Monocular Microscope with Accessories by A. Ross, London, Before1859

This copper alloy instrument is carried on trunnions on a flat tripod foot, inscribed with the maker's name. The upper part of the limb has a square cross section and houses a rack and pinion mechanism operated by two mill-edged knobs at the rear of the limb. This raises a bar, with a triangular cross section, from within the limb that carries the body tube on an arm. Additional accessories include eyepieces, a camera lucida with two lenses, a Lieberkühn, a condenser, a bullseye condenser and a handkerchief. The eyepiece assembly pushes into the top of the body and the objective screws into the underside of the arm. A bracket on the limb supports the rectangular stage. A bracket to hold slides dovetails onto the stage plate. A rotating disk with three apertures is fitted to the underside of the stage. The lower part of the limb is cylindrical and a sliding sleeve carries the Plano-concave mirror in a horseshoe mount.