T01»0GRAPIIY. 57 highly efficacious. Sulphur bod.s uro numerous in this region, unci u littlo to the north of the ousis uro Hituated the mines whoso produce is exjwrted from the littlo port of limitja. The oasis of Zilla, or Zalla^ lying in a rock-enclosed cirque at the northern foot of the Black Hariij, is one of the most densely jK^opled in the whole of Trii>olitana. In 1879 it contained about twelve hundred persons, members for the most part of the Arab tribe of the Aulad Khris. The cirque has a length east and west of 7 miles, with a breadth of 3 north and south. With the Tirsa oasis lying farther north, it contains about a hundred thousand date-palms. At the time of Beurmann's visit, in 1802, Tirsa was still inhabited, but has since been abandoned, probably owing to the dangerous proximity of the Orfella Arabs. This tribe, say the Aulad Khris, arrived ten centuries ago from Egypt, and after driving out the Christian ix)pulation8, became the guides and escorts of caravans bound for Central Africa. Edrisi relates that their town was the chief station between Sort and the Zwila oasis in Fezzan. But the " City of the Sultan," as it was called, has disappeared, and at present the chief outlet for the exports of the country lies nmch farther west, at the port of Tripoli. The people of Zolla take no part in this traffic except by devious ways. At the time of Rohlf's visit, in 1879, they had for several years been compelled to avoid the direct route to Tripoli, fearing the vengeance of the Orfellas, whose territory lay across their path, and some fifty members of which tribe they had killed in a fray. On the other hand, they venture freely far into the southern wilderness, and to them in recent times has been due a real geographical discovery, that of the inhabited oasis of Wau-el-Namus, which no European has yet visited. Of all the Tripolitan Arabs, the inhabitants of Zella are the richest in camels. They are also the only tribe still occupied with ostrich farming, although since the journey of Hamilton this industry has fallen ofp. In 1879, two of these birds, fed on dates, yielded to their owner a net yearly profit of from £6 to £8. Although larger and more populous than that of Zella, the Jofra oasis is far less rich in cultivated palms. Scarcely a twentieth part of the 800 square miles com- prising its whole area is under cultivation for dates, corn, or fruits. Its very name of Jofra, irovcvjof, stomach, indicates the form of the oasis, which is an elongated cirque stretching east and west, and everywhere encircled by hills rising 650 feet above the plain. A range of heights, running north and south, that is, in the direction of the short axis of the cirque, and interrupted at intervals, divides the oasis into two equal parts, each with its gardens, palm groves, grassy steppes, stony wastes, and saline lakes. Sandy gorges, in which water is rarely seen on the surface of the ground, converge towards the north of the twin oases in the Wady Missifcr, which, under another name, winds through the plain as far as the Great Syrtis. Although situated on the Mediterranean slope, Jofra belongs administratively to the province of Fezzan. Its inhabitants long maintained their independence, paying no taxes either to Tripoli or to Murzuk. At that time they constituted a small but sufficiently powerful republic, which afforded a refuge to the oppressed 86— AF
