Excerpt:
Certainly, most microscope collectors are familiar with the firm E. Leitz, Inc. and many of them probably have several Leitz microscopes represented in their collection. Some, however, may not realize that the founder of the firm was not Ernst Leitz I, but Carl Kellner. Kellner founded what was named the Optical Institute in Wetzlar Germany in 1849. By 1851 he employed twelve workmen and was producing his first microscopes. Among the more notable graduates of the Institute was one, Ernst Gundlach, familiar as the designer of the first Bausch & Lomb stands, who was employed during the years 1859-1862.1 Other opticians who at one time worked at the Optical Institute and later founded their own firms include Riechert and Hensoldt.2 Kellner's microscopes met with wide acclaim and were furnished with his noted invention, the orthoscopic eyepiece. While first applied as an eyepiece for telescopes and then later adapted to the microscope, it enables a large flat field of view.