Fig. 329.—Plan of Apse, St. Bartholomew’s Church, Smithfield.
In both, the narrow arches are greatly stilted; and at first sight the two may appear to be similarly treated; but on closer examination there will be found to be much difference between them. In the Tower Chapel the transverse ribs are made to increase prodigiously in width towards the outer wall, so as to reduce the want of parallelism of the groined compartments, a very unsightly expedient; and the capitals of the columns are square, which makes the backs of the arches they support nearly double the width they present in front: while at St. Bartholomew’s, the ribs are of uniform width, and the capitals, instead of being square, have their sides radiating from the centre of the apse, so as to share with their arches the spreading of their outer side. The difficulty is really increased in the later work, but is met by more skilful workmanship. Somewhat similar to the case of the aisle round a semicircular apse, is the case of vaulting a circular building with a central pillar. In each, the main surrounding vault, if uncut by others, would assume the form of a portion of an annulus or ring. In the aisle such a ring would be wide in the opening it surrounds, but in the circular building its opening would be reduced to the diameter of the central column or its capital.
This annulus, or curved vault, would become divided in plan into triangular portions by the transverse ribs which would meet on the central pillar and the cross vaults, proceeding from the surrounding arches, would intersect with only the outer portion of the vault, the inner portion which rests on the pillars being uncut by them, and assume the form of a concave conoid, something like the flower of the convolvulus.
Fig. 330.—Chapter-house, Worcester Cathedral.
Fig. 331. Plan of Crypt, Worcester Cathedral.