Nineteenth-century historians have described how science became secular and how scientific theories such as evolution justified colonialism. This book changes this narrative by offering the first account of the relationship between nineteenth-century science and Christianity outside the Western world. At focus are the intrepid missionaries of the London Missionary Society who reverently surveyed the oceans and islands of the Pacific and instructed converts to observe nature in order to interpret God's designs. Sujit Sivasundaram argues that the knowledge that these missionaries practiced functioned as a popular science that was inextricably linked with religious expansion.