Compound pocket microscope

This microscope comprises a uniform cylindrical tube with the eyepiece and lens at the ends. The tube is screwed into an arm extending from the pillar, where the manufacturer is identified as: "Casella Garden Microscope." The pillar is in 2 parts: an internal part slides inside an outer part using a rack mechanism controlled by a side screw. As it moves, so does the tube holding the eyepiece and lens, enabling macroscopic focus. The fixed quadrangular stage has a central hole where slides are placed, and to allow light to pass through. It also has holes for magnifying glasses or clips. At the bottom of the pillar is a plane mirror held by a metal ring. The entire microscope body sits on the lid of a wooden box, which serves as the base.

Optician and wholesale scientific instrument manufacturer L. Casella received commissions from a range of British, American, and Canadian institutions, among others, including the London Royal Geographical Society and the United States Naval Observatory. The Casella Garden Microscope was one of the most popular instruments of its time. It was an improvement on the conventional "field microscope," which was so popular among botanists and naturalists. It was valued for its educational uses because it was easy to operate and its improved optical system made examining samples easier.