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Summary: A History of Timekeeping and its contribution to navigation
Review: This book is a historical story of mans long search for a reliable method of navigation and surveying and how the reliable determination of longitude at sea was achieved. The book tells of an age from the early 18th Century when accurate methods for sailors to determine their longitude at sea was not available and how the search for such knowledge spawned the British Parliament to establish the Board of Longitude and offered a "kings ransom" prize of twenty thousand pounds to whomever could present a "Practicable and Useful" method for determining longitude at sea. After years of work, one man, John Harrison developed a series of clocks that would work aboard a ship at sea and keep time to within the tolerances required to maintain accurate time. This timekeeping was vital in that age and was the only then available method of knowing the time in ones home port which was need to compute positions of longitude when sailing at sea. The book chronicles John Harrison's inventions (H-1 thru H-4) and his lifelong struggles with and against others who were proposing and developing other methods of navigation utilizing lunar and celestial observations. Chronicled are his battles with the Board of Longitude and its commissioners, some of whom became his archrivals in proposing alternative methods. Harrison was ultimately awarded the Copley Medal in recognition of his work by the British Royal Astronomical Society, an award that was later bestowed on persons such as Benjamin Franklin, Captain James Cook and Albert Einstein. The book includes accounts of alternative methods being developed, including a somewhat humorous account of the quack proposal of using the "Powder of Sympathy" which involved the magical curative powers over long distances of a medicinal powder that could cause an injured ship board dog to yelp at prescribed intervals. Such was the desperation of mariners to solve the longitude problem. Ms. Sobel has written a very readable book that is short enough to finish easily in a day. My copy was the hardcover bookstore version that had a nice color card insert with the photographs and descriptions of the John Harrison timepieces, H-1 thru H-4. An illustrated version of the book is available and I would suggests it or other version with pictures, drawings or photographs as the insert card photos helped immensely in my appreciation of the clocks and John Harrison's life work. The book is very enjoyable reading that formed the basis for the acclaimed A&E movie by the same name.
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Summary: Brief but enjoyable
Review: This slim volume tells the story of John Harrison who, although untrained, built four revolutionary clocks that changed how ships navigate at sea. It also tells about the political fight Harrison was forced to fight to win recognition for his work. Written in a easy-to-read, "magazine" tone the tale goes quickly, whole years pass in a couple sentences. I wanted more details and this is where the book disappoints but it may not be the authors fault The book hints that many events weren't recorded and more details just aren't available. One technical note: I think the font used in this tiny, five by eight inch book is a little small and the page numbers, even smaller, aren't readable at a glance. Or maybe I'm getting old.
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Summary: What a Wonderful Little Read!
Review: We may not designate people "living national treasures" here in the States as they do in Japan, but if we did, Dava Sobel would get my vote in a heartbeat. She has taken on a subject that would be as dry as dust in the hands of almost any other writer and breathed such life into it that you'll have a hard time not reading it in a single sitting.
The problem of determining a ship's longitude at sea may seem now seem obscure at first thought, but it was in fact the premier technological challenge of the age and its resolution helped lay the foundation of the British Empire and thus the modern world.
John Harrison was exactly the kind of common-born, inventive, hard-headed, stubborn, practical, independent-minded Englishman who created the Industrial Revolution, and his lonesome struggle to build an accurate marine chronometer reminds the reader of how great achievement always comes at great cost and as a measure of one's character. His final triumph may look like just a big pocketwatch to us now, but was the first of its kind and did not come easily.
But most of all, "Longitude" is simply a tremendously enjoyable little read, as compact and precisely crafted as the device whose creation it depicts.
Simply a classic.
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Summary: It All Hangs on a Minute
Review: What is time? Is it anything more than an agreed arbitrary splitting up of a ?day? into shorter intervals? May be not, but the ability to measure those intervals with repeatable accuracy is nowadays taken to be a given fact. For the most part, my ability to tell the time accurately is not a matter of life and death. But for sailors, it once was so.
