This microscope has a screw thread focus mechanism that moves the stage mounting block up or down. The focus knob descends from the upper support. At the base of the microscope is a single sided plane mirror. The box is probably not original, but rather made for a Gould-type instrument. On the back of the upper support is engraved in script John Clark Inv. Fec. Edinb. The microscope is 9.5cm tall.
John Clark was an optical instrument maker, jeweller, and goldsmith whose shops were located in Edinburgh Scotland between 1749 and 1796. He was the second earliest Scottish microscope maker (John Finlayson was the first in 1743) and produced high-quality instruments that optically were much better than compound microscopes at the time. Clark first offered microscopes, made in silver, for sale in 1749, subsequently modifying their design in 1754, and ultimately advertising a brass instrument in 1773. John Clark had at least three shops: one at James Gilliland's Jeweller, at the upper-end of the Luckenbooths (1749); one at Parliament Close (1751-55); and one at Sir Isaac Newton's Head, a little above the Guard, north side of the High Street (1773-82). The microscope shown here was made at his location on High Street in Edinburgh.
The microscope is a modification of Clark's "New Silver Microscope" of 1754; an example of which is in the Royal Scottish Museum. The fact that this microscope is silver plated made it more expensive to buy and therefore more rare than his other brass examples.