ISLAND OF ATAB inner walls were built in alternate layers of pieces of black basalt and mud bricks, and when in a complete state must have been very strong. On the east side were some small chambers, with little side rooms, which may have been used for prisoners or for bedrooms. We searched everywhere, hoping to find something which would give us a clue to the age of the building, but found nothing. The scenery of this portion of the Cataract was wild and picturesque in the extreme, and the view of the river to the south, in which bright green eyots, massive black rocks, yellow sand, patches of emerald green vegetation, stretches of rugged desert, and hills sloping down to the water's edge on both sides were mingled together in harmonious confusion, is one which, of its kind, cannot be surpassed. From the southernmost point of the " Castle," which must have been about 50 feet above inundation level, a splendid view of the country for many miles was obtained. The numerous rapids round the island make the work of landing, even at low Nile, very difficult, and during the inundation it must be almost inaccessible.

Between the Island of Atab and Kosha, our destination, the river contains many rocky barriers which are visible, and large numbers of sunken rocks, of which the whereabouts are only known to the most expert watermen. Our captain knelt down on the sand and pra)'ed with great fervour before he started to take us to Kosha, and when we were floating between the treacherous rocks which his skill enabled us to avoid, we noticed that he had tied a small cotton bag to his rudder post. In answer to our question he told us that the bag contained a small quantity of dust which he had taken from the tomb of Shekh Idris, and that he had brought it with him to secure the protection of the shekh, who, he believed, would vouchsafe us a safe journey. Every traveller in the East is familiar with the native belief that dust taken from the grave of a holy man forms an effective amulet, but it was interesting to note the survival of this belief and the practical expression of it in the Sudan in the twentieth century. When we had been floating down the river for an hour or so, we began to realize that there were reasons for the precautions which the captain had taken, for we found ourselves hemmed in with rocks. We steered to the bank and the crew got out and began to tow 469