Where the channel began to widen there were some curious narrow gaps or crevices on both sides, the one to the right, with its smooth rounded surface, bearing a great similarity to the famous Ear of Dionysius in Syracuse. The walls contained strata of chalk and ironstone, and Overweg found here some interesting petrifactions. The crevice to the left was less deep, and rather resembled a cell or chamber. Having here waited some time for the boat to come up, we started together, but had still to get through two more narrow passes of the wady, and at four o’clock in the afternoon entered another very narrow defile, the steep cliffs forming it being covered with inscriptions. At length, after a descent of altogether four hours, we emerged into the open plain some 600 feet below, and had a wide view of the high precipitous cliffs of the plateau, stretching out in several buttresses into the plain, which is interrupted only by detached hills. Amongst these was a rather remarkable one upon a terrace-like base, and opening with three caverns towards the roadside. Ascending the terrace, I found the westernmost of the caverns vaulted, as if by art, in the shape of a large niche, but it was a little filled with sand; I found, however, no inscriptions nor anything but four round holes, about nine inches in diameter, hollowed out in a slab on the terrace in front of the cavern. Beyond this hill, where Hatíta told us that he had once passed the heat of the day with ʿAbd Allah (Clapperton) and the tabíb (Oudney), the country is quite open towards the north. About sunset we encamped in the deep Erazar-n-Tese; there were a few talha-trees and some herbage. The following day our route lay over the dreary plain, where nothing but the varied form of the rocky buttresses projecting from the plateau into the plain interrupted the monotony of the prospect. Near the slope the country seems a little less desolate, and the valley Támelelt, which extends between two of the promontories, has even a great reputation among the natives. In the afternoon we entered a sandy region, when we began to ascend gradually till we reached the summit of the sand-hills. We then continued on the higher level, where chalk protruded to the surface. After a long march we encamped on stony ground, covered only with a scanty growth of sebót.