In the first part of the 19th century, geologists explained volcanoes, earthquakes and mountain-formation on the assumption that the earth has a large molten core underneath a very thin solid crust. This assumption was attacked on astronomical grounds by William Hopkins, who argued that the crust must be at least 800 miles thick, and on physical grounds by William Thomson, who showed that the earth as a whole behaves like a solid with high rigidity. Other participants in the debate insisted (...) that there is evidence for a fluid or plastic layer not far below the crust. It was also suggested that the interior of the earth is a supercritical fluid. By the end of the century many geologists had incorporated the doctrine of a completely solid earth into their theories. Acceptance of a relatively small liquid core, indicated by seismological research, was delayed for another two decades. (shrink)

Though the name of Robert Mallet was once inevitably associated with the scientific study of earthquakes, it is less well known today. As part of an overdue reappraisal, this essay examines Mallet's major seismological projects and publications, emphasizing his theoretical contributions. Mallet's own claim to be a founder of modern seismology is upheld. Beyond that, however, he is also seen to be an important precursor of plate tectonics.

Originally published in 1830, this book can be called the first modern work in the philosophy of science, covering an extraordinary range of philosophical, methodological, and scientific subjects. "Herschel's book . . . brilliantly analyzes both the history and nature of science."—Keith Stewart Thomson, American Scientist.

This intriguing volume provides a thorough examination of the historical roots of global climate change as a field of inquiry, from the Enlightenment to the late twentieth century. Based on primary and archival sources, the book is filled with interesting perspectives on what people have understood, experienced, and feared about the climate and its changes in the past. Chapters explore climate and culture in Enlightenment thought; climate debates in early America; the development of international networks of observation; the scientific transformation (...) of climate discourse; and early contributions to understanding terrestrial temperature changes, infrared radiation, and the carbon dioxide theory of climate. But perhaps most important, this book shows what a study of the past has to offer the interdisciplinary investigation of current environmental problems. (shrink)