Brass Gunter sector made by Elias Allen in 1623, near St Clement's Church (without Temple Bar), London. It is signed 'Elias Allen fecit 1623.'
Elias Allen made the sector according to the designs of the mathematician Edmund Gunter who published a description of it in the same year. Sectors are mathematical instruments that were used for calculations concerning proportion and for making small measurments. They were particularly useful for technical drawing. This example contains logarithmic and trigonometric lines and scales used in drawing and calculations of area and volume. Elias Allen (active 1607-53) was a mathematical instrument maker who was apprenticed to Charles Whitwell in 1602 and became a Freeman of both the Grocers' and Clockmakers' Company (eventually becoming Master of the latter). His workshop was located near St Clement's Church, near what is now Aldwych, in London.