The Nile tributaries of Abyssinia, and the sword hunters of the Hamran arabs, Sir Samuel White Baker [open ebook TXT] 📗

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As the supply of water raised by the sageer is received in a reservoir, from which the irrigating channels radiate through the plantations, so should great reservoirs be formed throughout the varying levels of Egypt, from Khartoum to the Mediterranean, comprising a distance of sixteen degrees of latitude, with a fall of fifteen hundred feet. The advantage of this great difference in altitude between the Nile in latitude 15 degrees 30 minutes and the sea, would enable any amount of irrigation, by the establishment of a series of dams or weirs across the Nile, that would raise its level to the required degree, at certain points, from which the water would be led by canals into natural depressions; these would form reservoirs, from which the water might be led upon a vast scale, in a similar manner to the insignificant mud basins that at the present day form the reservoirs for the feeble water-wheels. The increase of the river's level would depend upon the height of the dams; but, as stone is plentiful throughout the Nile, the engineering difficulties would be trifling.

Mehemet Ali Pasha acknowledged the principle, by the erection of the barrage between Cairo and Alexandria, which, by simply raising the level of the river, enabled the people to extend their channels for irrigation; but this was the crude idea, that has not been carried out upon a scale commensurate with the requirements of Egypt. The ancient Egyptians made use of the lake Mareotis as a reservoir for the Nile waters for the irrigation of a large extent of Lower Egypt, by taking advantage of a high Nile to secure a supply for the remainder of the year; but, great as were the works of those industrious people, they appear to have ignored the first principle of irrigation, by neglecting to raise the level of the river.

Egypt remains in the same position that Nature originally allotted to her; the life-giving stream that flows through a thousand miles of burning sands suddenly rises in July, and floods the Delta which it has formed by a deposit, during perhaps hundreds of thousands of inundations; and it wastes a superabundance of fertilizing mud in the waters of the Mediterranean. As Nature has thus formed, and is still forming a delta, why should not Science create a delta, with the powerful means at our disposal? Why should not the mud of the Nile that now silts up the Mediterranean be directed to the barren but vast area of deserts, that by such a deposit would become a fertile portion of Egypt? This work might be accomplished by simple means: the waters of the Nile, that now rush impetuously at certain seasons with overwhelming violence, while at other seasons they are exhausted, might be so controlled that they should never be in excess, neither would they be reduced to a minimum in the dry season; but the enormous volume of water heavily charged with soil, that now rushes uselessly into the sea, might be led throughout the deserts of Nubia and Libya, to transform them into cotton fields that would render England independent of America. There is no fiction in this idea; it is merely the simple and commonplace fact, that with a fall of fifteen hundred feet in a thousand miles, with a river that supplies an unlimited quantity of water and mud at a particular season, a supply could be afforded to a prodigious area, that would be fertilized not only by irrigation, but by the annual deposit of soil from the water, allowed to remain upon the surface. This suggestion might be carried out by gradations; the great work might be commenced by a single dam above the first cataract at Assouan, at a spot where the river is walled in by granite hills; at that place, the water could be raised to an exceedingly high level, that would command an immense tract of country. As the system became developed, similar dams might be constructed at convenient intervals that would not only bring into cultivation the neighbouring deserts, but would facilitate the navigation of the river, that is now impeded, and frequently closed, by the numerous cataracts. By raising the level of the Nile sixty feet at every dam, the cataracts would no longer exist, as the rocks which at present form the obstructions would be buried in the depths of the river. At the positions of the several dams, sluice gates and canals would conduct the shipping either up or down the stream. Were this principle carried out as far as the last cataracts, near Khartoum, the Soudan would no longer remain a desert; the Nile would become not only the cultivator of those immense tracts that are now utterly worthless, but it would be the navigable channel of Egypt for the extraordinary distance of twenty-seven degrees of latitude--direct from the Mediterranean to Gondokoro, N. lat. 4 degrees 54 minutes.

The benefits, not only to Egypt, but to civilization, would be incalculable; those remote countries in the interior of Africa are so difficult of access, that, although we cling to the hope that at some future time the inhabitants may become enlightened, it will be simply impossible to alter their present condition, unless we change the natural conditions under which they exist. From a combination of adverse circumstances, they are excluded from the civilized world: the geographical position of those desert-locked and remote countries shuts them out from personal communication with strangers: the hardy explorer and the missionary creep through the difficulties of distance in their onward paths, but seldom return: the European merchant is rarely seen, and trade resolves itself into robbery and piracy upon the White Nile, and other countries, where distance and difficulty of access have excluded all laws and political surveillance. Nevertheless, throughout that desert, and neglected wilderness, the Nile has flowed for ages, and the people upon its banks are as wild and uncivilized at the present day as they were when the Pyramids were raised in Lower Egypt. The Nile is a blessing only half appreciated; the time will arrive when people will look in amazement upon a mighty Egypt, whose waving crops shall extend, far beyond the horizon, upon those sandy and thirsty deserts where only the camel can contend with exhausted nature. Men will look down from some lofty point upon a network of canals and reservoirs, spreading throughout a land teeming with fertility, and wonder how it was that, for so many ages, the majesty of the Nile had been concealed. Not only the sources of that wonderful river had been a mystery from the earliest history of the world, but the resources and the power of the mighty Nile are still mysterious and misunderstood.

