- Brief Description
- An example of the improved layout of the standard sector by the notable London maker Thomas Heath, who unusually gave these instruments a serial number.
- Item type
- Object
- Makers
- Thomas Heath
- Provenance
- Presented by Howard Dawes.
- Primary inscriptions
- "T * Heath London | No 109"
- Object type
- Sector
- Dimensions
- Height: 5mm Width: 423mm Depth: 72mm
- Inventory No
- 18805.1.1
Description
Brass sector to a 12 inch radius, with folding thin metal strut and a decorated circular hinge. The signed side has sectoral scales for Sin (0-90), Tan (0-45) and tan (45-75); with the instrument fully unfolded, there are plain scales for Num (a double scale of logarithms, 1-10, 1-10), Sin (10'-90), V.Sin (versed sine, 168-0) and Tan (10'-45). The reverse has sectoral scales for Cho (0-60), Lin (0-10), sec (10-75) and POL (polygons, 12-6); with the instrument fully unfolded, there are two two-foot scales, one conventionally divided, the other decimally, with 100 parts to the foot. There are also plain scales for In.Mer. (inclination of the meridian, 0-90), Cho. (chords, 0-90), Lat. (latitude, 0-90) and Hou. (hours, 0-VI).
Related Items
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Sector, by Thomas Heath, London, c. 1730Inventory Number 36704
Sector, by Thomas Heath, London, c. 1740Inventory Number 49772- Architectonic Sector to the Design of Thomas Carwitham, by Thomas Heath, London, 1720-30Inventory Number 18805.1.3
Architectonic Sector (Carwitham Pattern), by Thomas Heath, London, c. 1720-30Inventory Number 25362