Sir Roderick Murchison (1792–1871) was a giant of the imperial age. His career was tied intimately to the expansion of the political, economic and scientific realm of the British Empire. A founding father of geological science and geographical exploration, he was both President of the Royal Geographical Society and Director-General of the Geological Survey. His identification of the Silurian system in geology - and subsequent prediction of the location of economic riches - are as notable as his patronage of David Livingstone and other figures of Victorian exploration. More than any contemporary, Murchison emerged as the eminent Victorian who 'sold' science to the imperial government, on the grounds of utility as much as prestige. Robert Stafford uses this study of a man's life and work to investigate the bargain struck between science and the forces of imperialism in mid-Victorian Britain. This illuminates the broader, and still present, intimacy between science and government.