J. Zentmayer, Philadelphia, The United States Army Hospital Microscope, ~1863-5
The United States Army Hospital model microscope was manufactured by the optician and instrument maker Joseph Zentmayer of Philadelphia. It is signed on the base: J. Zentmayer, Philadelphia. The model was originally designed for use by the U.S.A. Medical Department during the Civil War. It was first introduced in 1862-1863 for use by the U.S.A. Medical Department during the Civil War, and continued to be sold to the government as well as to the civilian market until the end of the 19th century. Over that time span, the microscope incorporated a number of modifications and improvements. While later versions of this model usually bear a serial number and a draw-tube, this item is similar to that of the Billings Collection, assigned to the earliest line of the production. The only difference is that it has two rather than one coarse focusing milled knob. Hence it is very likely that it can be attributed to the era of the US Civil War.
This is the earliest example of a microscope that was designed specifically for wartime field hospitals. It was related to the contemporaneous rise of the germ theory of disease by John Snow and Louis Pasteur of the late 1850s. Though not a field microscope by the design, this is the first microscope ever to be designed specifically for front-line (and wartime) hospitals, thus it is a milestone in the history of the military portable microscope.
Provenance: Previously from the collection of Dr. Allan Wissner, Ardsley, NY, USA.