Binocular microscope by Erntz Leitz Gmbh Commercially manufactured binocular microscope oculars and head, with four lenses, in an original velvet lined case. Instrument engraved with the maker’s mark ‘Ernst Leitz Wetzlar’ on a circular black enamelled plate. Each of two paired lenses (designated ‘1’ and ‘3’) are similarly marked. Case lid engraved with the company name ’E.Leitz, Wetzlar.’ in gilding. A later Royal Society classification ‘Z.R.S.1’ has been glued above the maker’s mark. c.1913