The windows show the same regard to reason. The inside is nearly always widely splayed, to spread the light equally in the room. The external recess depended partly on the degree of architectural character aimed at, and partly on the depth required for the arch. Where the openings were but narrow, and the resources small, one arch-rim would suffice; and this would often be chamfered at the edges, to prevent obstruction to light.
If the opening were wider, and so required a deeper arch, or if the architectural effect aimed at were greater, we find two or more such orders as the above, with, perhaps, columns supporting the outer ones; the receding orders, in either case, doing away with undue obstruction of light or view; the sill always well sloped, to throw off the water, and having usually a string-course below, to prevent it from running down and discolouring the walls. In all this, strict regard to practical reason and utility is manifest; every step is argued out on the basis of construction and requirement, and every decoration is founded on, and results from, the conclusions come to on these practical grounds.
In domestic architecture, if a window were beyond the width of a single casement, a small pillar was often interposed, and the inner order of the window was divided into two arches, while the outer one, if there were any, was in one, the casements or shutters falling into rebates in the back of the column, by which a window of double width, which would not otherwise be conveniently attainable was produced. In window-like openings in which glazing was not needed—as in triforiums, cloisters, and screens—this system was used for beauty where not demanded for the same reasons as in windows, and the subdivisions were often increased to three or four under one comprising arch.
Fig. 144.—St. Trophimus, Arles. Cloisters, north side.
In other instances of the same kind, where light arcading was needed, as in cloisters, and the wall was too thick to rest upon a single capital, two small columns were placed one behind another, or a sort of bar or double corbel placed on the capital of a single pillar to support the springer of the arch, for the sake of avoiding the use of thick piers, which were not needed for strength, and would obstruct view and light; and all these practical contrivances were made elements of beauty and varied effect.
Fig. 145. Priory Church, Bridlington. Part of remains of Cloisters.