The accessories include three objectives (3/4, 1/5, and 1/8 immersion) signed E.Gundlach, each with a hard rubber canister, two eyepieces made of hard rubber labeled A and C, a hard rubber aperture stop holder with three stops, and an eyepiece micrometer that fits the C eyepiece. The stage is also made of hard rubber, as is the mirror housing.
This microscope was
designed and made by Ernst Gundlach while employed by
Bausch & Lomb. Initially, Gundlach manufactured
microscopes in his own establishment in Berlin. He sold
his workshop there and then emigrated to America in
1871 where he started off producing microscope
objectives. In 1876, he was hired by Bausch & Lomb
to head their newly established microscope business. It
was during this time that the microscope shown on this
page was produced. By the end of 1879, he was no longer
in the employment of B&L, but instead, he started
his
own ventures in microscope production.
One aspect of this
microscope, which is characteristic of the earliest
microscopes produced by the Bausch & Lomb firm, was
the extensive use of hard rubber to fabricate the
components of the microscope stand and its optics. This
was a holdover from the firm's earlier production of
hard rubber eyeglass frames. Ultimately, these hard
rubber components proved not to be very durable and
were replaced with those made of brass. The microscope
shown here is rather rare, being in production for only
about two years. Two versions of this model were
produced, one which remains upright and one which can
be inclined. The microscope shown here is an example of
the latter version. Remarkably, it appears to be in
nearly unused condition.
The following
descriptions were extracted from the Aloe &
Hernstein's Illustrated Catalogue, 1879
540: LABORATORY
MICROSCOPE: Large heavy cast Iron foot
carrying a strong solid brass pillar, to which the body
stage and mirror motion is attached; draw tube allowing
2 1/2 inch shortening; coarse adjustment by sliding
tube; fine adjustment by our new patent frictionless
motion; large hard rubber stage, resting upon two brass
arms; spherically formed revolving diaphragm under the
stage, fixed in such a manner as to be very close to
the object slide; plain and concave mirror arranged so
that their distance from the object may be varied.
These mirrors may also be brought to any obliquity or
above the stage for opaque objects; two eye-pieces, A
and C; two objectives 2/3 inch and 1/5
inch magnifying powers, when the tubes are
completely drawn out, from 50 to 375 diameters;
eye-piece micrometer. This instrument is intended
especially for student's work in histological
laboratories. In its general construction, therefore,
it has been simplified to the last degree, so as to the
cost as much as possible; the quality of the optical
part has been fully maintained and the objectives will
compare favorably with the general run of first-class
lenses. In upright walnut case with handle, lock, and
drawer for accessories. -------- $50.00
545: INCLINING
LABORATORY MICROSCOPE: The same stand as No
540, except that the pillar is provided with a strong
joint, which allows the body to incline to any angle
(shown by cut No. 560); the revolving diaphragm is also
replaced by a sub-stage of standard size, in which
slides a ring carrying one of three different sized
diaphragms, which when pushed up, will closely reach
the object slide, (Hartnack's cylinder diaphragm). This
Instrument has the same optical parts as No. 540, and
camera Lucida, in upright walnut case, with handle,
lock and key, and drawer for accessories. -----
$55.00