Karl Wilhelm Siemens (1823-1883), English-German engineer. Born in Germany, Siemens came to England in 1843 where he settled and became a naturalized citizen in 1859. He changed his name to Charles William Siemens, and was later knighted in 1883 before his death. Siemen's work in the fields of heat and electricity lead to many discoveries and the formulation of laws, which the Royal Society recognised by making him a fellow in 1862. His greatest success was in his work on the electric telegraph, designing the cable-laying ship Faraday that laid the first trans-Atlantic cable in 1874. The electrical unit of conductance, the siemens, is named in his honour.