 We have many different kinds of clocks including wall clocks, alarming clocks and cuckoo clocks today. When did these kinds of automated time telling devices start?
We now examine JAGYEOKRU.
It is a MULSIGYE with an automatic time teller, so it tells time by hitting the bell automatically, drum or gong without any other external assistance. It was invented by JANGYEONGSIL, ICHEON, and KIMJO in 1434 being given Se-jong's order.
/until its invention, the time needed to be reported by regularly watching a clock. So when the person in charge of reporting the time fell asleep missing the time, he got fired. There are records about such an episode in JOSEONWANGJOSILLOK. The invention of automatic time telling MULSIGYE was the long dream of clock manufacturers and Kings also put a great deal of efforts to invent this device in order to show their technological powers and imperial authority to people. JAGYEOKRU was placed on 'borookak' located in the south of GYEONGBOKGUNG. As mentioned earlier, JANGYEONGSIL was promoted from a slave to a inventor working for the palace with the kindness of Se-jong King. He had an opportunity to study foreign technologies in China and made remarkable contributions to Korean science history, and one of his inventions was JAGYEOKRU. | |  Sejongsilrok offers a description of the structure of JAGYEOKRU as below.
It consists of four water tanks called 'PASUHO' and two sets of SUSUHO, 12 lattices, a power transfer equipment and time telling equipment. The water coming down from Pasooho enters Soosooho and floats the lattices. When they float, the buoyancy makes beads fall and the time telling wooden figurine move to higher than PASUHO. Also, there is a flat wheel lower than the figurine and there are twelve animal god figurines (each is responsible for one of the twelve time divisions) arranged around the wheel. The god figurines can move up and down along the wires.
JAGYEOKRU was used as the standard clock in JOSEON Dynasty , located at Borookak in the Kyungbok palace. Later, two more JAGYEOKRU were installed in Borookak at the CHANGGYEONGGUNG and CHANGDEOKGUNG during the Shungjong King regime. At present, one is preserved in the Duksoo palace and desgnated as a national treasure known as one of the greatest water clocks in the world.
JAGYEOKRU at the CHANGDUKGUNG had the same structure as the one Jang,young-sil made, according to Choongjongsilrok. It was used for telling the time, and also improved so as to announce to start and finish night passing prohibition at 10pm and 4am respectively by itself. It consists of three PASUHO and two Soosootong. The big PASU is made of bronze and the other two are made of pottery. Two Soosootog are made of bronze, to which the water comes down from the Pasooho. They are also engraved with two dragons and the names of the chief manufacturers and other participants. JAGYEOKRU is also printed on the 1000 won Korean bill. |
