The lower portion of a tower had evidently little to do directly with the defence of the city, but served mainly as a store-room or guard-house. There, soldiers returning home or leaving for the field were allowed to take up their temporary quarters.[190] The proprietors of the ground upon which the towers stood were also allowed to use them,[191] but this permission referred, doubtless, only to the lower chambers, and that in time of peace. The upper chamber was entered from the parapet-walk through an arched gateway, and was well lighted on its three other sides by comparatively large windows, commanding wide views, and permitting the occupants to fire freely upon an attacking force. Flights of steps, similar to the ramps that led to the summit of the wall, conducted to the battlemented roof of the towers. There, the engines that hurled stones and Greek fire upon the enemy were placed;[192] and there, sentinels watched the western horizon, day and night, keeping themselves awake at night by shouting to one another along the line.[193] The Inner Terrace. Ὁ Περίβολος.[194] The Inner Embankment, or Terrace, between the two walls was 50 to 64 feet broad. It was named the Peribolos, and accommodated the troops which defended the Outer Wall. The Outer Wall. Τὸ ἔξω τεῖχος:[195] τὸ ἔξω κάστρον:[196] τὸ μικρόν τεῖχος.[197] The Outer Wall is from 2 to 6-½ feet thick, rising some 10 feet above the present level of the peribolos,[198] and about 27-½ feet above the present level of the terrace between the Outer Wall and the Moat. Its lower portion is a solid wall, which retains the embankment of the peribolos. The upper portion is built, for the most part, in arches, faced on the outer side with hewn blocks of stone, and is frequently supported by a series of arches in concrete, and sometimes, even, by two series of such arches, built against the rear. Besides strengthening the wall, these supporting arches permitted the construction of a battlement and parapet-walk on the summit, and, moreover, formed chambers, 8-½ feet deep, where troops could be quartered, or remain under cover, while engaging the enemy through the loophole in the western wall of each chamber. The towers which flanked this wall[199] were much smaller than those of the inner line. They are some 30 to 35 feet high, with a projection of about 16 feet beyond the curtain-wall. They alternate with the great towers to the rear, thus putting both walls more completely under cover. It would seem as if the towers of this line were intended to be alternately square and crescent in shape, so frequently do these forms succeed one another. That this arrangement was not always maintained is due, probably, to changes made in the course of repairs.