model microscope (second form), c. 1883
This microscope is signed: Bausch & Lomb Optical Co. and marked: Pat. Oct. 3, 1876. The serial number, 2188, is stamped onto the inside of the storage case. It an example of the second version of the “Physician’s Model” The main focus is by rack and pinion. The fine focus utilizes the “frictionless” mechanism which is the subject of the 1876 Gundlach patent. The stage is made of glass and has a nickel plated slide carrier, the subject of the 1877 Gundlach patent. The microscope dates c. 1883. The mirror housing and aperture wheel are made of hard rubber. With later versions of this model hard rubber was replaced by brass.