How Was the Microwave Invented? The Melted Candy Bar

A man stood next to a humming radar tube, and the candy bar in his pocket began to melt. His name was Percy Spencer, and he had left grammar school as a boy to earn money. Within two years, his company was selling a cooking machine built around that tube. It weighed 750 pounds and cost about $5,000, and it took roughly twenty years to reach an ordinary kitchen. This video follows Spencer from a Maine mill to a radar test room, then through the failed deals and the dinner in Chicago that finally put a microwave on a counter. What this covers: Percy Spencer's path from a Maine mill and the Navy to Raytheon's power tube division How the cavity magnetron reached America and how Spencer redesigned the build The candy bar, the popcorn and the egg that burst on a coworker The 1947 Radarange: 750 pounds, water-cooled and $5,000 The Tappan home oven that sold poorly, and the Chicago dinner that led to Amana The 1967 countertop oven for $495, and the slow climb into American kitchens The story behind the thing. Narration is computer-generated (text-to-speech); research, script and drawings are original. Wren S O U R C E S THE DISCOVERY MIT Technology Review, "Melted Chocolate to Microwave" (https://www.technologyreview.com/s/40... Spencer as a grade-school-educated engineer, the candy bar, the popcorn, the egg, the Radarange name, the Tappan failure, the executive dining room and the Amana dinner in Chicago. The year of the candy bar is 1945 in most accounts and 1946 in some, so the video says both. The year Raytheon bought Amana is 1963 in this article and 1965 in the other sources, so the video says both. IEEE Spectrum, "A History of the Microwave Oven" (https://spectrum.ieee.org/the-institu... the metal box, the months of development, Marvin Bock's prototype in a Boston restaurant, the 1933 Westinghouse demonstration, the 1967 Amana oven at $495, the 1968 leakage law and Walter Reed study, the 1975 sales and the 1976 Japan and US figures. SMECC, "Microwave Oven" (https://smecc.org/microwave_oven.htm): the egg the next morning, the air-cooled tube, the 1967 controls, the 35-second hamburger, Amana's year of retailer training and 24-hour home economists, the slow early sales, the gimmick criticism and the 1975 passing of gas ranges. PERCY SPENCER Wikipedia, "Percy Spencer" (https://en.wikipedia.org/wiki/Percy_S... the loss of his father and uncle, leaving grammar school, the paper mill, the Navy and the Titanic, the power tube division, the MIT radar contract, the Navy award, his later rank and death. Wikipedia calls the candy bar story a legend, and Lemelson-MIT names a weaving mill where Wikipedia names a spool mill, so the video says only "a mill". National Inventors Hall of Fame (https://www.invent.org/inductees/perc... the magnetron redesign and the figure of 2,600 a day, and the 1999 induction. Sources disagree on the rate before the redesign, so no starting figure is used. Lemelson-MIT (https://lemelson.mit.edu/resources/pe... the Navy years and discharge, and that Spencer did not realise at first why the chocolate melted. History.com (https://www.history.com/this-day-in-h... the patent filing in October 1945 and the grant in 1950. THE OVEN AND THE MARKET Wikipedia, "Microwave oven" (https://en.wikipedia.org/wiki/Microwa... the 1946 press showing at $1,250, the 1947 Radarange and its lease, about 100 units by March 1948, the 1954 forecast of $1,000, Litton's 1972 prices and forecast, and US ownership of about 1% in 1971, about 25% in 1986 and over 90% by 1997. Tappan's price is about $1,250 here and $1,295 in the IEEE article. The 1940 hand-over of the British magnetron is from the Tizard Mission record summarised there. Own arithmetic: $5,000 is four times $1,250, and $495 is about a tenth of $5,000. #MicrowaveHistory #PercySpencer #Raytheon #Radarange #TrueStory