Compound microscope by Smith & Beck, 3/4 19th C.

Signed: Smith & Beck 6 Coleman St. London 371

 

The Y-shaped foot is made in black painted cast brass, with the two side plates forming trunnions to sustain the limb. The plano-concave mirror can slide along a rod by a collar. A joint allows to the limb to be placed in vertical, horizontal or any intermediate position. The upper limb has a bracket to support the body tube and for the adjustment of the focus a quick motion is obtained turning either of the large milled heads, the smaller one giving slow motion and is divided 0-9. Under the stage there is a diaphragm with three holes. A bull's eye on a stand for illuminating from above the stage is present.
This is an example of the "Second Class Microscope. The Best Student's, or No. 3 Stand", illustrated in R. Beck A Treatise (1865). The objective, signed with numbers from 0 to 9 and Uncovered, has a focal length of ¼ inch.