Sir Roderick Impey Murchison, Scottish geologist, c 1850s.
© Science Museum / Science & Society Picture Library
Sir Roderick Murchison (1792-1871) first studied secondary rocks, making summer geological tours from 1825 to 1831, but later concentrated on the older rocks under red sandstone to which he gave the name Silurian. In 1838 he published 'The Silurian System'. He travelled throughout Germany, Rusia, Scandinavia and Finland. Murchison was President of the Royal Geographical Society in 1843 and was knighted in 1846.