Engineer-knight, Small Long View In Speckled Brown Tortoiseshell And Brass, Nineteenth.

Small retractable long sight, speckled brown tortoiseshell trim with brass setting. Inscription "the engineer chevalier opt". Normal wear. Good condition. Dimensions: Closed length: 11.5 cm, Open length: 15.5 cm, Diameter: 6.2 cm --- Jean-Gabriel Augustin Chevallier ( 1777-1848) Optician-lunetier and French engineer of great renown, he was appointed “optician of the king [of Condé] and the princes" and was a member of the Royal Society of the Academy of Sciences of Paris. In 1796, he inherited of his grandfather's optical shop on Place de l'Horloge in Paris. It had been founded in 1740, which makes this house one of the oldest in Paris. He produced optical, engineering and and scientists, and it was the sale of microscopes from 1807 that made him a reference in the field.In 1810, he published the famous manual “The Conservator of Sight”, on the anatomy of the eye and sight and then engineering in optics. He spent his career developing new instruments or improving existing ones. In 1842, he moved his shop to Po nt-nine. Six years later, he died, it was his daughter and son-in-law who took over the business and named it “Maison de l'ingénieur Chevallier”. A conflict existed until the middle of the 19th century with the Maison Chevalier, which produced great confusion in the advertisements. In the 1880s, Chevallier and Chevalier were both bought and merged by the Avizard brothers.