Ten volumes, alphabetically arranged and illustrated with some three thousand of the author’s own drawings, that explained French medieval architecture as a rational system in which every form follows from structure and material: the most influential book on Gothic ever written.
Viollet-le-Duc (1814–79) learned medieval building not in a school but on the scaffold, as restorer of the abbey church of Vézelay from 1840, of Notre-Dame de Paris (with Jean-Baptiste Lassus) from 1844, and later of Carcassonne, Pierrefonds and dozens of other monuments. The Dictionnaire distils that experience. Its articles range from Arc-boutant (flying buttress) and Voûte (vault) to Cathédrale, Construction, Fenêtre and Pinacle, each explained with cutaway perspectives and exploded views that are still reproduced in textbooks.
His thesis was that Gothic was not a mystical or merely decorative style but the logical outcome of a structural idea: concentrate the loads of the vault on a few points, carry the thrusts outward to buttresses by flying arches, weight those buttresses with pinnacles, and fill what remains between the supports with glass. Every moulding and every profile, he argued, had a constructive reason. The rib vault in particular he read as a frame of arches erected first, with the thin webs laid on afterward.
Twentieth-century critics, notably Pol Abraham in the 1930s, objected that he overstated the structural role of ribs and read the buildings too much like iron frames, and much of the detail of his reconstructions and restorations has been questioned. But his way of seeing, in which form is explained by the forces it carries, shaped the Gothic Revival, the rationalist theory of the nineteenth century and, through it, modern architecture.
The book, part by part
I Arc, Arc-boutant, Contrefort
The arch and its thrust; the flying buttress as a strut of stone that transmits the thrust of the high vault across the aisle to the external buttress, and the history of its development from the 1170s.
Rules: The flying buttress · Pointed arches reach any height on any span · How the pointed arches are drawn
II Voûte
The barrel, groin and rib vault; the problem of vaulting oblong bays, and its solution by pointed transverse and wall arches and semicircular diagonals; sexpartite and domical (Angevin) vaults.
Rules: Ribs first, webs after · Level crowns over an oblong bay · The sexpartite vault spans a double bay · The Angevin vault: a dome with ribs
III Cathédrale, Construction, Pinacle
The cathedral as the collective work of the communes in the late twelfth and thirteenth centuries; the whole structure explained as a balance of thrusts; the pinnacle as a weight that steadies the buttress.
Rules: Concentrate the loads; fill the rest with glass · The pinnacle is a weight