Optical Cabinet, by Benjamin Martin, London, c. 1780

The mahogany case contains optical instruments. These include a brass solar microscope, with worm and rack movements for the rectangular mirror. The screw-barrel slide carrier has three projection lenses and can function as a hand held microscope. Also a brass drum microscope with three objectives and a telescope. The telescope has an outer tube covered in green shagreen and three inner tubes covered with green vellum. The first inner tube is signed by the maker. The accessories with these instruments are two shutter screws, a brass dish with a glass bottom, two lenses in a card box and five ivory sliders. The supports and the lid of the case are covered in green felt.