It was so accurate that it could be used by sailors as a portable time standard, who compared their local time to Greenwich Mean Time to calculate longitude, or east-west location on the Earth.

The idea was to stop hitting them and the best way, everyone figured, was to figure out how to calculate the precise longitude of a ship at sea. While latitude was never hard to figure ...

On global maps, longitude lines loop from the North Pole to the South in great circles that converge at the ends of the Earth. When trying to navigate your way across an open ocean, the ability to ...

Harrison’s clocks were major steps toward a reliable way of calculating longitude at sea Today’s Google Doodle celebrates clockmaker John Harrison, whose efforts to calculate longitude helped ...

Longitude needed to be known for the safety ... The “ artificial stars” are used as references to calculate a terrestrial position to within a few meters; and, through advanced forms of ...