Ross's Diatom-finder or Field Hand Microscope, c. 1875
Simple Pocket Microscope
Although unsigned,
this small simple microscope appears in the 1875
Ross & Co. catalog where it is called the
Diatom-Finder or Field Hand-Microscope.
The microscope is supplied with a single 1/10-inch
objective that focuses by a screw mechanism onto a
removable live box. At the upper end is a container
that holds extra glasses for the live box. There is
an eyelet at the end for attachment to a lanyard.
The instrument was sold with its leather covered
case.
An identical example,
also unsigned, is located at the Science Museum,
London: Inventory No.: 1921-222
The following is from the1875
Ross catalog. Note item 4.