Chronicling the British pursuit of the legendary El Dorado, Masters of All They Surveyed tells the fascinating story of geography, cartography, and scientific exploration in Britain's unique South American colony, Guyana. How did nineteenth-century Europeans turn areas they called terra incognita into bounded colonial territories? In answering this questions, D. Graham Burnett brings to light the work of several such explorers, particularly Sir Robert H. Schomburgk, the man who claimed to be the first to reach the site of Raleigh's El Dorado, who explored and mapped regions in modern Brazil, Venezuela, and Guyana, always in close contact with Amerindian communities. Drawing heavily on the maps, reports, and letters that Schomburgk sent back to England, Burnett shows how a vast network of traverse surveys, illustrations, and travel narratives not only laid out the official boundaries of British Guiana but also marked out a symbolic landscape that fired the British imperial imagination. Engagingly written and beautifully illustrated, Masters of All They Surveyed will interest anyone who wants to understand the histories of colonialism and science.