Ganpyeongui

This ganpyeongui, held by the Seoul Museum of History, is known as a scientific artefact used to observe time and the calendar of the heavenly bodies, and is the first such example ever found in Korea. The ganpyeongui is said to have first been made in 1680, the nineteenth year of the Kangxi reign, by Western missionaries who had come to China. In Korea, the Silhak scholar Damheon Hong Dae-yong (1731–1783), active in the reign of King Yeongjo, is recorded to have made an instrument called a "cheukgwan" between 1752 and 1762, after returning from a visit to China, and installed it inside Nongsugak, a kind of private observatory he had built; although the physical object does not survive today, this is said to have been Korea's first ganpyeongui. Unlike a "pyeongui" (planar instrument), which refers to spherical instruments such as a globe or an armillary sphere that project the heavens onto a sphere, the term properly refers to an instrument that projects the heavens onto a flat surface; the name "ganpyeongui", meaning a simplified pyeongui, was given because it further simplified such planar instruments. This ganpyeongui is a disc-shaped brass plate, on the front and back of which are marked the constellations, the twenty-four solar terms, the five night watches and a yearly calendar. The front consists of two plates. The lower one is the celestial plate, engraved with the constellations of the northern hemisphere and those of the southern hemisphere down to a declination of about 52°, together with the celestial equator and the ecliptic; placed above it is the terrestrial plate, marked with the horizon and the meridian line, part of which is cut out in a circular shape so that the two plates can be rotated together to identify the constellations. On the back, over a disc marked with the time, the twenty-four solar terms and a calendar dial, sits a smaller disc 5.6 cm in diameter engraved with the twelve zodiacal branches, allowing the length of the night to be measured according to the solar term. The structure of this instrument is similar to the Chinese ganpyeongui made in 1680, and the back in particular is identical; on the front, however, there are differences in the constellations marked at the centre of the celestial plate. In this ganpyeongui, the declination of the fixed stars due south on the horizon is shown as about 52°, which is the range within which stars culminating over Hanyang could be observed, indicating that the instrument was made domestically. This instrument is the first ganpyeongui relic ever discovered in Korea, and, being finely made, it is of great value for the history of astronomy and science.

AI Translation

Where it is

Region

Jongno-gu, Seoul

Designation

Provincial Tangible Heritage · 시도유형문화유산