The curtain, from Bell to Beauchamp Tower, 138 feet in length, 37 feet high above the outer, and 18 feet above the inner ward, and 10 feet thick, is very perfect, but still much encrusted by dwelling-houses. The exterior of this wall shows eleven loops about 12 feet from the ground, and 12 feet apart, and these are found within to represent eleven recesses of 7 feet 4 inches opening, with drop arches of 3 feet 4 inches rise, so that the curtain was pierced by an arcade intended for the defence of its base against the outer ward, but which would have been fatal to the security of the heavy superstructure, had the most ordinary battering engine been brought to bear upon it. The recess next to Beauchamp Tower seems to have been walled up when that tower was built. At the base of the parapet was a stringcourse, now much mutilated. The rampart walk remains open, but a part of it lies between the roofs of houses. The loops are of one pattern, of about four inches opening, and cruciform. The three upper ends are square; the lower expands into a round oillet. [Illustration: THE CURTAIN.—GROUND PLAN.] This mural arcade is very singular. Such of the recesses as are accessible are found to be lined with brick, and can scarcely, in their present form, be earlier than the reigns of Edward IV. or Richard III., if so early. In fact, they much resemble the work of Henry VIII. The openings themselves are, however, original. They evidently exist also beyond the Beauchamp to the Devereux Tower, as the loops are visible, although the back of the wall is so shut in with dwelling-houses and the vaults of the church, as to be inaccessible. Nothing like them has been detected between the Bell and Bloody Tower, or in the fragments of the original curtain on the east side, about the Broad Arrow Tower. In the short low cross curtains connected with Salt Tower, something like these recesses may be seen, and apparently of early date. In rebuilding the curtain next to Broad Arrow Tower these recesses have very judiciously been copied. The Beauchamp, or Cobham Tower, stands towards the centre of the west wall, into which it has been inserted, either as an addition, or more probably in place of an earlier tower. Its plan is a semicircle of 36 feet exterior diameter, and 18 feet projection beyond the curtain. The exterior wall is 8 feet, and the gorge wall 4 feet thick, and ranging with the inner face of the curtain. This tower is of three stages, not vaulted, the middle being at the rampart level. A well-stair, 9 feet diameter, in the curtain, close south of the tower, opens from the inner ward, and communicates with each floor, the curtain ramparts, and the battlements of the tower. The stair is looped toward the field, and its passage has a small window towards the inner ward.