Graphometer, 1701-1800

Graphometer, 18th century.
Circumferentors (with a full circle scale) and graphometers (with a half circle scale) were widely used in the 17th and 18th centuries for angle measurement. A joint on the support allowed for both vertical and horizontal use. This graphometer has a ball and socket fitting.
 
Year made :
1701-1800
Inventory number :
1980-1626