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Melted Chocolate to Microwave

An imaginative engineer turned a mess into a universal machine.

If you live in the United States, odds are a machine much like those stacked on the right rests on a kitchen countertop in your home. If so, your microwave is a descendant of the device on the right. This is the first microwave oven, built by Massachusetts-based Raytheon in 1947; it operated for three decades in the kitchen of one of Raytheon’s founders. Raytheon named the original microwave the “Radarange” because it cooked food using the same radio-wave-producing magnetron tubes that the company manufactured for use in military radar.

Raytheon credits the discovery of microwave cooking to a grade-school-educated engineer named Percy L. Spencer. One day in 1945, Spencer was walking through a radar test room with a chocolate bar in his pocket; he came too close to a running magnetron tube and the candy began to melt.

Spencer was already known at the company for his curiosity and ingenuity, and he reacted true to form-he pointed the magnetron at kernels of corn and watched them pop, aimed for an egg and saw it cook so quickly it exploded. Soon, Raytheon officers were sampling microwaved meals in the executive dining room and within a few years the company was marketing the Radarange for $2,000 to $3,000.

At that price, the Radarange was primarily a commercial cooker, providing warm meals on trains and ocean liners, and in restaurants and hotel dining rooms; some establishments offered special all-microwaved meals to promote the new technology. Early efforts to sell home machines through a licensing agreement with the Tappan Stove Co. were unsuccessful. But in 1963, a chance dinner meeting between two Raytheon executives and the president of Amana Refrigeration, Inc., all visiting Chicago, resulted in the sale of Amana to Raytheon. Raytheon capitalized on Amana’s experience in marketing and distributing consumer goods, and in 1967 introduced the under-$500 countertop Amana Home Radarange.

Today, 90 percent of American homes have microwave ovens. And though Spencer never profited from his patent on the device, his early snack experiments were prophetic; many of us use our microwaves most often to pop popcorn and, some pastry chefs argue, a few seconds in the microwave is simply the best way to melt chocolate.

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Illustration by Rose Wong

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