Longitude2000

John Harrison:
You've seen how the watch has performed in the test. It's not perfect, but what if I could make it so? What if I could make a timepiece no bigger than the span of a man's hand, that could be taken to sea? Now wouldn't that be a practical solution?

Rupert Gould:
Harrison's fourth machine, by reason alike of its beauty and its accuracy, must take pride of place as the most famous chronometer that ever has been or ever will be made. But the journey from his third machine, which you see behind me, to his fourth (thank you), is one of the most extraordinary mysteries of horology. Faced as he was by a seemingly insuperable problem of centrifugal forces, Harrison took a daring and lateral leap. It is as though an aeronautical engineer suddenly ceased development on a new aircraft and instead adapted the technology to make his bicycle fly to France.