Compound Microscope, English, c. 1770

The body tube of this copper alloy microscope is in two sections that screw together. The upper part has two lenses and a blackened eyecup with a sliding dust cover. The lower section also has a lens and the narrow nose has an external thread for objectives. A socket, with a tightening screw, on the body fits a square peg on a hinge at the top of the pillar. The upper part of the pillar has a square cross section. The lower part is turned and stands on a flat, folding tripod base. A socket on the base holds the plano-concave mirror. The stage has a circular, recessed stage hole and two wings. These carry a keyhole slot with a leaf spring and a smaller stage hole. The spring clips on the under side of the stage have detached. The stage is held on the pillar by a sleeve that slides for coarse focusing. A second sleeve with a locking screw is mounted above the first. Fine focus is achieved by a vertical screw between the two. The fitted case is covered in black fish skin and lined in red velvet. It also holds five objectives, an Ivory talc box, a live box, a fish plate, a lens in an eyecup, Lieberkuhn in a can, a Bonani spring stage, copper alloy forceps, a black and white disk, five mica disks, seven bone sliders in a wooden case covered with black fish skin and a copper alloy mount with a dark filter.