240 On a Mode of erecting light Vaults, 8fc. 



quently of the radius of the sphere of the cupola, to be fastened 

 to its middle point by a double hinge, in such a manner that it 

 could be carried round in all directions, and consequently 

 could touch each point of the interior surface of the dome of 

 the assumed diameter*. The four gussets were then vaulted, one 

 after the other, in horizontal courses, and each stone pushed 

 forward so far that it could be touched with the end of the 

 moveable pole. In this way a circular ring was obtained of 

 the breadth of the square, on which were vaulted in a second, 

 third, and so forth, to the completion of the cupola. From 

 time to time, by the application of the pole, the complete regu- 

 larity of the spherical form was secured and properly preserved. 



M. de Lassaux adds, that if he should hereafter have the 

 good fortune to erect other vaulted churches, he would limit 

 himself rigorously to the round-arch style. This style possesses 

 a superiority in the simplicity and completeness of its forms. 

 Moreover its spherical vaults, in consequence of the saving 

 of the ribs and their centerings, are considerably cheaper ; and 

 we can, therefore, with given funds, make our churches larger, 

 which, in consequence of the universally limited means, are 

 always built on too small a scale. This style is, moreover, the 

 more agreeable, because less that is fine in it has come down 

 to us ; while, on the contrary, our buildings in the pointed 

 style, compared with those of the ancients, always appear more 

 or less as a miserable subterfuge. 



* Eton, in his ( Survey of the Turkish Empire,' says, ' I have seen cupolas of 

 a considerable size built, without any kind of timber support. They fix firmly in 

 the middle a post about the height of the perpendicular wall, more or less, as the 

 cupola is to be a larger or a smaller portion of a sphere ; to the top of this is 

 fastened a strong pole, so as to move in all directions, and the end of it describes 

 the inner parts of the cupola.' 



