<P> The compass was invented more than 2,000 years ago . The first compasses were made of lodestone, a naturally magnetized ore of iron, in Han dynasty China between 300 and 200 BC . The compass was later used for navigation by the Song Dynasty . Later compasses were made of iron needles, magnetized by striking them with a lodestone . Dry compasses begin appearing around 1300 in Medieval Europe and the Islamic world . This was replaced in the early 20th century by the liquid - filled magnetic compass . </P> <P> Prior to the introduction of the compass, geographical position and direction at sea were primarily determined by the sighting of landmarks, supplemented with the observation of the position of celestial bodies . On cloudy days, the Vikings may have used cordierite or some other birefringent crystal to determine the sun's direction and elevation from the polarization of daylight; their astronomical knowledge was sufficient to let them use this information to determine their proper heading . The invention of the compass enabled the determination of heading when the sky was overcast or foggy, and when landmarks were not in sight . This enabled mariners to navigate safely far from land, increasing sea trade, and contributing to the Age of Discovery . </P> <P> The compass was invented in China during the Han Dynasty between the 2nd century BC and 1st century AD, where it was called the "south - governor" (sīnán 司南). The magnetic compass was not, at first, used for navigation, but for geomancy and fortune - telling by the Chinese . The earliest Chinese magnetic compasses were possibly used to order and harmonize buildings in accordance with the geomantic principles of feng shui . These early compasses were made with lodestone, a form of the mineral magnetite that is a naturally occurring magnet and aligns itself with the Earth's magnetic field . People in ancient China discovered that if a lodestone was suspended so it could turn freely, it would always point toward the magnetic poles . Early compasses were used to choose areas suitable for building houses, growing crops, and to search for rare gems . Compasses were later adapted for navigation during the Song Dynasty in the 11th century . </P>

Who invented the compass in the middle ages