A mid 19th century recording pressure gauge, brass with box wood base and pulley.
Column engraved: INDICATEUR de PRESSION PAR CLAIR
P & M Clair, 93 Rue du Cherche-Midi, Paris.
Clair exhibited such indicators at the Great Exhibition, London, 1851.
See page 236 of the Official Catalogue of the Great Exhibition of the works of Industry of all nations, 1851. Entry 1151: Clair’s indicator.