Page:Africa by Élisée Reclus, Volume 2.djvu/40

 the valley;" otherwise the caravan folk heap the surrounding stones into a cairn to serve as tho tomb of the niggard. This is a kind of "anathema" analogous to that raised by the Greek peasantry against the tax-gatherer.

Thus limited southwards by the Wady Fareg, the Bir Rassam, the Wady of the Aujila oases, Gerdoba uud Siwah, the limestone plateau of Cyrenaica and Marmariea would seem to form a large island almost detached from the rest of the continent. There can be no doubt that the whole of this depression of the wadies and oases was formerly flooded with the Mediterranean waters. After their separation from the sea by intervening strips of coastlands, the marine basins gradually evaporated under the fierce sun of Africa. But the waters have left clear traces of their existence in the banks of recent shells, the deposits of salt, gypsum, saltpetre, magnesia, and numerous "bitter lakes." Thus from one extremity to the other of the Gulf of Sidra, there is an exact parallelism in the

physical aspect and relief of the several regions, and in the natural phenomena of which they have been the scene. On both sides low-lying tracts stretch far inland, some of which lie below sea-level, and are supposed to have formed marine inlets at some more or less remote period. It has been proposed to convert both basins into an "inland sea," through which the Mediterranean waters might penetrate into the interior of the continent. After his first explorations in the Libyan oases, Rohlfs thought that by simply piercing the riverain sill on the Gulf of Sidra, it might be possible to flood a large part of the continent as far as the Kufra oasis, under the 22° north latitude, “whereby the largest vessels might reach Fezzan, perhaps even the oasis of Wajanga." But more recent surveys have shown that the geographical changes produced by these projects would be far less important than was supposed; in any ease, the results of more accurate measurements must be awaited before there can be any question of creating an "inland sea."