Gohau's volume is a tidy summary of the historical roots of geology. Chapters are arranged around major themes, such as mountain building, subterranean fires, the use of fossils, the work of God, biostratigraphy and the birth of oceans. Good histories of geology are hard to come by and this is an extraordinarily lucid volume. Occasional excerpts of original works give a flavor of the time--de Saussure recounting the climbing of Mt. Blanc, for example, or several geologists conveying their amazement of finding animals frozen in ice in Siberia.

The book has its limitations, however. First, it focuses on historical geology only (omitting mineralogy, etc.)--hoping to highlight the interaction of geology as a science (yielding general laws) and geology as history (documenting specific events). There is a handy glossary, but an index only for names. There is also a precoocupation to describe who was "right" (and often, who was neglected) and who was "wrong" (and often, "excuses" why): we often lose the sense of what propelled the science and what led to conclusions that we, in retrospect, have labeled mistaken.

Hallam's approach is to focus selectively on a few specific episodes and explore each in more depth (never striving to be comprehensive). He thus covers only 4 of Gohau's 17 chapters (while adding one on the Ice Age; the other debates are: neptunism vs. plutonism; uniformity v. catastrophe; the age of the Earth; and continental drift). This approach is more helpful for teachers who want to use the history to probe possible student perspectives or to model debate in class. By focusing on controversies, Hallam sharpens our sense that what seems obvious now was not always so--and that students may follow in the footsteps of their predecessors and have good reasons for not immediately accepting some explanations. Here again, Hallam provides the basic material for the teacher to draw out those views and develop them in discussion.

--Douglas Allchin