# Longitude prize

 related topics {math, energy, light} {work, book, publish} {law, state, case} {film, series, show} {land, century, early} {island, water, area}

The Longitude Prize was a reward offered by the British government for a simple and practical method for the precise determination of a ship's longitude. The prize, established through an Act of Parliament (the Longitude Act) in 1714, was administered by the Board of Longitude.

## Contents

### The problem of longitude

The measurement of longitude was a problem that came into sharp focus as people began making transoceanic voyages. Determining latitude was relatively easy in that it could be found from the altitude of the sun at noon with the aid of a table giving the sun's declination for the day.[1] For longitude, early ocean navigators had to rely on dead reckoning. This was inaccurate on long voyages out of sight of land and these voyages sometimes ended in tragedy. Finding an adequate solution to determining longitude was of paramount importance.

For details on many of the efforts towards determining the longitude, see History of longitude.

### Prizes offered

The main longitude prizes were:

• £10,000 for a method that could determine longitude within 60 nautical miles (111 km)
• £15,000 for a method that could determine longitude within 40 nautical miles (74 km)
• £20,000 for a method that could determine longitude within 30 nautical miles (56 km).

In addition, the Board had the discretion to make awards to persons who were making significant contributions to the effort or to provide ongoing financial support to those who were working productively towards the solution. The Board could also make advances of up to £2,000 for experimental work deemed promising.[2]

As a result of the disputes and changes in the rules (legislated or otherwise) for the prize, no one was deemed qualified for any of the official prizes. None of the major prizes were ever awarded.

### Significant recipients

Many persons benefited from the awards offered by the Board. In total, over £100,000 was given in the form of encouragements and awards. Significant among these are:[3][4]

Harrison also received £8,750 from Parliament in thanks for his work, bringing his total lifetime award to £23,065.

### In culture

Rupert T. Gould's 1923 "The Marine Chronometer" (ISBN 0907462057) is the definitive reference work on the Marine Chronometer. It covers the chronometer's history from the earliest attempts to measure longitude while including detailed discussions and illustrations of the various mechanisms and their inventors.