John Harrison and the Quest for Longitude, in a revised and updated edition, is a fascinating account of the life and achievements of John Harrison, the man who designed and built the first accurate marine chronometers. Inspired by the prize offered in 1714 to provide a solution to the problem of determining longitudinal position at sea, John Harrison – a carpenter by trade – set out to develop portable clocks that would rival even the most precise watches of the time. His famous ‘H’ timepieces went on to revolutionise sea travel and save many thousands of lives. Now housed in the collection of Royal Observatory Greenwich, they are milestones in clock- making history. Beautifully illustrated with images that showcase the intricate detail and mechanisms of the timepieces,John Harrison and the Quest for Longitudetells the story of one man driven by the need to solve one of the greatest practical problems of his time. Jonathan Betts is curator emeritus of horology at Royal Museums Greenwich. He is the author of Marine Chronometers at Greenwich: A Catalogue of Marine Chronometers at the National Maritime Museum, Greenwich .