keep, where the garrison could hold out long after the rest of the town had
fallen into the hands of the enemy.

[Illustration: Fig. 33.--Plan of walled city at Kom Ombo.]

[Illustration: Fig. 34.--Plan of fortress of Kùmmeh.]

[Illustration: Fig. 35.--Plan of fortress of Semneh.]

[Illustration: Fig. 36.--Section of the platform at A B, of the preceding
plan.]

The rectangular plan, though excellent in a plain, was not always
available in a hilly country. When the spot to be fortified was situate
upon a height, the Egyptian engineers knew perfectly well how to adapt
their lines of defence to the nature of the site. At Kom Ombo (fig. 33) the
walls exactly followed the outline of the isolated mound on which the town
was perched, and presented towards the east a front bristling with
irregular projections, the style of which roughly resembles our modern
bastions. At Kûmmeh and Semneh, in Nubia, where the Nile rushes over the
rocks of the second cataract, the engineering arrangements are very
ingenious, and display much real skill. Ûsertesen III. had fixed on this
pass as the frontier of Egypt, and the fortresses which he there
constructed were intended to bar the water-way against the vessels of the
neighbouring negro tribes. At Kûmmeh, on the right bank, the position was
naturally strong (fig. 34). Upon a rocky height surrounded by precipices
was planned an irregular square measuring about 200 feet each way. Two
elongated bastions, one on the north-east and the other on the south-east,
guarded respectively the path leading to the gate, and the course of the
river. The covering wall stood thirteen feet high, and closely followed the