Solar Microscope with Case, by Dollond, London, Late 18th Century

The back plate has two holes for shutter screws and two winged screws adjust the position of the rectangular mirror on the rear of the plate. The body tube screws into the centre of the plate. A thread on the end of the body takes a rack barrel assembly. A projection lens screws into the end of the barrel and a dovetail slot behind the stage holds a condensing lens in a copper alloy slide. There is rackwork on the side of the barrel to move it over an inner cylinder and a stage, consisting of two disks held together by a steel spring. There are six projection, three condensing lenses, two shutter screws, copper alloy forceps and a low power lens in a copper alloy setting with a thread that can screw into the rack barrel. The fitted case is mahogany with green felt facing the supports.

(..1: Back plate & mirror; .2: Body tube; .3: Rack barrel; .4: 6x projection lenses; .5: 3x condenser lenses; .6: 2x shutter screws; .7: Forceps; .8: low power lens; .9: Case)