Details

Autor(en) / Beteiligte

• Boulerice, Dominic

Titel

La géométrie de l'espace ou le trait de la voûte sur croisée d'ogives

Ort / Verlag

ProQuest Dissertations & Theses

Erscheinungsjahr

2009

Link zum Volltext

Quelle

ProQuest Dissertations & Theses A&I

Beschreibungen/Notizen

• The predominant role medieval builders assigned to vaults in their trade casts no doubt. Villard de Honnecourt was already depicting them in the ground plans of his sketchbook (c. 1225). In these sketches, the rib network is superimposed on the imprint of the buildings, a well-known architectural convention that still stands today and that Villard most certainly emulated. With the exception of these rudimentary drawings, the design and the construction of rib vaults are not supported by documentary evidence in France. The situation is quite different in the Holy Roman Empire where cathedral lodges provide rich documentary evidence in the form of drawings of all kinds that inform us about the geometry of Late Gothic rib-vaults. The drawings show that these vaults were devised using the so-called Prinzipalbogen method in which the ribs of the vault were given the same curvature, that of the principal arch; this was usually a quarter-circle whose radius was determined more or less arbitrarily by adding the linear measures of the ribs in plan from the springing point to the keystone. Through a simple projection (Bogenaustragung), it was then possible to draw the elevation of the vault. This constructive method proved particularly effective in the case of figured or net vaults because of their numerous keystones. The French builders as well made use of geometrical procedures to design their rib-vaults. There is evidence to believe that their techniques differed from those of the Imperial workshops. Indeed, in the Kingdom of France, figured and net vaults never attained the popularity they had in the Holy Roman Empire where they proliferated. French Gothic is instead characterized by simple four-part vaults and stellar vaults that required less complicated working drawings. The geometrical schemes to describe the French Gothic rib-vaults put forth until now turn out, for the most part, to be very systematic. The models proposed by the architects of the 16th and the 17th centuries display rounded vaults that do not reflect medieval or even late medieval practice. Rather, Viollet-le-Duc argued that the ribs of Gothic rib-vaults were normalized and hence shared the same curvature. None of the authors that examined the geometry of rib-vaults paid particular attention to its great flexibility, which allowed vaults to be adapted to the utmost irregular arrangements either in plan or in elevation. In light of my research, measured drawings of rib curvatures undertaken by me reveal that rib-vault design and construction, although based on geometrical schemes, rested chiefly on empirical procedures. Extracted from the ground plan, the rib curvatures were mostly determined according to height and span. That is, standardization was not excluded. Although some vaults could have been designed with only one radius, as Viollet-le-Duc suggested, it was not common practice.