'Easiwork' pressure cooker, c 1936.
© Science Museum / Science & Society Picture Library
The cooker is of insulated cast aluminium, with a lid secured by a removable yoke, and has an Easiwork pressure gauge. A spring-loaded piston acts as a pressure regulating and warning device. The cooker's airtight structure creates high pressure and allows water to go beyond its boiling point. This leads to food cooking more quickly.