The wall has been so altered and strengthened by modern casemates, and so encrusted by buildings, that it is difficult to arrive at its original dimensions. The height varies from 15 feet to 20 feet inside, and is about 12 feet more to the bottom of the present ditch. The usual thickness is about 6 feet. On the river front the wall was only 10 feet high, and apparently only of moderate thickness.
The north-east and north-west angles are capped by drum bastions, parts of circles of about 80 feet diameter. They are called Brass Mount and Legge’s Mount, probably from cavaliers once upon them. Legge’s Mount has the lesser projection, and seems to be solid. The lower part of its exterior wall looks as old as the adjacent curtains, but the upper part is new, and contains a casemate pierced for six guns. Brass Mount, that towards Little Tower Hill, is pierced by a well-stair from above and a cross gallery below. This leads from a door in the gorge to the middle of a circular gallery, vaulted in brick, which envelopes the bastion and has numerous loops for musketry, and others altered to suit small cannon. This gallery is probably an addition of the Tudor period, excavated within the old retaining walls. The salient between these two mounts has recently been capped by the north bastion, an additional and perfectly new work, being two-thirds of a circle of about 60 feet diameter, with flattened sides, and containing three tiers of casemates, each pierced for five guns.
The only regular towers of the outer ward are upon the south front, where the ditch is narrow and the palace buildings were most exposed. These are five, Develin, Well, Cradle, St. Thomas’s, and Byward Tower.
Develin Tower, in 4 Richard II. “Galighmaies Tower,” when no cart or dray was to come before it into St. Katherine’s unless the brethren paid a fine to the constable, was, in 1549, Galleyman, and in 1641, Iron Gate Tower. Until recently it was a powder-magazine, and not to be entered with a light. These conditions are not favourable to the study of its interior. It is a long rectangular tower, 18 feet by 32 feet, and built wholly in the ditch, one end being applied to the face of the curtain, so that it projects like a buttress from the south end of the east curtain, while its south side is a prolongation of the river front. The exterior has been partially cased, but it is evidently old, and in substance as originally built. Its basement is solid, but about 10 feet above the ditch is a line of loops on the north and south, or two longer faces. There has been an upper story, the walls of which remain, but seem later than the lower. At this level, in the east face, is the outline of a door, which, if a postern, opened 20 feet above the ditch. The view of 1597 shows a double wall, probably an embattled dam serving as a bridge, extending from this tower across the ditch, and crowned on the counterscarp by a small work, called the “Iron Gate.” If this drawing be correct, the roadway was through the basement chamber, and the upper floor led to the rampart of the wall. This gate led into the precinct of St. Katherine’s. The tower is probably the work of Henry III., and connected with an original dam for keeping up the water of the ditch. Forty feet west of Develin is Well Tower.
WELL TOWER.
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.
CRADLE TOWER.—BASEMENT.