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.
