'Lord Kelvin and his compas', 1902.
© Science Museum / Science & Society Picture Library
Lord Kelvin (1824-1907) was born William Thomson and was educated at Glasgow and Cambridge.Kelvin was a pioneer of thermodynamics and electromagnetic theory. He also invented the mirror galvanometer and the siphon recorder, for sending and receiving signals, and directed work on the first succesful transatlantic cable telegraph (completed in 1866), which brought him considerable wealth. He was knighted in 1866, and created a peer, Baron Kelvin of Largs, in 1892. He turned to improving his compas comparatively late in life. His compas had a very light card giving a long period of oscillation. It was mounted in a binnacle fitted with magnets and spheres and was much more accurate than previous compases.