J. Quincy Octant

This octant has a mahogany frame, flat brass index arm with ornate floral pattern, and ivory name plate. The ivory scale is graduated every 20 minutes from -5° to +95° and read by vernier to single minutes of arc. There is also a back sight and a back horizon glass that could be used to measure angles greater than 90°. The "QUINCY, MAKER, N. YORK" inscription refers to J. Quincy, a mathematical instrument maker in New York City in the 1780s. In the stepped wooden box is a trade card of William Hooker, who operated a nautical shop in New York around 1820.
Ref: Deborah J. Warner, "American Octants and Sextants: The Early Years," Rittenhouse 3 (1989): 86-112, on 107.
Currently not on view
date made
ca 1800
J. Quincy
place made
United States: New York, New York
radius: 18 in; 45.72 cm
overall in case: 4 13/16 in x 18 5/8 in x 21 1/4 in; 12.22375 cm x 47.3075 cm x 53.975 cm
ID Number
catalog number
accession number
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Medicine and Science: Physical Sciences
Measuring & Mapping
Data Source
National Museum of American History