on 26 February 2015
It is not that I dislike this book - not at all. I just do not understand enitrely why everyone seems to think this is the bestest book ever written (or at least the best since the invention of sliced bread). Again, do not get me wrong, this is not a diss, and Dava Sobel did a really good job - it is not easy, after all, to write compellingly about clocks. But just why this book is as famous as it is, eludes me. Perhaps that, to many out there, it is a spectacular relevation for just how long people at sea had no clue how far East or West they actually were. Anyway, I still would recommend this compact & well written book.
on 4 March 2014
I first heard about this some time ago as one of the best ‘popular science’ books of recent years. It was somewhat shorter than I thought it would have been, but then my perception may be skewed by having only recently read Richard Holmes’ The Age of Wonder which may have spoilt me.
Sobel introduces us to the problem at hand, namely that of working out what your longitude is when at sea. It was comparatively easy to work out what your latitude is; this can be done with some astronomical/solar observations. However, if you are on the equator, then to sail east or west by one degree of longitude will entail travelling further than if one is sailing at a constant latitude of, say 30 degrees. Though in so doing, Sobel does betray a lack of understanding of spherical geometry by stating that sailing on a line on constant latitude yields the shortest route west, instead of following a great circle.
The book then focuses on the work of John Harrison who thought the best way to solve the problem was with accurate timepieces that could be kept on board ships at sea. He was not without his rivals, though, with some convinced that further astronomical measures would avoid the need for accurate clocks. Yet the overriding sense one gets is that there was an institutional snobbery which Harrison was subjected to as he attempted to prove to the relevant authorities that his work was up to the task.
In so doing, Sobel avoids much of the science after having fumbled a little bit at the start and the rest is much more “pure” history. That left this reader a little frustrated, not least because I had heard such high praise for Longitude. As it is, it’s interesting enough but did not capture my attention as I had hoped it might. So it’s a pleasant enough read with some interesting aspects of history noted that I was previously unaware of, but it’s nowhere near as fine as The Age of Wonder. For anyone interested in the history of science, it is one to put on the reading list, but there is no need to unduly rush into reading it straight away.
on 5 February 2013
So many women have written so many great books on history (Fraser's The Gunpowder Plot, Scurr's Robespierre, Eisler's Byron, Collingridge's Cook, Salmond's Bligh, Alexander's Bounty, Ann Wroe's Perkin, Weir's The Princes in the Tower, Wise's The Italian Boy) that I'm beginning to wonder if there's a special historian gene that only women possess. Which brings us to Dava Sobel's LONGITUDE. Sobel does a wonderful job of telling the story of how longitude was finally pinpointed, a discovery which allowed Britain to become an empire. Sobel tells us about 4 warships lost in 1707 because of a miscalculation. A seaman aboard, before the disaster, had warned the captain that he, the seaman, had been keeping track of distances, and that they were all in for trouble if they continued forward. The captain had him hanged for mutiny! But due to this incident, London offered 20,000 pounds (millions in today's money, writes Sobel) for someone who could find a way to calculate longitude. What was needed was an exact clock (Sobel explains why) which was difficult because clocks needed oil, but oil speeded up or slowed down a clock depending on temperature. William Harrison finally built a clock, 4 feet high, 4 feet deep and 4 feet wide, weighing in at 75 pounds! Little by little he did better until he finally won the money, 40 years after his first version! Alas, Harrison never explained how he came upon the discovery of gems--rubies and diamonds--for his clocks. Totally fascinating.
My own books can be found on Amazon under Michael Hone.
on 2 February 2012
Longitude is a brilliant weaving of science, history and biography all in one. Dava Sobel has created a first class look at the life of a forgotten English genius, and how his life long quest would allow humans to master travel in the deepest ocean, and in the process save thousands of lives.
In the great age of exploration Sobel tells us, all the great explorers were essentially sailing blind. Without the knowledge of tracking longitude they could not properly navigate the deep ocean, making travel difficult and dangerous. Since the days of the Ancient Greeks some of the greatest minds had tried and failed to find a solution, among them great luminaries such as Galileo, Newton and Edmund Halley. It seems odd therefore that the solution would come from an unexpected place, from the mind of a self educated, untrained country bumpkin called John Harrison. Harrison who had taught himself entirely from books borrowed from friends, would dedicate most of his life in pursuing the £20,000 goal set by parliament to solve the longitude problem. His story is one of perseverance against the odds, faced with huge technological barriers, as well as opposition from men like his worst enemy, Nevil Maskelyne.
