English-Style Sector
date: label: date made
content: 19th century
notes: label: Description
content: This yellowed ivory instrument has two rectangular arms with flat edges and is held together by a circular brass hinge. The lower arm is broken. 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 45 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 3 to 45 degrees; log sine, running from 1 to 70 degrees; and logarithmic numbers, running from 1 to 10 twice. A double line separates these scales from the inner, diagonal set of scales. 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 20 to 75 and labeled s; and a scale of chords, running from 10 to 60 and labeled C. The scales for dialing typically found on 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. Compare to MA.321755, MA.333937, and 1985.0580.06.
label: Description
content: This sector may have been used at the New York Meteorological Observatory in Central Park, established and directed by Daniel Draper from 1868 to 1911.
label: Description
content: References: Christopher J. Sangwin, "Edmund Gunter and the Sector," January 21, 2003, http://web.mat.bham.ac.uk/C.J.Sangwin/Sliderules/sector.pdf; Robert S. Harding and Jeffrey L. Tate, "Draper Family Collection, ca. 1826–1936," Archives Center, National Museum of American History, http://amhistory.si.edu/archives/d8121.htm.
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
label: See more items in
content: Sectors
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content: Science & Mathematics
creditLine: label: Credit Line
content: Gift of John William Christopher Draper and James Christopher Draper
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: MA.335351
label: accession number
content: 304826
label: catalog number
content: 335351
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: .3 cm x 16 cm x 3.5 cm; 1/8 in x 6 5/16 in x 1 3/8 in