Metal artifacts from the Joseon Dynasty have been found in an excavation by the Sudo Research Institute of Cultural Heritage in Insa-dong, in Seoul's Jongno-gu District.
The most noteworthy find are 16-hundred metal movable types -- a thousand in Chinese and the rest in Hangeul -- the Korean alphabet.
Before this discovery, the oldest collection of Hangeul metal movable types, made in 1455, only contained 30 pieces.
"An important fact is that a great number of Hangeul metal movable types that reflect the donggukjeongun style orthography, which was only used in the 15th century when Hangeul was invented, have been excavated."
Given that lots of types in various sizes have been found, and the research hasn't been done yet, experts are saying there is high chance that the types could be even older than those made in 1455.
The Chinese metal types discovered in the excavation are believed to be from 1434 as they match the printing found in a book from that year.
Also discovered was a jujeon, a key part of a water clock.
"A jujeon is a device that is needed for the time signal device to work. It is very significant as this is the first time the artifact has been found."
The expert says the jujeon would be a part of one of the two automatic water clocks of the early Joseon dynasty; Jagyeokru and Okru.
The Ilseongjeongsiui , an astronomical clock which used Sun during the day and constellations at night has also been found.
It is said four of these were made during the era of King Sejong.
"The water clock was a standard clock and to correct its error, the astronomical clock was used. It is so sophisticated that one-fourth of a degree is measured and can reflect the extra day in a leap year."
Through this excavation, experts are hoping to understand the science and technology of the early Joseon dynasty more deeply.
Kim Bo-kyoung, Arirang News.