The objective is a single, convex lens (diameter=8mm; f=4.2cm). A small (1mm) aperture helps decrease spherical aberration from this single lens. This microscope is the typical three-lens system of the 17th and 18th Century microscopes. It has a single-lens objective, a single-optic Field lens, and an eyepiece consisting of two lenses.
The eyepiece lens has Huygenian two lens elements, 3cm apart. The eyepiece tube is covered with lacquered black paper. The total length of the assembled eyepiece is 11.4cm
A: Top element (diameter=14mm, f=4.5cm)
B: Bottom element (diameter=28m, f=12cm)
There is a removable dust cover with a decorative ivory topknot.
This cardboard and wood tube holds the Field lens (dia=28mm, f=68mm). The entire assembly sits in this orientation into the bottom of the body tube.