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The dramatic human story of an epic scientific the search for the solution of how to calculate longitude and the unlikely triumph of an English genius. With a Foreword by Neil Armstrong.
‘Sobel has done the impossible and made horology sexy – no mean feat’ New Scientist
Anyone alive in the 18th century would have known that ‘the longitude problem’ was the thorniest scientific dilemma of the day – and had been for centuries. Lacking the ability to measure their longitude, sailors throughout the great ages of exploration had been literally lost at sea as soon as they lost sight of land. Thousands of lives, and the increasing fortunes of nations, hung on a resolution.
The quest for a solution had occupied scientists and their patrons for the better part of two centuries when, in 1714, Parliament upped the ante by offering a king’s ransom (£20,000) to anyone whose method or device proved successful. Countless quacks weighed in with preposterous suggestions. The scientific establishment throughout Europe – from Galileo to Sir Isaac Newton – had mapped the heavens in both hemispheres in its certain pursuit of a celestial answer. In stark contrast, one man, John Harrison, dared to imagine a mechanical solution.
Full of heroism and chicanery, brilliance and the absurd, LONGITUDE is also a fascinating brief history of astronomy, navigation and clockmaking.
Note that it has not been possible to include the same picture content that appeared in the original print version.
191 pages, Kindle Edition
First published October 19, 1995
“One method is by a Watch to keep time exactly. But, by reason of the motion of the Ship, the Variation of Heat and Cold, Wet and Dry, and the Difference of Gravity in different Latitudes, such a watch hath not yet been made.”
“A good watch may serve to keep a reckoning at Sea for some days and to know the time of a celestial Observation; and for this end a good Jewel watch may suffice till a better sort of Watch can be found out. But when the Longitude at sea is once lost, it cannot be found again by any watch.”





"Harrison never learned to add or multiply. Yet, using little more than sticks, pendulums, and loops of gut, he'd found a way to calculate the new day's noon as soon as the old day's was over. A day's worth of those bits and pieces would eventually add up to the only quantity that meant anything at all to him: time."

"The British Parliament, in its famed Longitude Act of 1714, set the highest bounty of all, naming a prize equal to a king’s ransom (several million dollars in today’s currency) for a “Practicable and Useful” means of determining longitude.”