The earliest reference to a magnetic device used for navigation is in a Song Dynasty book dated to 1040-1044, where there is a description of an iron "south-pointing fish" floating in a bowl of water, aligning itself to the south.
The earliest reference to a magnetic device used as a "direction finder" is in a Song Dynasty book dated to 1040-1044. Here there is a description of an iron "south-pointing fish" floating in a bowl of water, aligning itself to the south.