Brass Drum Microscope by Robert Gogerty (No. 29 )

Age: c1850
Made by: Robert Gogerty
Made in: England

This is a small brass microscope made by Robert Gogerty c1850. The microscope is a "Drum-Type" instrument having a microscope body that slides into a cylindrical base as opposed to being cantilevered out from the base as with the Cuff-type microscopes. The base has a cutout on one side to accommodate the sample. At the bottom of the cutout is the sample stage, which is a platform just above the illuminating mirror located at the bottom of the base. In this microscope the mirror can be titled. Focusing is accomplished by sliding the microscope body up or down. Optics of this microscope consist of a single eye lens, field lens and objective. There is only one objective remaining with this instrument. The name of the maker, Robert Gogerty, is engraved on the body tube and printed on the trade card inside of the oak case.

Drum microscopes were popular in the mid 1800s, and are an evolutionary step from the Benjamin Martin Pocket Reflecting Microscope described in 1738. These instruments were designed to be portable, thus the name "Pocket". Although Benjamin Martin popularized the Drum microscope, he apparently was not the only one to have invented it. In a 1717 publication, J.G Doppelmayr gave a description of the earliest drum microscope invented by Nicolai Bion.

Featured 08/2012

Wed, Aug 1, 2012