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Cabin Dweller

Precise Writing on Precision

Reviewed in the United States on December 21, 2016

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Longitude is west to east, east to west. But it's not that simple because, for example, the equator is wider around the earth than the Tropic of Capricorn or the Arctic Circle. Although latitude is fixed by the earth and Columbus could sail a "straight line" in 1492 relative to a fixed latitudinal parallel, longitude made sailors feel they were on a train and looking at another train, trying to determine which one just began moving.

After reading a book about Mason and Dixon and all of the incredibly (for me) complex math and astronomy involved, I was slow to begin this book. Author Dava Sobel, however, cuts through all the more complicated principles like a good pre-calculus teacher. I would even suggest this book could appeal to adventurous 8th graders. The history is impressive. The Harrison family were watchmakers, but as very precise and diligent watchmakers competitive with the Royal Society and haughty astronomers like Nevil Maskelyne. John Harrison had size, cost, material, temperature fluctuations, moisture, waves, and many more atmospheric obstacles to confront while those relying on lunar readings went much further to produce much less. For the record, I had never heard of John Harrison. His predecessors include Halley, Tycho Brahe, and Galileo, whose attempts to time the speed of light is briefly retold here.

This is summer reading, a hero's tale, good defeating bad, The Little Engine that Could. If you or your child is interested in sailing, navigation, astronomy, inventions, machining, or how the British came to rule the word for a time, this is a book to read and re-read.

LoudZenGuy

Shallow and Repetitive

Reviewed in the United States on December 25, 2019

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The shipwreck of Sir Shovell's fleet, the fact that longitude was impossible to determine, and the term "bimetallic" is the limit of the author's analytical depth in this book. Skip it. Seems like she repeats the Shovell story nearly every chapter, along with the fact that sailors couldn't determine longitude without a clock. Yeah, we know. We all knew that before buying this book. The analysis of Harrison's clocks is far more focused on the decorations of their faces than on his novel engineering. Detailed descriptions of the clocks and their engineering advancements are absent. Simplistic terms like "bimetallic strip" are promoted as the entire explanation, with no further information provided. Perhaps the author feels the story of Longitude should focus on people instead of engineering. Unfortunately, the people involved are history's greatest astronomers and physicists. The author adds nothing to their well-researched biographies in this book, and fails to communicate even the most basic functions of a clock. This is an extremely disappointing read. I do not recommend it.

Missus Sunshine

I was left hoping for more detail and depth

Reviewed in the United States on May 16, 2017

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I was left hoping for more detail and depth. This story is sort of a biography about a person whom the author explains there is not much known. The subject's work product is and has been well known and studied at length, but there are not enough details about the technology included in this book. At the end of the book the author explains that she purposefully omitted information that she did not think her readers are smart enough to consider.
The premise of using a clock to compute longitude is mentioned repeatedly through the first half of the book, but an explanation of the operating principal and technique is only finally hinted at in the later stages of the book. The idea is that at any instant one can correlate "local" time to some known "reference" time as it occurs at some specific reference location and compute the local angle of longitude in relation to the reference location. The clocks being discussed are the devices used to reliably transport the "reference" time for comparative use in other locales. I have been aware of the technique for a long while and it became a guessing game to anticipate when the idea was finally going to be presented to, and shared with, readers. I think that many readers will enjoy the book much more if the premise is described, in detail, in an earlier portion of the story so that it is more obvious why one may appreciate all the great efforts made in the field of horology to achieve a series of incremental advances in performance and reliability.

This book reads like a book report or a term paper rather than as a comprehensive book. It seems as if the author knows her subject well, but did not benefit from effective editing and/or insightful guidance regarding the perspective of a reader when formatting the story line into book form.

I am surprised that some other more satisfying explanation of the history and circumstances has not been offered as a replacement for this book and its best seller status.

J. Otero

An adventure in genius

Reviewed in the United States on March 9, 2017

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This book is a fascinating history of the development of a mechanical chronometer. The author lays out the historical background and competing interests so that the reader can fully appreciate the challenges faced by John Harrison and his son William. It shows that John Harrison was like the Indian mathematician Srinivasa Ramanujan (central character in the movie "The man who knew infinity") in that he was poor and therefore self educated. His vocation was carpentry and his intimate knowledge of wood was employed in his first chronometer. He knew how to build sound grandfather clocks and that experience fed into his first chronometer for seafaring. He almost let his £20,000 prize slip away, because he wasn't satisfied with his first clock designed for the sea. Had he resisted the urge to build a better clock before claiming the prize, he would have won the prize out right. Instead, he ended up competing head-on with a lunar distance technique created by people favored by the committee that oversaw the giving of the prize money.
The books paints the complex story of Harrison's Great achievements and does so in an easy to read format.

Top reviews from other countries

T. K. Elliott

An engaging overview of the solution(s) to the longitude problem - recommended

Reviewed in the United Kingdom on September 8, 2018

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If you are expecting 200 pages of mechanical drawings and equations, or even a detailed explanation of how Harrison's clock worked, you're out of luck. Likewise, if you're expecting a a blow-by-blow account of his inventions and dealings with the Board of Longitude, you are also going to be disappointed.

However, if you are looking for an interesting, fast read about the problems of calculating the longitude of a point on earth and how these were eventually solved, you have come to the right place.

