Wikipedia
Cheugugi
Cheugugi (Hangul: 측우기, Hanja: 測雨器) is the well-known first rain gauge invented and used by the Joseon Dynasty of Korea. It was invented and supplied to each provincial offices during the King Sejong the Great's reign. As of 2010, only one example of the Cheugugi remains, known as the Geumyeong Cheugugi (Hangul: 금영측우기, Hanja: 錦營測雨器), which literally means "Cheugugi installed on the provincial office's yard." It is designated as National Treasures #561 of Korea and was installed in provincial office of Gongju city, 1837 by King Yeongjo, the 21st king of Joseon. In addition, the official record of the rainfall by Cheugugi from King Jeongjo's reign to Emperor Gojong's reign is preserved.