A wry view of life for the world-weary

There Ain’t ‘Alf Some Clever Bastards – Part Fifty Nine


Percy Spencer (1894 – 1969)

One of the things that has revolutionised the kitchen and accelerated the acceptability of convenience foods is the microwave oven. I remember buying my first one in the 1980s and was astonished how heavy it was as I carried it from the shop to my flat. What many people don’t know is who invented the microwave. This is where the latest inductee into our illustrious Hall of fame, Percy Spencer, comes in.

Born in Howland, Maine, by 1939 Spencer was one of the leading experts in radar tube design, working for Raytheon. Magnetrons were used to generate the microwave radio signals that were fundamental for radar and Spencer developed a more efficient way of manufacturing them, by punching out the parts and soldering them together rather than using machined parts. This meant that the rate of production increased from a stately 17 per day to around 2,600.

Whilst standing by an active radar set, our Percy noticed that a chocolate bar in his pocket had melted. He decided to investigate the phenomenon by experimenting to see the effect that exposing various foodstuffs to a magnetron would have. Some popcorn kernels became the world’s first microwaved popcorn. More amusingly, an egg was placed in a kettle and the magnetron was placed directly above it. To the doubtless consternation of one of his colleagues who was peering over the contraption to see what was going on the egg exploded in his face.

Undaunted by this set back Spencer persevered and before long had produced a contraption which consisted of a metal box to which a high density electromagnetic field generator was attached – the world’s first microwave oven. The magnetron sent microwaves into the metal box, trapping them and enabling them to be used in a controlled and, mercifully, safe environment. His experiments demonstrated that not only could food be cooked in the microwave oven so that they were edible, it could be done much more quickly than in a conventional oven.


His employers, Raytheon, applied for a patent for his oven, the Radarange, on 8th October 1945. A prototype was installed in a restaurant in Boston and by 1947 the first commercially available microwave oven was launched on to the unsuspecting public. They were around 6 feet tall, weighed 750lbs and phenomenally expensive, retailing at around $5,000 a time. The magnetron had to be water-cooled which meant that the device had to be plumbed in.

Not unsurprisingly, initial sales were disappointing but soon after further refinements and modifications, an air-cooled, lighter oven was developed. Not only was it cheaper – retailing at around $2,000 to $3,000 but it didn’t require the services of a plumber to instal. The food industry began to twig on to the advantages of a microwave, allowing them to keep refrigerated food up to the point that it was required and then heat it up, resulting in fresher food, less waste and financial savings.

By 1967 the first counter-top, 100 volt domestic oven was available, costing $500. The take-up was phenomenal and by 1975 sales of microwaves had exceeded those of more conventional gas-powered ovens. And the rest is history.

As for Percy, whilst he climbed up the greasy corporate pole at Raytheon, ending up as a Senior Vice President and Board member of Raytheon, he didn’t receive a share of the royalties. All he got was $2, the standard gratuity paid by Raytheon to employees who invented things.

Percy Spencer, for inventing the microwave oven and not sharing in the financial success of your product, you are a worthy inductee into our Hall of Fame.


If you enjoyed this, why not try Fifty Clever Bastards by Martin Fone which is now available on Amazon in Kindle format and paperback. For details follow the link


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: