Episode 29: RadaRange

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There is a good chance you have heard the story about the inventor of the microwave standing in front of radar and noticing that the chocolate bar in his pocket had melted.  You probably haven't heard that the event that story was based on occurred more than 70 years ago, or that it wasn't actually a chocolate bar, or that despite growing up in poverty and having almost no formal education the invention of the microwave was among the least important contributions that the inventor of the microwave left to mankind.  Learn the real story on this week's episode of Hang Your Hat.

Show Transcript

Welcome to Hang Your Hat.  This is episode 29: RadaRange

When it is time to pop popcorn, heat a frozen dinner, or warm up leftovers, there is a good chance that you will turn to a kitchen device that wasn’t a part of our parents or grandparents kitchens - the microwave.  The microwave is now a part of over 90% of American kitchens, but how did it get there and where did it start?  On today’s episode of Hang Your Hat I will discuss the birth of the microwave and its unlikely inventor.

 

Percy LeBaron Spencer was born in 1894 in Howland Maine population just 171, the 2nd child of Jasper and Myrtle Spencer.  He was born into poverty, but I imagine that his parents still oohed and awed over their new bundle of joy, glad to welcome a new member into their happy little family.

Unfortunately, their happiness didn’t last long.  Less than 2 years later Spencer’s father died.  His mother couldn’t afford to keep him and his brother, and Spencer was shipped off to live with his Aunt and Uncle.

We don’t know much about his early life, but I think he must have been a precocious child, exploring his world, figuring out how things work, and asking why often enough to make the most understanding of caregivers nuts.  Then when Spencer was 7, his uncle, his 2nd father, died as well.  

Spencer had to grow up quickly.  When he was only 12 he left school and started working in the local spool mill making wooden spools that thread would be wound on.  He had to help support his Aunt and himself.  He had only an elementary school education.  Most people in Spencer’s situation would have continued to work in the mill until it closed, or they died, but Spencer was different.

When he found out the paper mill was installing electricity he applied to be an installer, despite knowing nothing about electricity.  In the rural town he lived in there was no-one to teach him, but he gathered up all of the reading material he could find on the subject and taught himself.  He was one of only 3 people that were hired to electrify the mill.

In 1912 the Titanic sank and Spencer turned 18.  He had become interested in wireless communication after learning about the wireless operators on the Titanic and joined the Navy so he could explore it further.  He was in the Navy for less than 2 years.  He was discharged early due to a chronic ear disease, but he wasted no time while he was there.  He became an expert on radio technology while he was in the Navy, and used his spare time to teach himself trigonometry, calculus, chemistry, physics, and metallurgy.  He studied every textbook he could get his hands on while standing watch at night.

When he left the Navy he got a job in Boston at the Wireless Specialty Apparatus Company, which designed and manufactured crystal radios.  His bother worked there too.  Both of them had the title “radio electrician.”

The Wireless Specialty Apparatus Company was absorbed by RCA sometime in the 1920’s.  It is not clear if that was the impetus for Spencer leaving the Wireless Specialty Apparatus company, but he started working for Raytheon in 1925.  He again followed his brother who was already working for Raytheon when Spencer made the move.  

Spencer’s brother appears to have left Raytheon soon after Spencer joined the company.  In 1928 he filed a patent for his Spencer Thermostat and started the Spencer Thermostat Company.

Fortunately for quick cooking enthusiasts, Spencer didn’t follow his brother’s lead.  For the next 20 years, he worked at Raytheon on radio and radar systems eventually earning the Distinguished Public Service Award from the US Navy for his important research into magnetrons during World War II.  

In 1940 the British set out on a scientific mission headed by Sir Henry Tizard.  Their goal was to bring a black tin trunk to the United States that was filled with items that were strategically important for the war effort.  Their mission was risky.  If the trunk fell into enemy hands it could have been disastrous for the allies, but the risk turned out to be worth it.

