This particular example is fully equipped for observations using reflected or transmitted polarized light. Note that the Bertrand lens, which has a built in mechanism for focusing, can be screwed onto the 8X eyepiece. Special low power oil immersion objectives are supplied. The objectives are corrected for a 215 mm tube length. In use, the draw-tube should be set to zero (fully extended).
The following was taken from the 1929 Leitz Catalog of Microscopes:
POLARIZING
MICROSCOPE "MOP"
This microscope which has
been designed in collaboration with Prof.
Schneiderhoehn is primarily intended for the
examination of crude ores having one surface ground
plane and polished. It is, however, likewise available
for every other kind of petrographical and
metallurgical work. Microscope "MOP" is adapted for
investigations under transmitted as well as reflected
light. Both modes admit of the use of polarized
light.
The stand is equipped
with inclination joint. The coarse focus is effected by
rack and pinion and the fine adjustment by micrometer
screw. The object stage can be raised and lowered by
rack and pinion motion. The stage is circular and
provided at its periphery with scale and vernier. The
objectives are interchanged and centered by means of
the three-point objective clutch and centering
adapters, the clutch being attached to a vertical
illuminator in a stationary manner. For investigation
in transmitted light, the microscope "MOP" may be
supplied with the petrological illuminating apparatus,
the latter being equipped with either a "Nicol,"
"Glan-Thomson," or "Ahrens" prism as may be preferred.
For investigation in reflected polarized light, a
polarizer is provided which is inserted into the
entrance tube of the vertical illuminator. The analyzer
is mounted within the tube on a slide fitting and is of
the anastigmatictype; it can be rotated within an angle
of 90°. For the reception of compensators, the tube is
provided with a slit. For use with microscope "MOP" a
special set of objectives is furnished, all of which
are corrected for a tube length of 215mm. These
objectives are adjusted for examination of opaque
objects and at the same time are free from
polarization. During use, the microscope draw tube
should be set to its zero mark. The special set of
objectives which we recommend includes two low-power oil
immersions, the importance of which for examination of
opaque ores is well evident.
Microscope
"MOP" as
described, complete with anastigmatic tube analyzer on
slide fitting; large vertical illuminator, equipped
with total reflecting prism and reflecting glass plate,
iris diaphragm and illuminating lens; objective clutch
changer with three objective adapters; polarizer to fit
entrance tube of vertical illuminator; object stage
with rack and pinion for vertical motion and clamp by
which to arrest the rotating motion; selenite plate,
red, 1. order, in metal mounting; mica plate, 1/4λ, in
metal mounting; "Huyghenian" ocular 8X with adjustable
eye lens and cross-webs, in cabinet.
Accessories that could be supplied with the MOP
model:
LARGE VERTICAL ILLUMINATOR
A total reflecting prism
and a reflecting glass plate are simultaneously mounted
to a bar. The bar, fully inserted into the illuminator
housing, places the total reflecting prism within the
optical rays and when the bar is withdrawn to its
extreme stop, the reflecting glass plate is within the
optical rays. The use of either depends upon the nature
of the specimen and the objective employed. This
vertical illuminator is furthermore equipped with a
condensing lens and iris diaphragm, by means of which
the light rays can be stimulated for proper contrast. A
removable polarizer fits into the entrance tube of
vertical illuminator.
A brass tag on the top of the storage cabinet reads: C. S. Stephano, Elkins Park, Penna, U.S.A. Constantine S. Stephano along with a brother operated a tobacco business out of Philadelphia. The business was active from the late 19th century and was named the Stephano Brothers. The business was later carried on by other family members and was sold in 1974. C. S. Stephano was granted a number of patents related to tobacco product manufacture.
