Leland asserts that Bishop COBHAM (1317-1327) vaulted the north aisle of the nave. This fixes the date of the Decorated work on the north side. The bases of the piers differ from those opposite, and the capitals of the shafts are enriched with excellent leafage, much undercut. This “runs continuously round the pier, being inflected around the shafts, so as to distinguish the groups without separating them, and with the richest effect.” At the angles of the exterior hood-mouldings are small heads of kings and bishops. The triforium has two pointed arches in each bay, each arch enclosing two smaller ones. The shafts which support these arches have capitals of leafage, and the tympana in the heads of the larger arches are filled with sculptured figures. These, before the late restoration, were so greatly decayed as to be quite undecipherable. They have been re-worked as carefully as possible, but in most instances the original subject was completely uncertain. The clerestory consists of three pointed arches, with leafage on the capitals of the shafts, and at the angles of the outer mouldings. The windows at the back are Perpendicular insertions. Professor Willis has been the first to point out that the triforium and clerestory of the two bays adjoining the transition Norman work on this side of the nave, differ from the rest, and are in fact Perpendicular, of the same character as the entire south side. “We may conclude, therefore, that the north side of the Norman nave was taken down first, and that when the portion in the Decorated style had been completed, a pause in the work or a change of architects happened, and the triforium and clerestory of these bays were then completed in a different style[67].” The vaulting-shafts run upward between each bay in groups of three. The abacus from which the groining-ribs apparently spring, is partly a continuation of the stringcourse at the base of the clerestory, and is gracefully trefoiled. The whole work on the north side of the nave is bolder and more effective than that on the _south_. We have no record of the construction of this side, but from its strong Perpendicular character it can hardly be earlier than 1360. The clustered pier-shafts have much smaller capitals of leafage than those opposite, and the leafage does not pass round continuously. The design of the triforium resembles that on the north side; but at the junction of the two smaller arches is a bracket, once no doubt the support of a figure which rose against the tympanum of the larger arch. All traces of these figures, however, had disappeared, and they have been replaced by modern sculpture, executed by BOULTON, under the direction of the architect. Small ancient figures remain at the sides and intersections of the larger arches.