Climbing to the top of one of the highest of these hillocks, we began by surveying the ground. The desert here is firm to the tread, flat, compact, and thickly strewn with pebbles. Of the fine yellow sand which characterizes the Libyan bank, there is little to be seen, and that little lies like snow in drifts and clefts and hollows, as if carried thither by the wind. The tumuli, however, are mounded of pure alluvial mold, smooth, solid, and symmetrical. We counted thirty-four of all sizes, from five to about five-and-thirty feet in height, and saw at least as many more on the opposite side of the river. Selecting one of about eight feet high, we then set the sailors to work; and although it was impossible, with so few men and such insufficient tools, to cut straight through the center of the mound, we at all events succeeded in digging down to a solid substratum of lumps of crude clay, evidently molded by hand. Whether these formed only the foundation of the tumulus, or concealed a grave excavated below the level of the desert, we had neither time nor means to ascertain. It was something at all events, to have convinced ourselves that the mounds were artificial.[126] As we came away, we met a Nubian peasant trudging northward. He was leading a sorry camel; had a white cockerel under his arm; and was followed by a frightened woman, who drew her shawl over her face and cowered behind him at sight of the Ingleezeh. We asked the man what the mounds were, and who made them; but he shook his head, and said they had been there “from old time.” We then inquired by what name they were known in these parts; to which, urging his camel forward, he replied hesitatingly that they had a name, but that he had forgotten it. Having gone a little way, however, he presently turned back, saying that he now remembered all about it, and that they were called “The Horns of Yackma.” More than this we could not get from him. Who Yackma was, or how he came to have horns, or why his horns should take the form of tumuli, was more than he could tell or we could guess. We gave him a small backshîsh, however, in return for this mysterious piece of information, and went our way with all possible speed; intending to row across and see the mounds on the opposite bank before sunset. But we had not calculated upon the difficulty of either threading our way among a chain of sand-banks, or going at least two miles farther north, so as to get round into the navigable channel at the other side. We of course tried the shorter way, and after running aground some three or four times, had to give it up, hoist our little sail, and scud homeward as fast as the wind would carry us.