Recognition given by the jury of the Paris Exposition Universelle (1855) brought Nègre an important commission. In October of the previous year, Jean Baptiste Lassus, chief architect in charge of restoration at Chartres Cathedral, had invited Nègre to dinner to show one of his damascened plates to the sculptor Auguste Preault (French 1809-1879) and Charles-Laurent Marechal (French 1801-1887), a painter. In February 1855, Lassus wrote to Taschereau, the Director of the catalogue at the Imperial Library of the Louvre, recommending the use of Nègre’s photogravure process to reproduce all the architectural monuments and works of art that were in danger of being destroyed in France. By September Lassus had succeeded in having the government commission from Nègre two photogravure plates of Chartres Cathedral. Three plates were eventually included in a large and luxurious volume, Monographie de la Cathedrale de Chartres, with text by Lassus, published in 1867. [1]