Accessories include four
Crouch objectives with canisters (1/2, 1, 2, and
1/5-inch), two pairs of matched eyepieces, a sub-stage
aperture wheel, a sub-stage condenser with aperture
wheel and cap, a parabolic condenser for dark field
use, an analyzing prism, a polarizing prism in a
rotating mount, a camera lucida (missing its glass), a
double objective changer, a live box (not shown in the
above photo), a frog (or fish) plate, a stage forceps,
a limb-mounted side reflector, one (of two) stage clips
which are used instead of the sliding slide carrier,
and a free standing bulls-eye condenser. The case has a
lock and its key.
The following is extracted from the James
W. Queen catalog, 1880:
Crouch's
Student's Binocular: The Stand (as figured in
No. 3105) is 16 inches high, and is of brass
throughout, handsomely finished. The new form of Foot,
with which this instrument is now made, combines
elegance with great firmness and stability. The body is
of the standard length, 1 3/16 inches in diameter,
and has rack adjustment to draw tubes, for adaptation
to the varying distance between the eyes in different
individuals. Rack and pinion adjustment for focus,
giving sufficient range even for a 4-inch objective;
fine lever adjustment, which works well with the
highest powers. Glass Concentric Rotating Stage (giving
the greatest range and most delicate movement of any
stage of its class extant), with complete rotation.
Revolving Diaphragm of 3 apertures, removable Concave
and Plane Mirrors, with complete adjustments; for
oblique light the mirror bar swings as in the
"Histological" Microscope, being hinged back of and
just below the stage. This arrangement admits of the
mirror being swung above the stage, thus giving a
brilliant illumination for opaque objects, and
rendering the bull's-eye condenser unnecessary for this
purpose. This Microscope, in its "Binocular form-the
first introduced to the scientific public at a
reasonable cost-has steadily increased in reputation,
and has now attained the highest position of any
microscope of its class. Either as "Binocular" or
"Monocular," it has been selected by the first
microscopists in England and America for personal use.
Its thorough excellence of performance, stability in
any position, freedom from tremor (in this respect
being unrivaled), simplicity of construction, and
consequent non-liability to derangement, renders it by
far the most perfect working microscope extant. It has
now for many years been favored with the approval of
Dr. Carpenter as his own working microscope, and was
the instrument selected by him for use on the important
expeditions of H. M. S. "Porcupine." It was also
supplied to the naturalists of the "Alert" and
"Discovery," of the Arctic expedition.
In using the Binocular as
a Monocular Instrument, it is only necessary to
withdraw the prism about 1/4-inch, thus leaving the
field of the direct tube entirely clear where
required.
Should the coarse
adjustment be found in course of time to work too
easily, it may usually be remedied by tightening the
two small screws acting upon the bearings of the
pinion.
The accessories applied
under the stage are often found to accumulate dirt upon
the fitting, making them slide uncomfortably. This is
best remedied by carefully wiping off all accumulation
with a clean rag slightly oiled, and also in the same
manner cleaning out the fitting under the stage, taking
care to wipe them finally with a perfectly dry
cloth.
The Crouch Student's
monocular and binocular microscopes were
usually sold having an oxidized brass finish on
base and limb. This particular example
is exceptional given that it is finished entirely in bright
lacquered brass. The
early form of the Crouch Student's binocular
microscope is also represented in this
collection.
A detailed essay about the Crouch firm
is online