Plate XVII. Square Halls with Vaulted and Domical Ceilings

Plate XVII. — Further arrangements of square apartments which form points of interest in extensive plans are given in Nos. I and II on this Plate. In both schemes an inner square is formed by means of four detached columns carrying entablatures, the small square spaces in the angles having flat ceilings at the cornice level, and the side spaces being covered with barrel vaults allowing of lunettes on all four sides. But different treatments are adopted over the central areas: in No. I cross vaults complete the scheme, while in No. II pendentives are introduced to carry a saucer dome. In Nos. III and IV the square plan is treated not so much as a unit of scenic interest as a large apartment in which the maximum floor space is a necessity and in which it is desired to present interest and contrast in the ceiling. These plans have been selected from those evolved by Sir Christopher Wren for some of his churches in the City of London: they should be studied carefully as outstanding examples of geometric and perspective skill. No. III excels through its forceful simplicity as well as its ingenuity and variety. The Order is omitted and by means of a series of pendentives springing from corbels, a large saucer dome is carried encircling the supports and contrasting with the square plan. Such an arrangement increases the apparent size of an apartment and produces an impressive effect. No. IV shows a square apartment in which an attached Order is introduced: this in turn carries an entablature which is taken across the angles and forms an octagon supporting an octagonal vaulted ceiling.