46 A History of Art in Ancient Egypt. the side of the desert. An attack upon the flank facing the stream was impossible ; on that side the walls rested upon precipitous rocks rising sheer from the rapids of the Nile. The trace of the walls was a polygon not unlike a capital L. The principal arm was perpendicular to the course of the river. Its flat summit (see Fig. t,o) was about 250 feet by 190 feet. The interior was reached by a narrow passage in the thickness of the masonry, the entrance to which was reached by an inclined plane. The entrance is not visible in our illustration but the incline which leads to it is shown. The walls on the three sides which looked landwards were from fifty to eighty feet high, accord- ing to the ground. They increased in thickness from twenty-six Fig. 31. — A besieged fort, Beni- Hassan ; from ChampoUion, pi. 379. feet at the base to about twelve or thirteen at the summit. Externally their upper parts fell backwards in such fashion that no ladder, however high, would have availed to reach the parapet. We find a similar arrangement in the walls of a fortress represented at Beni-Hassan (Fig. 31).^ The walls of Semneh were strengthened, both structurally and from a military point of view, by salient buttresses or small bastions on all the sides except that which faced the river. These buttresses were either twelve or thirteen in number and from six to eight feet v/ide at the top. In the re-entering angle 1 In this case the incUnation is, however, in the lower half of the wall ; a device which would be far less efficient in defeating an escalade than that at Semneh. — Ed.
