Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time

A mediocre book , the author clearly has no scientific knowlegde and drags the story out as if it was a Soap opera . No diagrams / drawings / patent descriptions are included , meagre technical information . NOT worth the effort of reading . this publication is an insult to the intelligence . ABSOLUTE RUBBISH . ( and I have read it ). William Asquith .

A fascinating biography of an self-educated diligent and talented man who beat the academic snobs with his invention of a new way to determine longitude.

Dava Sobel's 'Longitude' makes for a quick, light read. The story covers an interesting slice of history, but Longitude hardy distinguishes itself as being a great book. The largest problem is that the "lone genius who solved the greatest scientific problem of his time," John Harrison, is not a man about whom very much is known. Everything that is known about him could be fitted onto one of the (paperback) book's 175 pages. It's a bit remarkable that Sobel was able to milk a book from minimal and disjointed known facts. The story is really about the longitude problem itself, and the Harrison 'enemies' long-running success in undermining Harrison's solution, a precision chronometer that could maintain accuracy under the widely varied environmental conditions encountered by mariners.

Sobel's 'Galileo's Daughter: A Historical Memoir of Science, Faith, and Love,' is, in every way, a better book. For those interested in a fast-paced historical exposition of "a lone genius" advancing science but meeting maddening resistance from England's celebrity scientific elite (yes, it's a theme that parallels Sobel's 'Longitude'), by all means secure a copy of Tom Standage's 'The Neptune File: A Story of Astronomical Rivalry and the Pioneers of Planet Hunting,' the story of John Couch Adams' startling genius and the developments of planetary astronomy from William Herschel to our current spectroscopic and mathematical hunt for distant exoplanets.

Not a bad book, but not great either.

Sobel brings science to life in this tell of the quest to solve the navigational conundrum of measuring position. Her writing is visual and fluid. The book tells a gripping story that brings in bits of politics, geography, economics, philosophy, and many other disciplines. It proves that fact can be stranger than fiction. This is a great read for anyone of any age and with any area of interest.

Longitude and latitude tell a sailor or aviator or hiker where in the entire world he or she is. If latitude is known, one knows how far north or south of the equator he or she is. But that's a circle all the way around the earth. To find the point on that circle, the sailor's longitude must be known. Without longitude, ships missed resupply islands in the south pacific by a couple of miles or by hundreds of miles - and never knew it. They crashed into rocks wandering around like you would in a dark room - the door is on the other side but, where?

The earth is round and, therefore, there are 360 degrees in the circumference. The earth makes one rotation every 24 hours and the sun stays put. That is, the earth rotates at the rate of 15 degrees per hour. So, if I know the time at some point in the world and I know the local time, I can calculate where I am on the circle of latitude. I can determine local noon and then I look at my very accurate clock and determine the time in, say, London. If it's four hours earlier in London, I know I am 4 x 15 or 60 degrees around the world from London. I shoot the sun with my sextant to find my latitude and now I know where I am.

The problem was - how do I know what time it is in London when I'm in the south pacific. Even on land, clocks were not even close to accurate - they'd lose several minutes a day. Many solutions were proposed - my favorites were the "sympathetic dogs" and the line of cannon firing ships. The dog solution involved having a dog in London and a dog on the ship. Since it was well known that dogs communicate telepathically, if the dog in London was pinched, the dog on the ship would feel it and yelp. So - pinch the dog at noon and - voila! That didn't work so the next idea was to put a string of ships across the oceans beginning in London. Put them at one mile intervals and have the crews listen. At noon a cannon would be fired in London and the first ship would fire its cannon. The second ship would hear it and fire its cannon. and so forth across all the oceans. When a cruising ship heard the cannon, the captain knew it was noon in London. Too many ships, too much money and what to do during a storm.

Harrison's first clock was accurate to 1/2 second per day. That's in the mid seventeen hundreds. That's better than most clocks and watches made anywhere in the world up to about 30 years ago. He ultimately made a large watch - about five inches across - that was able to keep London time so accurately the British Navy could go anywhere and find what they were looking for and the way home. But think of the problems - the ship is rolling and pitching so a pendulum won't work. The temperature and humidity change so the mechanism slows or speeds up or rusts. There were no computer chips or quartz crystals. And there were many important people saying, "God is the answer - look to the heavens."

It's a story about something we take so easily for granted today. Our throwaway watches are more accurate than anything imaginable when Harrison started. An atomic clock measures time to the billionth of a second and we think nothing of it - but without those clocks we would have no satellite communication, no weather satellites, no space program. It's a story about a man who didn't know the answer but was determined to find it. Harrison had no computer, no modern machine tools, no precedent. His story is absolutely amazing. And it is told wonderfully by Dava Sobel. I've read it three times and have enjoyed it each of them.