Technology to Freeze Time at Lassus and Viollet-le-Duc’s Notre-Dame of Paris: Learning from the Past for the Cathedral of the Future

Abstract:This article considers the use of plaster casting, an artistic technology, and silicatization, a scientific technology, in Jean-Baptiste Lassus and Eugène-Emmanuel Viollet-le-Duc’s nineteenth-century restoration of Notre-Dame of Paris. Plaster casting, practiced widely in academic artistic circles in the century prior to the restoration campaign, facilitated the work of the sculptors who toiled in the lodge just south of the cathedral’s southern face. The technology was employed in the early years of the restoration campaign and merited mention in an entry recorded by Lassus in the architects’ daybook of 1847. Entries in the 1853–59 daybooks from Viollet-le-Duc’s pen attest to the sustained use of silicatization, a process that involved coating the building’s limestone surfaces in a protective layer of water-soluble sodium silicate. Its practitioners touted it as a miraculous technology that would “stop the ravages of time on monuments.” Plaster casting was a tried-and-true artistic technology, exploited at Notre-Dame to a novel end, whereas silicatization was a cutting-edge application of water glass, the German chemist Johann von Fuchs’s early-nineteenth-century invention. This article places Lassus and Viollet-le-Duc’s restoration practice of the 1840s and 1850s at the crossroads between art and science, between nationalist competition and international collaboration, and considers what we might learn from their approach for the twenty-first-century restoration following the 2019 cathedral fire.