The National Palace Museum of Korea, affiliated to the Cultural Heritage Administration, has recreated the Jagyeongnu, a self-striking water clock made on the order of King Sejong during the Joseon Dynasty (1392-1910).

The Jagyeongnu was a standard timekeeper composed of a water clock and time-announcing devices and is one of the greatest inventions in the Korean science history. In the 16^th year of his reign (1434), King Sejong had Jang Yeong-sil lead a project to invent astronomical instruments and clocks.

An account in the Joseon wangjo silok, or Annals of the Joseon Dynasty, saying “Concerned about the responsible officials who are subject to severe punishment if they fail to announce time precisely, (King Sejong) ordered Jang Yeong-sil to make wooden dolls to replace the officials and announce the hour, relieving their burdens,” implies that the water clock reflects the ruling idea of the time: “respect the heavens and love the people.”

After initiated by the Cultural Heritage Administration in 1997, the Jagyeongnu restoration project was implemented in earnest for a year from December 2004, in cooperation with the Industry-Academic Cooperation Team of Kunkuk University led by Professor Nam Mun-hyeon.

 

The restoration was based on the only extant water clock in Deoksugung Palace, which was made in the 31^st year of King Jungjong (1536) and designated as National Treasure No. 229, involving the measurement of the surviving clepsydra, thorough researches on ancient documents, three seminars on its restoration, and the subsequent analyses.

The restored water clock consists of the water-supply and water-receiving vessels and the devices announcing time by striking a bell during the day and a gong or drum during the night.

The most significant meaning of the restoration lies in the fact that the water clock including the automatic time announcing devices has been restored to its original form and a prototype for clepsydra realized.

The clepsydra in Deoksugung Palace has a two-tier vessel structure with a larger pouring vessel on the top and two smaller ones at the bottom, a mistake made by Japanese scholars in the early 20^th century when they relocated it from Gyeongbokgung to Changgyeonggung. In contrast, the newly-restored water clock has a three-tier structure with a pouring vessel on each tier.

The restored clepsydra has been on public display at the National Palace Museum of Korea since November 28th.