'Lord Kelvin', c 1890
© NMeM / Royal Photographic Society / Science & Society Picture Library
Platinum print photograph by Frederick Hollyer (1837-1933) of Sir William Thomson, Lord Kelvin (1824-1907). Thomson was the son of the Chair of Mathematics at Glasgow University, and at the age of ten he began his studies there. At 21, Thomson graduated from Cambridge. In 1846 Thomson became Professor of Natural Philosophy in Glasgow, a post he held until 1899. His findings were instrumental in laying submarine cables across the Atlantic, and in developing an absolute scale of temperature, the 'Kelvin scale', in 1848.