The caravan spent six days in the double oasis of Ghat and Barakat, where crops of green millet, taking the place of barley and rye, indicated the neighbourhood of Nigritiá. The gardens were neatly fenced and carefully cultivated; turtle-doves and pigeons cooed among the branches; the clean, well-built houses were each provided with a terraced roof. Dr. Barth observed that the male inhabitants worked with industry and intelligence; as for the women, almost every one had a babe on her shoulders, and children swarmed by the wayside. As a whole, the population was far superior, physically and morally, to the mixed, hybrid race of the Fezzan. They left the gracious and grateful oasis to plunge into the desert, a chaos of sandstone and granite rocks. On the 30th of July, they reached the junction-point of two ravines which formed a sort of “four-ways” among these confused masses. The wady which crossed their route was about sixty feet broad, but, at a short distance, narrowed suddenly into a defile between gigantic precipices upwards of a thousand feet in height—a defile which in the rainy season must be converted into a veritable cataract, to judge from an excavated basin at the mouth, which, when Dr. Barth and his companions passed, was full of fresh and limpid water. This “four-ways,” and these defiles, form the valley of Aguéri, long known to European geographers by the name of Amaïs. The unpleasant intelligence now arrived that a powerful chief, named Sidi-Jalef-Sakertaf, projected an expedition against their peaceful caravan. Fortunately, it was only a question of the tribute which, by right of might, the Towaregs levy from every caravan that crosses the desert. Sidi-Jalef-Sakertaf was pacified; and the enthusiasts went on their way through sterile valleys and frowning defiles that would have daunted the courage of any but a votary of science and adventure. They next arrived at Mount Tiska, which is six hundred feet in height, and surrounded by numerous lesser cones. It forms a kind of geological landmark; for the soil, hitherto so broken and irregular, thenceforward becomes smooth and uniform, while rising gradually, and the vast plain stretches far beyond the limit of vision without anything to interrupt its arid monotony. A two days’ journey brought our travellers to the well of Afelesselez. It is utterly wanting in shade; only a few clumps of stunted tamarisks grow on the sandy hillocks; but, desolate as it is and uninviting, the caravans resort to it eagerly, on account of its supply of fresh water.