The objectives and aperture-stops are housed in a small leather-covered box with the serial-number burned inside as well. The optical equipment consists of the objectives No.3, No.5 and No.7 and two eyepieces No.2 and No.3. The microscope allows a magnification up to 300 linear with eyepiece No.3 and objective No.7.

This microscope-stand was offered already in the early 1860ies and was equipped with the hard-rubber-plate for the table in the early 1870ies. This stand VIII was modified with a condenser-system and offered as stand IV in the early 1890ies.

Compared with this description the microscope is complete (missing only the 12 slides and 12 cover-glasses as well as the tweezers and scalpel) and has an additional eyepiece.

E. Hartnack (1826-1891) was one of the most respected makers of his times. He joined the firm of his uncle, Georges Oberhaeuser (1798-1868), in Paris in 1857, and assumed full control of the firm in 1860. He moved to Potsdam, Germany, in 1870, as a result of the Franco-Prussian war and left his partner, A. Prazmowski, in Paris. The Parisian branch of the business was eventually taken over by Nachet et Fils. Hartnack continued the manufacture of microscopes with the same skill and innovation that made his uncle famous. He is credited with the first use of water-immersion lenses in the commercial production of microscopes and the adoption of the substage condenser in his later instruments.