How many of you have a rain gauge in your yard? One of the first things my dad does after it rains is go and check the rain gauge to see how much rain we got from the storm. Cheugugi was the first rain gauge and it was invented in the Joseon Dynasty of Korea.
The Joseon Dynasty began in 1392 after the overthrow of Goryeo and would rule through 1897 until it was replaced with The Korean Empire. The Joseon Dynasty would see the height of Korean culture, trade, literature, science, and technology and this is where the Cheugugi comes in.
In the early days of the Dynasty, the only way to measure the amount of accumulated rainfall was by the depth of puddles on the ground. As I’m sure you can imagine, this was not an overly reliable system and King Sejeong the Great soon commissioned the Gwansanggam (Joseon’s research institute for astronomy, geography, calendar and weather) to craft a new system. On the suggestion of the Crown Prince, later to become Munjong of Joseon, the Cheugugi was born from iron in 1441.
Today there is only one example of the Cheugugi remaining. It is known as the Geumyeong Cheugugi and has been designated as National Tresure #561 of Korea. It was installed in the provincial office of Gongju in 1837 by King Yeongjo, the 21st King of Joseon.