Papin's Steam Digester

Timeline

1. 1679London · BritainDenis Papin designed and built a sealed iron steam digester in London, raising internal steam pressure by tightening the lid to achieve cooking above 150°C. He also designed a weight-controlled safety valve that automatically lifted to release pressure when it grew too high—the earliest recorded pressure safety valve device in history.
2. 1679–1680Royal Society, London · BritainPapin publicly demonstrated the steam digester to the Royal Society and in 1681 published a pamphlet, A New Digester or Engine for Softning Bones, describing the device's principles and experimental results in detail. Royal Society members including Robert Boyle took keen interest, and the safety valve concept gradually permeated steam power engineering.