Antique Brass PARALLEL NAVIGATION RULER, Nautical Maritime Instrument - NEGUS

1800's parallel ruler made of brass great patina. Brothers Thomas Shufeldt Negus, Jr. (1828-1894) & John Davidson Negus (1833-1890) manufacturers and merchants of chronometers and other marine instruments established T.S. & J.D. Negus Company in 1845, New York City.