Heliostat

A mirror turned by clockwork followed the sun and threw its light in one fixed direction for experiments.

Date: ca 1830
Maker: Henri Prudence Gambey
Place: France: Île-de-France, Paris
Dimensions: overall: 22 in; 55.88 cm; overall: 16 1/2 in x 15 1/2 in x 10 1/4 in; 41.91 cm x 39.37 cm x 26.035 cm
Museum: National Museum of American History
Credit line: U.S. Military Academy

A heliostat throws sunlight where it might be used for photography or scientific observations. This example has one glass mirror 9.5 cm in diameter, a clockwork mechanism, and a tripod base with leveling screws. The “Gambey à Paris” inscription refers to Henri-Prudence Gambey, a mathematical instrument maker who won a gold medal at the Paris exhibition of 1823 for his heliostat of new construction.

Ref: D. J. Warner, “Gambey’s American Customers,” Rittenhouse 4 (1990): 65-78

The museum's own record (Smithsonian, National Museum of American History)