| Song I-yeong | |
| Birth Date: | 1619 |
| Death Date: | 1692 or before 1687 |
| Father: | Song Jeong-su (宋庭修<ref name=kim2018/>) |
| Mother: | Lady Gim (金氏<ref name=kim2018/>) |
| Spouse: | Lady Jo (趙氏<ref name=kim2018/>) |
| Children: | Song Gyeong-sim (宋慶心<ref name=kim2018/>) Song Gyeong-yun (宋慶胤<ref name=kim2018/>) Song Gyeong-yeom (宋慶濂<ref name=kim2018/>) |
Song I-yeong ([1] 1619–?) was a Korean court astronomer of the Joseon dynasty. He invented a weight-powered astronomical clock (possibly the Honcheonsigye) and contributed greatly to the implementation of the Shixian Calendar (from Qing China) in Joseon. He also made systematic observations of two comets.[2]
In 1659, during the reign of King Hyeonjong, Song I-yeong made an astronomical clock by combining an armillary sphere, long used in East Asia, with the western alarm clock. The result was a device that could both trace the movements of the sun and the moon, as well as display and announce the time.[3]
The clock was repaired in 1687–1688, after which it disappeared from historical records. In the 1930s, Kim Seong-su purchased the honcheonsigye, which is still housed at Korea University.[3] The historian of science Jeon Sang-woon (全相運), who examined the device in 1962, assumed that it was Song I-yeong's device, and the British historian of science Joseph Needham adopted this view.[4] However, Gari Ledyard[5] and O Sang-hak have separately argued that the object dates from much later.[6]