The wax thermostatic element was invented in 1934 by (1899–1968). Its principal application is in automotive thermostats used in the engine cooling system. The first applications in the plumbing and heating industries were in Sweden (1970) and in Switzerland (1971). Wax thermostatic elements transform heat energy into mechanical energy using the thermal expansion of waxes when they melt. This wax motor principle also finds applications besides engine cooling systems, including heating system thermostatic radiator valves, plumbing, industrial, and agriculture.