Compound Microscope, by John Marshall, London, c. 1715

Compound microscope. Unsigned, but certainly made by John Marshall, one of the leading optical instrument makers of the day. The microscope is an example of Marshall's 'New Invented Double Microscope' announced in 1704.

The instrument stands on a ball joint on an octagonal box with a drawer for accessories and decorative carving. A lens is mounted on an articulated arm in a screw tightened fitting on the box. The stage is a brass frame holding a glass plate and a trough for specimens.

The mounting for the stage is at the base of the square cross-sectioned pillar. The body is supported on the pillar by two brass sleeves and a screw between them facilitates fine focusing. The pasteboard tubes are covered with red gold-tooled leather and vellum. The fitting for the eyepiece is lignum vitae and the nosepiece is brass. Among the accessories are six objectives, forceps, stage forceps, a black and white disc, a brass disc and a brass stage to hold them.