The eyepiece screws into the objective-bearing base (left). Objectives are ivory with simple lenses held in place within a brass mount. There are two objectives with this instrument, but only one has a lens element present (lens dia=1mm, f=2mm). Total length of this magnifier is 3.5cm.
This section of the microscope holds the two concave specimen holders (only one is shown). It is possible that the sample was placed between the concave surfaces of both. The ivory retaining ring fixes the two glasses in place.
Three objective lenses. Each single lens is held in place within a brass mount. These objectives screw into the body.
Components of the screw-barrel microscope:
A: Body (objective facing away); B: condenser lens, C: inner mount for condenser.