It is most difficult, owing to the darkness of the place, to obtain accurate sketches, but the annexed diagram (Fig. 577) gives an idea of the shaft in the east wall of the south-west chapel and its cap, on which Mr. Honeyman lays stress as proving their transition character. The abacus is transitional in section, but the carving is undoubtedly first pointed. Mr. Honeyman thinks that the cap may have been left rough at first, and the carving executed in first pointed times. Whether this shaft and cap and the vaulting of the south-west chapel are transitional, or of the early first pointed date of the lower part of the nave walls, there can be no doubt that Mr. Honeyman’s main contention is correct--viz., that part of the south-west chapel and the lower part of the walls of the nave were constructed before the rebuilding of the lower church and choir was carried out by Bishop Bondington about the middle of the thirteenth century. [Illustration: FIG. 576. St. Mungo’s Cathedral. Detached Rib.] The lower church (see Fig. 571) is about 125 feet long, and is about 17 feet in height at the west end; but owing to a fall in the level of the floor at the east end, the height of the vault at that end measures about 4 feet more than at the west end. From the choir floor to the floor of the lower church the height is about 19 feet 3 inches. In order to obtain this height, the floor of the choir is raised about 3 feet above that of the nave. The height of the choir from the floor to the apex of the roof inside is 74 feet 6 inches. The following are the entrance doorways to the cathedral--viz., a wide double entrance doorway at the west end of the nave, and a south doorway in the second bay from the west end. There are also north and south doorways in the lower church, and a doorway from the landing of the north stair to the lower church. [Illustration: FIG. 577.--St. Mungo’s Cathedral. Pillar and Rib in South-West Angle of Lower Church.]