42 A History of Art in Ancient Egypt and it still exists in a fair state of preservation, to the west of the northern necropolis (Fig. 28). After examining many possible hypotheses, Mariette came to the conclusion that this was a military post intended to watch over the safety of the necropolis, and to keep an eye upon the caravans arriving from the desert. Robber tribes might otherwise be tempted to make use of any moment of confusion for the pillage of the temple. There were Fig. 28. — Military post at Abydos ; perspective from the plans, etc., of Mariette. curious arrangements for the purpose of guarding against a coup- de-main. Within the outer wall, which is provided with small gateways, there is a covered way extending round the whole fort, and commanded by the inner wall. Before the inner court could be reached, an enemy had to traverse a narrow and crooked passage in the thickness of the wall, which was well calculated to secure the necessary time for a moment of preparation in case of surprise (Fig. 29). i I i I FT
Fig. 29. — Military post. Plan of the entrances ; from Mariette. The most curious relic of the military engineering of the Egyptians is to be found in Nubia. Thirty-seven miles south- ward of the cataracts of Wadi-Halfah the Nile has worn a channel through a long chain of granite hills which run across the valley from east to west. On each side of the river-bed these hills rise to some height and across its torrent there are a few detached rocks, which once formed a natural dam, but between which