'Challenge' Compound Microscope with Accessories and Case, by J. Swift, London, 1877-81

This binocular microscope is carried on trunnions on a heavy base. The body tubes are held on the limb by a rack and pinion. Coarse focusing is by two milled knobs and fine focusing is by a vertical screw on the side of the body. The slides are held on the circular rotating stage by a mechanical bracket that adjusts their position. On the underside of the stage is a condenser which can be racked up and down within a copper alloy  cylinder. A rotating disc mounted below the cylinder holds a Nicol prism and an aperture disk. A Plano-concave mirror is mounted on a pivoting arm attached to a post below the condenser assembly. The wooden case also holds three objectives in cans and two pairs of eyepieces. There are also two pairs of screw-on eyecups for one of the pairs of eyepieces, a live box, a lever compressor, a dark-ground stop, a tommy bar, and two pasteboard boxes