Denis Papin

Pressure cooker

The steam digester is a 1679 experimental vessel that used trapped steam to raise boiling temperature and cut cooking time. It introduced the safety valve and demonstrated atmospheric pressure’s mechanical action — directly enabling Papin’s 1690 piston engine. It was never mass-produced, never used outside demonstration, and had no domestic adoption. Its value is archival and conceptual: it is the first device to treat pressure as a controllable variable in thermal systems.