The age of the earth is a question that has been pondered upon since the earliest times, The first ideas came from religious texts, but in the eighteenth century people started to get an idea of the vast timescales involved in geological processes. 'The Man who found Time' tells the story of James Hutton, whose saw that geological formations implied slow laying down and erosion of rocks. He put a great deal of effort into promoting his ideas including writing a book, but this was difficult for the public to understand. Repcheck shows how his ideas might have died with him were it not for the work of John Playfair, who summarised Hutton's work in a more understandable form, thus saving it for a later re-emergence.
The book looks at the environment which influenced Hutton - the Scottish Enlightenment following the Jacobite Uprising - and the effect which his work had on future scientists, including Charles Lyell and Charles Darwin. This means that in a short book there isn't actually that much about the life of Hutton himself. If you are looking for a comprehensive biography of Hutton then you should look elsewhere, but if you are looking for a broader picture of the beginnings of geology then I can recommend this book.