††††A compass is a device used to pinpoint magnetic north. Inside the compass, a magnetic needle pivots freely on a point.
The Chinese experimented with the principle of the compass from around 1000 BC. Louen Heng described a compass around 80 AD which was basically a spoon made of iron ore placed on a polished surface, which pointed north-south. However, it was about a thousand years later that magnetic needles were placed in water and used for navigation.
When the compass is properly adjusted, the north-seeking pole of the needle will point to the magnetic north, from which true north can be found. A gyrocompass, found on ships and aircraft, takes the Earth's rotation into account. The first radio compass system was built by an American, Frederick Kolster, in 1913.
