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[TREASURE] Celestial Globe and Armillary Clock

Published: 03 Mar. 2025, 13:22

YIM SEUNG-HYE
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Celestial Globe and Armillary Clock [KOREA HERITAGE SERVICE]

Name: Celestial Globe and Armillary Clock

Period: Joseon Dynasty (1392-1910)

Location: Seongbuk District, central Seoul

Status: National Treasure

This is an astronomical clock made by Song I-yeong, who was an astronomy professor in 1669 during the reign of King Hyeonjong of Joseon.

The diameter of the clock is 40 centimeters (15.74 inches), and the circumference of the terrestrial globe positioned in the center is about 8.9 centimeters. This clock works by the movement of two weights. One rotates a wheel and other toothed wheels to show the time. The other weight rings the bell. Several metal beads roll down the inside of the eaves and hit a hammer that rings the bell, thereby making it possible for the bell to ring. The metal beads are then picked up by large, flat wooden spoons, attached to the spokes of the rotating wheels, allowing the function to be repeated. In other words, by connecting the clock device, in which various saw-toothed wheels move thanks to the two weights, and the celestial globe, which has installed in it a terrestrial globe, the time and the location of the universe can be known.

This celestial globe clock has been highly valued as an astronomical clock in the history of the world's timekeeping technology. It inspired a new astronomical clock model utilizing a spinning wheel, which was a traditional feature of clocks during the Joseon Dynasty beginning with King Sejong, and the principles of the alarm clock, a Western-type machine clock.

It is known to have been installed at Hongmungwan and used for measuring time and for educational purposes regarding astronomy. It is the only relic remaining among the astronomical clocks made during the Joseon Dynasty (1392-1910).