Longitude -- a review



In this day and age with our GPS and our smart phones and our Google Maps, it's hard to imagine a time when the world was being explored and travelled by people who literally didn't know where they were and had no dependable way to find out.

Longitude is well-written and follows a straight-forward path from need to discovery and implementation. Why longitude? Because in the middle of the ocean without knowing what your longitude is, you were lost. And being lost most likely meant death. You could misjudge the nearness of land and like Admiral Sir Clowdisley Shovell who, on a foggy night in October of 1707, ran his flag ship and three more of his five warships aground on the Scilly Isles, "dooming almost two thousand" of his troops. Or too often a captain misjudged the distance and the direction of land and "missed his mark -- searching in vain for the island where he had hoped to find fresh water, or even the continent."

They knew about longitude, but could not track it at sea. Latitude could be deduced "by the length of the day or by the height of the sun or known guide stars above the horizon." Longitude does not lend itself to these easily recognized and readily available markers. Scientists and mathematicians devised methods to tell where a ship was in relation to its longitude. Their methods like them reflected deep thinking and cumbersome equations, not easily implemented by the general sailing public. Nor were their equations all that dependable when a navigator was able to follow the instructions.

What they needed was a reliable clock. And this is the story of the self-educated English common man who developed just such a clock. For want of just such an instrument, countless lives and fortunes were lost.

The story of John Harrison's development of a clock that would keep time dependably during the rough and tumble of a sea voyage is a cautionary tale for those societies that  circumscribe their people's talents based on class. Or, though not applied in this clockmaker's case, based on race or religion or gender or sexual orientation or any other arbitrary measure of a human's value.