Preparation of this volume has been a daunting task for both editors and authors. We have had to create a workable framework through which to present an overview of the development of a diverse range of sciences through a period of major conceptual, methodological, and institutional changes. Equally problematic has been the need to ensure that the presentation takes note of both the enduring traditions within the history of science and the major historiographical initiatives of the last few decades. We have tried to ensure adequate treatment of both the sciences themselves and historians’ concerns about how they should be studied. Some sacrifices have had to be made to create a viable list of topics. The result is, we hope, representative, but it is by no means encyclopedic. Topics that might have been expected were dropped either because there was not enough space to cover them adequately or, in a few cases, because the editors could not find authors willing to synthesize vast ranges of information and insights in the space that could be allowed. We are particularly conscious that agriculture and related sciences are barely present and that some areas of the environmental sciences could not be covered, including oceanography and meteorology. Delays have been inevitable in the production of so complex a text, and although some efforts have been made to update the references in the chapters, we and the authors are conscious of the fact that what we are presenting will not always reflect the very latest developments and publications.