Combined graphometer and plummet clinometer, 1663.
© Science Museum / Science & Society Picture Library
This instrument was made by Christoff Kohler of Dresden. Circumferentors (with a complete circle scale) and graphometers (with a half circle scale) were widely used through the 17th and 18th centuries for angle measurement. A joint on the support allowed for both vertical and horizontal use. The clinometer was used for measuring the angle or elevation of slopes. The inscription engraved on back of the object reads 'Christoff Kohler Mech Dresten Fecit'.