Place elephants for want of towns.”
The last generation has seen these mediæval ideas considerably modified. Travel and war have been the means of filling much of the blank space; the arts of peace have followed in their wake; African railways would occupy quite a respectable page in a world-wide Bradshaw; and the Stock Exchange in a searching for economy of syllables has irreverently shortened the poetical Tanganyika to the practical Tank. The great flat plain is last to go;—the millions of acres of rather light soil which the French have been so unaccountably anxious to daub with their colour on the map. We have given up the lions; we know that such carnivorous beasts can only live in a fairly fertile country which supplies sufficient food to their prey. But we have clung to the plain and the sand. Nevertheless it seems that they must go too. We read that you may travel for days in the Sahara on rocky hills and not find enough sand to dry your signature. So perish the beliefs of youth.
Yet to any picture of Algeria the Sahara supplies a romantic background. The sight of a caravan arriving from some distant oasis still has power to stir the imagination. Even in face of our information as to the Sahara’s only partial sterility, we cherish some shreds of wonder at the men who can wring a livelihood and find the means of travel under such inhospitable conditions.
The Sahara has been defined as the region which receives only as an exception any rainfall, whether of Mediterranean origin, or from the tropical regions of West Africa. It is only relatively a desert in the strict sense of the word; no part of it is absolutely without rain, and even in the districts which are reputed the most dry the traveller may meet with violent storms. The generally arid nature of the soil is due to the fact that water circulates not on the surface, but underground. Where it comes to light either by natural or artificial means, a focus of intense cultivation, an oasis, is produced.
The Algerian Sahara is only a portion of the great desert of Northern Africa. Yet it is ten times the size of Algeria itself. It consists roughly of two great depressions separated by an isthmus of calcareous hills. Each of these basins contains a great expanse of dunes, and the two chief groups of oases occur in their lower levels. A generation ago it was commonly believed that the Sahara was the bed of a sea which had disappeared at no very distant date; and projects were formed of admitting the Mediterranean by means of a canal. But more precise knowledge has shown that its sterility is due to other causes; that like the rest of the continent it has its ancient conformation of mountain and plain; that it has distinctive flora and fauna long established; and that the portion which lies below the level of the Mediterranean is of very small extent.
Between eighty and ninety per cent of the surface is of rock, slightly undulating and broken occasionally by perpendicular ravines and large crevasses. Here, as a rule, no water can be found, and the only vegetation is an occasional thorny shrub. With the regions of the sand dunes it is different. Their sterility is by no means absolute. They have a vigorous vegetation of their own, which will support camels, and even sheep at a favourable season. They absorb eagerly the rainfall which runs off the rocky plateaux, and acting as a sponge retain it for a long period. Their comparative barrenness is due only to the dryness of the climate; wherever they can be irrigated they become fertile.
Of the underground rivers the best known is the Oued Rir, which is met with about fifty miles to the south of Biskra, and extends as far as Temacin, fourteen miles south-west of Touggourt. Its course is marked by a number of oases, some of which have been created, and others much improved by the Artesian wells of the French engineers. The first experiment of this sort was tried as early as 1856 at the oasis of Tamerna. After twenty-two days of work, in the presence of a crowd of incredulous and scarcely friendly natives the bore produced a veritable river of a thousand gallons a minute.
“In the desert a fountain is springing.”
At this welcome spectacle, the ingrained distrust of and smothered hostility towards the stranger and his methods vanished; all gave way to a transport of joy and enthusiasm. The work thus begun has been continued with great success, chiefly by French companies; new wells have been sunk and old wells repaired; and it is estimated that the value of the oases of the Rir has increased fivefold, and their population more than doubled.
