Learn about the stories behind 10 extraordinary inventions. In this video, you'll learn about the microwave oven.
Read the full transcript »
Male Speaker: The microwave oven was recently rated as the number one technology in making people's lives better, ahead of the answering machine and the ATM. The first consumer model, the Amana Radarange, was introduced in 1967 and cost $495, equivalent to $3000 today and sparked a revolution in American lifestyle. Once thought of as a gimmick, they are now found in 90% of all homes. And it all started with a bar of melted chocolate. Percy Spencer was born in the rural town of Howland, Maine in 1894. His father died when he was 18 months old and his mother left shortly thereafter. Percy moved to live with an aunt and uncle in south Lincoln, Maine. When Spencer was 5, a Lombard log hauler broke down in front of their house. Unique for being the first vehicle to use a caterpillar track, it was essentially a steam locomotive without a track. Percy spent many a day exploring the hulking machine as his uncle Henry worked to fix it. They would enjoy riding in the engineer's cab together until Henry passed away when Spencer was 7. Percy was now head of the family. He dropped out of school and began work at a machine shop in Dexter, Maine where he became a skilled machinist. When the shop was converting to electrical power, a 16-year old Spencer, with no prior training, signed up as one of three men to outfit the factory with the new source of power. Through trial and error, Spencer emerged a competent electrician. Inspired by the heroism of the wireless operators during the sinking of the titanic in 1912, Spencer joined the navy to learn wireless telegraphy. Lacking much of a formal education, Percy taught himself what he needed to know while standing watch late at night. After the war, Percy Spencer became the fifth employee of the growing Raytheon Company in Lexington, Massachusetts. There, he was exposed to some of the brightest minds in physics at nearby MIT. Spencer proved to be an invaluable asset to Raytheon as he began work on photoelectric vacuum tubes. Throughout World War II, the power tube division at Raytheon expanded from 15 employees to over 5,000. This was due largely to Spencer's intense work ethic. For seven years he worked every single day of the week, including holidays. This legendary drive coupled with Spencer's ingenuity was mainly responsible for Raytheon landing a major combat radar construction contract. During the battle of Britain, the United States military obtained a model of a microwave magnetron from the English. The magnetron was the power tube of the radar sets and increased the radar's sensitivity tremendously. The British hoped Raytheon could mass produce the magnetron. Upon the United States entrance into World War II, fifteen of Spencer's radar sets called maggies were installed into US bombers. The new radar sets were sensitive enough to spot the periscope on German U-Boats. However, it took a master machinist an entire week to bore the tube out of a solid piece of copper with tolerances of less than ten thousandths of an inch. Squeezing every bit of efficiency out of the Raytheon factory's machinery and manpower, Spencer was only able to increase production to 100 a day. The Royal Air Force needed thousands to fight off the Luftwaffe. A stack of coins in Spencer's pocket provided the answer. Instead of creating the magnetron from a solid piece of copper, Percy devised a way to create it out of thin cross-sections stamped out by a machine that any semi-skilled worker could operate. Slices of copper alternated with slices of silver-solder were stacked on top of each other and fused together in an oven. To further increase efficiency, he designed an ingenious conveyor-belt oven. This was the advantage that the Royal Air Force needed to slow the German onslaught. Production sky-rocketed from 100 to over 2,600 magnetrons a day. For this and other achievements, Spencer was awarded the highest honor a civilian can receive from the navy, the distinguished public service award. Shortly after the end of