Trigonometer for Use with Artillery
date: label: date made
content: ca. 1942
notes: label: Description
content: The solution of right and oblique triangles is central to firing artillery. This circular disc is marked around the edge with scales labeled D (inverse sine), E (logarithmically divided), B (inverse cosine), and C (tangent and cotangent) This side also is marked: SOLUTION OF RIGHT TRIANGLE. Two clear plastic arms, one long (L) and one short (S), are held by a metal pivot at the center. A table in the center of the disc explains how to set arms L and S to solve for different sides of the triangle and/or an acute angle, given different other sides and/or an angle. The instrument is marked on the other side: SOLUTION (/) OF OBLIQUE ANGLES and has a similar table. It is also marked on this side: SOLUTION TO THE TRIAL SHOT DATA PROBLEM. Below this is a grid of lines like those on graph paper for plotting relevant observations.
label: Description
content: A signature on the object reads: CAND. B.C. KEENEY (/) BAIM PLAT (/) AAA CAMP DAVIS, N. C. There is no maker's mark.
label: Description
content: According to the Brown University Archives, Barnaby Conrad Keeney (1914-1980) was an officer candidate the Antiaircraft Artillery School at Camp Davis, North Carolina, in 1942. Keeney would be discharged from the Army as a captain. He went on to become the twelfth president of Brown University.
label: Location
content: Currently not on view
place: label: place made
content: United States
topic: label: Subject
content: Mathematics
setName: label: See more items in
content: Medicine and Science: Mathematics
label: See more items in
content: Trigonometry
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content: Science & Mathematics
creditLine: label: Credit Line
content: Gift of Louise D. Campbell
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1979.3002.001
label: catalog number
content: 1979.3002.001
label: nonaccession number
content: 1979.3002
objectType: label: Object Name
content: Rule, Circular
label: Object Name
content: trigonometer
label: Object Name
content: calculating instrument, trigonometric
physicalDescription: label: Physical Description
content: plastic (overall material)
label: Physical Description
content: wood (overall material)
label: Physical Description
content: white (overall color)
label: Physical Description
content: green (overall color)
label: Physical Description
content: metal (overall material)
label: Measurements
content: average spatial: .5 cm x 32.5 cm x 31 cm; 3/16 in x 12 25/32 in x 12 7/32 in