One of the items in the trunk was a cavity magnetron developed by British physicists Henry Boot and John Randall.  It was pivotal in our radar design.

A magnetron is basically a vacuum tube that generates microwaves.  A basic vacuum tube consists of a negatively charged cathode on one side of the tube and a positively charged anode on the other.  The cathode is heated till it is so hot that electrons gain enough energy to escape from the cathode and travel toward the positively charged anode.

In a magnetron, the cathode is in the middle of the tube and the anode is a ring that surrounds the cathode.  But that is not what makes a magnetron special.  The anode also has holes or slots cut in it called resonate cavities.  There is also a powerful magnet under the anode that creates a magnetic field.

Because of the magnetic field when the electrons try to travel from the cathode to the anode they are forced to travel in a curved path around the cathode, and while the electrons are whipping around the cathode they are also passing the cavities in the anode.  The cavities resonate and emit microwave radiation.  The size of the cavities determines the resonate frequency.

You can think of it kind of like blowing through a whistle.  The air that goes straight through the whistle is like the electrons traveling directly between the cathode to the anode.  But some of the air escapes through the hole in the top of the whistle - which is like the groves in the anode.  The air escaping through the top of the whistle resonates at a frequency that creates a sound wave.  In the magnetron the resonate frequency creates microwaves.  

Boot and Randall’s magnetron design was an improvement over previous designs.  Their design was both stronger and more powerful than previous designs, making it possible to install radar in smaller air crafts.

Magnetrons are used in radar systems, and they were extremely important to the war effort during World War II because they were used to find enemy ships, submarines, and planes.  Without radar, military personnel would have to actually visually see the enemy vessel to know where to target their weapons.  

But there was a problem with the magnetron too.  It was very hard to make.  The war effort required 1000s of magnetrons, but each device took a skilled machinist weeks to complete.  They had to be machined out of solid copper, which was both time consuming and wasted a lot of metal.

In 1941 Spencer invented a machine that could mass produce magnetrons for use in radar sets.  His method stamped cross sections of the magnetron out of thin copper and silver solder.  The cross sections were then stacked up into the shape of the magnetron and cooked in a conveyer belt oven until the pieces fused together into a whole magnetron, kind of like a layer cake.  His invention increased the production of magnetrons from 17 per day to 2600 per day.  

He also developed to ways to make the radar sets that the magnetrons were used in sensitive enough to detect German u-boats from fairly high up in the sky.

He eventually racked up over 300 patents and an honorary doctorate from the University of Massachusetts.  He also became a Fellow of the American Academy of Arts and Sciences; a member of the Institute of Radio Engineers, became senior vice president, and a member of the Board of Directors at Raytheon and had a building named after him at Raytheon.  All with almost no formal education.

Then in 1945, Spencer was standing in front of an active radar set at Raytheon and noticed that the candy bar in his pocket had melted.

The myth is that Spencer had a chocolate bar in his pocket and he noticed that it had melted, but noticing that chocolate, which melts at about 90 degrees Fahrenheit, less than body temperature, doesn’t seem like something that would be terribly notable.

According to Spencer’s Grandson George Spencer Jr, Spencer liked to feed squirrels and chipmunks and carried a peanut cluster bar in his pocket to feed the little critters during his lunch break.  It was a melt-resistant peanut cluster bar that Spencer found melted in his pocket that peaked his curiosity.  

Spencer was not the first person that noticed that things melted around radar,  but he was the first that bothered to figure out why.  He was curious about what had happened, so, like any good scientist, he experimented.  First, he put popcorn kernels near the magnetron and watched them all pop - making the very first microwave popcorn.  Then he put an egg in a kettle and positioned the magnetron to direct the microwaves into the hole in the kettle.  The egg ended up exploding in the face of one of Spencer’s coworkers.  

Then Spencer created the first microwave oven.  He connected a high-density electromagnetic field generator to an enclosed metal box that would keep the microwaves from escaping and did further experimentation by placing food in the box and monitoring it’s temperature as the microwaves cooked it.