In all rainless countries, artificial irrigation is the first law of nature, it is self-preservation; but, even in countries where the rainfall can be depended upon with tolerable certainty, irrigation should never be neglected; one dry season in a tropical country may produce a famine, the results of which may be terrible, as instanced lately by the unfortunate calamity in Orissa. The remains of the beautiful system of artificial irrigation that was employed by the ancients in Ceylon, attest the degree of civilization to which they had attained; in that island the waters of various rivers were conducted into valleys that were converted into lakes, by dams of solid masonry that closed the extremity, from which the water was conducted by artificial channels throughout the land. In those days, Ceylon was the most fertile country of the East; her power equalled her prosperity; vast cities teeming with a dense population stood upon the borders of the great reservoirs, and the people revelled in wealth and plenty. The dams were destroyed in civil warfare; the wonderful works of irrigation shared in the destruction; the country dried up; famine swallowed up the population; and the grandeur and prosperity of that extraordinary country collapsed and withered in the scorching sun, when the supply of water was withdrawn.

At the present moment, ten thousand square miles lie desolate in thorny jungles, where formerly a sea of waving rice-crops floated on the surface; the people are dead, the glory is departed. This glory had been the fruit of irrigation. All this prosperity might be restored: but in Egypt there has been no annihilation of a people, and the Nile invites a renewal of the system formerly adopted in Ceylon; there is an industrious population crowded upon a limited space of fertile soil, and yearning for an increase of surface. At the commencement of this work, we saw the Egyptians boating the earth from the crumbling ruins, and transporting it with arduous labour to spread upon the barren sandbanks of the Nile, left by the retreating river; they were striving for every foot of land thus offered by the exhausted waters, and turning into gardens what in other countries would have been unworthy of cultivation. Were a system of irrigation established upon the principle that I have proposed, the advantages would be enormous. The silt deposited in the Mediterranean, that now chokes the mouths of the Nile, and blocks up harbours, would be precipitated upon the broad area of newly-irrigated lands, and by the time that the water arrived at the sea, it would have been filtered in its passage, and have become incapable of forming a fresh deposit. The great difficulty of the Suez canal will be the silting up of the entrance by the Nile; this would be prevented were the mud deposited in the upper country.

During the civil war in America, Egypt proved her capabilities by producing a large amount of cotton of most excellent quality, that assisted us materially in the great dearth of that article; but, although large fortunes were realized by the extension of this branch of agriculture, the Egyptians suffered considerably in consequence. The area of fertile soil was too limited, and, as an unusual surface was devoted to the growth of cotton, there was a deficiency in the production of corn; and Egypt, instead of exporting as heretofore, was forced to import large quantities of grain. Were the area of Egypt increased to a vast extent by the proposed system of irrigation, there would be space sufficient for both grain and cotton to any amount required. The desert soil, that is now utterly worthless, would become of great value; and the taxes upon the increased produce would not only cover the first outlay of the irrigation works, but would increase the revenue in the ratio proportionate to the increased surface of fertility. A dam across the Atbara would irrigate the entire country from Gozerajup to Berber, a distance of upwards of 200 miles; and the same system upon the Nile would carry the waters throughout the deserts between Khartoum and Dongola, and from thence to Lower Egypt. The Nubian desert, from Korosko to Abou Hamed, would become a garden, the whole of that sterile country inclosed within the great western bend of the Nile towards Dongola would be embraced in the system of irrigation, and the barren sands that now give birth to the bitter melon of the desert (Cucumis colocynthis), would bring forth the water-melon, and heavy crops of grain.* The great Sahara is desert, simply because it receives no rainfall: give it only water, and the sand will combine with the richer soil beneath, and become productive. England would become a desert, could it be deprived of rain for three or four years; the vegetation would wither and be carried away by the wind, together with the lighter and more friable portions of the soil, which, reduced to dust, would leave the coarser and more sandy particles exposed upon the surface; but the renewal of rain would revivify the country. The deserts of Egypt have never known rain, except in the form of an unexpected shower, that has passed away as suddenly