Solar Microscope with Accessories, by George Adams, London, c. 1750

This is an example of an early solar microscope by George Adams Senior. The square back plate has two screws with wing-nuts to secure it to a shutter. A disc set in the plate supports a rectangular mirror on the rear of the instrument. The position of the mirror is adjusted by two knobs on the front of the plate and a steel spring holds it in place. The body has a condensing lens at one end and screws into the centre of the back plate. A draw tube pushes into the body and a bracket on the end has a thread for the screw-barrel specimen holder. A condensing lens in a dovetail setting pushes into the assembly behind the spring stage and a projection lens screws onto the end. An ivory handle is present so the specimen holder can be used as a hand held screw-barrel microscope. A brass disk with a crystal in its centre, two projection lenses and two dove tail slides, one with no lens, are also present. The screw-barrel specimen holder has a dovetail slot for lenses before the specimen and a threaded hole for the objectives. There are also two small condensers on sliding mounts, two objectives, and a copper alloy disc holding a crystal.