It was in 1673, while the regalia were in Martin’s Tower, that the attempt of the notorious Colonel Blood was made upon them. Constable’s Tower stands 102 feet south of Martin’s Tower. It seems to have resembled Broad Arrow Tower in pattern and dimensions; but it has, to all appearance, been recently rebuilt from the foundations. It is now a half-round tower of 32 feet diameter, rising a story above the curtain, which seems also to have been rebuilt. It bore its present name under Henry VIII., and was a prison at least as early as 1641.—[Harl. MS., 1326.] From hence to Broad Arrow Tower, the curtain, 102 feet in length, seems, for the most part, to be old; but it is completely locked in, on both faces, by houses. Broad Arrow Tower, though obscured by modern buildings, does not seem to have been much altered. In general arrangement it resembles Beauchamp Tower, but has only two stages, and is much smaller, being 26 feet diameter, with a projection on the curtain of 13 feet. Its inner face is flush with the curtain. On each flank is a small square turret. That on the north contains a steep narrow stair, not a well, entered below by a Caernarvon doorway. That on the south contains a small chamber, probably a garderobe. The ground floor is entered from the gorge, and is a rude, half-round chamber with three loops under drop-pointed arches. The upper chamber seems to have had four outward faces, and a loop in each; and another in the gorge wall. The mural chamber, 6 feet by 4 feet, has a lancet vault and door, and a loop commanding its curtain southward. A passage from the rampart traverses the upper floor, making it a _place d’armes_. The stair is continued to the battlements. In 1532, this was “the tower at the east end of the wardrobe,” and as late as the reign of Elizabeth, the wardrobe gallery abutted on this tower, extending from it towards the keep. The curtain from Broad Arrow to Salt Tower, 156 feet, is so completely locked in by high buildings on each face, that its rampart walk serves as a gutter between the two lines of roof. It is evidently original, about 30 feet high, and 12 feet thick at the base. It does not appear to contain any cells like those in the west curtain. Salt Tower, in 1532 Julius Cæsar’s Tower, caps the south-east angle of the ward. It is circular in plan, 30 feet in diameter, and 62 feet high. It is constructed of uncoursed rubble, with vertical lines of ashlar, resembling coigns, as in Beauchamp Tower. [Illustration: SALT TOWER.—BASEMENT.] The ground floor, entered from the inner ward between the two curtains, is an irregular pentagon with five loops beneath drop-arched recesses. The door opens into a short passage at the north end of the west wall under a segmental arch, against which abuts a similar but half arch in the north wall, under which a small door with a drop-arch leads into the ascending well-stair. The arch-rings are all of good ashlar, but the room is not vaulted.