Contact goniometer hinged at the 90° graduation

Deleuil, Paris
Contact goniometer hinged at the 90° graduation (brass and steel, outside diameter 8.2 cm) in its brown Moroccan leather covered case with red chamois lining (11.5 cm wide). 
Signed (on the back side) "Deleuil à Paris", first half 19th century.
Louis-Joseph Deleuil was an engineer-optician and scientific instrument maker who founded his company in 1820.

private collection