First Reveal of 'Ilyeongwon-gu', a Portable Sundial Resembling a Globe

Rare Artifact Unknown to Academia Purchased at US Auction
Two Interlocking Hemispheres Measure Time Anywhere

The first spherical portable sundial confirmed in Korea is unveiled. It is the 'Ilyeongwon-gu (日影圓球)', purchased by the Cultural Heritage Administration and the Overseas Korean Cultural Heritage Foundation at an auction in the United States last March. It will be revealed on the 19th through the special exhibition on repatriated cultural assets, "The Journey of Cultural Heritage Outside the Country," held at the National Palace Museum of Korea.

Standing 23.8 cm tall with a sphere diameter of 11.2 cm, the Ilyeongwon-gu is a rare artifact previously unknown to academia. The common sundial, called 'Angbuilgu (仰釜日晷)', has a hemispherical shape. It features a fixed shadow pointer (yeongchim, 影針) that indicates the time by the sun’s shadow. It can measure time only in one specific region. The Ilyeongwon-gu, however, is a spherical globe shape. Two hemispheres are interlocked, allowing time measurement from any location.

According to experts, the measurement method follows the sequence of ▲ leveling horizontally ▲ measuring direction ▲ adjusting latitude ▲ measuring time. One hemisphere is inscribed with the twelve Earthly Branches and ninety-six vertical lines indicating time. This reflects the late Joseon period timekeeping system, which divided a day into 12 hours and 96 segments. Below the noon mark is a round hole (time indication window). By moving the other hemisphere according to the sun’s movement, the time is displayed. A Cultural Heritage Administration official explained, "The Jagyeokru and Honcheonui also had time indication devices using the twelve Earthly Branches," adding, "It is presumed to be an artifact newly devised to inherit Joseon’s scientific technology while enabling use in other countries."

The Ilyeongwon-gu was kept by the family of a U.S. military officer stationed in Japan before passing into the hands of a private collector. It was auctioned last March and successfully repatriated. The Cultural Heritage Administration confirmed the production period and maker before acquiring it. One hemisphere bears an inscription stating, "Newly made in the early July of the 499th year of the Great Joseon Kingdom, the Gyeongin year," along with the name "Sangjik-hyeon In." This means it was made in July 1890 by a person named Sangjik-hyeon In. According to the Annals of King Gojong and the Diaries of the Royal Secretariat, Sangjik-hyeon was a military officer appointed to positions such as Commander of the Royal Guards and Special Military Officer, responsible for protecting the king and defending the palace and capital.