The drawtube slides within this brass collar. These cutouts act as friction tabs to hold the drawtube in place.
Only one objective remains with this instrument. It is a plano-convex lens mounted with the flat side out.
Lens dia=5mm, f=20mm.
The objective screws into the distal end of the brass body tube.
The hole at the end of the drawtube acts as the objective aperture.
The drawtube is a brass cylinder containing the eye and field lenses.
Eyelens dia=14mm, f=28mm
Field lens dia=60mm, f=60mm
Both lenses are plano-convex.