For his latest book, Christopher Somerville, walking correspondent of The Times, travels a thousand miles and across three billion years. In Walking the Bones of Britain, Doubleday, £25), he starts in the Outer Hebrides, among the most ancient of rocks, and finishes at the Thames Estuary, where “nature and man are collaborating to build new land”. 

  “Geology,” he says, “can be very hard work. I have written Walking the Bones of Britain to demystify the subject, and to unearth from its dry, stony vocabulary and dense layers of facts the really vivid and extraordinary events that give these islands the world’s richest and most remarkable geological story.” You can read a brief extract on his own website.