"Spherometer By Ducretet/lejeune, C. 1890"
Spherometer allows a device that allows the measurement of the curvature and the pencil of a spherical surface. This one is signed by Ducretet and Lejeune and therefore datable to the 1890s. It measures 12 centimeters wide by 16.5 cm high. The main circle measures 9cm. Good working condition.