William Thomson (1824-1907), British physicist, better known as Lord Kelvin. Co-discoverer in 1852 of the Joule-Thomson effect, he proposed the existence of absolute zero in 1848 and the use of an absolute temperature scale (the Kelvin scale). Knighted (1866) for his work on Atlantic telegraph cable signals and galvanometers, he was made Baron Kelvin (1892), President of the Royal Society (1890-95), President of the Institution of Electrical Engineers (1874, 1889, 1907) and appointed to the Order of Merit (1902). Artwork from 'Electricite' (1911) by Max de Nansouty, part of the 'Les merveilles de la science' series of 1867-1891 by Louis Figuier.