Kubilai dispatches Guo Shoujing on survey

1280

The Yuan emperor sent his chief astronomer across the empire to build twenty-seven observatories and measure latitudes from Siberia to the South China Sea. The resulting data would anchor the Shoushi calendar and demonstrate Kublai's interest in administrative precision. The survey's scope, spanning nearly fifty degrees of latitude, surpassed any comparable astronomical project in Europe or the Islamic world at the time.