The optics supplied
with this microscope consist of oculars numbered 1-3,
a three-part divisible objective with parts numbered
1-3, and separate objectives numbered 4 and 6. The
removable substage slider would have had a
holder for two aperture stops, which are no longer
present.
The above illustration
from Das Mikroskop by Leopold Dippel,
1882
In the Schmidt & Haensch Price List of
1865, the closest model corresponding to the
example presented herein is listed as the No 4 model;
this is the model shown on the right in the above
illustration. The example in this collection is
identical except for the addition of the rack and
pinion coarse focusing of the tube. Note that the upper
section of the microscope can rotate in the optical
axis relative to the lower section.
After completing their apprenticeships with Wilhelm Langhoff,
Herrmann Haensch and Franz Schmidt founded, in 1864, the firm Franz Schmidt & Haensch in Berlin. Schmidt was in charge of the production of saccharimeters (polarimeters) and other polarization instruments, while Haensch was responsible for microscope and spectroscope production. Microscopes by the firm are relatively uncommon compared to those produced by the other leading German firms of the period. It has been estimated that the firm produced about 2500 microscopes in total with the last one being made in 1893. To this day, the firm remains a family owned business, Schmidt & Haensch GmbH & Co., with headquarters in Berlin.
