Estimation of the Latitude, the Gnomon’s Length and Position About Sinbeop-Jipyeong-Ilgu in the Late of Joseon Dynasty

다국어 초록 (Multilingual Abstract)

In this study, the characteristics of a horizontal sundial from the Joseon Dynasty were investigated. Korea’s Treasure No.
840 (T840) is a Western-style horizontal sundial where hour-lines and solar-term-lines are engraved. The inscription of this sundial indicates that the latitude (altitude of the north celestial pole) is 37° 39´, but the gnomon is lost. In the present study, the latitude of the sundial and the length of the gnomon were estimated based only on the hour-lines and solar-termlines of the horizontal sundial. When statistically calculated from the convergent point obtained by extending the hourlines, the latitude of this sundial was 37° 15´ ± 26´, which showed a 24´ difference from the record of the inscription. When it was also assumed that a convergent point is changeable, the estimation of the sundial’s latitude was found to be sensitive to the variation of this point. This study found that T840 used a vertical gnomon, that is, perpendicular to the horizontal plane, rather than an inclined triangular gnomon, and a horn-shaped mark like a vertical gnomon is cut on its surface. The length of the gnomon engraved on the artifact was 43.1 mm, and in the present study was statistically calculated as 43.7 ± 0.7 mm. In addition, the position of the gnomon according to the original inscription and our calculation showed an error of 0.3 mm.

참고문헌 (Reference)

1 이근호, "광삼각법 측정 원리를 이용한 금석문 가독성 향상 방법" 한국IT서비스학회 11 : 103-111, 2012

2 최원호, "각자된 글자의 형태적 시각화를 이용한 금석문 판독방법" 한국콘텐츠학회 17 (17): 740-749, 2017

3 韓永浩, "朝鮮의 新法日晷와 視學의 자취" 대동문화연구원 (47) : 361-396, 2004

4 Lee ES, "the horizontal sundial made of marble and crown prince Sohyeon" 6 : 124-126, 1984

5 Yu KL, "The first Korea – Japan history of science seminar : on the introduction of Chinese calendars during the Joseon Dynasty" 4 : 98-101, 1982

6 Chen MD, "The Whole History of Chinese Astronomical Timekeeping Instrument (Ancient Volume)" Anhui Education Publishing 361-366, 2011

7 Lee ES, "The Western-style horizontal sundial made of marble and crown prince Sohyeon" 48 : 85-124, 1985

8 Rohr RRJ, "Sundial: History, Theory, and Practice" Dover publications 49-52, 1996

9 이기원, "Study on the Period of the Use of Datong-li in Korea" 한국우주과학회 27 (27): 55-68, 2010

10 Song SY, "Our science cultural properties" Korea Science and Technology Promotion Foundation 49-52, 1994

11 Yu KL, "Korean astronomy in the Joseon late period" 5 : 126-131, 1983

12 Lee ES, "History and fundamental of sundial" 33 : 81-156, 1982

13 Lee EH, "Gukjo-Yeoksang-Go translated in Korean" Somyeong Press 216-230, 2004

14 이용삼, "Family of the Sun-and-Stars Time-Determining Instruments (Ilseong-jeongsi-ui) Invented During the Joseon Dynasty" 한국우주과학회 33 (33): 237-246, 2016

15 김상혁, "Analysis on the Hour-lines of Yangcheon-cheok" 한국우주과학회 34 (34): 55-65, 2017

16 이용삼, "A Study for the Restoration of the Sundials in King Sejong Era" 한국우주과학회 28 (28): 143-153, 2011

17 Sang-Hyuk Kim, "A STUDY ON THE STRUCTURE INNOVATION OF ASTRONOMICAL INSTRUMENTS IN JOSEON DYNASTY - FOCUSING ON THE SOGANUI, THE ILSEONGJEONGSIUI, AND THE JEOKDOGYEONGWIUI -" The Korean Astronomical Society 27 (27): 61-69, 2012