Ernst Leitz Wetzlar Stand IIa Microscope, No. 74142

An early 20th-century Stand IIa compound microscope made in Wetzlar, Germany by Ernst Leitz and distributed through the firm's New York branch. The base is stamped Ernst Leitz Wetzlar / No. 74142 / Filiale New York; the serial number places production approximately between 1905 and 1910.

The Stand IIa was a professional medium-size laboratory model intended for routine biological and medical work. Construction is lacquered brass with the original black enamel stage and fittings, and the instrument retains its correct early 20th-century configuration: inclinable body tube, fixed square stage, coarse focus by rack and pinion, fine focus by micrometer screw, graduated draw tube in millimeters, substage illuminating apparatus with swing-out condenser, iris diaphragm with lateral control, triple nosepiece, and plane and concave mirror.

Optics included are a Bausch & Lomb 16mm objective (NA 0.25) and a 12X eyepiece, giving approximately 120X total magnification, well suited to prepared slides, botanical samples, and fibers. The original fitted wooden case accompanies the instrument.