Page:Africa by Élisée Reclus, Volume 2.djvu/90

 the Ben-Afien serir, plateaux of slight elevation strewn with stones and shingle, which greatly impede the progress of the wayfarer. South of the erest of the Jebel-es-Soda a space of about 80 miles has to be traversed before reaching the escarpment at the foot of which begins Fezzan properly so called. In this almost absolutely desert district the stony surface is broken only by a single green depression, that of the Fogha oasis. The base of the Red Harûj is abruptly limited by the Wady Heran, the first occurring in Fezzan proper. A few trees are here occasionally met in the moist depressions near the wells; but throughout nearly its whole course the wady presents little to the traveller's wearied gaze beyond shifting sands interspersed with sandstone blocks blackened by the heat. Nevertheless,

the aspect of the valley changes at its confluence with a broader wady skirted on the north by the escarpments of the spurs of the Black Mountains. The bed of this Wady-esh-Shiati, as it is called, is covered with a layer of humus, through which the roots of the palm-trees penetrate to a mean depth of 10 feet before striking the moist sands underneath. According to the measurements taken by different explorers, the altitude of the wady varies from 1,150 to 1,650 feet, but from these data no idea can be formed of the real slope of the valley, which may possibly be even more elevated towards the centre than at either extremity.

South of the Wady-esh-Shiati, which is lost eastwards amid the cliffs of the White Harûj, the ground merges in a terrace which in some places has a breadth