Draft:Jang Yeong-sil Science Garden

The Jang Yeong-sil Science Garden (Korean 장영실 과학 정원) in Busan (South Korea) was built in honor of Jang Yeong-sil, one of the most important scientists of the Joseon Dynasty (1392-1910). He is considered to have invented or contributed to 19 scientific instruments from this period. Eleven of them were placed along the shape of the Big Dipper. The Science Garden was completed on October 15, 2009 with an investment of 500 million won (US$380,000).

Information board in the science garden created in honor of Jang Yeong-sil.
Translation of the information board: "This garden was created to commemorate the achievements of Jang Yeong-sil, a native of Dongnae and one of the greatest scientists of Joseon, and to inspire young Koreans toward scientific pursuits. On display in this garden are the reproductions of 19 astronomical instruments whose invention owes wholly or partially to Jang Yeong-sil, including the famous sundial. The astronomic instruments are placed in this garden, opened in November 2009, in such a way that their positions match the geographic coordinates of Dongnae-gu."

Cheonsang Yeolcha Bunyajido (1395)
Cheonsang Yeolcha Bunyajido (Korean 천상열차분야지도) is the second oldest stone-carved star map in the world, known to originate from the Kingdom of Goguryeo. It was first created in the 4th year (1395) of King Taejo's reign in the Joseon Dynasty and shows 1,467 stars engraved in different sizes according to their brightness, unlike the stone-carved Chinese star charts. The engraved stone was set up by Kwon Geun (1352-1409) and other eleven members of the Seoun-gwan (Bureau of Astronomy) based on the calculations of astronomer Yu Bang-taek (1320-1402).

In addition to this star chart, which was carved on a flat black stone, there is another star chart that was carved in marble during the reign of King Sukjong. The star chart is divided into three fields to describe the celestial bodies: The top panel describes the sun and moon and takes the shape of the sky to show the celestial equator and the zodiac divided into 12 regions near the ecliptic. The field also illustrates the sizes and positions of the constellations in relation to the corresponding terrestrial regions. The Milky Way and 1,467 stars are drawn in a circle in the middle panel. The bottom panel shows the names of the people involved in the creation of the star chart and contains descriptions of ancient cosmology and the 28 constellations as well as an explanation of why the star chart was created.

Kanui (1432)
Kanui (Korean 간의) is an astronomical instrument for measuring the position of celestial objects. Alongside the Angbuilgu, the Jikyungru and the Honcheonui, it was the most important observation instrument in the astronomical observatories of Joseon. It had a similar structure to today's protractor and was a simplified version of the Honcheonui. In 1432 (the 14th year of King Sejong), he had a wooden kanui made by Icheon and Jang Yeong-sil, and when the attempt was successful, he had it cast in copper. This is one of the most outstanding achievements in the maintenance of astronomical instruments. In 1438 (the 20th year of King Sejong), he built an observatory on the north side of Gyeonghoe-ro in Gyeongbokgung Palace, and in addition to a large observatory, he had a small observatory built that was convenient to transport.

Honcheonui (1433)
Honcheonui (Korean 혼천의) is an astronomical instrument used to measure the positions of the sun, moon and the other five planets in the sky - Mercury, Venus, Mars, Jupiter and Saturn. This instrument was set up for educational purposes in educational institutions or astronomical government offices. The Honcheonui, also called "seongi-okhyeong" or "honui", was first designed by Jeong Cho, Pak Yon and Kim Jin in 1433 (the 15th year of King Sejong's reign). This instrument is a 2.5-fold enlarged and restored version of the armillary sphere of the Honcheon Sigye (a clock) invented by Song Yi-Yeong in 1669 (in the 10th year of King Hyeonjong's reign). The Honcheonui consists of a horizontal ring, an equatorial ring, an ecliptic ring, a moon path ring and an earth globe.

Borugak Jagyeongnu (1434)
Commissioned by King Sejong, the Borugak Jagyeongnu (Korean 보루각자격루) water clock is a new type of water clock created by comparing and studying Chinese and Arabic water clocks and was created in 1434 (the 16th year of King Sejong). It is an ornate automatic clock with bells, gongs and drums that ring spontaneously depending on the time of day, and a doll that appears with a tablet showing the time. The water clock worked by pouring water into the largest bronze vessel, which flowed into the smaller vessels, which in turn flowed into the long water containers. When the water level reached the appropriate height, a floating rod touched a lever device, which set a ball rolling and hit another ball at the other end. The rolling ball triggered the gong, the bell, the drum and even a wooden puppet that indicated the hour with a sign.

Angbuilgu (1434)
Angbuilgu (Korean 앙부일구) is a concave sundial in the shape of a hemisphere with 24 divisions for the year and hour lines at intervals of 1 hour and 10 minutes. It consists of the hour lines, the seasonal lines and the horizontal surface.

