![]() In his later life, Harrison wrote a small book in which he criticized many of his colleagues and claimed that he could make a wall clock with a then-unheard-of-precision of just one second over 100 days!Įven with the reputation Harrison had, that level of accuracy seemed like sheer lunacy at the time, the rantings of a madman. That’s the precision of a modern quartz watch, and it was very impressive in the early eighteenth century.īut as impressive as Graham’s regulators were, Harrison, who had trained as a carpenter and made his clocks largely in wood, started making timepieces that were 30 times more accurate, losing just one second per month rather than Graham’s one second per day.īut that wasn’t enough for him. Graham was making pendulum clocks called regulators with an accuracy of one second per day. That isn’t the case however in a high-precision pendulum wall clock, and while it’s less known, before he started developing a marine chronometer to win the Longitude Prize, Harrison was already extremely good at developing high-precision pendulum wall clocks that only have temperature variations to contend with rather than the extreme conditions of months or years at sea.ĭuring Harrison’s early career, George Graham (1673-1751), was widely acknowledged as the finest horologist in England. Precision is secondary to reliability for a marine chronometer. ![]() John Harrison (1693-1776) is renowned for his H4 marine chronometer, but marine chronometers are far from being pure timekeepers: the first consideration for marine chronometers has to be reliability and consistency in the extremely hostile environment of a humid and salty atmosphere on a widely pitching and tossing ship subjected to a wide range of constantly varying temperatures. Two hundred and fifty years might not be a long time on a geological scale, but it is a long time for humans great-great-grandparent does not even get halfway. Improvement is also largely thanks to a constantly expanded knowledge base and centuries of input from brilliant and creative minds. In the last 250 years we have invented driverless cars, pilotless planes, widespread electricity, computers, internet, space travel, and the smartphone.Īnd we are continually improving in virtually all areas thanks to better materials and our understanding of those materials as well as better and more precise machines. ![]() Harrison was one of the world’s greatest horologists, but 250 years is a long time and we have advanced so far since then. But the British Admiralty never actually awarded the Longitude Prize to Harrison or anybody else for that matter: it’s believed that was to avoid paying out the full prize money. This invention heralded precision timekeeping as offering much superior navigation at sea compared to celestial observations. ![]() Two hundred and fifty years ago, the British Admiralty belatedly and begrudgingly paid Harrison for revolutionizing nautical navigation and saving thousands of lives lost at sea with his H4 marine chronometer, which enabled a precise and reliable determination of longitude (east-west position) at sea. Mea culpa: in the title I described John Harrison as both “the inventor of the marine chronometer and winner of the British Admiralty’s Longitude Prize.” While the first of those statements is true, the second − though widely believed to be so − isn’t. Burgess Clock B, completed by Charles Frodsham & Co
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