Dollond Microscope, early 19th century.

This microscope has two important features, the oil lamp mounted on gimbals remaining vertical for all inclinations of the microscope, and the completely enclosed horizontal stage movements. The objective is an achromatic combination. On one of the legs is the inscription 'Dollond, London'. Dollond's were the first to introduce on the market an achromatic combination of lenses for telescopes, and took out in 1758 a patent for the method of making this combination.