Editing Longitude rewards (section)

==Background: the longitude problem==
{{main|History 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#Sun|declination]] for the day.<ref>Latitude can also be determined in the Northern Hemisphere from the angle above the horizon of [[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.</ref> For longitude, early ocean navigators had to rely on [[dead reckoning]], based on calculations of the vessel's heading and speed for a given time (much of which was based on intuition on the part of the master and/or navigator). This was inaccurate on long voyages out of sight of land, and these voyages sometimes ended in tragedy. An accurate determination of longitude was also necessary to determine the proper "[[magnetic declination]]", that is, the difference between indicated magnetic north and true north, which can differ by up to 10 degrees in the important trade latitudes of the Atlantic and Indian Oceans. Finding an adequate solution to determining longitude at sea was therefore of paramount importance.

The Longitude Act 1714 ([[13 Ann.]] c. 14) only addressed the determination of longitude at sea.  Determining longitude reasonably accurately on land was possible, from the 17th century onwards, [[History of longitude#Satellites of Jupiter|using the Galilean moons of Jupiter]] as an astronomical 'clock'.  The moons were easily observable on land, but numerous attempts to reliably observe them from the deck of a ship resulted in failure.

The need for better navigational accuracy for increasingly longer oceanic voyages had been an issue explored by many European nations for centuries before the passing of the Longitude Act 1714 in England. Portugal, Spain, and the Netherlands offered financial incentives for solutions to the problem of [[longitude]] as early as 1598.<ref name=Andrewes_1>{{cite journal|last1=Andrewes|first1=William J.H.|title=Introduction|journal=The Quest for Longitude: The Proceedings of the Longitude Symposium|date=1996|pages=1–10}}</ref>

Addressing the problem of longitude fell, primarily, into three categories: terrestrial, celestial, and mechanical.<ref name=Andrewes_1/>  This included detailed atlases, lunar charts, and timekeeping mechanisms at sea. It is postulated by scholars that the economic gains and political power to be had in oceanic exploration, and not scientific and technological curiosity, is what resulted in the swift passing of the [[Longitude Act 1714]] ([[13 Ann.]] c. 14) and the largest and most famous reward, the Longitude Prize being offered.<ref name=Knowles>{{cite journal|last1=Knowles|first1=Jeremy R|title=Opening Address at the Longitude Symposium|journal=The Quest for Longitude: The Proceedings of the Longitude Symposium|date=1996|pages=11–12}}</ref>