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.


Sotheby & Company, Catalogue of a Collection of Scientific Instruments, the Property of the Late Henry Russel Wray, London, 1959 (a copy of the catalogue is in the accession file).

Date Made: ca 1840

Maker: Cox, William Charles

Location: Currently not on view

Place Made: United Kingdom: England, Devonport

Subject: MathematicsProtractor


See more items in: Medicine and Science: Mathematics, Science & Mathematics, Protractors


Exhibition Location:

Data Source: National Museum of American History

Id Number: MA.316927Accession Number: 228694Catalog Number: 316927

Object Name: protractor

Physical Description: brass (overall material)Measurements: overall: .2 cm x 22.5 cm x 11.8 cm; 3/32 in x 8 27/32 in x 4 21/32 in


Record Id: nmah_904337

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.