Focus is by rack and pinion (C). Two views of the rack & pinion mechanism (top). The hole at the bottom is for the illuminating mirror. The dovetail (B) supports the sample stage. Leaf spring (A) holds the microscope support arm.
The rack (C) is mounted on the outside circular support pillar. Turning the focus knob (pinion) moves the inner, microscope support pillar up or down relative to the sample stage (B).
Microscope #87 focus mechanism
