LONGITUDE; The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time  By Dava Sobel.  Walker Publishing Company, 1995, Penguin Books, 1996, 184pg  


 On the foggy night of 22 October 1707, British Admiral Sir Clowdisley Shovell had a most unfortunate experience while trying to return to England from Gibraltar after an otherwise successful deployment including a series of skirmishes with French Mediterranean forces.  His navigators had misjudged the longitude and the fleet of five ships-of-the-line ran aground on the Scilly Isles about twenty miles from the English shore.  Four ships, including the flagship Association, sank in minutes with the loss of some two thousand men.  That tragic incident was merely the latest in a rapidly growing list of often-horrific mishaps occurring in the seafaring community during the fifteenth, sixteenth and seventeenth centuries as a result of mariner’s inability to accurately ascertain ship’s position because there was no known reasonable method to determine longitude at sea.  Besides running into rocks, ships would miss landfall and run out of food and water.  Malnutrition and scurvy were rampant.  Entire crews became so weak the ships could not be worked.  Many died and many were never heard from again.

 That the Clowdisley incident happened so close to English shores provided impetus to solve the longitude problem and eventually precipitated the Longitude Act of 1714 in which the Parliament provided a prize of 20,000 pounds, the equivalent of millions today, to anyone who could solve the problem.  The Act set up a blue ribbon panel, The Board of Longitude, consisting of the leading mathematicians, physicists and astronomers of the day to judge adequacy of the entries and choose the eventual winning solution. 

There were two possible solutions.  The favored one was celestial observation to produce tables of heavenly body positions and motion and then provide each ship with copies of the tables and instruments to make their own comparative celestial observations and thus determine the ship’s position on planet Earth.  To produce the required data (and collect the loot) the leading mathematicians and astronomers of Europe set to work.  Observatories were constructed.  Observations and calculations commenced in Europe, the Americas and Africa.  The second solution was the theory that a super-accurate transportable timepiece able to show the exact time at a known fixed geographic location, e.g., the observatory at Greenwich, could be used to accurately calculate longitude anywhere on the planet.  The rules stipulated the solution had to determine longitude within a half a degree.  Thus the clock could not gain or lose more than three seconds in twenty-four hours.  Such a timepiece did not exist and the technology to make it possible was unknown in the early seventeen hundreds. 

 Enter our hero, one John Harrison a Yorkshire carpenter, turned into a self-educated clockmaker.  Between 1730 and 1770 Harrison built five successively different revolutionary timepieces which completely changed the world.  Along the way he did away with pendulums and big clumsy boxes. 

He invented, among other things, bi-metallic strips and caged ball bearings.  He did not have an easy time and might have gone unremarked by history if not for his tenacity and the personal intervention of George III late in Harrison’s life.

 This is a great tale, brilliantly told, of science, greed, jealousy, intrigue, politics and bureaucracy. It is also a tale of perseverance, dedication and generosity.  Anyone who reads this book will be thoroughly satisfied with the reading.

 Dava Sobel is an award winning former science reporter for the New York Times who writes frequently about science for numerous magazines including Audubon, Discover, Life and The New Yorker.  Her latest book is “Galileo’s Daughter:  A Historical Memoir of Science, Faith and Love.

Reviewed by Cdr. George G. Fisher, USN (ret)

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