Angbu-ilgu

Angbu-ilgu

Angbuilgu (仰釜日晷)  is a sundial produced and used since 1434, the 16th year of King Sejong's reign in the Joseon Dynasty. It was designated as Korea's National Treasure No. 845 on August 9, 1985 in recognition of its scientific, historical, and artistic value .  Jang Yeong-sil , Lee Cheon , and Kim Jo participated in the early production of Angbuilgu , and since no Angbuilgu made at this time remain, those made in the 18th century were designated as treasures. The portable Angbuilgu , designated as a treasure, was made by Kang Geon in a size small enough to fit in a pocket . In addition, there are inventions by Jang Yeong-sil such as Jagyeokru, armillary sphere, sundial, water clock, and celestial train field map.

Overview [ Edit ]

It is said that he referred to 《Yuan History 》, Cheonmunji (天文志), and 「Angui (仰儀)」.  It was named Angbuilgu because it is a round cauldron the size of a concave brazier and looks up at the sun in the shape of a clock face. It looks like a concave Earth and is effective in indicating visual and seasonal lines. It was made by casting bronze as a material, and the letters and lines were inlaid with silver on a black lacquer background to make them clearly visible. In order to level the four feet, the horizontal standard device was in the shape of a cross.

Sipan drew the 24 solar terms starting from the winter solstice to the summer solstice with 13 lines of latitude, and visual lines were drawn perpendicular to them. In order to vary the length of the shadow according to latitude, the shadow needle was used by inserting it at an angle according to the North Pole point of 37 degrees and 20 minutes, which was used in Hanyang at the time.

At that time, time was expressed in 12 zodiac signs , and since the unit of time was 12, 2 hours was a bundle of time. For the illiterate people, the 12 zodiac signs were drawn and installed in front of Hyejeong Bridge and Jongmyo Shrine on November 2, 1434 ( October 2 in the lunar calendar ) , but they disappeared during the Japanese invasions of Korea and no remains of Angbuilgu remain during the reign of King Sejong.  Afterwards, it was produced in various forms until the end of the Joseon Dynasty and was widely distributed to palaces, government offices, and the homes of noblemen.

Time during the Joseon Dynasty [ Edit ]

Please refer to the twelve o'clock and twenty-four o'clock documents.

During the Joseon Dynasty, the day was divided into 12 o'clock or 24 o'clock hours, based on the actual sun. Based on the current Coordinated Universal Time, there is a difference of about 30 minutes from the standard time in Korea, which applies Korean Standard Time at 135 degrees east longitude. In other words, if the shadow in Angbu Ilgu points to the exact center of 5 o'clock, the actual time is approximately 12:30, not 12 o'clock, and this varies slightly depending on the region and season.

How to measure time [ edit ]

Time and seasons are measured by referring to horizontal and vertical lines.

• Visual line: It is a vertical line along the angle.
• Jeolgiseon: It is the horizontal line of Angbuilgu.

See also [ Edit ]

• Ilseongjeongsiui (日星定時儀): A clock that can measure the time of day and night, produced in 1437 , the 19th year of King Sejong's reign, based on Angbuilgu's technology and experience
• Youngsil Jang
• Jagyeongru
• solar time
• Portable embossing tool

External Links [ Edit ]

• National Palace Museum

Footnotes [ Edit ]

detail

1. ↑ Bu (釜) refers to a cauldron, Angbu (仰釜) refers to a cauldron that looks up to the sky, and Gu (晷) refers to a shadow, and Ilgu (日晷) refers to a sundial.
2. ↑ The name at the time of designation was ‘Angbuilgu (仰釜日晷)’.

source

1. ↑ ^{movement:Gazette of Ghana No.} 10111, 9 August 1985. Pages 5-6. Page 6. Ministry of Culture and Public Information Notice No. 645. Designated as a national treasure and treasure. Minister of Culture and Information. Checked on May 20, 2016.
2. ↑ 《Story of Korean Science》, Seoul Newspaper, 1984.
3. ↑
4. ↑ Standard time comes and goes… What about buying and selling shares? Archived December 22, 2015 - Wayback Machine , 《Seoul Newspaper》, 2005.3.24.
5. ↑ Angbuilgu - Cultural Heritage Administration National Cultural Heritage Portal
6. ↑ ^{[ Broken Link ( Find Past Content )]}

References [ Edit ]

• Angbuilgu - Cultural Heritage Administration National Cultural Heritage Portal

This document contains an article written based on the “Angbuilgu” entry in the Global World Encyclopedia distributed by Daum Communications (now Kakao ) under a GFDL or CC-SA license.