Skip to main content
PBS logo
 
 

Book Review of Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time

bup avatar reviewed on + 166 more book reviews


A friend of mine told me about this book - I never knew that longitude was beyond navigators' collective grasp as late as it was, or that it was monumentally harder to determine than latitude. It's fascinating.

Besides the central story of how a self-taught clock-maker, John Harrison, spent his lifetime perfecting a clock accurate and hardy enough to remember Greenwich time on long voyages through various temperatures, the rolling of the sea, and different humidities and barometric pressures, the book explains other ways to determine longitude using the skies (if you can get an accurate reading and the data exists to predict where the moon should be with respect to the sun for 3 hour periods for the length of your voyage, and it's not cloudy).

Navigators also were able to determine longitude, theoretically, by observing the moons of Jupiter, whose orbits were easier to predict, but were much harder to see on a rocking boat.

So Galileo, who discovered the Jovian moons, gets a couple of cool points. In fact, the Jupiter moon method (and *every* method is about figuring out what time it is in Greenwich right now - if we know when a person in Greenwich would see a moon of Jupiter go behind the planet, we know how far ahead or behind Greenwich we are), while so impractical on ships that navigators on ships had to wait for a good clock, although that took 150 years after the invention of Galileo's method), was great on land, and it's the cause of maps suddenly looking accurate and not grossly distorted east/west-wise just after 1600.

Isaac Newton also makes a special appearance (you know, predicting *our* moon's orbit well).

Oh yeah - you also have to see the wonderful clocks this guy made (there are color plates in some editions, or google "John Harrison H1")- they're steampunk perfection.

Anyway, I hope I've conveyed the enthusiasm I feel for this short, but just-right-length, science history.