of York, which has no vault, but in place of it a wooden imitation of one, and other similar buildings, present substantially the same characteristics. Westminster Abbey is an exception, and is, after the choir of Lincoln, the most Gothic structure in England, having a complete and continuous vaulting system, including a Gothic system of buttresses.
Nor are Gothic principles carried out more fully in the later structures of the thirteenth century in England. Of these later structures one of the most famous is the Presbytery of Lincoln which dates from about 1270. Its vaults have, in addition to the full system of functional ribs, two tiercerons in each compartment. The ribs which span the central aisle spring from a level a little above midway between the triforium and clerestory strings, while the longitudinal rib springs from the clerestory ledge. There is, therefore, something of Gothic form in the lower portion of the vaulting conoid, which is gathered against the wall in a vertical line for several feet from the springing, and presents, accordingly, somewhat twisted surfaces. Five small and compactly grouped vaulting shafts carry the five greater ribs, but these ribs so interpenetrate at their springing as to become greatly reduced in bulk, and consequently in the numbers of their mouldings. Of these mouldings the tierceron is reduced to one member, the transverse rib to one and parts of two others, and the diagonal rib to two. The adjustment of the shafts to this group is peculiar. The two lateral shafts, instead of carrying each a separate rib, carry each one moulding of the same rib—namely, the diagonal; while all that remains of the transverse rib and the tiercerons together is carried by the central shaft. Hence, though the number of shafts corresponds to the number of great ribs in the vault, yet there is no really functional relationship between them—that is to say, each rib does not, as in French-Gothic, find its own independent support in the shaft group.
The upper parts of the vaults of this Presbytery are less like those of true Gothic form than are the lower portions. They approach more nearly to the character of simple intersecting vaults of pointed section. Their ridges are almost, if not quite level, and their surfaces are hardly at all
