Compass

A compass is a navigation instrument that shows direction using a magnetized needle that aligns itself with the Earth's magnetic field, pointing toward magnetic north. The device originated in China during the Han dynasty as a divination tool and was adapted for maritime navigation by the Song dynasty in the eleventh century, later reaching Western Europe by around 1190 and the Islamic world in the thirteenth century. Counted among the Four Great Inventions of ancient China, the compass made long distance sea voyages far safer and remains a basic tool of navigation today.