Compound microscope

Inside this microscope's cylindrical tube there is another tube marked in centimeters numbered from 14 to 19 and subdivided into millimeters. When this is moved up, it shows the length of the tube. The front of the tube bears the manufacturer's inscription: "NACHET A PARIS." The eyepiece is housed at the top and there is a revolver at the bottom, with a circular, slightly concave base and 2 discs, the undersides of which hold 3 lenses. When the bottom disc turns it moves the lens, placing it directly under the bottom of the tube and above the hole in the stage lying beneath. This provides a simple way to swap the lenses.

The tube houses the eyepiece and lens. It is held on a kind of bridge with a rack mechanism on the back pillar. The whole thing slides vertically thanks to 2 screws at the same level as the rack for macroscopic focusing. A screw at the very top of the pillar is used for fine focusing. Between the pillar and base is a pedestal, which is attached with a joint system for tilting the instrument and has a stage at the tip. The latter has 2 clips for holding slides or samples, and a system to move them using screws that shift the top plate in all directions. Below the stage is a condenser and an iris-style diaphragm system to control light intensity. The front of the pedestal has a mirror with an arm system that enables it to be moved in any direction. The pedestal is uniformly cylindrical with a wider part where it joins the horseshoe-shaped base, which has cuboid limbs and a heel.

Born in Paris, Camille Sebastian Nachet (1799–1881) was an optician and lens maker who started out working for the famous manufacturer Chevalier. His first microscopes were drum-type models. He received an award for the quality of his lenses at the 1851 Great Exhibition. On his death, his son took over from him and ran the business from 1880 to 1890, changing his microscope signature to "A. Nachet." Nachet, Chevalier, and Oberhauser were the 3 most outstanding French manufacturers of microscopes. The Nachet brand still exists today.