Longitude Act passed in July 1714. For details on many of the efforts towards determining the longitude, see History of longitude. The Longitude Act offered a series of rewards, rather than a single prize. The rewards increased with the accuracy achieved: £10,000 (worth over in ) for anyone who could find a practical way of determining longitude at sea to an accuracy of not greater than one degree of longitude (equates to at the equator). The reward was to be increased to £15,000 if the accuracy was not greater than 40 minutes, and further enhanced to £20,000 if the accuracy was not
Triangle angles is equal to 90°, adding up to a total of 270°. Specifically, on a sphere the sum of the angles of a triangle is where "f" is the fraction of the sphere's area which is enclosed by the triangle. For example, suppose that we draw a triangle on the Earth's surface with vertices at the North Pole, at a point on the equator at 0° longitude, and a point on the equator at 90° West longitude. The great circle line between the latter two points is the equator, and the great circle line between either of those points and