John Bendall. A background in economic history, political science and marketing and is now an independent researcher living in Greenwich. John has a long-standing love of the Royal Observatory and National Maritime Museum, Greenwich, including the Caird Library. He is a member of the Society for Nautical Research and Nantucket Historical Association, which have both provided interesting material, as has the National Archives in West London. This book was inspired by American author Dava Sobel’s renowned ‘Longitude’, covering Harrison’s timepieces in revolutionising maritime navigation. John has researched a fascinating follow-up story of Larcum Kendall and the K2 timekeeper. John is also a director of an English language school in Canterbury and a document management services company. His supportive wife, Jane, worked at the NMM for many years and is founder of the Flamsteed Astronomy Society.Mike Dryland. Mike retired from a career in industry in 2001 and has since been spending time as a voluntary curatorial assistant at the Royal Observatory, Greenwich, where he specialises in tours and talks about the Harrison marine timekeepers (sea clocks) and the history of the Observatory. He studied physics and has a long-time interest in astronomy, horology and naval history. Mike contributed two chapters and the appendix for this book, and helped generally with navigation and horology issues.