Signed on the back of the base: L. Schrauer, Maker, New York
and on one leg of the base: W. M. Keene, B. Sc. M. D.
Continental style monocular microscope, c.1890
The mirror arm can be
raised above the stage to illuminate opaque objects
from above. Imbedded within the stage is wheel with 5
Leopold Schrauer only
made the microscope stands and never made his own
objectives. He supplied his microscopes with
objectives manufactured by both American and European
firms. The optics supplied with this particular
microscope consist of two eyepeices and two Hartnack
objectives numbered 2 and 7.
One leg of the base is
engraved with the name of the original owner of the
microscope, W. M. Keene, B. Sc. M.
D. So far, I have not been able to
locate any information about a medical doctor with
that name. It is engraved in the same hand that
engraved the Schrauer signature suggesting that the
microscope was made by Schrauer specifically for Dr.
The microscope, with its horseshoe base and tapered pillar,
resembles the continental model that was popular at the end of the 19th century.
However, the microscope differs from the standard continental microscope in some
important ways. In the continental model, the fine adjustment mechanism moves
the entire limb along with the body-tube. With this Schrauer model however,
the fine adjustment is actually a spring-loaded long lever mechanism. One end
of the lever engages the screw of the adjustment knob while the other end
moves the body tube along with the main focusing adjustment. The limb remains
stationary. The substage of this microscope consists of an aperture wheel
embedded in the stage. In addition, unlike a typical continental model, the
mirror on this microscope is mounted on an adjustable swinging arm capable
of being positioned above the stage for illumination of opaque objects.
Leopold Schrauer first began the manufacture of microscopes in the late 1850's
in Boston. By 1877, he was located in New York City. While an 1878 advertisement
lists Schrauer at 50 Chatham St. NY, an 1879 advertisement lists him at
42 Nassau St. NY. Schrauer microscopes are relatively uncommon compared
to those sold by some of the other contemporary American manufacturers.
A similar continental style
microscope is located elsewere in this collection.
It differs from the present example in the method used
to focus the mirror and the use of aperture stops
instead of a diaphragm wheel.