Sectioned "Swan" brand electric copper kettle, the first type of kettl e to be fitted with a totally immersed heating element and thereby doubling the efficiency of electric kettles, provisional patent no. 33221/ 21, by Bulpitt and Sons Ltd., Birmingham, 1921-1922 Electric copper kettle, with immersed element, sectioned, c. 1921. 1921-1922
Copper electric kettle with external heating element, sectioned to reveal bare wire heating elements wound around mica formers and bolted to the false bottom of the kettle, heat efficiency 50%, English, 1890 1910 Copper electric kettle with external heating element 1890-1910
"Magnet" electric copper kettle with external heating element bolted on to the false bottom, and with safety cut-out device consisting of a plug (missing) which melts and causes spring to slide a switch to the "off" position, provisional patent no. 18976/29, by General Electric C o., English, 1929-1935 "Magnet" electric copper kettle with external heating element bolted on to the false bottom 1929-1935