This thin volume explains the problems of longitude in beautiful clarity. It is not just about the striving for perfection of John ?Longitude? Harrison, but also of two competing solutions to the same problem; that of being able to determine the accurate position of ?here?, in terms of both latitude (which is easy) AND longitude. Harrison was way ahead of his time (pun intended) as he sought to bring order from chaos. Time does not matter if you always have the sun and stars to anchor you to the universal time of your (fixed) location. However, if you move, then there can be significant problems. How do you know how far you are from ?home?? This is especially important to sailors, and the floundering of 4 vessels on the rocky Scilly Isles in 1707 with the loss of more than 2,000 lives was the impetus for creation of the Longitude Board, with its prize of ?20,000.
Harrison chose keeping the time of some fixed place (possibly the port of departure) as a mechanism to determine longitude; every hour difference between actual time and the fixed time means a difference of 15? of longitude. The key to navigation at sea is an accurate record of the fixed time, as a point of reference. There were many innovations and modifications introduced by John Harrison to reduce the number of moving parts, reduce or eliminate the need for lubricants, or compensate for fluctuations in conditions. The restorer of 4 of the timepieces of Harrison was constantly astonished at the innovations that were employed; this restoration work was carried out in the 1920?s and 1930?s, almost 200 years after the first item (?H1?) was completed. That Harrison continued to be his own severest critic spurred him on to improvements that would make his timepieces of an accuracy that many would crave, even into the last quarter of the 20th century.
The author herself readily admits that this is a popular telling of a serious story, yet there is much scope for further serious research if a reader is so inclined. However, the book succeeds in asking important questions of the reader, and invites such to consider the marvels of the universe, almost as an aside. The telling of the tale with simple clarity leads the reader onwards through the self-taught clock engineer?s path as he struggled with the complex difficulties of computing time in a way that compensated for changes in temperature and pressure. This was not the least of his struggles; having built a small version of a timepiece (known as ?H4?) that lost just 5 seconds during 81 days at sea (and hence well within the Board of Longitude?s criteria of tolerance), John Harrison and his son William were made to repeatedly jump through artificial hoops to gain official acceptance. It is significant that the person to meet William on the quayside at the end of a second journey to the West Indies with H4 was Rev Nevil Maskelyne, later to become Astronomer Royal, and someone who had a vested interest in finding fault with the use of timepieces in calculating longitude. There was a determination from some of the early Astronomers Royal to persevere with the lunar method of determining longitude. The prize of the Board of Longitude was never awarded in full, although Harrison was rewarded. However he never jumped through enough hoops to receive the full ?20,000.
The legacy of Harrison is all around us. It is so commonplace that we do not realise that it is there. In some ways the location of the Greenwich Meridian as a fixed point is his legacy. It is therefore fitting that his clocks are on display there. Read this book, and then go and see his clocks on display there. Both are a fitting tribute to someone who was ill-treated and misunderstood at the time.
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Summary: Amazing subject, fascinating story
Review: With "Longitude" Dava Sobel has written a very interesting book about the greatest scientific problem of the 18th century. As a result of the 1707-shipwreck story (with a loss of 4 out of the 5 ships), the English Parliament offered in 1714 a 20.000 pounds reward to the person that could provide a practicable and useful way of determining longitude. (If you have forgot, longitude is the "lines" that runs from pole to pole). Not being able to determining longitude was a great problem. Ships spent excessive time trying to find its way back to port, or worse men, ship and cargo were lost at sea. John Harrison (1693-1776) spent his lifetime trying to solve the longitude mystery. Harrison was a son of a countryman, with minimal schooling, and was self-educated in watch making. He made several timepieces, which all qualified for the reward, but the reward was delayed several times by the Longitude committee whom believed that other ways of measuring longitude were the preferred ones. Ultimately after a lot of harassment and trouble, Harrison was given the reward money. Dava Sobel has done a wonderful job in this book, capturing Harrison's fascinating character, his brilliance, preserving and hard working nature. The author has also managed to strike a perfect balance between technical jargon and personal anecdotes, and she does it in such a way permitting the lay readers of the book to admire the elegance of Harrison's discoveries. I believe it is a sign of excellent quality when an author makes learning so interesting. I was hooked from the first page of this book and I read it in 50-page gulps at a time. Highly recommended!
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