Compound Binocular Microscope and Accessories, by R. & J. Beck, London, c. 1870

The binocular body tube is mounted on a rack and pinion, for focusing, on the shaped limb. The inter-ocular distance is adjusted by a knob near the top of the body. At the lower end of the body a vertical screw adjusts the fine focus and the nose has an internal thread to take objectives. The limb is carried on trunnions on two pillars that stand on the flat tripod foot. The circular rotating stage is attached to the limb at the level of the trunnions. Three knobs adjust the position of the mechanical stage plate which has a sliding bracket with a pinhole to hold specimens and accessories. A rack and pinion is set below the stage that holds a Nicol prism analyser. A post with a triangular cross section extends beneath the stage and a sliding sleeve supports the plano-concave mirror. There are two eyepieces for the microscope one of which has a pin or pointer inside. There are three objectives in cans, the sizes are 1 ½ inch, 2/3 inch and 1/5 inch.