From wikipedia
http://en.wikipedia.org/wiki/Eugene_Viollet-le-DucThroughout his career Viollet-le-Duc made notes and drawings, not only for the buildings he was working on, but also on Romanesque, Gothic and Renaissance buildings that were to be soon demolished. His notes were helpful in his published works. His study of medieval and Renaissance periods was not limited to architecture, but extended to furniture, clothing, musical instruments, armament and so forth.
All this work was published, first in serial, and then as full-scale books, as:
* Dictionary of French Architecture from 11th to 16th Century (1854-1868) (Dictionnaire raisonné de l'architecture française du XIe au XVe siècle)
* Dictionary of French Furnishings (1858-1870) (Dictionnaire raisonné du mobilier français de l'époque Carolingienne à la Renaissance.)
* Entretiens sur l'architecture (in 2 volumes, 1858-72), in which Viollet-le-Duc systematized his approach to architecture and architectural education, in a system radically opposed to that of the Ecole des Beaux-Arts, which he had avoided in his youth and despised. In Henry Van Brunt's translation, the "Discourses on Architecture" was published in 1875, making it available to an American audience little more than a decade after its initial publication in France.