This book interprets Robert Hooke's Lectures and Discourses of Earthquakes, and Subterraneous Eruptions (1667-1694). Hooke's hypotheses concerning the origin of terrestrial features were of major importance to the development of geology. The volume consists of the original text of the Discourses transposed into modern type and paired with explanatory annotations; a brief up-to-date biography of Hooke, with emphasis on his geological contributions; and a comparison of selected passages from James Hutton, to show the transmission of ideas and Hooke's influence on later geologists.