Spencer and Raytheon filed for the first microwave oven related patent on October 8th, 1945.  It was called a “Method of Treating Foodstuffs.”

In 1947 the first commercial microwave oven hit the market.  It was called the RadaRange.  It was 6 feet tall, weighed 750 pounds and cost $5000 (that is about $45,000 in 2018 dollars).  It also had to be connected to a water line because the magnetron had to water cooled.  It wasn’t a big seller; however one was installed in the galley of the nuclear-powered merchant ship the NS Savannah in 1961 and it remains there now. 

The microwave was introduced to the domestic market in 1955 under license to the Tappan Stove company.  It was a large wall unit that sold for $1295 - or about $12,000 in today’s money.  It also didn’t sell well.  Not only was it super pricey, the average domestic consumer didn’t really know about microwave technology.

In 1967 microwaves finally started to gain a place in American homes.  Amana, a subsidiary of Raytheon produced a smallish Radarange that could fit on a countertop.  It cost $495, about $3700 today, which was relatively affordable - especially when compared to prior offerings.  

In 1970 there were about 40,000 microwaves in US homes - by 1975 there were a million.  By 1986 25% of US homes had a microwave, now that number is around 90%.

However in recent years sales of microwaves have been on a downward trend due to concerns over microwave safety and potential nutritional impacts of microwaving.

If you are not sure if the microwave should have a place in your home be sure to listen to the next episode of Hang Your Hat.

 

Since starting this show I have been consistently surprised by the history behind the mundane objects in our homes, and microwaves have been no exception.  Who would have guessed that they were the brainchild of a man with an elementary school education, and a direct result of World War II technological innovation?

If you would like to know the backstory behind one of the objects in your home let me know.  I am always looking for a great new story to tell.  

You can drop me a comment on hangyourhatpodcast.com or you can email me at hangyourhatpodcast@gmail.com.  

Hang Your Hat Podcast is a member of Patreon.  If you would like to help support the show please consider becoming a patron by going to Patreon.com/hangyourhat    

If you are not up to becoming a patron but would still like to support the show please leave a review on iTunes or wherever you get your podcasts, or just let a friend know about the show.

And as always, thanks for listening.

Sources

 

 

 

Episode 25: The Throne

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What is the most important invention ever?  If you base your answer on the number of lives saved then it is the toilet.  Toilets have reduced disease, improved child mortality rates, and made it possible for humans to live in close quarters.  In this episode, I explore the long history of the toilet from Neolithic drainage to today's porcelain wonders.

Show Transcript and Pictorial History of the Flush toilet:

Click the pictures for links to articles with additional information.

Welcome to Hang Your Hat, I’m Amy, and this is Episode 25, the Throne

In this week’s episode, we are going to talk about one of the most important inventions in human history.  One that has reduced disease, improved child mortality rates, and made it possible for humans to live in close quarters.  Yet we rarely talk about it.  What is this magical invention?  The Lavatory, the Loo, the John, the Privy, the Latrine, the Bog, the Potty, the can, the toilet.

It may surprise you just how old the toilet is, but it turns out that even ancient peoples didn’t want to live in their own filth.  

Excavation of the Skara Brae.  The toilet room is the opening in the upper right of the home.  It is thought to be one of the first examples of a toilet with a drainage system.

Excavation of the Skara Brae.  The toilet room is the opening in the upper right of the home.  It is thought to be one of the first examples of a toilet with a drainage system.

One of the earliest example of what we believe to be a toilet is from Skara Brae, a Neolithic settlement in Scotland that dates back to about 3000 b.c.  And believe it or not, most toilet researchers think they had not only toilets but indoor toilets with built-in drainage systems. 

The Skara Brea settlement was discovered around 1850 and was remarkably well preserved.  When excavated archeologists found small rooms in the settlement’s dwellings that were connected to drainage chutes.  While they fell short of indoor plumbing with running water they were able to flush their toilets by pouring pots of water into what was essentially their sewer system.

