Contact goniometer hinged at the 90° graduation

Pixii, Paris
Contact goniometer hinged at the 90° graduation (brass and steel, outside diameter 10.2 cm).
Signed (on the back side) "Pixii Neveu et Succ[ess]eur de Dumotiez à Paris", first half 19th century.
Nicolas Constant Pixii-Dumotiez (1776-1861), nephew of the Dumotiez brothers, was one of the foremost constructors of physical instruments of the 19th century.

private collection