Two centimetre dental amalgam micrometer, in case, U.S.A., 1880-1914 Two centimetre dental amalgam micrometer 1880-1914
Boys radio-micrometer made in 1907 by, The Cambridge Scientific Instrument Co. Ltd., Cambridge, England, no.5426 with wooden box (sighting tube and several nuts missing) C V Boys' radio-micrometer, with outer casing removed, 1907. 1907