High Middle Ages · East Asia · Technology

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Song navigators adopt the magnetic compass

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Chinese mariners began routinely using magnetized iron needles floating in bowls of water to determine direction at open sea, a revolutionary technology described in Zhu Yu's contemporary Pingzhou Table Talks. The maritime compass transformed tentative coastal navigation into confident open-ocean voyaging, enabling Song merchant fleets to reach Java, the Malabar coast of India, and the ports of the Persian Gulf with unprecedented speed and reliability.