Era: Han Dynasty (~200 BC) - Spoon Song Dynasty (~1040 AD) - Needle Song Maritime (~1117 AD) - Ship Ming Dynasty (~1400 AD) - Dry Declination: Disturbance:

The Chinese discovered magnetism ~400 BC. The earliest compass was a south-pointing spoon (si nan) made of lodestone. By the Song Dynasty, magnetized needles floated on water. The compass revolutionized maritime navigation worldwide.