Denis Papin (1647–1712), a French physicist who invented a steam digester (pressure cooker) in 1679. The digester operated by raising the boiling point of water by increasing steam pressure within a vessel. Papin's pressure cooker demonstrated the influence of atmospheric pressure on boiling points. Although Papin’s design was not practical, it was later improved by others, ultimately leading to the development of the steam engine, a major impetus to the Industrial Revolution. Papin also devised a pump with a piston raised by steam in 1690 and designed a safety valve to prevent the pressure of steam from building up to dangerous levels. Papin was an assistant to Christian Huygens and Robert Boyle, leading intellectual figures of their time.