IRRIGATION IN LOWER EGYPT.
How many of the engineering works of the nineteenth century will there be in existence in the year 6000? Very few we fear, and still fewer those that will continue in that far-off age to serve a useful purpose. Yet there is at least one great undertaking, conceived and executed by an engineer, which during the space of 4000 years has never ceased its office, and on which the life of a fertile province absolutely depends to-day. We refer to the Bahr Joussuf, the canal of Joseph, built, according to tradition, by the son of Jacob, and not the least of the many blessings he conferred on Egypt during the years of his prosperous rule. This canal took its rise from the Nile at Asiut, and ran nearly paralle with it for nearly 250 miles, creeping along under the western cliffs of the Nile valley with many a bend and winding, until at length it gained an eminence, as compared with the river bed, which enabled it to turn westward through a narrow pass and enter a district which was otherwise shut ofl from the fertilizing floods on which all vegetation in Egypt depends. Just as the modern miller diverts a part of the water of a river, and leads it in a gently flowing stream along an almost level course, until he can deliver it on to the top of a high wheel whose lower edge revolves above the river’s brink, so Joseph prepared a smoothly flowing channel, of which the northern end stood seventeen feet above low Nile, while at the southern end it was at an equal elevation with the river. Through this cut there ran a perennial stream which watered a province named the Fayoum, endowing it with fertility and supporting a large population. In the time of the annual flood a great part of the canal was under water, and then the river’s current would rush in a more direct course into the pass, carrying with it the rich silt which takes the place of manure, and keeps the soil in a state of constant productiveness.
All this, with the exception of the tradition that Joseph built the canal, can be verified to-day and is not mere supposition or rumor. Until eight years ago it was firmly believed that the design had always been limited to an irrigation schemo, larger no doubt than that now in operation, as shown by the traces of abandoned canals and by the slow aggregation of waste water which had accumulated in the Birket el Qerun, but still essentially the same in character. It is true there were Mohammedan traditions, which related that the part performed by the canal in irrigation was merely a subsidiary portion of its functions, and that it served a much grander purpose, one that ranked among the greatest, if it were not the greatest, of the many marvels of Egypt. But the western mind is apt to despise the tales of the Orient, finding the modicum of truth they contain overlaid with such an intolerable amount of exaggeration and poetical hyperbole, that it does not usually repay the laborious process of winnowing, which is necessary to separate from the fiction with which it is associated. Other accounts there were, written by Greek and Roman historians, such as Herodotus, Strabo, Mutianus and Pliny, and repeated in monkish legends or portrayed in the maps of the middle ages, which agreed with the folk-lore of the district. These tales explained that the canal dug by the ancient Israelite served to carry the surplus waters of the Nile into an extensive lake lying south of the Fayoum, and so large that it not only modified the climate, tempering the arid winds of the desert and converting them into balmy airs which nourished the vines and the olives into a fullness and a fragrance unknown in any part of the country, but also added to the good supply of the land such immense quantities of fish that the royal prerogative of the right of piscary at the great weir was valued at ,£50,000 annually. This lake was said to be 450 miles round, and to be navigated by a fleet of vessels, while the whole circumference was the scene of industry and prosperity.—Engineering.