This book is a short, very readable and well written tour through the ages, as we follow from Galileo up to the restoration of Harrison's chronometers in the 20th century at the hands of Rupert Gould. If it has any flaws, it's the lack of illustrations, but even so this is still an excellent book and Sobel should be congratulated for the amount of work she has poured into this book.
This is the story of John Harrison (1693-1776) a self-taught Yorkshire clockmaker, and his quest to claim the prize of £20,000 offered by the British Parliament in 1714 for solving the longitude problem.
In the eighteenth century and earlier while establishing latitude was relatively straightforward, determining longitude was not. Longitude was established via dead reckoning: the time it took for a log thrown overboard to be left astern measured speed; and the height of the sun at noon was used to establish local time. This was not a reliable method of establishing longitude, and as a consequence sailors were often ignorant of their position at sea. One tragedy, in 1707, resulted in 2000 men drowning when a squadron of ships ran onto the rocks of the (British) Scilly Isles.
This tragedy resulted in the British government deciding to find a reliable method to determine longitude. The British Longitude Act of 1714 promised a prize of £20,000 to anyone who could establish longitude within ½ of a degree.
As Dava Sobel explains: `to know one's longitude at sea, one needs to know what time it is aboard ship and also the time at the home port or another place of known longitude - at the very same moment. The two clock times enable the navigator to convert the hour difference into geographical separation.'
While many astronomers thought that a celestial solution would provide the answer, others thought that perfecting a ship's clock so that it would keep more accurate time by not losing or gaining more than 3 seconds in 24 hours (a total of two minutes on a six week voyage - the ½ degree accuracy required by the Longitude Act) would provide the solution.
To John Harrison, the answer was a simple one. He knew that the Earth takes 24 hours to rotate 360 degrees and that one hour (1/24 of a rotation) was 15 degrees. If a sailor knew the exact time at a fixed place (say, his home port) and the exact time on ship, then a simple calculation would determine his longitudinal position. The challenge for Harrison was to build a portable timepiece that could be guaranteed to be accurate even after months at sea.
Thus, the scene was set for a battle between the scientists, led by the 5th Astronomer Royal Rev. Neil Maskelyne and a mechanical solution, ultimately developed by John Harrison. John Harrison worked for forty years to create an accurate, portable timepiece (a chronometer) for use at sea. He developed a series of chronometers between 1737 and 1770.
In this book, Dava Sobel explains the history of the search for an accurate measurement of longitude, the science and the personalities involved. What could be a dry subject is explained clearly, and John Harrison's story is fascinating. I have read other books about John Harrison, but I particularly enjoyed the way this book explains concepts and provides context and overview for the work undertaken by Harrison and others. Dava Sobel provides a wonderfully clear explanation of some quite complex ideas.
We owe a great deal to John Harrison: his focus and determination has doubtless saved many lives.
on 15 May 2010
I picked up Dava Sobel's book "Longitude" at a second hand book sale this week of 1. This must be one of the best 1 I have ever spent - it is an excellent book which I read in just two sittings. The book is short (175 pages) - and I was already familiar with the story of John Harrison and his efforts to win the Board of Longitude prize for solving the biggest problem on the 18th century - how to determine longitude at sea. See a summary in the article John Harrison and the Longitude problem on the British National Maritime Museum website. The story of John Harrison was also made into a two part film starring Jeremy Irons and the wonderful Michael Gambon as Harrison - this film is based on Sobel's book.
Sobel does a wonderful job of describing the problem of determining Longitude at sea. She describes the numerous efforts of many inventors to claim the £20,000 prize for a "Practicable and Useful" way to help navigators at sea figure out where they are. Harrison's rivalry with the Rev Maskelyne, and his difficulties with getting his time-pieces approved by the Board of Longitude are lovingly described by Sobel, who is clearly in awe of Harrison. It is well written and extremely easy to read - as she notes in the "Sources" section at the end - the book "is intended as a popular account, not a scholarly study".
