This book interprets Robert Hookes Lectures and Discourses of Earthquakes, and Subterraneous Eruptions (1667-1694). Hookes 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 acomparison of selected passages from James Hutton, to show the transmission of ideas and Hookes influence on later geologists.