Geologist, born in Ross-shire; entered the army and served in the Peninsular War, but retiring in 1816 gave himself to science; he explored many parts of Europe, predicted the discovery of gold in Australia, was President of the British Association, and knighted in 1846, and subsequently received many other scientific appointments and honours; he founded the Chair of Geology in Edinburgh University in 1870; but his fame rests on his discovery and establishment of the Silurian system; his book on "The Silurian System" is the chief of several works (1792-1871).