path amid the exuberant growths; where pedestrians, riders, and animals had to move about along the embankments of countless canals. Now a land of roses, of the vine, olive, sugar-cane, and cotton, where the orange and lemon plants attain the size of our apple-trees, it was in primeval times an arid depression of the stony and sandy Libyan waste.”
North of the Fayum the Nile flows on to Cairo, where the narrow water way allowed to its course by the two lines of cliffs widens, and the cliffs recede to the right and left. There is thus space for the waters to spread and ramify over the alluvial plain. Nearly all this portion of Egypt has been covered by the sediment of the Nile, and from the earliest times there have been numerous distinct branches or channels of the river running out by separate openings into the sea. As several of these branches have been tapped to a great extent for irrigation, all except two have ceased to be true outlets of the Nile. In the Greek period there were seven mouths and several [...Greek...], or “false mouths.” The two remaining mouths are those of Rosetta and Damietta, and these were always the most important of the number. They branched off formerly close to the present spot where Cairo stands, a little below Memphis; but during two thousand years the fork has gradually shifted to about thirteen miles lower down.
The triangular space enclosed by these two branches and the sea-coast was called by the Greeks the delta, on account of the likeness in shape to the Greek letter of that name A. At the head, or apex, of the triangle stands the famous barrage, or dam, begun in 1847 by Mehemet Ali, for the twofold purpose of reclaiming many thousand acres of waste land, and of regulating the discharge and the navigation through the Delta. The idea was originated by a Frenchman in his service named Linant Bey. This engineer desired to alter the course of the river and build a weir at a point farther to the north, where the contour of land seemed to favour the design more than that of the present locality. Mehemet Ali thought his plans too costly, and accepted in preference those of Mougel Bey. Unexpected difficulties were encountered from the very beginning. Mehemet was exceedingly anxious to hurry the work, and Mougel Bey had only made a beginning, when an exceptionally high Nile carried away all the lime in the concrete base. Mehemet Ali did not live to see the completion of this work. The object, could it have been realised, was to hold up the waters of the Nile during the eight months of the ebb, and thus keep them on a level with the soil, and at the same time to supply Lower Egypt with an amount of water equal to that which came down during flood-time. It was hoped to cover the very large expenditure by the additional land which it was expected would come under irrigation, and by doing away with the primitive shadoofs and setting free for productive enterprise the numerous army of the agricultural labourers who spent the greater part of their time in slowly raising up buckets of water from the Nile and pouring them into the irrigating channels.
