THE KIJFEA OASIS. 29 like a mass of petrified lentils. Not a single well affords refreshment to caravans in this frightful solitude, and the inhabitants of Eufra take care that none arc sunk. They are anxious to keep aloof from the rest of the world, for they are a " feeble folk," probably less than a thousand souls altogether, and they would have long ago lost their independence had the Turkish troops been able easily to reach the depression. But although wrongly marked on many maps as included in the government of Tripolitana, the Kufra oases have none the less been conquere<l by a foreign power, that of the Seniisiya brotherhood. Through their religious propaganda, the Algerian Khwans have become the true masters of the district ; and were the mother-house at Jarabiib threatened by any Christian or Osmanli forces advancing from the coast, they would endeavour to establish the centre of their power farther inland, in their great Zawya of El-Istat. At the time of his visit, Rohlfs had ample opportunity of observing how absolute was their authority in the place. Threatened by them, he escaped with his life only by flight ; but as soon as he found himself protected by a formal order of the Mahdi of Faredgha, he commanded the homage of all, and his property was strictly respected. The Kufra oases do not lie below sea-level, as was supposed when the series of depressions was discovered which stretches from the Egyptian oases to the Gulf of Sidra. From the Aujila oasis, which stands below the Mediterranean, the ground rises imperceptibly towards the Taiserbo oasis, the northernmost of the Kufra group, where it already attains an elevation of 830 feet. Kababo, southernmost of the same group, is 1,300 feet high, and the land probably continues to rise in the southern desert as far as the Wajanga oasis. While an ocean of shifting sands rolls away to the north and north-east, dunes are everywhere rare in the Kufra district, except towards the centre, where they enclose the Buseima oasis. West and south they disappear completely, and here is everywhere visible either the bare rock or the marshy soil constituting the ground of the oases. The hills rising abruptly above the palm groves and the surrounding steppes consist of masses of Nubian sandstones and limestones overlaid with lavas. Separated one from the other, these hills appear to be the remains of a formerly continuous plateau, which has been mostly weathered or eroded by running waters, leaving nothing but detached fragments as proofs of its former existence. They are of almost uniform height, except that the ideal plain connecting all the summits, and probably coinciding with the ancient surface of the plateau, gradually ascends in the direction from north to south. Rohlfs nowhere discovered any fossiliferous rocks, but the sand contains a large number of vitrified tubes, products either of electric discharges or of organic secre- tions. Here and there the surface is also strewn with lound sandstone masses of all sizes, producing the effect as if the plain were some vast arsenal stored with shells, balls, and bullets of all kinds. Of these concretions some are hollow, while others have a solid core or are filled with loose sand. Good water exists in superabundance in the Kufra oases, and may be everywhere reached by sinking wells to a depth of from 3 to 10 feet. In ihis respect Kufra is
