You Are What You Read

Reviews of books as I read them. This is basically a (web)log of books I've read.

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Location: Lawrenceville, Georgia, United States

I am a DBA/database analyst by day, full time father on evenings and weekends.

Saturday, August 09, 2008


Dava Sobel's book Longitude is an historical account of the search for the solution of finding the longitude of a location at sea.
Finding a latitude had been a common skill for centuries, based on the location of the North Star, or other stars in the southern latitudes. But finding a longitude was a difficult task and many ships ended up way off course or even crashing due to not knowing exactly where they were.

After a major sea disaster losing hundreds of lives, the English Parliament passes the Longitude Act in 1714, promising 20000 pounds for whoever can solve the problem. Many astronomers devote much time to methods of determining longitude by using the heavens. However, the methods are complicated and lengthy, requiring detailed charts and hours of computations. They also depend on either the Moon or Jupiter being visible.

John Harrison, a man trained in carpentry but not timekeeping, takes it upon himself to create a timepiece accurate enough to keep time on a ship traveling across the world. Harrison had already built a clock tower made of wood that still tells time to this day. After years of work, he demonstrates the H-1, a large timepiece weighing 75 pounds that was accurate to within a few seconds a day. The Board of Longitude was pleased and sent the chronometer on a voyage to be tested. It did well but he had to create another one, the H-2, which took many years to complete.

Finally after many years he produces a chronometer only inches big. The H-4 is much lighter and more accurate than its predecessors. Yet Harrison and his son have trouble convincing the Board that their solution is the winner. The Board is full of astronomers who think that a purely astronomical method is the only answer. Finally, soon before his death, Harrison's chronometer is awarded the prize.

I found the story very interesting and informative. It is full of details on astronomy and history. I would never have guessed that the pursuit of the solution of longitude would be as long, as complicated, nor as political, as it was. The chronometers themselves are complex and breathtaking in their ingenuity. I might have liked a little more detail on the working of the pieces, but the book did a fine overview. I think anyone interested in naval history or navigation needs to read this book. A-


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