Protractor and Ruler Scale
date: label: date made
content: 1879-1907
name: label: maker
content: W. & L. E. Gurley
label: maker
content: Gurley, Lewis E.
label: maker
content: Gurley, William
notes: label: Description
content: This steel semicircular protractor is divided by half-degrees and is marked by tens from 360 to 180 and from 180 to 0, both in the counterclockwise direction. A 3/8" line is engraved at the origin point. On its left side, the protractor slides along a steel bar or straight edge. Two thumbscrews at the top of the protractor hold in place a removable scale, which is divided into units of four and marked by 40s from 0 to 720. Forty units correspond to approximately one centimeter. The bottom of each screw is marked "2." The scale moves approximately 60 units to the left or right by turning a third screw against a serrated edge on the scale.
label: Description
content: An additional scale accompanies the object. This scale is divided by fifties and marked by thousands from 0 to 12,000. Ten units correspond to approximately 1.5 centimeters. The protractor was originally stored in a mahogany case, apparently discarded by 1959. The protractor was purchased by the U.S. Geological Survey between 1879 and 1907.
label: Description
content: See also ID number MA.247968.
label: Location
content: Currently not on view
place: label: place made
content: United States: New York, Troy
topic: label: Subject
content: Mathematics
label: Subject
content: Protractor
label: Subject
content: Surveying
setName: label: See more items in
content: Medicine and Science: Mathematics
label: See more items in
content: Science & Mathematics
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content: Protractors
creditLine: label: Credit Line
content: Transfer from U.S. Geological Survey
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: MA.247967
label: accession number
content: 47736
label: catalog number
content: 247967
objectType: label: Object Name
content: protractor
physicalDescription: label: Physical Description
content: steel plate (overall material)
label: Physical Description
content: copper (overall material)
label: Measurements
content: overall: 2 cm x 23 cm x 30.5 cm; 25/32 in x 9 1/16 in x 12 in