The enterprise was put through with great rapidity, the project fully realising the designs of its inaugurators. By aid of this great structure, 2,500 square miles have been added to the area of the 10,500 miles hitherto subject to cultivation. Its value to the country is at the least worth $100,000,000. The dam extends for one and a quarter miles, and possesses 180 openings, each of which is twenty-three feet high, and will altogether allow the outpour of fifteen thousand tons of water per second. Navigation up and down the Nile has not been impeded, since, by a chain of four locks, vessels are able to pass up and down the river. Each lock is 260 feet long and thirty-two feet wide. During flood-time the gates of the dam are open; while the flood is subsiding the gates are gradually closed, and thus, in a long season of low water, the reservoir is gradually filled up for use through a system of canals, whereby the waters can be drawn off for irrigation and the main flow of the Nile can be increased. The lake thus formed is nearly three times the superficial area of Lake Geneva in Switzerland, and the waters are held back for a distance of 140 miles up the course of the river. The reservoir is filled during the months of January and February, and from April to the end of August the water is let out for irrigation purposes from the bottom of the reservoir, thus enabling the sediment, which is of such value, to be carried out through the sluices. Four or five waterings are allowed to percolate from it to the various regions which are thus brought under cultivation, and besides this the main supply of the river itself is artificially increased at the same time.
The dam has been constructed of granite ashlar taken from quarries near Aswan. These quarries are the very same from which the ancient obelisks were hewn. The amount of rock used was about one million tons in weight. In building the dam it was found to be very difficult to lay the foundation, since the bottom of the river proved to be unsound, although in the preliminary reports it had been declared to be of solid granite. In some instances it was found necessary to dig down for forty feet, in order to lay a perfectly secure foundation on which the heavy wall could be superimposed. This required much additional labour, and great risk and damage was encountered during the progress of the work at the date of the impending rise of the waters of the Nile. Rubble dams were raised to ward off the waters from the point where it was necessary to excavate. The holes were gradually filled with solid blocks of granite; then the base of the structure, one hundred feet in width, was laid, and the massive piers, capable of resisting the immense pressure of the water during the height of the floods, were raised, and the whole edifice was at length completed with great rapidity by the aid of many thousand workmen, just before the rise in the Nile occurred. The official opening of the dam took place on the 10th of December, 1902.
The dam at Aswan is the greatest irrigation project ever yet undertaken, but is by no means the last one likely to be executed in relation to the waters of the Nile. A smaller dam is to be constructed at Assiut, in order to supply a system of irrigation in the neighbourhood of that city, and also to carry water across to thousands of acres between this region and Cairo. This project is planned somewhat after the design of the barrage which is below Cairo.
It is impossible to forecast what engineering skill may have in store for the future of Egypt. One may hope, at least, that the most prosperous days of the Pharaohs, the Ptolemies, and the Romans will be reproduced once more for the modern Egyptians, as an outcome of the wise administration which has originated through the occupation of the country by the English, as an international trust held for civilisation. By aid of British initiative, Egypt now controls a vast empire in equatorial Africa and the Sudan, and the great water ways of this immense territory are being gradually brought under such control that the maximum advantage to all the population will be the necessary result. The whole Nile is now opened to commerce. The British have guaranteed equal rights, and what has been called the policy of the “open door,” for the commerce of all nations.
The history of the modern exploration of the Nile is closely associated with the history of Egypt in modern times. The men who first visited Egypt and ascended the Nile valley were in almost every case Indo-Euro-peans. The early Egyptians were familiar perhaps with the Nile as far as Khartum, and with the Blue Nile up to its source in Lake Tsana, but they showed little or no interest in exploring the White Nile. In 457 B.C., Herodotus entered Egypt, and ascended the Nile as far as the First Cataract. He then learned many things about its upper waters, and made enquiries about the territories which lay beyond. He heard that the source was unknown; that there was a centre of civilisation in a city of the Ethiopians, in the bend of the Nile at Meroë (Merawi of to-day), but about the regions beyond he was unable to learn anything. Eratosthenes, the earliest geographer of whom we have record, was born in 276 b. c. at Cyrene, North Africa. From the information he gathered and edited, he sketched a nearly correct route of the Nile to Khartum. He also inserted the two Abyssinian affluents, and suggested that lakes were the source of the river.
