Alan Cutler's The Seashell on the Mountaintop is the biography of the 17th century Danish scientist Nicolaus Steno, a celebrated anatomist, who was fascinated by rocks and the shells he found in the mountains of Italy. The book documents his explorations and theories about the earth and highlights the problems many scientists found with the church authorities. Steno is now recognised as the real founder of geology, though he abandoned science to become a Catholic Bishop and was made a saint after his death.
Steno appears, briefly in Revolutions in the Earth, Stephen Baxter's biography of James Hutton, a Scottish scientist of the late eighteenth century. He was a farmer, agricultural scientist, medical doctor and geologist. He was fascinated with rock formations and deduced that the rock strata belonged to an earth much older than the one allowed for by contemporary, religious inspired thought. This book for me was the more interesting one as it puts Hutton's life and work in the context of the troubled British politics of the time and the intellectual climate of the Scottish Enlightenment. Hutton was closely linked with many other great thinkers of the day, including James Watt, the engineer, whose work with steam engines directly influenced Hutton's ideas about how heat might have helped to form the earth's rock formations.
Taken together, these books form a fascinating insight into the development of geology as a science.