Harrison stood alone against the vested navigational interests of the scientific establishment. He became entrenched in this position by virtue of his own high standards and the high degree of skepticism expressed by his opponents.

Fascinating but too much fluff. Should have left it as the magazine article it originally was. I’ve learned to be wary of books with paragraph-length subtitles. This one was a unnecessary as most.

A novel antifriction device that Harrison developed for H-3 also survives to the present day—in the caged ball bearings that smooth the operation of almost every machine with moving parts now in use.

John Harrison was one of those lonely geniuses who labors against the scientific (and wrong) tide of his day. All the great and worthy members of the Board of Longitude knew he was wrong; some actively sabotaged his efforts. Harrison never got the credit (or credits) he was due, but the world of navigation (and beyond) benefited by his monomania.

With his marine clocks, John Harrison tested the waters of space-time. He succeeded, against all odds, in using the fourth—temporal—dimension to link points on the three-dimensional globe. He wrested the world’s whereabouts from the stars, and locked the secret in a pocket watch.

3.5 stars. RTC

Appropriately short. Not great, but held my attention enough.

Longitude offers a general overview of the development of scientific methods for the determination of longitude, but the primary narrative emphasis focuses on the biography of John Harrison, the brilliant English innovator who pioneered the art and science of marine chronometry.

Among other positive attributes, the text contains entertaining anecdotes involving notable personalities, as well as brief outlines of several early schemes proposed as solutions to the question of finding one's longitude. Stories of maritime misadventure highlight the fatal consequences related to the historical lack of adequate navigational information.

Because Dava Sobel writes with popular appeal in mind, this book does not describe the particular mathematics related to the calculation of longitude, except in basic terms. Longitude instead concentrates on extolling the exceptional genius of Harrison and his mechanical wonders, and on the tribulations forced upon Harrison by his rivals. Nonetheless, the inclusion of photographs or schematics would have been useful to the reader in understanding Sobel's descriptions of various devices and concepts; unfortunately, such visual aids are lacking here, other than a few small inset images on the book's dust jacket.

Aside from providing a good sketch of the life and work of John Harrison, this book serves as an accessible summary of the early history of the titular aspect of global positioning.

Longitude is a quick, enjoyable read, although readers are cautioned against expecting a thoroughly technical discussion of the subject.

Concise synopses of the same material presented in this book can be heard in these podcast episodes:
https://www.futilitycloset.com/2017/0...
https://www.missedinhistory.com/podca...

Thank you to my daughter who bought this for me at her school’s book sale.

ASTRONOMY IS NOT SOMETHING I'M INTERESTED IN BUT I READ THE GLASS UNIVERSE ANOTHER NON-FICTION BY SOBEL AND ENJOYED IT SO I GAVE THIS A TRY. IT WAS INTERSTING HOW THE MAN WHO SOLVED THE GREATEST PROBLEM WENT THRU SO MANY TRIALS TO GET HIS RECOGNOTION, BUT THIS JUST WASN'T FOR ME.

A short and entertaining history of the development of a sea-worthy clock which could be used to calculate longitude. Well written, with a story-like narrative, and lots of political intrigue. Yet another book that shows how science can be subverted by ideology, and how wealth and privilege can allow someone to remain in a position of power despite a clear conflict of interest. I would have liked a bit more science, and more detail on the technological innovations that Harrison and other accomplished, but this book was more focused on the history. Still a worthwhile read.

I'm so frustrated. It's nuts to me that someone would write the history of how clocks solved the longitude problem without actually explaining how the clocks worked or what hurdles they overcame. I understand it's highly technical, but the author writes how they were moved to tears seeing the clocks after years of studying how they work and how they were built - I don't think a simplified, accessible explanation is out of reach, and I think it's fair to expect it from this story, even if it is advertised as a brief history of a clockmaker. Maybe they didn't learn it well enough to teach it, but then I don't know why everyone else seems to enjoy this book.

I'm off to go learn more about clocks.

This book makes what may sound like a dry technical topic very interesting. The concept of Latitude and Longitude, now commonly understood as GPS coordinates, was not always readily available. While Latitude was relatively easy to deal with as the horizontal position from the equator between earth's two poles, Longitude was a major puzzle that was worked on and studied by many brilliant minds over hundreds of years. Conceptually it is very simple: By comparing the position east or west at your location from a known time at a standard location(called the Prime Meridian), the difference in hours gives your location in increments of 15 degrees (360 degrees around the globe divided by 24 hours) for each hour. Then, by knowing the circumference of the earth, you can convert it to distance or physical position on the earth. But with notoriously error prone time pieces that could gain or lose 10-20 minutes or more per day, especially in a humid, moving environment aboard ships with wide temperature variations, it was easy to be off 50, 100, 200 miles or more. this book presents the stories of the development of more and more accurate time pieces, alternative celestial positioning methods that were useless if overcast, and deciding and agreeing on where the standard time for comparison (today's Greenwich Mean Time) should be. Great diversionary read for anyone looking for something interesting as well as educational.

"He wrested the world's whereabouts from the stars, and locked the secret in a pocket watch."

Every year I teach my world geography students about latitude and longitude and how they aid navigators around the globe, but what I haven't been teaching is what I didn't know until I read this book. While latitude is a straightforward series of concentric parallel circles, the lines and measurement of longitude eluded astronomers and cartographers for centuries.

Learning about this problem and its eventual solution, you can't help but be impressed. This is an innovation that, in its own way, is as important as the development of penicillin or the phonetic alphabet. That the work of one humble man, clockmaker John Harrison, produced a solution to this problem really is incredible.

Ms. Sobel made a somewhat obscure topic interesting and informative. Definitely worth the read.

A short popular science book that examines the invention of the chronometer, or ships clock. Not just a clock, but one that remains uneffected by the humidity, heat and cold, atmospheric pressure and of course the passage in a ship on the high seas, being thrown about. Of course, it must keep time accurately enough to be relied on for navigation, as a clock that accurately keeps time in all conditions is the key to determining longitude. The actual key was knowing the time at a known location (home port or the like) and the current location simultaneously, allowing longitude to be calculated accurately.

And so, it is more than the story of a chronometer. This book describes the circumstances in which the clock finally won out as the recognised way to accurately determine longitude. It was a close thing, with astronomers seemingly unable to allow a mechanic to be recognised where astronomy and mathematics should (in their eyes) have been the way of navigation. The lunar distance method - with sextant, tables of figures and hours of calculations and then adjustments to be made was being put forward by the astronomers as the only reliable way. There were others of course, the mystical powder of sympathy being the most quacky of them (in essence, a powder of secret origin that can heal a wound at a distance, but causes some pain in doing so - the theory proposed an injured dog would be taken aboard a ship and at predetermined times the powder would be administered to the bandages in the home port; on the ship the dog would howl, and the local time could be compared to the home port time, and calculations made to measure the longitude. (This method didn't proceed to testing)).

Overseeing the longitude problem, and able to payout the prize money of twenty thousand pounds, was the (British) Board of Longitude, made up of scientists (astronomers and mathematicians featuring heavily), naval officers and government officials. They continued to adjust the rules and the burden of proof to make it ever harder to claim the prize.

So this is the story of John Harrison, self taught clock maker and his life long development of his chronometers, that became known as the Harrison 1 (H-1 for short) in 1737, the H-2 in 1741, the H-3 in 1759, the H-4 in 1760 and the H-5 in 1770.

A good short book, sadly lacking any photographs other than the one inside the cover. I see from other reviews that a newer edition does provide the photographs, which would be a great addition. Great effort to make the very complex relatively simple.

4 stars