When Rome extended her domains over Egypt, in 30 B.C., the interest of the Romans was aroused in the solution of the problem of the discovery of the source of the Nile. Strabo set out with Ælius Gallus, the Roman Governor of Egypt, on a journey of exploration up the Nile as far as Philæ, at the First Cataract. About 30 B.C. Greek explorers by the names of Bion, Dalion, and Si-mondes were engaged in active exploration of the Nile above the First Cataract and perhaps south of Khartum, according to the account of Pliny the Elder, writing in 50 A.D. The Emperor Nero, in A.D. 66, sent an expedition up the Nile, and its members journeyed as far as the modern Fashoda and perhaps even beyond the White Nile. Their advance was impeded by the sudd, and, after writing discouraging reports, their attempt was abandoned. Among the Greek merchants who traded on the East African coast was one named Diogenes, who had been informed by an Arab that by a twenty-five days’ journey one could gain access to a chain of great lakes, two of which were the headwaters of the White Nile. They also said that there was a mountain range, named from its brilliant appearance the Mountains of the Moon. He was informed that the Nile formed from the two head streams, flowed through marshes until it united with the Blue Nile, and then it flowed on until it entered into well-known regions. Diogenes reported this to a Syrian geographer named Marinus of Tyre, who wrote of it in his Geography during the first century of the Christian era. The writings of Marinus disappeared, it is supposed, when the Alexandrian Library was scattered, but luckily Gladius Ptolemy quoted them, and thus they have been preserved for us. Ptolemy wrote, in 150 A.D., the first clearly intelligible account of the origin of the White Nile, the two lakes, Victoria and Albert Nyanza, and the Mountains of the Moon. But no less than 1,740 years elapsed before justice could be done to this ancient geographer, and his account verified. It was Sir Henry M. Stanley who discovered the Ruwanzori mountain range, corresponding to the classical Mountains of the Moon, and who thus justified Ptolemy’s view of the topography of Africa. For many years after Ptolemy, the work of exploring the sources of the Nile was entirely discontinued, and the solution of the problem was still wrapped in impenetrable mystery.
The first modern explorer of any consequence who came from Great Britain was a Scotchman named Bruce. In 1763 he travelled through many ports of Northern Africa and visited the Levant, and subsequently Syria and Palestine. Wherever he went he drew sketches of antiquities, which are now preserved in the British Museum. Landing in Africa in 1786, he went up the Nile as far as Aswan. From there he travelled to the Red Sea and reached Jiddah, the port of Hajas. He then returned to Africa, stopping at Massawra, and from there penetrated into the heart of Abyssinia. The emperor received him with favour and suffered him to reach the Blue Nile, which to the mind of Bruce had always been considered as the main stream of the Nile. Having determined the latitude and longitude, he went down the Blue Nile as far as the site of Khartum, where the waters of the White Nile join with those of the Blue Nile. He next proceeded to Berber, and crossed the desert to Korosko, returning, after a three years’ journey, in the year 1773. In journeying through France many learned men took a great interest in the story of his explorations, but he was bitterly disappointed to hear that he had not been the first to reach the sources of the Blue Nile. Partly for this reason he delayed publishing his travels for seventeen years after his return. Bruce was a truthful and accurate writer, but nevertheless his book was received on all sides with incredulity. Although received at the British court, he was not given any special honours or decorations. He first pointed out the great importance to England of controlling the Egyptian route to India, and he also secured for English merchants a concession on the Red Sea.
In 1812, John Ludwig Burckhardt, of Swiss nationality, the first among Europeans, made a pilgrimage to Mecca and then travelled up the Nile to Korosko, after which he crossed the desert to Berber and Shendy. His death occurred after his return to Cairo, and he left a valuable collection of Oriental manuscripts to the University of Cambridge, England, which were published after his death.
In 1827, a Belgian, named Adolphe Lisiant, ascended the White Nile to within 150 miles of Khartum. The expedition which he led was aided by an English society, called the “African Association,” which became afterwards a part of the Royal Geographical Society. Many explorers visited the White Nile between 1827 and 1845. In 1845, John Pethrick, a Welshman, explored the Nile for coal and precious metals in the interest of Mehemet Ali. After the death of this pasha, Pethrick visited El-Obeid in Kordofan as a trader, and remained there for five years. In 1853 he ventured upon an enterprise relating to the ivory trade. For this purpose he travelled backwards and forwards upon the White Nile and the Bahr-el-Ghazal for a period of six years, reaching some of the important affluents of the Bahr-el-Ghazal, the Jur and the Jalo, or the Rol. Returning to England, he was commissioned to undertake a relief expedition to help Captains Speke and Grant, who had set out upon their journey of exploration, and in the year 1861 he returned to Central Africa. Interest in the slave-trade deterred him from following the directions under which he had been sent out, namely, to bring relief to Speke and Grant. Sir Samuel Baker anticipated him in relieving the expedition, and this so angered Speke that he attempted to have Pethrick deprived of his consular position. Pethrick died in 1882.