This very interesting, well constructed, and well written book is an important case study of scientific progression. The subject is a 19th century controversy about stratigraphy in Southwestern England. To a large extent, Rudwick uses this topic as a test of Thomas Kuhn's famous saltatory model of scientific progression. While apparently recondite, this stratigraphic controversy reflected a crucial issue in 19th century geosciences. A major aspect of geology in the early 19th century was the effort to reconstruct geohistory. Methodologically, this was quite difficult. The major method was direct observation of strata exposed by outcroppings, riverbeds, cliffs, and mines. Since strata were often disturbed in complex ways by many geologic phenomena, this was a difficult task requiring great experience. As time went on, relatively sophisticated paleontologic analyses of fossil assemblages became an important aspect of stratigraphy. Following success with analysis of more superficial (younger) strata, geologists of this period set out to map the deeper strata. The controversy over the stratigraphy became a major controversy about the nature of remote geohistory, whether or not such reconstructions were actually possible, the methods and criteria needed for appropriate stratigraphic reconstruction, and higher level theories about geological change.
Rudwick opens the book with a nice, concise description of the state of the geosciences at the beginning of the controversy, the structure of the geology community in Britain, and a discussion of the status of the sciences in British society. Many of the major figures are introduced as well. This is followed by the majority of text, a detailed reconstruction of the controversy generated from Rudwick's careful analysis of the relevant scientific work and an extensive study of communications between the major (and many minor) actors based on their voluminous correspondence. This is an impressively non-anachronistic account, showing readers events as they unfolded to the participants. Throughout this section, Rudwick discusses not only the scientific aspects but also relevant aspects of social history.
Following the reconstruction of the controversy, Rudwick concludes with a pair of analytic chapters with insightful discussion of the sociologic and epistemic aspects of the story. Rudwick is particularly good on the interactions between personalities, social elements (both of the geologic community and Victorian society), and the unfolding of the evidence. The transformation of the existing paradigm of stratigraphy and geologic research in the course of the controversy, and the epistemic value of data, though not a crude empiricist or realist interpretation, are the major themes. Scientists reading this book will find much that is familiar in Rudwick's account and devotees of Kuhn will find important aspects of his model undermined.