The lack of accuracy in the calculation of longitude had caused the death of countless sailors. In 1714 Parliament, worried by the loss of British ships and mindful to the military advantage of knowing where one was at sea, offered a £20,000 prize to anyone who could accurately measure longitude. This is the story of John Harrison, a brilliant carpenter, whose timepieces solved the problem that had long defeated the scientists, it was a hard fought victory and Harrison was forced to endure poverty and prejudice.