This microscope has an interesting lens system: The Huygens eyepiece (C, D) has an open air gap between the plano-convex lenses. The Field lens (E) is close to the objectives. There are multiple objective lenses (G) that may be stacked for higher magnification. Inserted into the eyepiece tube is a Nicol prism Analyzer (B).

There are also two flat glasses: A: is at the exit pupil of the eyepiece. B: is a reticle.

Non-refracting optics (or the Nicol) are shown in gold.

The eyepiece body has one lens (C) set into the base of the tube. Centrally located, in wax, is the Nicol prism. At the top is a single piece of
flat glass (A).
Objective lenses:
A: dia=15mm, f=19mm
B: dia=19mm, f=21mm
C: dia=26mm, f=42mm

Optic "C" is required, the other two screw onto it. The total magnification with all three lenses is approximately 12x.