Song I-yeong

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 (전상운, 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 (오상학) have separately argued that the object dates from much later.^[6]