# Marine Chronometer and Longitude

Pages: 4 (903 words) / Published: Oct 9th, 1999
Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time is written by Dava Sobel. The book is called Longitude because it is about a clock maker who was able to determine longitude. Determining longitude was the superlative scientific question in the eighteenth century that Galileo and Newton were not able to resolve. The principal inspiration behind the invention completed in this book is that many sailors were lost at seas as a result of their ignorance regarding longitude. So, without the competence to determine longitude, many innocent lives were disintegrated at seas. England’s Parliament was desperate for an answer to this problem. So, in 1714 England’s Parliament offered 20,000 pounds to anyone who invented a method or a device for measuring longitude and then proved successful. As a result, a Frenchman, sieur de St. Pierre, frowned on the moons of Jupiter as means of determining longitude. He theorized that longitude could be found by the position of the moon and select stars. At the time, Dr. Edmond Halley proved this theory wrong. After many observations, Halley concluded that the moon’s rate of revolution around the earth was accelerating overtime. John Harrison was a simple clockmaker and a self-educated person who was accredited for finding longitude by means of a timekeeper. John built his first pendulum watch in 1713. It was constructed entirely out of wood. Harrison called his first sea clock Harrison’s No. 1 or H-1 for short. H-1 was bar-shaped, built out of shinny brass, and was big in size. His second attempt was called H-2. H-2 was a heavy weight of 86 pounds, but fitted into a small box as John promised it would. H-2 was also bar-shaped and included an implement to ensure a unchanging drive and a more agreeable temperature reimbursement device. Although its motion was adequately regular and exact for finding the longitude of a ship within the