光武帝
Du Shi (, d. 38) was a Chinese inventor, mechanical engineer, metallurgist, and politician of the Eastern Han Dynasty. Du Shi is credited with being the first to apply hydraulic power (i.e. a waterwheel) to operate bellows (air-blowing device) in metallurgy. His invention was used to operate piston-bellows of the blast furnace and then cupola furnace in order to forge cast iron, which had been known in China since the 6th century BC. He worked as a censorial officer and administrator of several places during the reign of Emperor Guangwu of Han. He also led a brief military campaign in which he eliminated a small bandit army under Yang Yi (d. 26).