English-Style Sector
date: label: date made
content: 19th century
notes: label: Description
content: This ivory instrument has two rectangular arms with flat edges and is held together by a circular brass hinge. The scales run from top to bottom on each arm. On one side, each arm has a sine scale, running from 10 to 80 degrees; a tangent scale, running from 50 to 75 degrees; and a second tangent scale, running from 10 to 45 degrees. Spanning both arms on the outer edge are three scales: log tangent, running from 2 to 45 degrees; log sine, running from 1 to 70 degrees; and logarithmic, running from 1 to 10 twice. The top face of the instrument has a scale of equal parts that divides one foot into 100 increments and runs from 90 to 10. There is no maker's mark.
label: Description
content: The other side has a double scale along the fold line for regular polygons, labeled POL and running from 12 to 4 sides. Each arm has a scale of equal parts, running from 1 to 10 and labeled L; a secant scale, running from 40 to 75 and labeled s; and a scale of chords, running from 10 to 60 and labeled C. The scales for dialing typical of 18th-century English-style sectors are not present. Spanning both arms on the outer edge is a scale of inches, running from 12 to 1 and divided to tenths of an inch. The sector likely dates to the mid-19th century. Compare to 1985.0580.06, MA.335351, and MA.321755.
label: Location
content: Currently not on view
place: label: place made
content: United Kingdom: England
topic: label: Subject
content: Mathematics
label: Subject
content: Sectors
label: Subject
content: Rule, Calculating
setName: label: See more items in
content: Medicine and Science: Mathematics
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content: Sectors
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content: Science & Mathematics
creditLine: label: Credit Line
content: Gift of Samuel B. Magill
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: MA.333937
label: catalog number
content: 333937
label: accession number
content: 305959
objectType: label: Object Name
content: sector
physicalDescription: label: Physical Description
content: ivory (overall material)
label: Physical Description
content: brass (overall material)
label: Measurements
content: overall: .4 cm x 15.9 cm x 3.3 cm; 5/32 in x 6 1/4 in x 1 5/16 in