Kern Semicircular Protractor
date: label: date made
content: early 20th century
name: label: maker
content: Kern & Co.
notes: label: Description
content: 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.
label: Description
content: 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.
label: Description
content: See also ID numbers MA.247966 and 1977.0460.02.
label: Description
content: References: “(Product No.) 1248,” <I>Catalogue of Keuffel & Esser Co.</I> (New York, 1909), 172; <I>Catalogue of Keuffel & Esser Co.</I> (New York, 1936), 201.
label: Location
content: Currently not on view
place: label: place made
content: Switzerland: Aargau, Aarau
topic: label: Subject
content: Mathematics
label: Subject
content: Protractor
setName: label: See more items in
content: Medicine and Science: Mathematics
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content: Science & Mathematics
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content: Protractors
creditLine: label: Credit Line
content: Gift of Ruth E. Crownfield
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1978.2291.01
label: accession number
content: 1978.2291
label: catalog number
content: 336875
objectType: label: Object Name
content: protractor
physicalDescription: label: Physical Description
content: german silver (overall material)
label: Measurements
content: overall: .2 cm x 15.6 cm x 7.9 cm; 3/32 in x 6 5/32 in x 3 1/8 in