The stage and the
micrometer are interchangable thus providing a
microscope having a stage micrometer
A plaque on the inside
cover of the case is marked by the manufacturer:
Société Genevoise pour la construction
d'instruments de Physique, Geneve. The firm
was established in 1862 by two Swiss scientists,
Marc Thury (1822-1905) and
Auguste DelaRive (1801-1873). It
survived well into the 21st century. The firm
specialized in the manufacture of scientific
instruments, metrological instruments, and machine
tools. Early on, the firm produced microscopes among
which were conventional microscopes, petrological microscopes, and as
illustrated by the example on this page, metrological
(measuring) microscopes. A short historical synopsis (in French) of the
firm has been published.
The microscope measures
14-inches in height closed down and has a folding
tripod base with leveling screws having a spread of
about 9-inches. The micrometer mechanism is based on a
Frauenhofer design and it can rotate in a plane
perpendicular to the optical axis. The microscope can
be used in vertical configuration, or after
detaching the stage and mirror and reversing the upper
section in its slot, it can be put into a horizontal
orientation. In addition, the stage and the micrometer
can be interchanged. The instrument is supplied with
one eyepiece which can be focused on cross-hairs, a
sub-stage aperture stop, and three objectives.
The following page has
been extracted from the
catalog dating 1900.