Jang Yeong-sil

A groundbreaking Korean inventor and engineer during the Joseon Dynasty, whose innovations revolutionized science and technology.

Jang Yeong-sil (c. 1390–1450) was a Joseon Dynasty scientist whose inventions laid the foundation for Korea's scientific advancement. Born into a low-ranking family, his talent earned him royal recognition under King Sejong the Great. His most notable creation, the Cheugugi, was the world's first standardized rain gauge, enabling systematic meteorological data collection across Korea.

He also designed the Honcheonsigye, an astronomical clock combining celestial mechanics with a water-powered escapement. This device not only told time but predicted solar and lunar eclipses. His armillary sphere improved celestial navigation, critical for agriculture and calendar systems.

Despite political backlash due to his social status, Jang's work exemplified innovation against societal constraints. His legacy is celebrated at the Korean Heritage Museum, showcasing models of his inventions.