Object Details
maker
G. Felsenthal & Sons, Inc.
Description
This clear plastic semicircular protractor is divided by tens and marked by hundreds from 100 to 3,100 mils and from 3,300 to 6,300 mils. Mils are units used in artillery and other military applications; 1,000 mils is equivalent to 56.25°. A pinhole is at the origin point. The bottom edge of the protractor is divided by hundreds and marked by five hundreds from 0 to 7,000. A small vernier appears to the left of the scale, and the scale is labeled: 1/25,000 METERS.
The interior of the protractor has a semicircular opening with a groove parallel to the origin point. Below the opening is a maker's mark: 12 INCH (/) G. FELSENTHAL & SONS, INC. (/) FAE-21. Donor Ben Rau dated the object to 1945, but the form of the signature indicates the protractor was probably manufactured for the U.S. Army in the 1950s.
This protractor is very similar to 1977.1141.11. See also 1977.1141.01, 1977.1141.02, 1977.1141.03, 1977.1141.05, 1977.1141.08, 1977.1141.09, 1977.1141.10, 1977.1141.12, 1977.1141.19, 1977.1141.20, 1977.1141.21, 1977.1141.22, 1977.1141.23, 1977.1141.24, 1977.1141.30, and 1977.1141.39.
Location
Currently not on view
Credit Line
Gift of Ben Wharton Rau and Margery Felsenthal Rau
date attributed by donor
1945
date made
1960s
ID Number
1977.1141.22
accession number
1977.1141
catalog number
336406
Object Name
protractor
Physical Description
plastic (overall material)
Measurements
overall: .2 cm x 30.5 cm x 16.5 cm; 3/32 in x 12 in x 6 1/2 in
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Protractors
Data Source
National Museum of American History
Subject
Mathematics
Protractor
Artillery
Link to Original Record
Record ID
nmah_904374