Astronomical Instruments with Two Scales Drawn on Their Common Circumference of Rings in the Joseon Dynasty
This study examines the scale unique instruments used for astronomical observation during the Joseon dynasty. The Small Simplified Armillary Sphere (小簡儀, So-ganui) and the Sun-and-Stars Time-Determining Instrument (日星定時儀, Ilseong-jeongsi-ui) are minimized astronomical instruments, which can be cha...
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| Format: | Article |
| Language: | English |
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The Korean Space Science Society
2017-03-01
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| Series: | Journal of Astronomy and Space Sciences |
| Subjects: | |
| Online Access: | http://ocean.kisti.re.kr/downfile/volume/kosss/OJOOBS/2017/v34n1/OJOOBS_2017_v34n1_45.pdf |
| _version_ | 1797368330774904832 |
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| author | Byeong-Hee Mihn Goeun Choi Yong Sam Lee |
| author_facet | Byeong-Hee Mihn Goeun Choi Yong Sam Lee |
| author_sort | Byeong-Hee Mihn |
| collection | DOAJ |
| description | This study examines the scale unique instruments used for astronomical observation during the Joseon dynasty. The
Small Simplified Armillary Sphere (小簡儀, So-ganui) and the Sun-and-Stars Time-Determining Instrument (日星定時儀,
Ilseong-jeongsi-ui) are minimized astronomical instruments, which can be characterized, respectively, as an observational
instrument and a clock, and were influenced by the Simplified Armilla (簡儀, Jianyi) of the Yuan dynasty. These two
instruments were equipped with several rings, and the rings of one were similar both in size and in scale to those of the
other. Using the classic method of drawing the scale on the circumference of a ring, we analyze the scales of the Small
Simplified Armillary Sphere and the Sun-and-Stars Time-Determining Instrument. Like the scale feature of the Simplified
Armilla, we find that these two instruments selected the specific circumference which can be drawn by two kinds of scales.
If Joseon’s astronomical instruments is applied by the dual scale drawing on one circumference, we suggest that 3.14 was
used as the ratio of the circumference of circle, not 3 like China, when the ring’s size was calculated in that time. From the
size of Hundred-interval disk of the extant Simplified Sundial in Korea, we make a conclusion that the three rings’ diameter
of the Sun-and-Stars Time-Determining Instrument described in the Sejiong Sillok (世宗實錄, Veritable Records of the King
Sejong) refers to that of the middle circle of every ring, not the outer circle. As analyzing the degree of 28 lunar lodges (lunar
mansions) in the equator written by Chiljeongsan-naepyeon (七政算內篇, the Inner Volume of Calculation of the Motions
of the Seven Celestial Determinants), we also obtain the result that the scale of the Celestial-circumference-degree in the
Small Simplified Armillary Sphere was made with a scale error about 0.1 du in root mean square (RMS). |
| first_indexed | 2024-03-08T17:30:51Z |
| format | Article |
| id | doaj.art-9557ae261c29496ca9d62d7b01db6e23 |
| institution | Directory Open Access Journal |
| issn | 2093-5587 2093-1409 |
| language | English |
| last_indexed | 2024-03-08T17:30:51Z |
| publishDate | 2017-03-01 |
| publisher | The Korean Space Science Society |
| record_format | Article |
| series | Journal of Astronomy and Space Sciences |
| spelling | doaj.art-9557ae261c29496ca9d62d7b01db6e232024-01-02T15:43:26ZengThe Korean Space Science SocietyJournal of Astronomy and Space Sciences2093-55872093-14092017-03-01341455410.5140/JASS.2017.34.1.45Astronomical Instruments with Two Scales Drawn on Their Common Circumference of Rings in the Joseon DynastyByeong-Hee Mihn0Goeun Choi1Yong Sam Lee2Korea Astronomy and Space Science Institute, Daejeon 34055, KoreaKorea Astronomy and Space Science Institute, Daejeon 34055, KoreaDepartment of Astronomy and Space Science, Chungbuk National University, Cheongju 28644, KoreaThis study examines the scale unique instruments used for astronomical observation during the Joseon dynasty. The Small Simplified Armillary Sphere (小簡儀, So-ganui) and the Sun-and-Stars Time-Determining Instrument (日星定時儀, Ilseong-jeongsi-ui) are minimized astronomical instruments, which can be characterized, respectively, as an observational instrument and a clock, and were influenced by the Simplified Armilla (簡儀, Jianyi) of the Yuan dynasty. These two instruments were equipped with several rings, and the rings of one were similar both in size and in scale to those of the other. Using the classic method of drawing the scale on the circumference of a ring, we analyze the scales of the Small Simplified Armillary Sphere and the Sun-and-Stars Time-Determining Instrument. Like the scale feature of the Simplified Armilla, we find that these two instruments selected the specific circumference which can be drawn by two kinds of scales. If Joseon’s astronomical instruments is applied by the dual scale drawing on one circumference, we suggest that 3.14 was used as the ratio of the circumference of circle, not 3 like China, when the ring’s size was calculated in that time. From the size of Hundred-interval disk of the extant Simplified Sundial in Korea, we make a conclusion that the three rings’ diameter of the Sun-and-Stars Time-Determining Instrument described in the Sejiong Sillok (世宗實錄, Veritable Records of the King Sejong) refers to that of the middle circle of every ring, not the outer circle. As analyzing the degree of 28 lunar lodges (lunar mansions) in the equator written by Chiljeongsan-naepyeon (七政算內篇, the Inner Volume of Calculation of the Motions of the Seven Celestial Determinants), we also obtain the result that the scale of the Celestial-circumference-degree in the Small Simplified Armillary Sphere was made with a scale error about 0.1 du in root mean square (RMS).http://ocean.kisti.re.kr/downfile/volume/kosss/OJOOBS/2017/v34n1/OJOOBS_2017_v34n1_45.pdfastronomical instrumentring’s scaleratio of the circumference of a circleCelestial-circumference-degree ringHundred-interval ringJoseon |
| spellingShingle | Byeong-Hee Mihn Goeun Choi Yong Sam Lee Astronomical Instruments with Two Scales Drawn on Their Common Circumference of Rings in the Joseon Dynasty Journal of Astronomy and Space Sciences astronomical instrument ring’s scale ratio of the circumference of a circle Celestial-circumference-degree ring Hundred-interval ring Joseon |
| title | Astronomical Instruments with Two Scales Drawn on Their Common Circumference of Rings in the Joseon Dynasty |
| title_full | Astronomical Instruments with Two Scales Drawn on Their Common Circumference of Rings in the Joseon Dynasty |
| title_fullStr | Astronomical Instruments with Two Scales Drawn on Their Common Circumference of Rings in the Joseon Dynasty |
| title_full_unstemmed | Astronomical Instruments with Two Scales Drawn on Their Common Circumference of Rings in the Joseon Dynasty |
| title_short | Astronomical Instruments with Two Scales Drawn on Their Common Circumference of Rings in the Joseon Dynasty |
| title_sort | astronomical instruments with two scales drawn on their common circumference of rings in the joseon dynasty |
| topic | astronomical instrument ring’s scale ratio of the circumference of a circle Celestial-circumference-degree ring Hundred-interval ring Joseon |
| url | http://ocean.kisti.re.kr/downfile/volume/kosss/OJOOBS/2017/v34n1/OJOOBS_2017_v34n1_45.pdf |
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