The most curious and important, perhaps, is to be found in the treatment of the triforium. In the earlier bays east of the eastern transept this treatment is the same in essentials as on the nave. That is to say, the triforium is on the same plane as the clerestory, and the triforium passage runs outside the building. But when the choir proper was begun, after an interval of some years, the architects, seeing, no doubt, that the older design was flat and somewhat wanting in relief, were seized by a happy idea. They set the clerestory windows some inches back, so that they were no longer level with the interior wall and with the triforium, and placed the triforium passage in its customary place. The difference in the design may be easily observed both inside and outside the building.
By this simple change, a greater relief and depth, a greater contrast of light and shade, was given to the whole design; and this without breaking its continuity or harmony in any degree.
The following differences in plan and detail between nave and choir may also be remarked:—
Besides the transom dividing clerestory from triforium to be found in the nave, there is a second transom in the choir crossing the openings of the triforium. This gives a greater fulness and complexity to the design.
In the eastern bays, below the openings of the triforium, the bases of the mullions are elongated to about two feet in length, and between them are cusped arches. These arches and the mullions themselves are set on a slanting ridge, like the mullions of the triforium in the transepts.
The vaulting shafts also do not terminate altogether at the point at which the ribs of the vault converge, but the outer ones rise some ten feet higher than the central one, until they are cut short by the spreading ribs of the vault. This is a difference characteristic of the Perpendicular style, which tends to an interweaving of lines, and an abolition of capitals, where possible.
The mouldings of the main arches also are broader than on the nave, and the clusters of the piers bolder.
It must also be remembered that, as the floor of the choir rises gradually to the east, the proportions of the eastward bays are materially altered, and the main arches are smaller relatively to the clerestory than in the nave. There is no doubt that this change is a fortunate one. It is also lucky that it occurs in that part of the building which otherwise differs least from the design of the nave.
Finally, it must be remembered, in accounting for the greater effectiveness of the later work, that a choir design is made for different conditions, and has different objects in view, from that of a nave.
It has often been remarked that the nave of York, examined bay by bay, is logical and satisfactory enough. It is only when it is regarded as a whole, and judged as an avenue of stone, that its faults are evident.