Sejong Creates Korean Water Clock

1444

King Sejong's brilliant court engineer Jang Yeong-sil built the Jagyeongnu, an automated water clock that struck the hours, displayed visual time markers, and operated entirely through hydraulic mechanisms without any human intervention. It was the most sophisticated automated timekeeper in the world outside of Chinese imperial workshops, and a striking testament to Joseon Korea's extraordinary scientific ambitions under Sejong's restless and methodical patronage of practical knowledge.