Edward Troughton (1756-1835), a member of a distinguished family of precision instrument makers in London, went into partnership with William Simms (1793-1860) in 1824. The new firm of Troughton & Simms would produce numerous fine instruments for astronomy, surveying and navigation, and supply customers around the world. The firm became Troughton & Simms, Ltd., in 1916, Cooke, Troughton & Simms, Ltd., in 1922, and a part of Vickers Instruments, Ltd., in 1963.
Ref: Anita McConnell, Instrument Makers to the World. A History of Cooke, Troughton & Simms (York: 1992).
A. W. Skempton and Joyce Brown, "John and Edward Troughton, Mathematical Instrument Makers," Notes and Records of the Royal Society of London (1971): 233-262.