Optics of the Culpeper microscope
Recessed groove for the (missing) eyepiece lens. dia=2.5cm
Eyepiece lens from a similar Culpeper microscope at the University of California, San Francisco.
Optics consist of a single, biconvex objective lens (A), an interior "Field tube", and an eyepiece (D, missing). The tube contains two lenses (B,C). It is held in a central position by a circular collar located at the top of the body tube. The distance between top tube lens and eyepiece = 3.0cm. Other Culpeper instruments are described as having a single field lens, thus this may be the first Culpeper microscope discovered to have a central Field Tube consisting of two lenses.
The biconvex objective lens is glued into a brass mount. dia=4mm, f=4mm. Behind the lens is a 2mm aperture. There is a single "notch" mark in the base.
This tapered brass objective nosepiece ("snout") screws into the wooden base of the microscope body tube (right).
Bottom lens of the central optical tube. dia=2.0cm. Nosepiece screws into the threaded hole in the wooden base. The lens is held in place by a brass retaining ring.
Top lens of the inner optical tube. dia=0.8cm.