Longitude, Dava Sobel's no.1 bestseller, is the elegant biography of the lone genius who solved the greatest scientific problem of his times.

With new material from Dava Sobel and William Andrewes, and illustrated with over 200 integrated photographs, The Illustrated Longitude is the essential book for everyone who fell in love with John Harrison's story and wants to know more.

Anyone alive in the 18th century would have known that 'the longitude problem' was the thorniest scientific dilemma of the day - and had been for centuries. Lacking the ability to measure their longitude, sailors throughout the great ages of exploration had been literally lost at sea as soon as they lost sight of land. The scientific establishment throughout Europe - from Galileo to Sir Isaac Newton - had mapped the heavens in its certain pursuit of a celestial answer. In stark contrast, one man, John Harrison, dared to imagine a mechanical solution.

The Illustrated Longitude is a fascinating history of astronomy, navigation and clockmaking. Lavishly produced with over 200 illustrations, The Illustrated Longitude has much new material to help the reader learn more of John Harrison's extraordinary story and his times. There are biographical articles on all the major characters added; boxed information on the important scientific, nautical, historical and artistic background to the extraordinary story, time lines, and diagrams to explain the geography, horology and astrology of the Longitude problem.