QUEEN SUB-STAGE
CONDENSER
MAKER: QUEEN & Co.
c. 1880
DESCRIPTION:
This condenser came with a Sidle No. 2 microscope from about 1881. The fitting diameter is about 1.53 inches or 38.8 mm. It is an Abbe type of condenser. It is signed J.W. Queen & Co.
As the catalog entry notes, the condener is equipped with dividing combinations
; the top element can be removed for low power work.
The bottom element can also be removed. Beneath it, a drop-in light blue filter is present.
The drop-in light blue filter is easily removed after the bottom element is unscrewed.
Again as can be seen in the catalog listing, the condenser was originally supplied with three small caps fitting on top. These had different diameter apertures to allow the cone of light to be stopped down to different degrees for use with objectives of different magnifications and aperture angles. These caps are now missing, but replacements will be fabricated when time permits.
HISTORY OF THIS CONDENSER:
The Abbe condenser was invented by Ernst Abbe about 1873 or earlier. With an iris diaphragm rather than aperture stops, it is still used today and functions well except for the most exacting high power work where an achromatic aplanatic condenser is more suitable. A page on the history of condensers is in preparation.
