Demonstration of cooking by radio waves at the 1933 Chicago World's Fair, "Century of Progress", Chicago, Illinois, USA from radio magazine. This was a forerunner of modern microwave ovens which were developed in the 1950s. At Westinghouse Corp's "Powercasting" exhibit of futuristic shortwave technology, sandwiches were cooked by placing them between metal plates of a powerful 10 kW 60 MHz short wave transmitter, as shown. The magazine article (p. 394) says steaks, potatoes, and vegetables were also cooked in a few minutes. The exhibit also demonstrated wireless power transmission; a 1/4 horsepower motor was run by radio waves over a distance of 30 feet, and audience members could expose their bodies to the radio waves and feel the heat generated. The short wave technology was developed at Westinghouse research laboratories by I. F. Mouromtseff, and the demonstrations were conducted by G. R. Severance and film star Fifi D'Orsay "(shown)"