An Act for Providing a Publick Reward for Such Person or Persons as Shall Discover the Longitude at Sea

London: J. Baskett, Assigns of T. Newcomb, H. Hills, 1714. First edition. [ii], 355-357, [1] pp. 4to. Contemporary blind-panelled reverse calf, brown morocco spine label. Binding slightly rubbed and marked, else a very good, clean and tall copy. First edition. [ii], 355-357, [1] pp. 4to. The first publication of the Longitude Act, which encouraged the discovery of a method of quickly and accurately determining a ship's longitude. "An early example of a means adopted by a government for encouraging scientific discovery and progress" (Grolier/Horblitt). The Act established the Longitude Board, tasked with evaluating proposals for measuring longitude and awarding prizes. The top prize of £20,000 was reserved for any method that could measure longitude within one half of a degree. Subsequent Longitude Acts - there was a series of such acts throughout the 18th century - added various other incentives.
The problem of accurately determining longitude had confounded navigators and scientists for centuries. The common method of calculating longitude by dead reckoning relied on estimates of speed and direction and was therefore subject to cumulative errors. The need to more accurately determine longitude was brought to the fore by the Scilly naval disaster of 1707, in which four British warships and some 1500 men were lost off the Isles of Scilly after losing their bearings during a storm.
The Navigation Act lead to the development of the lunar distance method in 1763 by Nevil Maskelyne and the invention of the marine chronometer by John Harrison in 1773. Harrison received more prize money under the Act than anyone else, and the marine chronometer eventually came into wide use in the 19th century.
The act was issued separately and as part of the collected acts of Parliament. It is found here in a contemporary bound volume of Acts from the 12th year of Queen Anne's reign. Horblit/Grolier 42a; ESTC N53213