Compound microscope

The tube has a consistent diameter. The eyepiece and lens are at the ends. It is screwed into an arm protruding from the back pillar. The pillar is cylindrical with a screw for macroscopic focusing at the top. The tube also contains a ring with a magnifying glass. In the middle of the pillar is a stage with a central hole to allow light to pass through. The pillar then develops into a pedestal, with a joint at the connection so that the instrument can be tilted. The concave mirror is held by an articulated support on the front of the pedestal. The iron base is horseshoe-shaped and heavy enough to keep the microscope stable even when tilted to a fully horizontal position.

E. Hartnack was Oberhauser's nephew and protégé. In 1860 he took over the company and introduced improvements and innovations while trying to preserve the instrument's original shape. As a result of the Franco-Prussian War, he moved to Potsdam in 1870, where he continued his work.