<< >>
Usage conditions apply
This octant has an ebony frame, reinforced brass index arm, and ivory name plate. The ivory scale is graduated every 20 minutes from -3° to +100° and read by vernier with tangent screw to single minutes of arc. There is a telescopic sight, four shades for the index mirror, and three shades for the horizon glass. The inscription reads "SPENCER & CO LONDON." The U.S. Navy transferred it to the Smithsonian in 1930.
Ref: Gloria Clifton, Directory of British Scientific Instrument Makers 1550-1851 (London, 1895), p. 83.
Currently not on view
Object Name
date made
early 19th century
Spencer & Co.
place made
United Kingdom: England, London
radius: 9 3/4 in; 24.765 cm
overall: 4 5/8 in x 9 7/8 in x 11 1/4 in; 11.7475 cm x 25.0825 cm x 28.575 cm
ID Number
catalog number
accession number
Credit Line
U.S. Navy
See more items in
Medicine and Science: Physical Sciences
Measuring & Mapping
Data Source
National Museum of American History
Nominate this object for photography.   

Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.

If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.


Add a comment about this object