Jang Young Sil is the most famous inventor in Korean history. He was a scientist in period of the Great King Sejong who was the greatest king of all Korean times. He invented the first rain gauge and watermark in the world in 1441 so people could prevent rivers to overflow. And he invented the Korean first water clock named as JaGyukLu and many instruments. His mother was a official gisaeng so he could not be pointed as a government official. But he jumped over the barrier of a status system.
