Well Tower, also rectangular, forms a part of the curtain, and has a projection into the ditch 10 feet by 16 feet wide. Its basement, below the present level of the inner ward, and scarcely above the water level of the ditch, contains a chamber, 14 feet by 10 feet, vaulted at a high pitch in two unequal bays, the north the larger, parted by a transverse rib. Each bay is vaulted in four cells, with four hip-ribs meeting in a plain mitred joint. There is a half or wall-rib in the gable of each cell. The ribs are 7½ inches broad by 6¾ inches deep, with a plain chamfer, and spring from four corner and two intermediate circular bell corbels, the tops of which are 3 feet 4 inches from the floor. The height of the chamber is 11 feet 6 inches. There are four loops, one pointing northwards into the ward, and the rest opening towards the ditch. All are under drop arches. In the west side is a door of 3 feet, opening in a drop-arched recess, which may have led into a mural cell in the curtain, or have been an entrance from the ward. On the east side a rectangular appendage, entered by a square-headed door, contains a well-stair of 6 feet 3 inches diameter, looped upon the inner face of the curtain and the ditch. This stair leads to an upper room on the rampart level, not vaulted, 15 feet by 10 feet, looped to the field and upon the face of the west curtain. In its north wall an original door, 2 feet 3 inches wide, opens on the rampart. The second floor is modern. Well Tower is a good example of the early English style. Well Tower stands due south of Salt Tower, and a short curtain, with a gateway, connected them. Part of it remains, 12 feet high and 6 feet thick, pierced with loops at the ground level, and embattled against an attack on the east. This rampart was reached from Well Tower, and did not communicate with Salt Tower. A similar cross curtain connected Salt Tower with the outer ward wall westward. This also was looped, had a central gate, and was embattled for defence from a south attack. These two curtains thus enclosed the approach to the Iron Gate postern, and prevented either part of the outer ward from being entered by surprise. These arrangements are evidently as early as the time of Henry III., and are shown in the view of 1597. [Illustration: CRADLE TOWER.—BASEMENT.] Cradle Tower comes next west, at 118 feet distant. It stands on the outer wall, and projects 9 feet into the ditch, with a breadth of 16 feet. It is a gatehouse, and though of small dimension very complete in its design, and of excellent construction. It stood nearly in front of the bye-gate of the royal quarter, and allowed a direct passage thence to the quay. [Illustration: CRADLE TOWER, WINDOW.]