Portable Compound Microscope with Case and Accessories, by Powell & Lealand, London, 1850

Portable Compound Microscope with Accessories and Case. This instrument is made of German silver. An alloy of fifty percent copper, twenty five percent nickel and twenty five percent zinc. A bracket holding the limb is attached to the folding tripod by a compass joint. A triangular bar can be racked upwards from within the limb. The arm that holds the body tube is attached to the top of the bar. A micrometer screw on the arm adjusts the fine focus. The body has two draw tubes, one of which is moved by a rack and pinion. The eyepiece pushes into the top of the tube. Objectives, or a rotating nosepiece, screw into the underside of the arm. The stage is mechanical. It has a spring clip and a bracket to hold specimens. A condenser with various apertures is mounted on a dovetail plate below the stage and can be focused by a rack and pinion. A plano-concave mirror is mounted at the lower end of the limb. The wooden case holds a body and draw tube, seven objectives, one with three button lenses, four eyepieces, two specimen compressors, a polarizer, an analyser, two Lieberkuhns, two sets of stage forceps on steel pins, four blue glass filters, a thread adaptor, a Brooke double nosepiece, an Amici superstage prism and a Bull's-eye lens on a stand with a lead-weighted base.