Accession No

1018

Brief Description

gunter sector, workshop of Elias Allen, English, second quarter 17th century

Origin

England; London; The Strand

Maker

Workshop of Elias Allen

Class

calculating; mathematics

Earliest Date

1625

Latest Date

1650

Inscription Date

Material

metal (brass)

Dimensions

length 248mm; breadth 55mm

Special Collection

Trinity College collection

Provenance

On loan from Trinity College, University of Cambridge from 1951.

Inscription

‘Trin: Coll: Cant: EX DONO THO: SCATTERGOOD Arm’

Description Notes

Brass sector consisting of two arms joined by flat circular hinge; friction strut which also acts as indicator for dialling scale.

Obverse: various scales which appear on both arms. None of the scales are named.
(1) line of inscribed bodies, marked D, S, I, C, O, T.
(2) line of lines, divided [0] - 10, numbered by 1, subdivided to 0.5, to 0.1 and to 0.05.
(3) line of metals, combined with line of equated bodies, marked D, I, C, S, O, [gold], [mercury], [tin], [silver], [copper], [iron], [lead], T.
(4) line of solids, divided [0] - 10[00], numbered 1, 1[0], 1[00], 2[00],…10[00]. 1 - 1[0] subdivided to 5 and to 1. 1[0] - [50] subdivided to 10, to 5 and to 1. [50] - 1[00] subdivided to 10 and to 2. 1[00] - 10[00] subdivided to 50, to 10 and to 5.
Along the outer edges is a scale which is continuous when the sector is fully opened out. This is a scale of meridional parts, divided [0] - [85˚ 30´], numbered by 10˚, subdivided to 5˚, to 1˚ and to 15´ (rather worn).

Reverse: various scales which appear on both arms (none of them named).
(1) line of quadrature, marked 10, 9, 8, 7, S, 6, 5, 90, Q.
(2) line of sines, divided [0] - 90˚, numbered by 10˚, subdivided to 5˚, [0] - 80˚ subdivided to 1˚ and to 30´; 80˚ - 85˚ subdivided to 5˚.
(3) line of segments, divided 5 - 10, numbered by 1, subdivided to 0.5 and to 0.1.
(4) line of superficies, divided 1 - 10[0], numbered 1, 1[0], 2[0]…10[0]; subdivided to 5, to 1 and to 0.5.
Along upper arm is a line of secants, divided 10 - [58˚], numbered by 10˚, subdivided to 5˚ and to 1˚.
Along both arms forming a continuous scale when the sector is fully open is a line of tangents, divided [0] - [63˚], numbered by 10˚, subdivided to 5˚, to 1˚ and to 15´ (rather worn).

On outer edge of arm which does not hold friction strut is a line of lesser tangents, divided [0] - [76˚], numbered by 10˚, subdivided to 5˚ and to 1˚.
The outer edge of the other arm carries a line of inches divided [0] - 9, numbered 2, 3, 4…9.

good condition (slight wear and tarnishing); complete

Attributed to Elias Allen’s workshop on the basis of the style of engraving.

References

Events