[.ca] Longitud (ISBN 8483061457)

From Amazon.com:
The thorniest scientific problem of the eighteenth century was how to determine longitude. Many thousands of lives had been lost at sea over the centuries due to the inability to determine an east-west position. This is the engrossing story of the clockmaker, John "Longitude" Harrison, who solved the problem that Newton and Galileo had failed to conquer, yet claimed only half the promised rich reward.

The Man who Captured Time so Ships could Navigate Accurately:
=====> Note: This review has been written from a city with the following position on Earth: LATITUDE: (43 degrees 2 minutes North) LONGITUDE: (81 degrees 9 minutes West). In order to understand the significance of this remarkable book by Dava Sobel, the reader has to understand some words and phrases in the book's title and subtitle. "Longitude" along with Latitude are two numbers along with compass directions that are used to fix the position of anything on the planet Earth (as in the note above). Lines of Latitude are the imaginary, parallel, horizontal lines circling the Earth with the equator (fixed by nature) being the "zero-degree parallel of latitude." Lines of Longitude or "meridians" are the imaginary lines that run top to bottom (north and south), from the Earth's North Pole to its South Pole with the "prime meridian" (established by political means) being the "zero-degree meridian of longitude." (Since the mid-1880s, the prime merdian has passed through Greenwich, England. Before this time, the imaginary line that passed through a ship's home port was usually used as the zero-degree meridian.) Finding the latitude on land or at sea was easy and eventually a device was invented to make it even easier. But finding longitude, especially at sea on a swaying ship was difficult, a difficulty "that stumped the wisest minds of the world for the better part of human history" and was "the greatest scientific problem" of the 1700s. Ways of determining longitude astronomically were devised, but these proved to be impractical when used at sea. England's parliament recognized that "the longitude problem" had to be solved practically since many people and valuable cargo were lost at sea when the ship's navigators lost sight of land. Thus, this parliament offered a top monetary prize that's equivalent to many millions of dollars today to anybody who could solve the problem. Enter "a lone genius" named John Harrison (1693 to 1776). While most thought the solution to the problem was astronomical, Harrison saw time as the solution. To calculate the longitude using time on a ship at sea, you have to realize these two facts found in this book: (i) The Earth takes 24 hours of time to spin 360 degrees on its axis from east to west. (ii) Noon (12:00 PM) is the highest point the sun seems to "travel" in a day. To learn one's longitude at sea using time, as this book explains, it's necessary to do the following: (1) Know the time it is aboard ship (local noon was normally used because of fact (ii) above). (2) At the very same moment, know the time at a known longitude (such as at Greenwich, England). (3) The difference in time between (1) and (2) is coverted to a longitude reading in degrees and direction (using fact (i) above). Harrison's solution was the accurate determination of time of (2) above by inventing a reliable timepiece. This timepiece, in this case, would be set to Greenwich time. (Note that, as stated, (1) could be determined using the noon-day sun but this was not always practical. Eventually another timepiece was used to determine the ship's local noon for a particular day.) It has to be realized that this was the "era of pendulum clocks" where, on a deck of a rocking ship, "such clocks would slow down or speed up, or stop running altogether." Harrison was to capture time by building a marine clock or "timekeeper" (eventually called a "chronometer") that could be used on a ship at sea. This book tells the "true story" of Harrison and his chronometers. (There were five built over a forty-year period. Harrison's first timekeeping device was known as H-1, his second was H-2, and so on.) Sobel uses accuracy (as evidenced by her thirty references), extensive interviews, and an engaging, mostly non-technical narrative (only essential technical detail is included) to convey a story that's filled with suspense, heroism, perfectionism, and villiany. All this in less than 200 pages!! The only problem I had with this book is that it has hardly any pictures (photographs and illustrations). I would have liked to have seen pictures of the various people involved in this saga, maps showing where ships traveled, more photos of Harrison's amazing timepieces (both interior and exterior), and diagrams that explained important concepts. A diagram that actually showed how longitude, using a simple example, is calculated (using the steps above) would also have been helpful. Finally, there is a good 1999 movie entitled "Longitude" based on this book. Be aware that even though this book is short, the movie is long (over three hours). In conclusion, this book documents the exciting "true story" of how "a lone genius" solved "the longitude problem." Sobel states this more eloquently: "With his marine clocks, John Harrison tested the waters of space-time. He succeeded, against all odds, in using the fourth...dimension to link points on a three-dimensional globe. He \otook\c the world's whereabouts from the stars, and locked \oor captured\c the secret in a...watch." <=====>

Brief but enjoyable:
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.

