RENAISSANCE ARCHITECTURE IN FRANCE. 



so as to form a kind of retro-choir with a shallow apse and chapels to 

 right and left, while a small square tower is added to north and south 

 of these, outside the main line of wall. 



Section. The aisles are raised five steps above the general floor 

 of the building, and have flat coffered ceilings at the level of the entab- 

 lature of the colonnade (Figs. 437 and 439). In each of the arms, which, 

 as explained, are themselves individually cruciform, the central square is 

 covered by a round saucer dome on pendentives, while the arms of each 

 arm are spanned by semicircular barrel vaults or deep arches springing 

 from the entablature over the group of four columns in each angle. On 

 the outer sides, and above the colonnade, a semicircular window fills the 

 whole tympanum of the barrel vault, except at the east end, where there 

 is a semi-dome, and at the west end, where there is a blank wall. On 

 either side of each of these large windows is a tall narrow light, for which 

 small vaults interpenetrate the barrel each way, so that the pendentives 

 spread from a slender pier, like a groined Gothic vault, and an open 

 tribune or gallery fills the space behind them. 



The central hall of the church, originally intended for the choir, 

 is brought by pendentives to the circular form at the height of an 

 entablature placed above the barrel vaults, which open into it from 

 the four arms. Above this is a circular drum with twelve square- 

 headed windows and four similar recesses over the piers. Internally 

 there is an order of sixteen, and externally one of thirty-two columns, 

 the inner standing above the inner face of the barrel vaults, the outer 

 above their outer face. These orders are of equal height, but the 

 outer one stands higher by about the depth of its entablature. 



The dome (Fig. 437) consists like that of St Paul's, London, of 

 three shells, one within the other. But, unlike Sir Christopher Wren, 

 Soufflot constructed them all three in stone. The inner dome, which 

 is hemispherical with an oculus, springs from the blocking course of 

 the inner colonnade; the intermediate one elliptical and closed at 

 the apex springs from the same level and carries the lantern ; the 

 outer one hemispherical like the inner, and covered with lead rests 

 on an attic which stands upon the wall of the drum, and is pierced 

 with sixteen windows to light the intermediate dome. 



Elevations. Externally the whole church exclusive of the dome 

 consists of a single storey corresponding with the order of the western 

 portico, whose entablature runs round the building, and is surmounted 

 by a balustrade except at the four principal faces where pediments 

 occur (Fig. 438). The walls, which but for the doors are unpierced, 

 are so high that they conceal the clearstorey windows placed on the 

 line of the internal colonnades. The roofs are low pitched and 

 hipped at the ends, and they butt against the substructure of the 

 dome, which is square with recessed splays at the angles. Above 



