The Watson firm first
manufactured this type of microscope in 1891 at the
suggestion of the renowned Belgian microscopist Henri van
Heurck (1838-1909). When first introduced, the microscope
incorporated a continental (horseshoe) style base, but, as
with the present example, stands with an English tripod
base were also produced and these became the standard form.
The microscope is constructed in brass with bright
lacquered and oxidized surface finishes and is about 16
inches tall when set up for use with the draw tubes
partially extended as shown in some of the photos. The main
focus is by rack and pinion and the fine focus is by
calibrated micrometer screw (1 rev, 1/13 mm). There is a
rotatable mechanical stage and two drawtubes with the main
drawtube calibrated and having movement by rack and pinion.
The substage is focused by rack and pinion, has a fine
focus by micrometer screw located at the side of the stage,
and has centering adjustments.
Read the description of the
Watson Van Heurck microscope in the 1923
catalog.
Elsewhere on this website is
another example of the
Watson Van Heurck No.1, serial number 10884, with a
more elaborate stage having centering adjustments,
calibrated stage movements, and rack and pinion stage
rotation. This microscope is based on the design of the
Belgian botanist
Henri Van Heurck (Antwerp 1839-1909).
A short history of the Watson firm is online