If we turn first to the ground-plan, we find already in the Pergamos that the ancient walls were ?anked by salient, massive, tower-like bastions recurring at pretty regular intervals, from which the intervening wall-sections could be watched and laterally swept by the missiles thrown from the beleaguered stronghold. This is specially shown in the old central gate — a colossal, massive structure with a narrow, tunnel-like gate way, which in the first instance was intended to defend the causeway crossing the moat, but which also served to ?ank the S. Side, and therefore assuredly stood out like a great tower over the walls. From the fact that, in the later extension of the fortress, the ?anking position of this tower was almost. Whollv abandoned, we may be certain that its construction must belong to the time of the second citadel. The method of fortification in the earliest settlement being unknown. At all events, this Structure represents, in its conception, a combination of gate-tower and of salient outwork, which is architecturally of great value. The ?anking system, the application of which, in the heroic age, was even recently still so strangely denied, is absent neither from Mycenae nor from Tiryns; but, on account of the varying conditions of the ground, it has in neither of these citadels been so thoroughly carried out as at Troy. In the former two cases it was confined to a few very important points. At Troy, it was most fully developed.
