Protractor Signed by Cox

This semicircular brass protractor is graduated to half-degrees. It is marked by tens from 10° to 170° in both directions, from left to right and from right to left. A brass rectangle with a curved notch has been soldered on at the origin point. The rectangle contains a small hole for locating the vertex of the angle being measured. The base of the protractor bears the maker's mark: W. C. Cox, Devonport. The letters DB are scratched near the maker's mark.
William Charles Cox, a British instrument maker who worked in Plymouth and Devonport, had his shop in Devonport from 1830 to 1851. He presumably made this protractor during that period. The Smithsonian purchased this instrument in 1959 from the estate of Henry Russell Wray via an auction conducted by Maggs Bros. Ltd. of London.
Reference: Gloria Clifton, Directory of British Scientific Instrument Makers 1550-1851 (London: National Maritime Museum, 1995), 69–70.
Currently not on view
Object Name
date made
ca 1840
Cox, William Charles
Physical Description
brass (overall material)
overall: .2 cm x 22.5 cm x 11.8 cm; 3/32 in x 8 27/32 in x 4 21/32 in
place made
United Kingdom: England, Devonport
ID Number
accession number
catalog number
Science & Mathematics
See more items in
Medicine and Science: Mathematics
Data Source
National Museum of American History, Kenneth E. Behring Center

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