Signedon back of mirror: SPENCER / BUFFALO / USA [in achromat trademark]
on lid of box: SPENCER / BUFFALO / U.S.A. [in achromat trademark]
on boxes: SPENCER / SPENCER / BUFFALO / U.S.A. [in achromat trademark]
Primary SourcesSpencer Lens Company, Catalog of Spencer Products including Microscopes, Microtomes, Delineascopes and their Accessories with Other Scientific Optical Instruments (Buffalo: Spencer Lens Company, 1924), 69.
Spencer Lens Company, Catalog (Not complete) of the More Popular Spencer Microscopes, Microtomes, Delineascopes, Optical Measuring Instruments and Accessories (Buffalo: Spencer Lens Company, 1930), 63.