Magnetic Compass with Sights
notes: label: Description
content: This magnetic compass has a paper scale, a metal needle, a wooden case, and a glass cover. The scale is graduated every 10 grads and marked every 20, with a total of 400 grads in the circle. Folding metal sights are attached to the north and south edges. A plumb bob stored in the north edge of the case can be suspended from the east edge.
label: Description
content: From ancient times, mathematicians described a right angle as having ninety degrees. In the 1790s, the French introduced a right angle of one hundred decimal degrees or grads. Instruments divided this way were available in France and in the United States into the 20th century.
label: Location
content: Currently not on view
place: label: place made
content: France
setName: label: See more items in
content: Medicine and Science: Physical Sciences
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content: Metric System
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content: Measuring & Mapping
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: PH.314618
label: catalog number
content: 314618
label: accession number
content: 208046
objectType: label: Object Name
content: magnetic compass
physicalDescription: label: Physical Description
content: paper (scale material)
label: Physical Description
content: metal (needle, sights, plumb bob material)
label: Physical Description
content: wood (case material)
label: Measurements
content: overall: 1 3/4 in x 8 3/8 in x 4 1/2 in; 4.445 cm x 21.2725 cm x 11.43 cm
label: Measurements
content: overall: 1 in x 8 1/4 in x 4 1/2 in; 2.54 cm x 20.955 cm x 11.43 cm