This simple little mineralogical microscope from Nachet was very popular throughout Europe. It is microscope No. 5 of our SEIMC Collection.
Its macro focus is by turning an endless screw, which acts on the optical tube. The stage is square and fixed. It has a hole through which it receives the light from the base’s reflection mirror. Its petrological character is given by the reflection prism fixed on the objective and which facilitates incident polarized light.
These prisms can be of various types. Two examples of them can be seen in the image.
Nachet manufactured numerous models of petrological microscopes. This is the simplest. The 77b of this Collection is the most complex. Two others are shown in the images, the most complex being the 1879 model.