Object Details
Description
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.
Location
Currently not on view
Credit Line
Gift of William J. Ellenberger
date made
ca 1930
ID Number
1981.0933.19
accession number
1981.0933
catalog number
1981.0933.19
Object Name
protractor
Other 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
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Protractors
Data Source
National Museum of American History
Subject
Mathematics
Protractor
Link to Original Record
Record ID
nmah_904378