Sir Roderick Murchison's Humboldtian belief in a close linkage between the sciences of geology and physical geography finds its best illustration in his prediction of the three-dimensional structure of Africa in 1852 from explorers' reports, fossil discoveries, and a theory of crustal uplift and fracturing elaborated by the Cambridge mathematician William Hopkins. From this remarkably accurate hypothesis and other theories which he had developed concerning the occurrence of coal and gold, Murchison concluded that exploitable deposits of economic minerals which might (...) justify the foundation of a series of new British colonies could be systematically discovered around the continent's elevated rim. As the simultaneous President of the Royal Geographical Society and Director-General of the British Geological Survey, Murchison subsequently organized the dispatch of numerous scientific exploring expeditions to test his theory and reconnoitre commercial opportunities in Africa. While widening the frontier of British science, he thus schooled the imperial government in the belief that science could serve the drive for national expansion. His views on the physical, biological, and cultural conservatism of Africa also provided scientific justification for Victorian schemes of improvement, and his promotional activities helped set the stage for the British annexations in the continent during its fin de siècle partition by the European powers. (shrink)