The title is a reference to some of Hutton's own words - such as "pity the arse that's clagged to a head that will hunt stones" - a reference to the many miles he rode on horseback while studying rocks. The book, however, is about the geology of Scotland, not about Hutton.
Rider tells us about episodes in the geological history of Scotland, one per chapter. Each chapter also contains a description of the visible signs of the history covered in that chapter. For example, the chapter on the Moine Thrust describes the area north of Ullapool where the thrust can be studied, and also describes the controversy that arose over the different explanations for the observations made in the area. Each chapter concludes with a list of further reading (some of which look very learned!).
The only jarring note is what I can only describe as a rant at the end about wind farms in Scotland, but that is only a couple of pages.