Longitude by Dava Sobel
The next time you travel abroad by air or sea just stop to wonder how the pilot or captain of the ship actually find their destination? Of course, we take it for granted these days that one's position on the globe can be determined at the touch of a button with remarkable accuracy.
Not so long ago though it was not so simple and ships at sea regularly lost their way. In the 18th Century the problem became so acute that by act of Parliament a prize of 20,000 was offered to anyone who could demonstrate a reliable and accurate method of determining a ships position at sea.
To the scientific community the answer was in the heavens and leading astronomers endeavoured to prove that man could navigate the globe by observing the position of the moon and stars. Of course this was all well and good but not so easy during a storm or when the sky was overcast with cloud. Even with a clear sky the method of navigation by the moon and stars alone was far from reliable.
John Harrison was not a scientist, just a simple carpenter with a passion for creating timepieces. To Harrison the answer was simple - the Earth spins on its axis a full three hundred and sixty degrees every twenty four hours. Every hour it spins by fifteen degrees. If you know the time at your home port and you have an accurate idea of the time at your current location then it's a simple matter to calculate your position on the globe from east to west.
All Harrison had to do was prove his theory beyond doubt to Parliament and the scientific community. Of course, there was resistance and many problems along the way. It took John Harrison forty years to claim the prize of twenty thousand pounds (a true fortune at the time).
Longitude is the story of one man's determination to prove his idea worked against all the odds. The book is well written and the complexities explained with amazing clarity. I thoroughly recommend this book to anyone and although the subject matter might not immediately appeal the story is so well told that you'll enjoy the book just for that. You'll also learn something new and that can't be a bad thing?
Not so long ago though it was not so simple and ships at sea regularly lost their way. In the 18th Century the problem became so acute that by act of Parliament a prize of 20,000 was offered to anyone who could demonstrate a reliable and accurate method of determining a ships position at sea.
To the scientific community the answer was in the heavens and leading astronomers endeavoured to prove that man could navigate the globe by observing the position of the moon and stars. Of course this was all well and good but not so easy during a storm or when the sky was overcast with cloud. Even with a clear sky the method of navigation by the moon and stars alone was far from reliable.
John Harrison was not a scientist, just a simple carpenter with a passion for creating timepieces. To Harrison the answer was simple - the Earth spins on its axis a full three hundred and sixty degrees every twenty four hours. Every hour it spins by fifteen degrees. If you know the time at your home port and you have an accurate idea of the time at your current location then it's a simple matter to calculate your position on the globe from east to west.
All Harrison had to do was prove his theory beyond doubt to Parliament and the scientific community. Of course, there was resistance and many problems along the way. It took John Harrison forty years to claim the prize of twenty thousand pounds (a true fortune at the time).
Longitude is the story of one man's determination to prove his idea worked against all the odds. The book is well written and the complexities explained with amazing clarity. I thoroughly recommend this book to anyone and although the subject matter might not immediately appeal the story is so well told that you'll enjoy the book just for that. You'll also learn something new and that can't be a bad thing?
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