[Illustration: 592. Church at Issoire. (From Mallay.) Scale 100 ft. to 1 in.]
In the department of Puy de Dome there are at least four churches of the typical form of this style, which have been edited by M. Mallay—those of Issoire, of N. D. du Port at Clermont, of Orcival, and of St. Nectaire— which only differ from one another in size, and in the arrangement of their apsidal chapels. That of Issoire has a square central chapel inserted, which is wanting at Clermont and Orcival, while St. Nectaire has only three instead of four apsidal chapels.
The largest of these is that of Issoire, of which a plan is here given, from which it will be seen that, though small, it is beautifully arranged. The transepts are just sufficiently developed to give expression to the exterior, and to separate the nave from the choir, which are beautifully proportioned to one another.
[Illustration: 593. Elevation of Church at Issoire. (From Mallay.) Scale 50 ft. to 1 in.]
They all possess central towers, raised on a mass of masonry extending to the whole width of the church, which gives them a breadth of base found in no other style. The want of this is painfully felt in most of our own central spires, all of which need something more to stand upon than the central roof, out of which they seem to grow; but I do not know that any attempt was ever made to remedy the difficulty anywhere but in Auvergne. All these churches were intended to have western towers, the massive foundations for which are found in every example, though there does not appear to be a single instance in which these exist in a complete state.
[Illustration: 594. Section of Church at Issoire, looking East. (From Mallay.) Scale 50 ft. to 1 in.]
The side-aisles are always covered by intersecting vaults, but that of the nave is invariably a simple tunnel-vault, as in the Southern styles, ornamented by occasional transverse ribs, and which in the church at Issoire is slightly pointed.
To support this great vault, a semi-vault is carried over the side-aisles—as shown in the section—which forms a massive and perfect abutment to the thrust of the great arch, besides, as before pointed out, rendering the vault independent of a wooden covering, which, though in some instances supplied, was certainly not originally intended. The defect of this arrangement is of course evident, as compared with the Northern styles, inasmuch as a clerestory was impossible, and the only effective light that could be admitted was through the side-aisles. These churches, however, have an approach to a clerestory not found in that at Fontifroide, before quoted, in having a triforium or range of arches opening into the gallery, which gave a lightness of character to the superstructure, and admitted to a certain extent a borrowed light.