Brown & Sharpe Bevel Protractor

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This metal instrument consists of a circular protractor housed within an irregularly shaped blade. An 11-1/2" trapezoidal blade slides into the housing. A screw on the protractor fixes that blade in place. The protractor is divided by single degrees and marked by tens from 0° to 90° to 0° to 90° to 0°. A vernier, attached by another screw, permits angle readings to five minutes of accuracy. The protractor has a hinged case of leather over wood, lined with black satin. The case is gouged in several spots.
Brown & Sharpe Manufacturing Co. introduced a "universal bevel protractor" in 1899, according to "Trade Notes," Science and Industry 4 (1899–1900): 274–275. Although there is no signature on this instrument, this protractor matches the illustrations in this article and in Brown & Sharpe catalogs at least as early as 1899 and at least as late as 1948.
References: Kenneth L. Cope, intro., A Brown & Sharpe Catalogue Collection, 1868 to 1899 (Mendham, N.J.: The Astragal Press, 1997); Brown & Sharpe Mfg. Co., Small Tools: Catalog No. 27 (Providence, R.I., 1916), 92–93; The Brown & Sharpe Handbook: A Guide for Young Machinists (Providence, R.I., 1948), 49–54, 110–112.
Currently not on view
date made
Physical Description
steel (overall material)
satin (overall material)
leather (overall material)
overall: 3 cm x 35 cm x 10 cm; 1 3/16 in x 13 25/32 in x 3 15/16 in
ID Number
accession number
catalog number
Credit Line
Gift of Ursula N. Forbes
Drafting, Engineering
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Data Source
National Museum of American History


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