over Churches and similar Spaces. 235 



vaulting too round or too flat, and when he set about correct- 

 ing his mistake too suddenly. 



As to the epoch of the invention of this bold and uncommonly 

 ingenious mode of vaulting, the author has hitherto discovered 

 nothing exact or capable of being well substantiated. 



In the cathedral at Cologne, the vaulting of the choir, so far 

 as can be discovered from below, appears to be still rectilinear, 

 and consequently vaulted on a boarded centering. In the 

 north aisle of the nave, on the contrary, the curvature of the 

 intermediate surfaces, as well as the horizontal position of the 

 courses, is very distinctly recognizable. Now, as we may 

 presume that the workmen in this cathedral were acquainted 

 with the practices in building which existed in their time, we 

 may place the invention of this kind of vaulting between the 

 completion of the choir and that of this side-aisle ; and, con- 

 sequently, according to Boisseree, between 1322 and the be- 

 ginning of the sixteenth century. 



In books, the author, as has already been said, has been able 

 to discover nothing concerning the practical art of building. 

 There is, however, in De 1'Orme (CEuvres de Philibert de 

 VOrme, Rouen, 1648; the first edition appeared in 1568, during 

 his lifetime ; he died 1570, or, according to others, 1577), in 

 the 8lh chapter of the 4th book, a passage historically very 

 remarkable. These old church vaults are there called ' voutes 

 modernes et a la mode Fran9aise, que les maitres m^ons ont 

 accoustume de faire aux eglises et logis des grands seigneurs.' 

 He says further * Ces fayons de voutes ont este trouvees fort 

 belles, et s'en void de bien executees et mises en oeuvre en 

 divers lieux de ce Royaume et signamment en ceste ville de 

 Paris, comme aussi en plusieurs autres. Aujourd'huy ceux 

 qui ont quelque cognoissance de lavraye architecture ne 

 suivent plus ceste fac,on de voute, appelee entre les ouvriers 

 la mode Franchise; laquelle veritablement je ne veux depriser, 

 ains plutost confesser que Ton y a faict et pratiquer de fort 

 bons traicts et difficiles.' 



The separate ribs have here all particular names : thus in 

 Fig. 9, which occurs in De TOrme, the ribs A are called 

 Croissce d* ogives ; B, Liernes ; C, Tierccrons ou tiercerets ; D, 

 , when tlu-y lie against the wall and have only a half 