An epic 40 year struggle!:
Dava Sobel, like Simon Winchester or Canada's Pierre Berton, has clearly mastered the art of writing history in a form that is not only informative but, perhaps more important, is also compelling and entertaining. In eighteenth century Europe, although scientists had long wrestled with the problem, sailors had no method of determining their longitude. The economic losses and the loss of life was so staggering that finding a solution to the problem was elevated to the almost legendary level of finding the Holy Grail or the Fountain of Youth. In the Longitude Act of 1714, the British Parliament offered a prize of 20,000 pounds (equivalent to several million dollars today) to anyone who found a "practicable and useful" means of determining longitude. One need look no further than the list of stellar minds that were applied to the problem (and failed to find the solution) - Tycho Brahe, Christian Huygens, Robert Cooke, Edmund Halley, Galileo and Vincenzo Galilei, Sir Isaac Newton, Christopher Wren - to appreciate the almost insurmountable difficulty that this issue presented to the navigators of the day. "Longitude" presents the story of John Harrison, a self-taught Yorkshire clockmaker, who struggles alone to raise the art of clock making to unheard of levels of accuracy. The story of his ultimately receiving the prize from Britain's Board of Longitude is a dramatic, inspiring and heart-rending portrayal of 40 years of perseverance and struggle against political shenanigans and skullduggery as well as personal feuds, jealousy and outright espionage and sabotage. From Admiral Sir Clowdisley Shovell's catastrophic loss of over 2000 lives when his fleet crashed at Land's End in 1707 to the refurbishment of Harrison's prize-winning chronometer for posterity in 1833, Dava Sobel has brought this small but important piece of the 18th century to life in a way that few other writers could manage. Two thumbs up for a thoroughly enjoyable piece of non-fiction writing! Paul Weiss

Nice Lean Account of Quest to Calculate Longitude at Sea.:
For centuries, the inability to calculate longitude at sea doomed many a sailing vessel and its cargo. Unable to calculate their exact position, ships would run aground or miss their destinations entirely, leaving their crews to suffer and sometimes parish from starvation, scurvy, or infectious disease. By the 18th century, the lives and monies lost as a result of this inability to navigate properly had become such an obstacle to commerce and political ambitions that, in 1714, England's Parliament offered an extraordinary sum of money to anyone who could devise a method of reliably calculating longitude at sea. Dava Sobel's "Longitude" is the story of the approximately 60-year race to solve the longitude problem and its hero, a clockmaker from Yorkshire named John Harrison, who invented what we now call the chronometer. Ms. Sobel has written a short, very readable account of the technologies, personalities, and politics surrounding the quest for a solution to the longitude problem and its accompanying prize. The book owes its economy -only 180 pages- to the fact that the author doesn't attempt to place the longitude problem in a greater historical context or to say more than is necessary about the individuals who play a part in the story. "Longitude" concentrates on one story, which is the book's strength as well as a limitation. If the story intrigues you, there is more to be learned elsewhere about navigation at sea, the technology of the chronometer, John Harrison, and all the other grand personalities that inhabit this tale of discovery and the politics of science. But "Longitude" is a brisk, enjoyable account of the invention that solved a centuries-old problem and propelled Great Britain to global dominance.

Longitude:
I found this book to be a great read and quite informative. The topic is not something that I usually concern myself with, but when I came across the book awhile back, I figured that someday I should read it; that day came, and I'm quite glad I did. It's made me aware of a man I was heretofore not familiar with--John Harrison--and the significance of his inventions. What he accomplished was truly revolutionary, and his story deserves to be known; this highly readable account apptly serves that purpose.