Jagyeongnu was an advanced clepsydra system that told people the hour by varying levels of water. Made in 1434 (the 16th year of King Sejong’s reign) by Jang Yeong-sil upon orders from the king, it was used to keep the standard of time in the Joseon Dynasty. It has been lost through the ages. In 1536 (the 31st year of King Jungjong’s reign), it was remade, with three water bowls (pasuho), and two cylindrical water containers (susuho), surviving to this day.
These components were treated for conservation at the Cultural Heritage Conservation Science Center from June 2018 to March 2020. The treatment clearly exposed the hard-to-read inscription on the upper part of the left susuho container. The vertical inscription carved in relief at the time of manufacture includes the names and positions of 12 people involved in the manufacture of Jagyeongnu. Four of the 12 could not previously be identified due to the wearing-down of some of the characters, but this mystery has now been revealed.
This conservation treatment is significant for it successfully preserved the Jagyeongnu components and reveals the missing information about people involved in its manufacture, manufacturing techniques and more.