Cornelius Varley was interested in studying living specimens. To this end, he designed and improved his lever stage controlled microscopes. His earliest versions used a stirrup-shaped control (see the page about the 'microscope for living objects' from 1831). He subsequently developed a lever stage controlled by a single understage lever as shown above, and later simplified and improved as shown on Dr de Groot's Varley microscope shown on this site. Varley patented this mechanism in 1841. To see his original 1843 publication from the Transactions of the Society of Arts, with his detailed engravings of this instrument, see the Varley SOA Page.