The eyepiece lens slides into the notched sides of the case (*). To protect the large front lens, a shade could also be slid into the case. It is missing in this specimen.
The front lens consists of two bi-convex lenses held in a wooden frame. The frame has machined tabs to allow it to slide into slots (arrow) in the front of the microscope body.
The microscope comes with eight objective lenses plus a Lieberkuhn reflector lens for opaque samples.
The objective construction is typical for 18thC microscopes with a single bi-convex lens held in by a brass retaining collar. The lens aperture is determines by the collar. This is objective No. 4.
Lieberkuhn with included high-magnification lens.
Condenser lens, dia=4.9cm, f=9.5cm.
The condenser lens slides along a long cantilevered arm. The arm is held in place by a jam screw (arrow).
|
Diameter
|
focal length
|
|
|
1
|
3mm
|
<2mm
|
|
2
|
4
|
3
|
|
3
|
4
|
14
|
|
4
|
5
|
25
|
|
5
|
6
|
30
|
|
6
|
6
|
40
|
|
(unmarked)
|
11
|
20
|
|
UM
|
13
|
25
|