18
GOTHIC ARCHITECTURE
CHAP.
the utmost, while the sustaining shafts and piers, for which the best materials were selected, were reduced to a minimum of thickness. As this development of an independent framework progressed, the intervening walls, now no longer needed for the stability of the fabric, were also reduced in thickness; and the small apertures of the Romanesque style gave place to larger openings, which were gradually more and more enlarged, until they filled the entire space between the supports.
The general form and constructive features of a developed Gothic building may be summarised as follows:—
1. The plan consists of a nave, the eastern portion of which forms the choir, with side aisles, sometimes single and sometimes double, and a transept, usually also with aisles. The nave and choir terminate at the east, almost invariably, in either a semicircle or a polygon, around which the aisles are continued. At the west the termination is square, the aisles at this end terminating in towers. The nave is separated from the aisles, and the aisles when double are separated from each other, by rows of piers which support the superstructure. The whole is enclosed, on the ground-story, by a thin wall beyond which, opposite the piers, are the far projecting and massive buttresses.
2. The vaults, whose plan and construction determine the number and arrangement of the piers and buttresses, are furnished with a complete set of ribs—namely, transverse ribs, diagonal ribs, and longitudinal ribs.[1] These ribs are independent arches, of which the transverse and longitudinal ones are pointed, while the diagonals are usually round; and upon them the vault masonry simply rests the one never being incorporated with the other.
- ↑ I call the rib which runs parallel with the long axis of the building the longitudinal rib, rather than by its common English name—wall rib—because in true Gothic there are no walls enclosing the ends of the vault compartments. The three ribs named in the text—transverse, diagonal, and longitudinal—are the only constructive ribs of any vault, hence they may be said to constitute a complete rib system. The additional ribs, liernes, tiercerons, etc., which appear in the later forms of vaulting, more especially in England, are mere surface ribs having no real function. The employment of such ribs may be considered a sign of misapprehension of Gothic principles.
