Octant

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Description
This octant has a mahogany frame and index arm. The boxwood scale is graduated every 20 minutes from 0° to 90° and read by transversals to 2 minutes of arc. An inscription penciled on the back of the scale reads: "Capt. Rowland Thompson = Lewes = Delaware 1792." A descendant donated it to the Smithsonian in 1882.
Location
Currently not on view
date made
ca 1792
Measurements
radius: 20 in; 50.8 cm
overall: 22 1/4 in x 18 5/8 in x 3 1/2 in; 56.515 cm x 47.3075 cm x 8.89 cm
overall: 3 3/8 in x 18 1/2 in x 22 3/8 in; 8.5725 cm x 46.99 cm x 56.8325 cm
ID Number
PH.308473
catalog number
308473
accession number
93249
Credit Line
George Andrews Thompson
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Data Source
National Museum of American History, Kenneth E. Behring Center

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