Sir Roderick Impey Murchison, Scottish geologist, c 1860.
© Science Museum / Science & Society Picture Library
Photograph. A former soldier, Sir Roderick Impey Murchison (1792-1871) was among the last of the independently wealthy gentleman geologists. He modernised geological thinking about time scales, naming the Silurian system, co-naming the Devonian system (with Adam Sedgwick, 1785-1873), and developing the modern clasification of the Paleozoic period. From 1840 to 1845, he headed the Geological Survey of the Rusian empire. Struck with the resemblance between the Ural mountains and Australian chains, he foreshadowed the discovery of gold in Australia in 1844. His principal works were 'The Silurian System' (1839) and 'The Geology of Rusia in Europe and the Urals' (1845). He was knighted in 1846.