60 NORTH-WEST AFRICA. a few cabins and shapeless ruins. But at least one " large city " formerly stood on this 8<'aboard, the i)lace in medioeval times by Abu Obeid Bakri named Sort, whose ruins are still known to the Arabs under the appellation of Medinet-en- Sultan, or " City of the Sultan." Sort, or Sirt, was formerly the starting-point of caravans bound for the interior of the continent through the oases of Wadan and Murzuk. But being unable to defend themselves against the attacks of the nomad Bedouins, its merchants were compelled to choose another route to the east of the plateaux, traversing oases which were inhabited by settled agricultural communities. Amongst the ruins of Sort are the remains of some Roman struc- tures, as well as aqueducts and reservoirs still in a good state of repair. Like the coastlands themselves, the whole of the steppe region stretching thence southwards is destitute of towns, although here the wells and depressions in the wadies, where water collects in greatest abundance, serve as natural trysting-places for the surrounding nomad pastoral tribes. Towns, properly so called, are found only at the foot of the Hariij and Jebel-es-Soda, where the running waters are copious enough to feed the palm groves and irrigate the cornfields. Even the natural oases following in the direction from east to west under the same latitude as those of Aujila and Jalo are uninhabited. Jibbena, to the east, Marad^, in the centre, and Abu Nairn, farther west, are the three chief depressions whose spontaneous vegetation seems most likely to attract future agricultural settlers. All these districts stand at least about 150 feet above the level of the sea. Towards the north, in the direction of the Great Syrtis, as well as on the opposite side towards the spurs of the Hariij, the surface is broken by limestone rocks, witnesses of a former plateau, weathered or perhaps eroded by running waters, and worked in all directions into the form of columns and fantastic struc- tures. These rocks abound in fossils, in many places constituting the whole mass, while the sands of the oases are strewn with countless shells and foraminiferae. In the east, towards the Aujila oasis, the view is obstructed by dunes which are amongst the highest in the whole region of the desert, some rising to a height of about 530 feet. The three oases abound in palms ; which, however, with the exception of a few thousand, all grow wild, or have lapsed into the wild state, springing up like scrub, and yielding a poor fruit without kernel. In the Abu Nairn oasis there are probably no male dates, while the female plants are not fertile. All three oases produce a species of crab or wild apple-tree, whose fruit is no bigger than a walnut. The neighbouring tribes, or bands of marauders roaming over the steppes, come occasionally to gather the dates and graze their camels in the grassy hollows of these oases. Jibbena and Marade were still inhabited down to the middle of the present century; but in 1862 only a solitary person remained in Marade, a slave left to watch the raiders, and report their depredations at the annual visit of his masters. The establishment of a colony at the fountains of Abu Naim is prevented chiefly by the bad quality of the water, which is very sulphurous, or charged with the sulphate of magnesia. Doubtless the time will come, says Rohlfs, when a visit to these sulphur baths of east Tripolitana will be recommended by European physjcians as