This is popular science-history - a tale of people and personalities as well as inventions and discoveries. Sobel's writing is accessible and her verve carries the reader along in the same way as reading a good novel. In just over 200 pages, there isn't much in the way of detail - but the reader does come away with a broad-brush overview of what the problem was, the reasons why it was so intractable, the various methods for solving it, and why the problem was solved in the way it was.

weltonian

Good. It could be much better

Reviewed in the United Kingdom on December 30, 2018

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This book does not justify its rave reviews. It could be so much better. The introductory chapter has been merited as an unorthodox opening whereby all is revealed in brief, then the rest of the book fills in the detail. For me that is the major problem. When you know what happens the genie is out of the bottle and the t ale is just routine. The author is not a good story teller, either. There is much wholly detail about early efforts to solve the Longitude problem. That becomes tedious and could have been briefer considering that those early ideas were useless. There are no illustrations in a book that screams. for such things. No diagrams to explain the text where it would assist the reader. What a let-down. It’s worth a read but will end up at our local charity shop.

M. Dowden

Still A Great Read

Reviewed in the United Kingdom on March 13, 2021

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First published in 1995, this popular science/history book by Dava Sobel has been read by many of us over the proceeding years. Nowadays of course so many of us use GPS in our phones, satnavs and other devices that we tend to not think about the past when such things were not possible. Here then we read of the problems of navigating the seas in the past, and the problems that occurred.

Although latitude had already been worked out, when it came to longitude, so the matter was far from simple, after all any simple navigation requires the navigator to be able to see things such as the sun, the moon and the stars. Bad weather can blanket the sky meaning that things cannot be made out, and then also something like the moon is not always visible, as it orbits us and obviously enters the southern hemisphere, and vice versa. To be able then to more accurately determine where you are it obviously becomes apparent that you need an accurate timekeeper.

This is a pop book so is relatively short and keeps to the main areas of interest, and so we read of the remarkable story of John Harrison, originally a carpenter, who made the major breakthrough in keeping accurate time at sea. But this also takes in more than that, as we see that longitude on land led to more accurate maps, that with trying to find an answer with the stars so eventually the speed of light was determined, and the fact that the Earth is slowing down, along with other discoveries. For the main part of this though, it is about Harrison and his ever-increasing work at adapting and trying to create smaller timepieces than his first version.

As we see, in this country so a board was set up and rewards offered for a person who could come up with an accurate way to determine longitude at sea, and how the rules always seemed to be changing, at least when it came to Harrison and his inventions. With greed and one-upmanship so there was some skulduggery that went on behind the scenes, which at times does add a somewhat thriller element to the tale. How perseverance and hard work makes things happen, so this also reveals to us that the whole issue of longitude brought greater understandings in physics and our understanding of the universe around us, and why the world uses GMT.

Dr Brian Metters

Science, politics, courage, history, it has everything!

Reviewed in the United Kingdom on October 1, 2021

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"Here lies the real, hard-core difference between latitude and longitude—beyond the superficial difference in line direction that any child can see: The zero-degree parallel of latitude is fixed by the laws of nature, while the zero-degree meridian of longitude shifts like the sands of time. This difference makes finding latitude child’s play, and turns the determination of longitude, especially at sea, into an adult dilemma—one that stumped the wisest minds of the world for the better part of human history."

To be brief, discovering a method of measuring Longitude in the 1700s was a "bit of a pig" until an amateur clockmaker from the North of England, entered the fray and battled royal astronomers, politicians, mathematicians, The Admiralty, and academics who believed that the "moon and stars" method was the answer. John Harrison believed that "the measurement of time" method was the answer. He was a simple carpenter from Yorkshire who the aristocracy delayed, hindered, cheated, lied to, threatened ……. but they were wrong in their assumptions, and John Harrison eventually proved it to claim the £20,000 prize with his H4 model.

It’s a heck of a story you can read in Dava Sobel’s book, and you can see all of John Harrison’s models H1 to H4 at The Royal Observatory, Greenwich, London. We were really motivated after reading this book to go and see these four mechanisms inside glass cases that changed the world, saved countless lives, enabling navigation not only on the high seas but also within our modern day satnavs. We stood in awe of Harrison just looking at them and knowing his story, his struggles, his battle to claim the prize money reinforced yet again how much this country gave the world through the Age of Reason then the Industrial Revolution. Sadly it seems that this kind of true story isn’t studied in our schools or universities these days!

Vasily Pugh

Captivating account of the battle for longitude

Reviewed in the United Kingdom on November 21, 2021

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There are longer and more detailed books on longitude and the history of attempts to find a viable way of calculating it at sea. There are some that might go into the mechanics of this a bit more readily. Yet 'Longitude', in a reasonably condensed manner, tells you so much about this fascinating subject and especially the great people behind it. The key to this is, of course, the mechanical genius John Harrison and not only his remarkable efforts (especially as he received no formal education) but also is determination to get recognised. It makes for a enthralling read and you cannot help but feel in awe of how the minds of these great men worked, either in the field of astronomy or in mechanics. Like any great Hollywood story though, 'Longitude' is about more than just the discovery; what an 'ordinary' man like John Harrison had to do to receive recognition was incredible and would test the patience of lesser men. Along the way, we learn about some of the more eccentric ways of calculating longitude and get introduced to a remarkable cast of intellects locked in battle to solve the problem. Riveting, well-written and highly recommended.

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