A brass 360-degree circular plotting protractor, with a geared mechanism and folding arms, complete within its original baize mahogany storage case.
The “Troughton – London” maker’s mark was used on scientific, navigational, and mathematical instruments spanning the years 1782 to 1826.
Case diameter 13cm

Ref: 26810

Troughton of London: A British scientific instrument firm. Its origins in the instrument-making business begun in 1764 by John Troughton (1716-1788). This business was successively passed down first to nephews, John Troughton (1739-1807) and then to Edward Troughton (1756-1835). Troughton & Simms was formed in 1826 when Edward Troughton in his old age took on William Simms as a partner in 1826. It became a limited company in 1915 and in 1922 it merged with T. Cooke & Sons to form Cooke, Troughton & Simms.