WATSON-TYPE MICROSCOPE WITH ROTATING MECHANICAL STAGE
YEAR: after 1881; ?c 1900.
SIGNED: W. Fairservice, Hastings
SERIAL NUMBER: None
MODEL: --?--
DESCRIPTION:
This
microscope arises from a modified tripod foot similar but not identical
to, that seen on some early Ross, and then Watson instruments. The signature
appears on the rear tapering toe of the tripod foot. The Lister limb
can incline from the vertical to the horizontal
with stops for the vertical attached to the back of the stage to rest
upon the front of the tripod, and when rotated into the horizontal
position, the limb rests on a bar suspended between the right and left
side of the rear foot. The tension on the suspending axle can be
adjusted. and its rotation is smooth yet holds the instrument firmly in
any position from vertical to horizontal. The
substage is supported by a fitting attached to the underside
of the stage by screws. The
substage has a diagonal rack and spiral pinion
adjustment and the fitting for the condenser has two knurled knobs to
adjust centration. As is also true for the slide in which the fine
focus movement occurs, and also the coarse focus, the substage slide
can be adjusted for wear, slits in
the brass with a screw through each slit allowing for tightening. A tubular tailpiece projects
down from the limb; on it rides a two sided gimbaled mirror. The
tension on the rotation of the mirror
in two directions can be adjusted
by a knob on one side of the mirror,
and a screw which can tighten the
tension on the pin of the mirror
fitting. The mirror
assembly rides up
and down the tailpiece. As in the
substage, the coarse adjustment is by
diagonal rack and spiral pinion. Fine focus is by a calibrated very
finely threaded, vertically acting engraved micrometer screw acting on
a long lever. The
five inch long tube has a calibrated draw tube allowing extension to
8-1/4. This short tube length is shorter than the traditional 10 inch
tube length popular in England in the late nineteenth century, but was
becoming more common after about 1900. Accessories
accompanying the microscope are a
substage condenser, a Watson 3 inch objective and a single ocular
signed 'C. Baker, London' in an insignia. The condenser has stacked
optical elements and has a wide aperture; it has an iris diaphragm
controlled by a lever and a swing out filter holder. The
rotating
mechanical
stage is controlled by the arrangement of a worm screw for
the X-axis and a diagonal rack and pinion for the Y axis, with the rack
in the center of the stage. A slide holder with clips
rides on a channel cut into the stage and has a knurled knob at the
back allowing fine control of friction or locking it in place,
like many Watson stages. The
mechanical stage rotates, its rotation only limited by knobs reaching
the limb on either side*. The entire instrument is finished in
lacquered brass. The finish is in excellent condition with minor losses
for the most part.
HISTORY RELATING TO THIS MODEL
Although signed
'W. Fairservice, Hastings,' I and my fellow-collectors have been unable
to find another microscope signed by Fairservice. William Fairservice
was an 'optician' from
about 1861, but in Hastings from 1881, and died in 1921; This
microscope then must date from that period; since the features found on
this microscope were introduced in the late 1880's and early 1890's; the short tube length may suggest it is even after c 1900 as this is when the English makers started to adopt the shorter continental tube length. Watson
introduced some of the features seen on this microscope with their
Edinburgh, Royal,
and Van Heurck microscopes. The Edinburgh was introduced in 1887 and
the Van Heurck was apparently first made in 1889, with the Royal later. This microscope has a rotating mechanical stage,
similar but not identical to those supplied with the Van Heurck Number 1 model. The use of diagonal
rack and spiral pinion is a feature invented by Swift about 1880, and
used by Watson and others from about then on all their better stands. Although the
foot is a lot like the Edinburgh, Van Heurck and Royal, it
is not quite the same configuration; it is closer to older Ross rather than Watson feet and also similar to some Baker instruments. The
provision of adjustments for wear of the focusing mechanisms, both for
the optical tube and the
substage are the type provided by Watson on the three other
Watson models mentioned here, but was also used by Baker on their Nelson-Curties stand, and
also Swift. As can be seen in the image to the left, this microscope is not nearly as massive as the Royal Watson model.
In summary this very high quality stand incorporates features of various makers including several different stands by Watson, and seems to be of unique design overall. One can only conjecture that
William Fairservice may have made (or had made for him), this
microscope incorporating features of various stands of the late 19th
and early 20th century. It closely resembles the plan of an Edinburgh H Stand but with the rotating stage seen in the Van Heurck, Baker, and Swift stands.
The author is indebted to Paul Ferraglio and Allen Wisner for their helpful advise, suggestions and insight, without which this page would not have been as complete nor as accurate.
*The stage is
similar but not identical to the rotating mechanical stages seen on the Van Heurck number 1.