Hyeonju-Ilgu (1437)
Hyeonju-Ilgu (Korean 현주일구) is a portable sundial and indicates the time by the shadow that falls on the round plate, both levels of which have scales. The upper level is used for the period between the vernal equinox and the autumnal equinox, and the scale on the lower level is for the period from the autumnal equinox to the next vernal equinox. The Hyeonju-Ilgu was used as a portable clock during the reign of King Sejong. It was originally hand-sized. This sundial, intended for outdoor use, is a 7-fold enlarged and restored version of the original described in the literature.

Ilseong Jeongsi-ui (1437)
Ilseong Jeongsi-ui (Korean: 일성정시의) was invented in the 19th year of King Sejong's reign and was used to measure the time of day and night. Its design was based on the principles of sundials and the idea that the stars revolve regularly around the North Star.

Su-Pyo (1441)
Su-pyo (Korean 수표) is a water gauge. In addition to using rain gauges to measure precipitation, another method is to measure changes in river levels. This method is based on the natural phenomenon that the water level of a river rises when it rains and falls when it dries up. In 1441, controls were built and installed on the Cheonggyecheon River and the Han River.

Cheuku-gi (1441)
Cheuku-gi (Korean 측우기) is a rain gauge that was created in August 1441. Rainwater was collected in a cylindrical metal bowl and its depth was measured using a standardized scale. Instruments and rulers of the same standard were installed in all districts, creating a nationwide system for observing and reporting rainfall.

Honsang (1669)
Honsang (Korean 혼상) is a celestial globe with groups of stars (or constellations) arranged on a spherical surface. During the Joseon Dynasty, the honsang was an important astronomical instrument used to measure night time and the seasons. In many private Confucian academies, known as seowon, it was also used for educational purposes, for example to describe the structure of the universe, the movement of the five planets and the principle of time measurement. The celestial globe shown here, with 1,464 stars engraved on the spherical bronze surface with a diameter of 120 cm, was made from the Honsang relic discovered in Toegye Seowon. The axis of rotation is well connected to both the horizontal and meridian rings to hold the weight of the globe. The four gods engraved on the stone plate under the four legs indicate the directions east, west, south and north. The copper used for this Honsang weighs around 1.8 tons.

Punggidae (year unknown)
Punggidae (Korean 풍기대) is a flagpole to which flags are attached to determine the direction and strength of the wind. This pole is made of granite and is 228 cm high, with a base on which a statue is carved and an octagonal column with an embossed cloud pattern at the top. At the top of the octagonal pole is a hole in the center for the flagpole, and drainage holes are cut into the side of the pole below. A narrow, long flag was attached to the end of the mast, which was used to measure the direction of the blowing wind and the strength of the wind by the flapping of the flag. It is assumed that the wind direction was indicated in 24 directions and the wind speed was divided into eight intensity levels. The measurement of wind direction was an indispensable observation for agriculture and was probably institutionalized at the time of King Sejong. It is believed that the Pungidae were originally made like temple pillars, as was the case with rainfall controls. The Punggidae are an empirical artifact of the Joseon Dynasty Observatory, which no longer exists and was a pioneer in weather observation.

Gwangjang (year unknown)
The Gwangjang (Korean 서양해시계 광장) is a sundial whose signs are modeled on the twelve constellations of the zodiac. In this sundial, the twelve signs of the zodiac are assigned to the twelve constellations of Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpius, Sagittarius, Capricornus, Aquarius and Pisces. The twelve signs of the zodiac are each depicted on twelve round stone pillars, and on the top of each stone pillar there is a description of the respective birth constellation and the corresponding birth dates. In the center of the sundial is a date display plate. The plate shows the position of the first day of each month and 24 points of the year. If you stand on the date marker, you can read the time from your shadow on the floor.

Ilgudae (year unknown)
This is a cylindrical sundial on the Ilgudae (Korean 일구대). It has 12 hour lines and directional indications for the four cardinal points. The shadow of Yeongchim in the center shows the time and direction of the sun. This sundial is used to read the time approximately. When the shadow falls on Sibanmyeon at the twelfth hour, it is about twelve o'clock and the sun is in the south. It was modeled on the sundial in King Sejong's memorial hall.

Jeokdosikaesigye (year unknown)
Jeokdosikaesigye (Korean: 적도식해시계) is an equatorial sundial. The watch consists of a dial plate parallel to the equatorial plane. There are 12 hour lines and 100 angle lines engraved on both levels of the dial plate. In the center of the dial plate is a gnomon that moves in the direction of rotation of the globe. The time can be read through the shadow of the gnomon. From the spring equinox to the autumn equinox, the shadow is cast on the upper level, from the autumn equinox to the next spring equinox on the lower level.

Byeok-myeon Haesigye (year unknown)
The Byeok-myeon Haesigye (Korean 벽면 해시계) sundial is installed in a vertical direction, with a dial in a horizontal direction. The time is read by the shadow of the gnomon cast by the hour line and the season line on the wall surface. This type of sundial was generally more developed in the western regions.