Throughout the book I felt that I would have liked to have seen some diagrams of the insides of the H-1 to H-5 clocks and watches, and to better understand what some of the parts looked like. For example, it is only now (after finishing the book) that I found out what an "escapement" is - see a description in Wikipedia. I was constantly looking back at the (small) photographs inside the front cover as a reference point. As Sobel writes on her website "Roughly one-quarter of the many letters I received after the publication of Longitude complained that the book contained no pictures, maps or diagrams". This lead her to produce "The Illustrated Longitude" with William J.H. Andrewes. I must watch out for this.
This is a wonderful true story that anybody with even a passing interest in history and science will enjoy. Recommended
on 12 May 2010
This is a short, well written book that investigates and reveals the history behind what was for a long time a major problem for seafarers, namely, determination on their position east or west of their starting point as defined by longitude. In our age of GPS it sounds so simple but until the problem was solved seafarers and merchants suffered significant loss of life and property as a result of the disasters that befell them when facing the hazards associated with encounters with unexpected rocks and landfall. The problem was enormous with some of the best brains of the time actively involved in the pursuit of a solution. To encourage work on the problem a very substantial prize was offered to anyone who could come up with an accurate solution, this had the effect of both stimulating interest and introducing competition.
The book identifies the various approaches to solving the problem of determination of Longitude and details the gradual processes of attaining the required information and skills that would slowly bring into existence the possibility of achieving success. Broadly speaking the two primary lines of approach were the accurate determination of time and positioning with reference to celestial bodies. Accuracy in determination of time was deemed generally to be unachievable and hence the popular approach to finding a solution was that related to positioning relative to celestial bodies.
One man, John Harrison(a carpenter by trade), with almost single-minded determination and in spite of obstacles deliberately placed in his way, pursued the approach of accurately measuring time. He designed and built some magnificent and extremely accurate time pieces that fully met, indeed exceeded, the original criteria set for the prize to be won and was finally recognised for his immense contribution to the solving of the problem of accurately determining longitude.
A very worthwhile read that captures a whole range of aspects of human endeavour.
on 26 September 2008
Harrison seems to have been one of those people who is his own worst enemy; too proud to be successful.
Sobel is almost as prejudiced in his favour as some of those who opposed him were prejudiced against him. So it's difficult to feel you have read this and got the true picture. It seems that the astronomical methods were more successful than she admits for most of the book.
Nevertheless this is a helpful read which puts the development of clocks into context and reminds us just how difficult it was to navigate the seas safely in the days before GPS.
on 8 April 2009
This popular science account of huge changes in the 18th century has no pretensions to be a scholarly work. Short and simple, with reference material consigned to the appendix, the style is simple and the book refreshingly short. There is no attempt to draw the story out into the wider history of the age, just a clear focus on the challenge and the conflicts between the people involved.
The challenge of solving the longitude problem taxed the greatest brains of the later middle ages, as greater commerce created more shipping and more losses from miscalculations of position. The book describes the creation of almost-perfect time-keeping devices by John Harrison, and his attempts to prove these were the solution to the problem. Opposed to him were some of the great astronomers, who proposed the lunar distance solution, and stood in judgement of Harrison's efforts. Although Harrison himself was perhaps his own worst critic, refusing to even submit his first two creations test until he had improved them ... taking another 30 years.
The book captures the detail of clock-making without becoming boring, balancing the details with the desires of Harrison to deliver perfection and the tension between the competitors for the prize. Striking a fine balance between science and personality, this is certainly one of the better popular history of science books.
on 11 April 2015
A simply and engagingly told account of the race to find a means of measuring longitude and thereby save thousands of sailors lives. Lives which were being lost because mariners simply did not know with a sufficient degree of accuarcy where they were in the ocean. Such was the importance of solving this problem, that literally a king’s ransom was offered as the prize to the person who could produce an accurate longitude measuring device. Eventually it would be King George III who would intercede to bring about John Harrison’s success.
Naturally John Harrison takes centre stage in this book, but first his work is set within its historical context. Sobel sets out the impact that not being able to measure longitude had had upon mariners, by citing a few examples of shipwrecks and disastrous sea voyages. She also recounts man’s historical attempts to measure longitude. You’ll learn something of the development of science, in particular in the astronomical and time-keeping fields.
Ultimately this is a story of a ‘David’ fighting a ‘Goliath’, the non-academic, meticulous craftsman eventually winning over the academic snobs, after spending a lifetime trying to succeed. This makes for an inspiring heart-warming and human story about the adherence to perfectionism and tenacity in the face of adversity.