Compound Microscope with Accessories in Case, by R & J Beck, London, 1870

This copper alloy instrument is carried on trunnions on a flat tripod base. The curved limb holds the binocular body on a rack and pinion, operated by two mill-edged knobs. The Huygenian eyepieces push into the top of the body and a Wenham prism is set in at the lower end of the tubes. A screw on the front of the body, above the nose, operates the fine focus. The mechanical stage rotates and has a bracket to hold slides. An achromatic condenser with a rotating disk with eight apertures is mounted on a rack and pinion below the stage. A bar with a triangular cross section extends below the condenser and holds the plano-concave mirror mounted on a pivoting arm. The wooden case also holds a bull's-eye lens on a copper alloy stand and a graduated draw tube for a monocular body.