Semicircular Protractor


This semicircular brass protractor is divided by single degrees and marked by tens from 10° to 170° in both the clockwise and counterclockwise directions. The origin point is marked with an arrow. A 2-1/2 inch ruler, divided by sixteenths of an inch, runs along the lower edge of the protractor. The letters U.S.A. are engraved above the right end of the ruler. No maker's mark is present.

Date Made: ca 1930

Location: Currently not on view

Subject: MathematicsProtractor


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


Exhibition Location:

Credit Line: Gift of William J. Ellenberger

Data Source: National Museum of American History

Id Number: 1981.0933.19Accession Number: 1981.0933Catalog Number: 1981.0933.19

Object Name: protractorOther Terms: protractor; Semi-Circular

Physical Description: brass (overall material)Measurements: overall: .1 cm x 9.5 cm x 4.5 cm; 1/32 in x 3 3/4 in x 1 25/32 in


Record Id: nmah_904378

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