Editing Sejong the Great (section)

===Science, technology, and agriculture===
[[File:Korean Waterclock.jpg|thumb|right|200px|A modern reconstruction and scaled down model of Jang Yeong-sil's [[Water clock#Korea|self-striking water clock]].]]

Sejong promoted science.<ref>{{cite book |last1=Haralambous |first1=Yannis |url=https://books.google.com/books?id=qrElYgVLDwYC&pg=PA155 |title=Fonts & Encodings |last2=Horne |first2=P. Scott |date=28 November 2007 |publisher=[[O'Reilly Media]] |isbn=9780596102425 |page=155 |language=en}}</ref><ref name="science">{{cite book|last1=Selin|first1=Helaine|title=Encyclopaedia of the History of Science, Technology, and Medicine in Non-Westen Cultures|publisher=Springer Science & Business Media|isbn=9789401714167|pages=505–506|url=https://books.google.com/books?id=GzjpCAAAQBAJ&pg=PA505|language=en|date=2013-11-11}}</ref> In 1420, Sejong created a royal academy within [[Gyeongbokgung]] known as the [[Hall of Worthies]]. The institute was responsible for conducting scientific research with the purpose of advancing the country's technology. The Hall of Worthies was designed to host Joseon's best and brightest thinkers, with the government offering grants and scholarships to encourage young scholars to attend.<ref>{{Cite web |last=Aw |first=Gene |date=22 August 2019 |title=King Sejong: The Inventor of Hangul and More! |url=https://gogohanguk.com/en/blog/king-sejong-hangul/ |access-date=1 October 2023 |website=Go! Go! Hanguk}}</ref><ref>{{Cite journal|url=https://www.jstor.org/stable/2059779|jstor=2059779|last1=Kim|first1=Chin W.|title=Reviewed work: King Sejong the Great: The Light of 15th Century Korea., Young-Key Kim-Renaud|journal=The Journal of Asian Studies|year=1994|volume=53|issue=3|pages=955–956|doi=10.1017/S0021911800031624|s2cid=162787329 }}</ref>

In 1428, Sejong ordered the printing of one thousand copies of a farmer's handbook.{{efn|This book is suspected to be the ''{{ill|Nongsang Jiyao|zh|农桑辑要}}'' ({{Korean|hangul=농상집요|hanja=農桑輯要|labels=no}}), a [[Yuan dynasty]] book on farming, imported to Korea during the Goryeo dynasty.<ref>{{cite web|script-title=ko:농상집요|url=http://contents.history.go.kr/front/tg/view.do?treeId=0104&levelId=tg_002_0070&ganada=&pageUnit=10|author=[[National Institute of Korean History]]|website=우리역사넷 [HistoryNet]|access-date=30 July 2024}}</ref>}} The following year, he published the ''[[Nongsa chiksŏl]]'' ('Straight Talk on Farming'), a compilation of various farming methods accommodative to Korea's climate and soil conditions.<ref>{{cite web|script-title=ko:농사직설[農事直設] 우리 땅에 알맞은 농법을 모아 편찬하다|author=[[National Institute of Korean History]]|website=우리역사넷 [HistoryNet]|access-date=30 July 2024|url=http://contents.history.go.kr/mobile/kc/view.do?levelId=kc_r300270&code=kc_age_30}}</ref> The book dealt with planting, harvesting, and soil treatment, and contained information about the different farming techniques that scientists gathered from different regions of Korea. These techniques were essential for maintaining the newly adopted intensive and continuous cultivation methods.{{sfnp|Kim|1998|p=57}}

One of Sejong's close associates was the inventor [[Jang Yeong-sil]]. Jang, who was originally a government-owned ''[[nobi]]'' from [[Dongnae]], appointed as court technician by Sejong in 1423.<ref>{{cite web|script-title=ko:장영실 (蔣英實)|url=https://encykorea.aks.ac.kr/Article/E0048697|author=전상윤|website=[[Encyclopedia of Korean Culture]]|access-date=11 August 2024}}</ref> Jang had been released from nobi by Taejong. Sejong appointed Jang to a ''byeoljwa'' ({{Korean|hangul=별좌|hanja=別坐|labels=no}}), responsible for crafting and repairing royal items.<ref>{{Cite web |script-title=ko:안숭선에게 명하여 장영실에게 호군의 관직을 더해 줄 것을 의논하게 하다 |url=https://sillok.history.go.kr/id/kda_11509016_003 |website=Veritable Records of the Joseon Dynasty |publisher=[[National Institute of Korean History]] |language=ko}}</ref>

In 1442, Jang Yeong-sil made one of the world's first standardized [[rain gauge]]s named ''[[cheugugi]]'' ({{Korean|hangul=측우기|hanja=測雨器|labels=no}}).<ref name="raingauge">{{Cite journal |last1=Strangeways |first1=Ian |year=2010 |title=A History of Rain Gauges |journal=Weather |volume=65 |issue=5 |pages=133–138 |bibcode=2010Wthr...65..133S |doi=10.1002/wea.548 |doi-access=free}}</ref> This model has not survived, with the oldest existing Korean rain gauge being made in 1770, during the reign of [[Yeongjo of Joseon|King Yeongjo]]. According to the [[Seungjeongwon ilgi|Daily Records of the Royal Secretariat]] ({{Korean|hangul=승정원일기|hanja=承政院日記|rr=Seungjeongwon Ilgi|labels=no}}), Yeongjo wanted to revive the glorious times of Sejong the Great, and started reading chronicles from that era. When he came across the mention of a rain gauge, Yeongjo ordered a reproduction. Since there is a mark of the [[Qing dynasty]] ruler [[Qianlong Emperor|Qianlong]] (r. 1735–96), dated 1770,{{sfnp|Kim|1998|p=51}} this Korean-designed rain gauge is sometimes misunderstood as having been imported from China.

In 1434, Jang Yeong-sil, tasked by King Sejong, invented the ''gabinja'' ({{Korean|hangul=갑인자|hanja=甲寅字|labels=no}}), a new type of [[printing press]]. This printing press was said to be twice as fast as the previous model and was composed of copper-zinc and lead-tin alloys.
[[File:Korean celestial globe.jpg|right|thumb|Korean [[armillary sphere]] first made by the scientist Jang Yeong-sil during the reign of King Sejong]]
Sejong also wanted to reform the [[Korean calendar]] system, which was at the time based upon the [[longitude]] of the Chinese capital. He had his astronomers create a calendar with the Joseon capital of Hanseong as the primary meridian. This new system allowed Joseon astronomers to accurately predict the timing of solar and lunar [[eclipse]]s.{{sfnp|Kim|1998|p=57}}

In the realm of [[traditional Korean medicine]], two important treatises were written during his reign. These were the ''Hyangyak Jipseongbang'' ({{Korean|hangul=향약집성방|hanja=鄕藥集成方|labels=no}}) and the ''Euibang Yuchwi'' ({{Korean|hangul=의방유취|hanja=醫方類聚|labels=no}}), which historian Kim Yong-sik says represents "the Koreans' efforts to develop their own system of medical knowledge, distinct from that of China".{{sfnp|Kim|1998|p=57}}