Object Details
- Description
- 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.
- 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.
- Location
- Currently not on view
- Credit Line
- Gift of Samuel B. Magill
- 19th century
- ID Number
- MA.333937
- catalog number
- 333937
- accession number
- 305959
- Object Name
- sector
- Physical Description
- ivory (overall material)
- brass (overall material)
- Measurements
- overall: .4 cm x 15.9 cm x 3.3 cm; 5/32 in x 6 1/4 in x 1 5/16 in
- place made
- United Kingdom: England
- See more items in
- Medicine and Science: Mathematics
- Sectors
- Science & Mathematics
- National Museum of American History
- Subject
- Mathematics
- Sectors
- Rule, Calculating
- Record ID
- nmah_1214777
- GUID (Link to Original Record)
- https://n2t.net/ark:/65665/ng49ca746aa-8c8f-704b-e053-15f76fa0b4fa
