The Longitude rewards refer to the system of inducement prizes offered by the British government for a simple and practical method for the precise determination of a ship's longitude at sea. The rewards, established through an Act of Parliament (the Longitude Act) in 1714, were administered by the Board of Longitude.
This was by no means the first reward to be offered to solve this problem. Philip II of Spain offered one in 1567, Philip III in 1598 offered 6,000 ducats and a pension, whilst the States General of the Netherlands offered 10,000 florins shortly after. However, these large sums were never won, though several people were awarded smaller amounts for significant achievements.
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. 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 at sea was of paramount importance.
For details on many of the other efforts towards determining the longitude, see History of longitude.
The main rewards offered by the Longitude Board were:
- £10,000 for a method that could determine longitude within 1 degree (equivalent to 60 nautical miles (110 km; 69 mi) at the equator) (£1.26 million in 2013)
- £15,000 for a method that could determine longitude within 40 minutes (£1.89 million in 2013)
- £20,000 for a method that could determine longitude within 30 minutes (£2.52 million in 2013)
The method would be tested by sailing through the ocean, from Britain to any port in West Indies (about six weeks) without losing its longitude beyond limits listed above.
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.
As a result of the disputes and changes in the rules (legislated or otherwise) for the rewards, Harrison received only half the official award after the second sea trial in 1765. However as a result of a petition to the King, Parliament authorized a further payment bringing his total to £22,000.
Many persons benefited from the awards offered by the Board. In total, £52,535 was given in the form of encouragements and awards, although the board spent another £105,000 in various ways. Significant among these are:
|John Harrison||£13,250||Received in several payments. £4,500 was awarded during his work on his chronometers from 1737 to 1764 with the remaining £8,750 provided in 1765.|
|Tobias Mayer||£3,000||Contributions to the lunar distance method. His widow received the money due to Mayer's untimely death.|
|Thomas Mudge||£3,000||Construction of chronometers with improvements to Harrison's designs.|
|John Arnold||£3,000||Design and improvements to chronometers.|
|Thomas Earnshaw||£3,000||Design and improvements to chronometers.|
|Charles Mason||£1,317||Various contributions and improvements on Mayer’s lunar tables.|
|Jesse Ramsden||£615||Design and construction of a superior dividing engine (£300) and publishing the design (£315).|
|Larcum Kendall||£500||Construction of K1, a copy of Harrison's H-4, used on his second and third circumnavigations by Captain Cook, who called it his "trusty friend".|
|Leonhard Euler||£300||Contributions to the lunar distance method in aid of Mayer.|
|Nathaniel Davies||£300||Design of a Lunars telescope for Mayer|
Harrison also received £8,750 from Parliament in thanks for his work, bringing his total lifetime award to £23,065.
Rupert T. Gould's 1923 "The Marine Chronometer" (ISBN 0907462057) is a thorough 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.
Dava Sobel's 1996 bestseller Longitude (ISBN 0-14-025879-5) recounts Harrison's story. A film adaptation of Longitude was released by Granada Productions and A&E in 2000, starring Michael Gambon as Harrison and Jeremy Irons as Rupert Gould.
- History of longitude
- Nevil Maskelyne
- Lunar distance
- John Harrison
- Larcum Kendall
- James Cook
- Longitude Prize 2014, modern prize for achievements in science, in the spirit of but not directly related to the longitude prize
- O'Connor, J J; Robertson, E F (1997). "Longitude and the Académie Royale". MacTutor History of Mathematics.
- Bell, A.E. (1950). The Life of Christian Huygens. Edward Arnold, London. p. 35.
- Latitude can also be determined from Polaris, the northern pole star. However, since Polaris is not precisely at the pole, it can only estimate the latitude unless the precise time is known or many measurements are made over time. While many measurements can be made on land, this makes it impractical for determining latitude at sea.
- UK CPI inflation numbers based on data available from Gregory Clark (2014), "What Were the British Earnings and Prices Then? (New Series)" MeasuringWorth.
- Taylor, E.G.R., The Haven-finding Art: A History of Navigation from Odysseus to Captain Cook, Hollis & Carter, London 1971, ISBN 0-370-01347-6
- Higgitt, Rebekah (March 7, 2012). "There was no such thing as the Longitude Prize". Retrieved Apr 17, 2015.
- Howse, Derek (Nov 1998). "Britain's Board of Longitude, The finances 1714-1828" (PDF). The Mariner's Mirror. 84 No 4: 400–417. Retrieved 17 Apr 2015.
- Sobel, Dava, Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time, Walker and Company, New York, 1995 ISBN 0-8027-1312-2
- Betts, Jonathan (2006). "4". Time Restored. Oxford University Press. Retrieved Apr 17, 2015.