Dictionnaire raisonné de l'architecture française du XIe au XVIe siècle
A dictionary of French architecture by Eugène-Emmanuel Viollet-le-Duc, published in Paris in 1858, aimed at architects and students of medieval building. Its plates are numbered architectural drawings: ground plans of churches with cross-hatched masonry, and a detailed view of a column capital with carved foliage and ribbed vaults. A designer might take from them the clean line hierarchy of plans, with solid black piers set against thin outlines of walls and vaults.
