Contact goniometer hinged at the 90° graduation

Bate, London
Contact goniometer hinged at the 90° graduation (brass and steel, outside diameter 7.6 cm) in red Moroccan leather covered case with cream velvet and silk lining (10 cm wide). 
Signed (on the back side) "Bate London", first half 19th century. Robert Brettell Bate was born in Stourbridge in 1782. He is recorded as working between 1808 and 1847.

private collection