H48 NORTH-WEST AFRICA. and all the land draining to the desert, as far as the Algerian frontier, have hitherto been traversed only by two or three Europeans. Of Caille's expedition little is known beyond its approximate line of march ; Rohlfs merely skirted on the north the main Atlas range, which Lcnz crossed at its southern extremity. But De Foueauld, disguised as a Jew, penetrated much farther inland, surmounting the Atlas at several points, discovering the Bani range, determining over forty astronomic positions and three thousand altitudes. But a detailed account of his explorations, with the maps and other documents embodying the result of his surveys, still awaits publication. The Atlas Highlands. In Marocco the Atlas system attains its greatest elevation. Here the main range runs south-west and north-east, following the axis of north-west Africa from Cape Blanc through Cape Bojador to the headland of Algiers. The whole coast region between the mouths of the SAs and Moluya lies, so to say, beyond the continental mass dominated by uplands already belonging to the intermediate zone now pierced by the Strait of Gibraltar. The range deviates slightly from the normal north-easterly direction, developing a sort of arc, with its convex side turned towards the Sahara. Excluding the subordinate ridges and those continuing the system in Algeria, it has a total length of about 360 miles between Cape Gher north of the Sds and the Jebel Aiashin, forming its extreme north-eastern rami- fication. No collective name is applied to the system by the natives, who restrict the general term Idraren, or " Mountains," or Idraren Deren, to its western section. The word Deren is evidently the same as the Dyris or Dyrin known to Strabo. The Jcbcl Aiashin (Aiashi) appears to be one of the loftiest chains in Marocco. According to Rohlfs and De Foueauld, the only modern explorers who have yet described this part of the Atlas, its summits are distinguished from all the sur- rounding crests by their snowy whiteness. Rohlfs even confirms the statement of the Roman general, Suetonius Paulinus, that they are covered with perpetual snows. But he visited these uplands in the month of May, and the natives questioned by him may have spoken of the snows which remain in the crevasses and ravines impenetrable to the solar rays. But however this be, the Jebel Aiashin, or Magran, as it is also called, probably rises to a height of 11,600 feet, being surpassed in elevation only by a few peaks in the main range. It is composed chiefly of sandstones and schists, and throws off some lateral ridges, constituting parting lines between several river basins.. Westward stretches the Ait-Ahia, continued through the Aian and the rocky spurs which rise above the plains of Fez. To the north-east the Jebel Tamarakuit, a branch of the Aian, follows the normal direction of the Atlas system. One of its depressions is flooded by the lovely alpine lake Sidi Ali Mohammed, in whose clear waters are mirrored the wooded slopes of the surrounding hills. The Tamarakuit 18 continued north-eastwards by a range, which is pierced by the Moluya and
