The thrust was thus shifted away from the vault’s corners via the flying buttresses set against it, toward exterior buttresses and abutments.
Romanesque architecture was characterized by thick walls—needed to support the thrust of the vaults—and by the darkness resulting from the impossibility of making large perforations in the walls. The Gothic builders of Île-de-France understood that the force exerted by a ribbed vault was not continuous, but rather directed toward the corners. The use of ribs, which were first tested in the late eleventh century in the Anglo-Norman world and Northern Italy, helped materialize this load-bearing structure, on which light voûtains could be placed. The thrust was thus shifted away from the vault’s corners via the flying buttresses set against it, toward exterior buttresses and abutments. The thickness of the walls could subsequently be reduced, with stone giving way to large glass walls. The use of the Gothic arch also allowed for increasing the height of buildings, with the 48.5 meters of the choir of Beauvais Cathedral setting a record in the second quarter of the thirteenth century. The astounding vertical push, remarkable luminosity, and effect of lightness of these structures were the primary components of the Gothic esthetic, which was conceived as a terrestrial image of the celestial Jerusalem.