1 August 2013 Last updated at 01:23

The crazy ideas that failed to solve the longitude problem

It was a complex conundrum that baffled 18th Century scientists and captivated the British public. How could sea navigation be made easier, by being able to accurately measure exact points east and west from a fixed meridian line?

For decades from 1714, experts and enthusiasts submitted their ideas to the Board of Longitude in the hope of winning a £20,000 prize - worth £1.5m in today's money.

Now, the full story of attempts to solve the longitude problem is available in Cambridge University's Digital Library - with documents and drawings online. Here, with Cambridge historian Prof Simon Schaffer, look at some of the ideas that failed, and the timepiece credited with providing the solution.