The Search For Longitude Book Report

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The Search for Longitude The book Longitude, written by Dava Sobel, discussed the issue of finding longitude. According to the author, determining longitude was a very difficult task to overcome. Several captains during the Age of Exploration were misplaced due to the issue of finding longitude, even though they possessed the most advanced charts and compasses of their time (Sobel, pg. 6). The book described that the main focus of this time was to discover a solution to the longitude problem. The author argued that John Harrison and his invention of the marine clock was the most successful solution to the longitude problem. In order to figure out the longitude on a voyage at sea the people had to know what time it was on the ship, also the time of home port (Sobel, pg. 4). The Longitude Act of 1714 pledged that if someone could obtain a practical solution for the longitude problem that they would receive €20,000. Many scientists, astronomers, mathematicians and carpenters spent years trying to discover the solution to finding longitude. The astronomers tried to find the solution by using the moon and the stars. While others tried to find the solutions through compasses, clocks and watches. The two main methods discussed in the book that were the most successful were the lunar distance method and the marine clocks (chronometers). The …show more content…

H-1 was successful during the trail run on the River Humber, but Harrison wanted to perfect his invention, so he made H-2, H-3, and H-4. Even though all of Harrison sea clocks were impressive the one that really won the longitude prize was H-4, which Harrison finished in 1759. H-4 was a pocket watch (five inches in diameter) and weighed three pounds. In 1760 Harrison presented his H-4 to the Board of Longitude where they tested both H-3 and H-4 on the same voyage. The sea clocks, according to the captain of the voyage, were successful in finding the

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