William Withering was a doctor, chemist, geologist and a botanist living in the 1700's. He is perhaps best known for his use of Foxglove extracts in the treatment of heart failure.
William was however a keen botanist writing several books on the subject and from his interest he designed/invented a folding pocket microscope for use on his botany trips. This small microscope was first seen around 1790. It consists of a wooden case which when opened automatically erects the microscope from the case. This type is known as the Withering botanical microscope. Originally the case would also have contained tweezers, needle maybe a scalpel.
The folding microscope had several variations over the course of only a few years. All of them had the stage and single magnifying lens attached to the support rods via pins. This allows the microscope to unfold from its flat storage condition to a stacked, open position. The Withering folding microscope had at least four different arrangements. The first had three support rods Subsequent microscopes had only one support rod to give easier access to the sample stage. All folded the stage and lens automaticallywhen the case was closed.
These pocket microscopes were popular at the time both men and ladies taking a keen interest in nature would carry them in their pockets on their travels. Now difficult to find.