Longitude Prize

John Harrison

In 1714, British Parliament established a prize of £20,000 to anyone who could accurately determine the position of a ship by longitude. Today, we can look at low cost GPS device and know exactly where we are at any time. However, in 1714 sailors only had a rough idea of their position north and south, and an even foggier idea about east and west.John Harrison, a working class joiner from Lincolnshire who had scant formal education built and repaired clocks in his spare time. Mr. Harrison won the longitude prize by producing the first portable and reasonably accurate chronometer. He took on the scientific establishment of his time and won the prize through his gifted mechanical insight and pure determination.

While £20,000 was a fortune in those days, the government received exactly what it wanted and risked nothing in return. The value of the prize drew the best minds in the world to the challenge and Harrison’s chronometer was quickly improved. The tiny chronometer allowed for accurate navigation and map-making giving the British supremacy of the seas that lasted for decades.

In 2000 The Discovery ChannelA&E produced a four-part miniseries on the Longitude Prize entitled Longitude. Unfortunately, we can not find a web site on the movie, the link goes to Amazon.

Examples of Harrison Chronometers:


A video describing the longitude prize and how Harrison built his clocks:

USS Scorpion

In 1968 the US Navy uses a statistical technique called Bayes Theorem to locate USS Scorpion (lost at sea) to within 200 yds of its actual position. Navy researches interviewed hundreds of crew and officers with similar assignments and functions to those on the Scorpion. By comparing and statistically weighting the probabilities of what each interviewee would have done in a similar situation, the researchers were able to make a statistically significant guess as to what actually happened.