"Drum" microscope

The tube has the eyepiece and lens at each end, and manually slides inside a fixed, peripheral supporting tube under slight friction to focus. The barrel is stamped with the inscription: "Crichton, 112 Leadenhall St, London." Under the tube is the stage, which is also round and has 2 side openings through which the slide is inserted. Further down is a round, concave mirror that can be moved forward and backward, and is supported by 2 side screws. The original mahogany box contains a range of accessories such as a magnifying glass, 5 lenses, and containers for examining liquids.

John Crichton was an English scientific instrument maker. He worked in London from 1831 to 1865 producing and selling barometers, magnetic compasses, drawing instruments, microscopes, and more.