Troughton & Simms was a British scientific instrument firm. It was formed 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. The firm had 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). In 1826 Edward Troughton took on William Simms as partner.