The Compass Came from Many Directions ; This Short History Spins through Many Inventors' Contributions

Article excerpt

It's easy to take familiar things for granted and lose history in the process. That's happened with the magnetic compass. It has become a quaint novelty in the era of Global Positioning Satellites and inertial navigation - useful for hiking, fun to wear on a wrist- watch band to show which way city streets run. But when it acquired its modern form some eight centuries ago, it helped change the commerce and geopolitics of the Western world.

This technological wonder did not spring from an inspired inventor's eureka moment. It was the product of humanity's collective genius applied incrementally over thousands of years.

As Amir Aczel documents in this interesting little book, even Flavio Gioia of Amalfi - who reputedly made the final crucial refinements - probably didn't exist. So much for romantic notions of the hero inventor. But we can indeed marvel at the ability of human intelligence to see useful potential in natural phenomena and to realize that potential in practical ways.

We now call that ability engineering. Taken in this sense, Aczel's account of the development of the magnetic compass is an exploration into the roots of that useful profession.

The beginnings of compass development predate history. Lodestone, a naturally magnetic mineral, can magnetize iron. Mount a magnetized iron needle on wood. Float the assembly on water or suspend it on a pivot. It then will align itself with earth's magnetic field, taking up a more or less north-south direction. All relevant legends and factual accounts that have come down to us take that knowledge for granted.

The Chinese have the earliest history of the compass. Their ancestors used magnetized needles to find south - a preferred direction for divination rituals and other mystical purposes. …