This is a brass Continental style monocular microscope made by the Rochester NY company of Bausch & Lomb. The heavy lead-filled horseshoe base and central compass joint allowed the operator to incline the microscope to any level, including horizontal. It is fitted with a B&L mechanical stage, an Abbe condenser, and four objectives. One objective is an oil immersion lens with a NA of 1.37. The microscope has a R&P coarse focus and a fine-pitch screw-thread fine focus. The mirror is mounted on a descending bar, and it has both a plane and parabolic surface. The microscope has three Huygens eyepieces however two are the same No. 2. Included with the microscope is an interesting immersion oil applicator device made from tortoise shell. The microscope is engraved in several places: Bausch & Lomb Optical Co. The microscope comes with a mahogany storage and carrying case.

JJ Bausch (1830–1926) and H Lomb (1828–1908) immigrated to Rochester NY in the 1850s. There they partnered and formed a company that initially made Vulcanite framed spectacles. Starting in 1874 the Bausch & Lomb Optical company mass produced microscopes, peaking at 30,000 instruments by 1900. This number was equivalent to the number made by their German competitors Reichert (30k), Zeiss (40k) and Leitz (55k). In 1875 the B&L company hired Ernst Grundlach from Wetzlar, Germany. Grundlach was an expert designer of microscopes and microscope objectives. The high-NA objectives on this B&L instrument attests to this. B&L holds many patents, including No. 57734 (Feb 16, 1897); which describes this particular instrument. Central to the patent is the fine focus mechanism.

This microscope was donated to the Golub Collection by Edgar and Joyce Lehmann

Microscope featured 12/2023