Dava Sobel by Longitude

The source provides extensive excerpts from Dava Sobel’s historical account, "Longitude," detailing the centuries-long struggle to determine longitude at sea. It explains the fundamental difference between latitude, which is fixed by natural phenomena, and longitude, which is determined by time difference from a reference point. The text chronicles the dangers of imprecise navigation through historical maritime disasters, notably the 1707 wreck of Admiral Shovell's fleet, which spurred the British government to offer a massive prize through the Longitude Act of 1714. Two main competing solutions are explored: the astronomical lunar distance method advocated by scientists and astronomers like Nevil Maskelyne, and the mechanical marine timekeeper championed by the self-educated clockmaker, John Harrison, who ultimately succeeded with his series of highly accurate chronometers. Despite Harrison's success, the text details the fierce resistance he faced from the scientific establishment, highlighting the eventual triumph and mass production of the chronometer by figures like John Arnold and Thomas Earnshaw.