Compound Microscope, by Andrew Pritchard, London, c. 1835

The copper alloy instrument stands on a flat tripod base. Two of the legs are shaped to fit into the case. The cylindrical pillar holds an internal pillar that telescopes upward and is held in place be a tightening collar on the outer pillar. A sliding sleeve on the pillar holds a post for accessories on an articulated arm. A compass joint carries the cylindrical limb in a sleeve with a tightening screw. A sliding sleeve on the lower part of the limb holds the plano-concave mirror. The rectangular stage is mounted on a bracket at the top of the limb. It has three pinholes, one on a pivoting arm, and spring clips. A ring with an internal thread set on two springs beneath the stage. A rack and pinion, operated by a triple mill-edged knob, extends a triangular bar. An arm is screwed to the top of the bar and the body tube screws into a ring on the arm. A ring clamp with a tightening screw is fixed to the top of the body. It is attached, by a pivoting joint, to two telescopic struts. Pegs at the lower end of the struts fit holes in the base. Accompanied by an interpretation label from when the object was on display.