Gebr. Mittelstrafs, (Mittelstrass), Magdeburg c. 1875

This microscope signed in script on the tube “Gebr. Mittelstrafs, (Mittelstrass), Magdeburg”. It focuses using rack and pinion. While the knob on the back of the limb looks as if it might control a fine adjustment, its only purpose is to attach the limb to the microscope. There is a draw tube, a tube mounted stage condenser, and aperture wheel mounted under the stage. The mirror is single sided with a concave glass. The microscope likely dates from the mid-second half of the 19th century. This is a relatively large and heavy instrument; it measures 18-inches in height inclined as shown in photo. The last photo compares its size to that of Zeiss IVa.

The firm Gebr. Mittelstrass, Magdeburg was established by two brothers, Carl and Otto, in 1867. The firm produced and sold a variety of optical, physical, chemical, and measurement apparatus. The advertisement shown below is from 1903.