_March 8th._ From Seras we ascended a high mountain. The rock, which had been everywhere sand-stone as far as Wady Halfa, changes its nature at the second Cataract, where grunstein and grauwacke predominate; these primitive rocks continue throughout the Batn el Hadjar. In the mountain beyond Seras are granite, and immense rocks of quartz: the grunstein rocks are also every where crossed by strata of quartz. Three or four hours east of our route, a high chain of mountains extends parallel with the course of the river; it bears the name of Djebel Bilingo (جبل بَلَنكو), and is uninhabited: it is regularly visited by winter rains, and the water remains in the clefts and hollows the whole of the summer. In two hours and a half we came to a plain on the top of the mountain, called Akabet el benat (عقبة البنات), the rocks of the girls. Here the Arabs who serve as guides through these mountains have devised a singular mode of extorting small presents from the traveller: they alight at certain spots in the Akabet el benat, which they call قبضه or مقبضه, and beg a present; if it is refused, they collect a heap of sand, and mould it into the form of a diminutive tomb, and then placing a stone at each of its extremities, they apprize the traveller that his tomb is made; meaning, that henceforward, there will be no security for him, in this rocky wilderness. Most persons pay a trifling contribution, rather than have their graves made before their eyes: there were, however, several tombs of this description dispersed over the plain. Being satisfied with my guide, I gave him one piastre, with which he was content. On the southern descent of Akabet el benat, the principal rock is micaceous schist and chlorite, and farther down, towards the Wady Attyre, fine porphyry rocks are met with. I saw only a few specimens of green porphyry, with red slabs of feldspath; the greatest part being red porphyry, and porphyry schist. I possess specimens of all these rocks. From Seras, our route lay S. W. by S. Four hours and a half, Wady Attyre (التّيره), the principal village in the Batn el Hadjar. Here again, there are several islands in the river, with ruins of ancient brick habitations and towers upon them. The shores seem to have offered little security, even in ancient times, for I met with no ruined buildings on the eastern bank of the Batn el Hadjar; the ancient inhabitants seem to have exclusively chosen the islands for their abode. There is another cataract in the river at Wady Attyre, and a similar one between that place and Seras, opposite to Samne, on the west bank. We continued in the Wady Attyre upwards of an hour. Some date trees grow in all these Wadys, but the Doum is more common. At five hours, a wild passage across the mountain begins, called Akabet Djebel Doushe (عقبة جبل دوشه). From the top of it I enjoyed a beautiful view of the course of the river to the southward; but its narrow verdant banks are almost lost in the wide expanse of the