Monocular Compound Microscope with Case and Accessories, by W. Watson & Sons, London, ?Early 20th Century

The limb of this instrument (.1) is supported on a compass joint at the top of a cylindrical, copper alloy pillar. The flat horseshoe base is inscribed with the maker's name and address. The copper alloy body tube is carried on a rack and pinion, for coarse focusing, worked by two mill-edged knobs at the top of the limb. Behind this mechanism is a graduated knob with a marker that controls the fine focus. The eyepiece pushes into a copper alloy draw tube, graduated in millimetres, that telescopes from the top of the body. The nosepiece has a pivoting mount that can hold two objectives. The mechanical stage has a blackened copper alloy plate with a circular hole and two copper alloy spring clips. Two knobs on the side of the stage control back and fourth and side to side movement. Below the stage a condenser is mounted on a dovetailed bar that can be racked up and down. It has an adjustable aperture and a pivoting setting for aperture disks. Two screws give fine adjustment to the position of the condenser. Below the condenser a plano-concave mirror in a horseshoe mount is held on an articulated arm on a pivoting joint. The fitted case is mahogany with a leather carrying handle. The accessories in the case are two eyepieces (.2), three objectives in cans (.3), a live trough with two spare glass plates (.4), two stage micrometers in black leather cases (.5), a specimen chamber on a copper alloy plate (.6), stage forceps on a copper alloy pin with a cork plug at the other end (.7), a Nicol prism on a rotating mounting (.8), a copper alloy canister containing four black disks with various apertures and dark backgrounds (.9) and a bull's-eye lens on a copper alloy pin mounted on a ball joint on a post on a circular, weighted copper alloy base (.10). The fitted wooden case is mahogany with a leather carrying handle and a hinged door with a locking mechanism (.11) and fits into a leather carrying case, lined with green felt (.12). The key to the case sits in the lock (.13) and has a loop of string attached to its handle.