The true story of a lone genius who solved the greatest scientific problem of his time

 

Anyone alive in the eighteenth century would have known the "the longitude problem" was the thorniest scientific dilemma of the day - and had been for centuries. Lacking the ability to measure their longitude, sailors throughout the great ages of exploration had been literally lost at sea as soon as they lost sight of land. Thousands of lives, and the increasing fortunes of nations, hung on a resolution.

The quest for a solution had occupied scientists and their patrons for the better part of two centuries when, in 1714, Parliament upped the ante by offering a king's ransom (£20,000) to anyone whose method or device proved successful. Countless quacks weighed in with preposterous suggestions. The scientific establishment throughout Europe - from Galileo to Sir Isaac Newton - had mapped the heavens in both hemispheres in its certain pursuit of a celestial answer. In stark contrast, one man, John Harrison, dared to imagine a mechanical solution - a clock that would keep precise time at sea, something no clock had ever been able to do on land.

"Longitude" is the dramatic human story of an epic scientific quest, and of Harrison's forty-year obsession with building his perfect timekeeper, known today as the chronometer. Full of heroism and chicanery, brilliance and the absurd, it is also a fascinating brief history of astronomy, navigation, and clockmaking.

 

Longitude is the measurement east or west of the prime meridian that runs through Greenwich, England. Half of the world, the Eastern Hemisphere, is measured in degrees east of the prime meridian. The other half, the Western Hemisphere, in degrees west of the prime meridian. Degrees of longitude are divided into 60 minutes. Each minute of longitude can be further divided into 60 seconds. For example, the longitude of Paris, France, is 2° 29' E (2 degrees, 29 minutes east). The longitude for Brasilia, Brazil, is 47° 55' W (47 degrees, 55 minutes west). A degree of longitude is about 111 kilometers (69 miles) at its widest. The widest areas of longitude are near the Equator, where Earth bulges out. Because of Earth's curvature, the actual distance of a degrees, minutes, and seconds of longitude depends on its distance from the Equator. The greater the distance, the shorter the length between meridians. All meridians meet at the North and South Poles.

 

I picked up this beautifully turned-out hardcover edition of Dava Sobel's book at my favourite op-shop for a mere gold coin. I already have one copy, and this one is not for myself but for one of the lifeguards at the Aquatic Centre who with her partner will go a-sailing again on their yacht presently moored at Yorkey's Knob just north of Cairns.

Of course, they have a Global Positioning Sydney (GPS) on board which gives them their position on the ocean within metres at the press of a button. For all I know, they may not even know the meaning of latitude and longitude but they will after they've read "Longitude".

 

 

And so will you after you've read this book online at www.archive.org.

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