THE KILE.

New Zealand Herald, Volume XLV, Issue 13781, 20 June 1908, Page 5 (Supplement)

THE KILE.

THE ASSOUAN DAM,

Ages and ages ago the old Egyptians knew nothing of the origin of their mighty Nile, or 'why it rose and sank at certain seasons. They imagined that it sprang from the ground somewhere above Phihe, and if anyone had told them that it rose from a. vast lake in the dim interior of an unknown continent, and measured 4000 miles between its sources and the sea, probably they would have set him down as a romancer'of the period. In the same way they had not the slightest idea of what was the cause of the annual inundation which gave them their wealth and had created the great Delta, and, indeed, all cultivable Egypt. They were unaware that the Nile is two Nilcs joining in the neighbourhood of the modern Khartum, some 1300. miles above what was their border. These separate rivers are, of course,. THE BLUE NILE AND THE WHITE NILE. The White Nile comes from Lake Victoria and the Blue Nile from Abyssinia. It is the latter that, together with the Atbara,-brings down the mud in which the inhabitant of the narrow land of Egypt grows, and always has grown his crops. In June the green flood water of tho White Nile appears at Cairo, and towards the end of July the red water of the Blue Nile, charged with soil from the Abyssinian hills (one wonders why this.never becomes exhausted), reaches the same place, after which arrives the flood from the Atbara. Now, of all this precious inundation water and the rich manurial matter which.it contains, an enormous proportion still runs to waste, for I believe it is calculated that nearly 37,000,000 tons,- of solid stuff are deposited annually from the Nile into tho sea, carried by over sixty-five billion cubic metres of water. The desert borders of narrow Egypt consist of sun-scorched, winddriven sand. But if water from the Nile can be brought over this sand, instantly, as though by the touch of the wand of a magician, it becomes a most opulent soil. In the same way, if the said water can at will be let on to lands already naturally inundated, after that inundation has gone down, instead of one crop they will produce two or three, for in a country devoid of rain artificial irrigation is everything. So long ago as the. middle of the last century a great barrage was begun above Cairo, which, after many vicissitudes and much failure, was at length completed in 1891 with splendid results to the land below. But a barrage is not what main'' people suppose it to be— dam; it is A GUIDING WALL, which turns water in any direction whither it is wanted. Soon it was felt that what was really needed was a huge dam at Assouan, to be supplemented by a barrage at Assiout, about three hundred miles lower down the river, which would direct the waters released by the dam in the dry season into canals that could otherwise receive little or none at this time of year. This Assouan dam, which cost about £2,000,000, was completed in the year 1902. A wondrous work it is to see, one, indeed, of which the old Pharaoh.? would have been proud i* their engineers could have found the skill to build it. A mighty granite wall, over 2000 yards in length, is set across the Nile from side to- vide. Above it to the south is a huge lake, in places nearly 200 ft deep, formed by the waters of the river, which the dam 'holds up for a distance of nearly 150 miles. In this wall there are 180 sluices worked by machinery, whereof more or less can be opened as is needful. Never till I stood upon that dam and watched the waters of the Nile tearing through certain of these sluices, did I quite understand the possibilities of force: Indeed, compressed, leaping, foaming, irresistible, these waters thus mastered and bitted by man are still almost fearful to look upon. On an average during the period of collection it holds, or held up when I saw it, about 10,000,000 tons of water a day, or, let us say, some eight per cent, of the total flow of the Nile. The collection ceases in March, after which only sufficient water is caught to balance the loss by evaporation. Then in June and July, when the river is at its lowest and the'tbirsty land aches for moisture, by degrees these pent up waters are let loose, doubling the natural flow of the Nile at that time of the year.—Rider Haggard..