BAROMÈTRE À l’AIGLE IMPÉRIALE PAR CHEVALLIER,... Lot n° 251

Rare barometer set under black and gold glass on a burgundy background, bordered by a frieze of Greciques, in a wood and gilded stucco frame surmounted by a crowned imperial eagle holding a thunderbolt. Minor chips and accidents. Signed at the bottom in a cartouche of "CHEVALLIER, ingénieur de S.M. le Roi de Vestphalie (sic), Membre de plusieurs académies, à Paris". First Empire period, 1807-1813. H. 100 x W. 62 cm (frame). History Jean Gabriel Augustin CHEVALLIER (1778-1848), known as "l'Ingénieur Chevallier", was an optician-engineer, member of the Royal Academic Society of Sciences, optician to S. M. Jérôme Napoléon, King of Westphalia (1807-1813), and in particular to S. A. S. le prince de Condé. His maternal grandfather was François Trochon, a renowned optician in Paris, who had established a store in the clock tower at 1 place de l'Horloge in 1740, which Chevallier inherited in 1796. His early catalogs show the production (or sale, at least) of a wide variety of optical, scientific and engineering devices. In addition to his scientific and political connections, Chevallier used a number of techniques to broaden his customer base. Early on, he mounted a very large thermometer on the wall outside his store, which drew crowds, particularly in very cold or hot weather. Chevallier also recorded weather conditions from an observatory at the top of his building, and reported daily observations. A skilled craftsman, he adopted the honorific "l'Ingénieur" and often signed his microscopes, telescopes and other instruments as "l'Ingénieur Chevallier". He received numerous honors from the Republic, Emperor Napoleon and subsequent royalty, and was knighted with the Légion-d'Honneur. Galignani's Nouveau Guide de Paris of 1827 recommended him to tourists: "Chevallier (le Chevalier), 1, Tour de l'horloge du Palais, face au Marché aux Fleurs, Optician to the King and Royal Family, inventor of the "gardien de vue", inventor of opera glasses called cylinders and isocentric glasses for reading, writing and seeing at a distance, for which he was granted patents. He invented sundials for different latitudes, the mechanical barometer, the Saccharimeter, the Galameter, etc. (see ill. 1 showing him in his workshop).