Kern Semicircular Protractor
- Description
- This German silver semicircular protractor bears the distinctive italic engraved numbers of Kern & Co. of Aarau, Switzerland. It is graduated by quarter-degrees and marked by tens from 10 to 170 both from left to right and from right to left. There are no other marks. The lower edge of the protractor is beveled, with a groove at the origin point.
- Ruth E. Crownfield, the widow of Albert C. Crownfield Jr., a mechanical engineer from Mohawk, N.Y., donated this protractor in 1978. The instrument is quite tarnished and scratched, suggesting Crownfield used it frequently. Similar protractors cost $3.50 in the first decade of the 20th century and $4.50 in 1936.
- See also ID numbers MA*247966 and 1977.0460.02.
- References: “(Product No.) 1248,” Catalogue of Keuffel & Esser Co. (New York, 1909), 172; Catalogue of Keuffel & Esser Co. (New York, 1936), 201.
- Location
- Currently not on view
- Object Name
- protractor
- date made
- early 20th century
- maker
- Kern & Co.
- Physical Description
- german silver (overall material)
- Measurements
- overall: .2 cm x 15.6 cm x 7.9 cm; 3/32 in x 6 5/32 in x 3 1/8 in
- place made
- Schweiz: Aargau, Aarau
- ID Number
- 1978.2291.01
- accession number
- 1978.2291
- catalog number
- 336875
- subject
- Science & Mathematics
- Protractors
- Mathematics
- Protractor
- See more items in
- Medicine and Science: Mathematics
- Protractors
- Data Source
- National Museum of American History, Kenneth E. Behring Center
- Credit Line
- Gift of Ruth E. Crownfield
- Additional Media
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