ARCHITECTURE - Karatunov.net

CH. xxn] FRANCE BURGUNDY 99at Cluny, as also at Autun and other churches whichwere built 60 or 70 years later, the nave was coveredwith a barrel vault, at V&zelayattempt was made to apply to the greatfor the first time thenave vault theprinciple of cross-vaulting which had till then only beenemployedin the lesser vaults of the aisles. This was agreat step in advance, and paved the way for the furtherdevelopment of vaulting into the Gothic construction ofrib and panel. It gotrid at once of a constructionaldifficulty and a practical inconvenience.The difficulty of constructinga barrel vaulted navelay in the necessary buttressing, for its thrust was continuousalong the whole length of the wall. Consequentlyin the churches of the Auvergne, and at S. Sernin,others the side aisles were vaultedToulouse, and manyvaultswith quadrant vaults, half semi-circular, starting froma stout outside wall, and abutting on the nave wallagainst the springing of the main central vault Theinconvenience of this is that no clerestory windows arepossible, and the nave, lit only from the ends, is verydark. To remedythis the next step was to raise thenave and to form a clerestory.But in doing this thenave vault was deprived of the supportof the aisle' vaults,and disaster followed. At Autun an improvement wasmade by making the nave barrel vault pointed instead of Pointedround, which diminished the thrust, but not effectually,and before long flying buttresses had to be applied toresist it 1 . At the best this plan only allowed very smallclerestory windows, low down in the wall, below thespringing of the barrel vault. The obvious way of1 The fine church at Saulieu is vaulted with a pointed barrel vault in thesame manner, and the walls have given way in consequence. When I sawit in 1908 its condition seemed very perilous.72