Wilson Type Screwbarrel and Compass Microscope with Accessories and Case, Attributed to Marten, English, c. 1750-75

Wilson-type screwbarrel and compass microscope attributed to Marten. The microscope consists of a copper alloy cylinder with a threaded hole at one end to take the eyepiece. A second copper alloy cylinder that has a condensing lens and an external thread screws into the first. Three copper alloy disks make up the stage and are held against the internal cylinder by a Steel spring. Two of the disks are thin and flat, the third has a semi-circular indentation for holding glass phials. There is a boss at the side of the outer cylinder to take an Ivory handle. The Ivory handle is fish-shaped and has a threaded copper alloy tip that attaches to the microscope. The accessories are a threaded ring on an arm with a hinge, two objectives with caps, an objective in a Lieberkühn, a talc box, a wet cell, a glass tube and three Ivory sliders. The case is softwood covered in black fish skin and lined with green velvet.