Despite their early entry into toilet technology, by 1970, 1 in four Scots was still having to share an outdoor toilet, a problem that has been rectified for the most part today.

Drainage at the Indus Valley city of Lothal.  It was incredibly advanced and efficient for the time.

Drainage at the Indus Valley city of Lothal.  It was incredibly advanced and efficient for the time.

The Indus Valley civilization which was in what is now western India and Pakistan was also an early entrant into the race for modern toilet technology, despite the regions current sanitation issues. 

The sanitation system used by the Indus Valley people was actually pretty similar to the system used at Skara Brea, in that they had indoor toilets that drained to the outside of the house, but the infrastructure was a lot more advanced.

Indus Valley homes had toilets that you could sit on and all of my sources described them as wet toilets, meaning that they held water.  The toilet drained out of the house through a clay brick pipe into a drain that was shared with other houses, like our modern sewer system.  From there the toilets would drain into cesspits, or be carried out of the city altogether.  The sewer system was publicly maintained and had man-hole covers and larger chambers to assist with its maintenance.  It really was a very modern sanitation system.

Public Roman toilets were actually considered dangerous places, and shrines to the goddess Fortuna were often near toilets so that bathroom goers would be protected while doing their business.

Public Roman toilets were actually considered dangerous places, and shrines to the goddess Fortuna were often near toilets so that bathroom goers would be protected while doing their business.

However, the Roman Empire is often cited as the pinnacle of sanitation in the ancient world, because they had toilets that flushed - at least sort of flushed.

The first flushing toilet that we know about was made by Minoans on the island of Crete.  The oldest example we have is from the palace of Knossos, which dates back to around 1700 b.c.  However, at that time toilets were used only by the elite.

The Greeks made toilets, even the fancy flushing kind, available to the masses.  They made large publicly available latrine rooms, which basically consisted of a bunch of seats with holes suspended over a drainage system.  While private toilets in the home were not available to the lower classes, many middle-class homes had toilet facilities, although they usually weren’t the flushing variety.

It was the Romans however, that whole-heartedly adopted the use of the toilet.  They became part of Roman life, as ubiquitous as the Roman bath.

Roman public toilets were a lot like their Greek predecessors.  They were basically rooms lined with benches with holes in the top connected to a drainage system below.  Water would run through the drainage system cleaning away the waste.   

The running water was a result of the Roman aqueduct system.  I was surprised to find while researching that the aqueduct system carried both potable and non-potable water.  The potable water was of course used for drinking and cooking, the non-potable water was used for things like the Roman baths and the sanitation system.  One source even suggested that water from nearby baths was used to flush public toilets.  That is using resources wisely.

However, despite the apparent modernity of Roman sanitation, it really didn’t do that much to reduce disease.  One of the big reasons is that their toilets lacked a very important part of modern toilet technology, the “S” bend.

The S bend is basically an S-shaped piece of pipe that traps a bit of water when you flush.  That bit of water keeps things from coming back up the pipe and into your toilet, like flies and sewer gas.

Since the Roman toilets didn’t have an S bend they stank, and more importantly, they harbored flies.  Flies are a disease vector.  They transfer whatever they have been eating or standing on, like human feces, to whatever they eat or stand on next, like your food. 

Roman public toilets were dangerous in other ways too.  They harbored rats, roaches, snakes, and god knows what else.  Fortunately for the Romans, one of their gods did know what else.  Many Roman latrines have shrines to the goddess Fortuna.  She was thought to protect toilet users from illness causes demons and other bad things that could happen while using the toilet.

In addition, archeologists now don’t think that the Roman sewer system was nearly as vast or advanced as we used to believe, so the removal of waste may not have even been that effective.

After studying the remains of pathogens in archeological sites, scientists found that the prevalence of intestinal parasites like roundworm and whipworm didn’t decrease from the Bronze and Iron ages to the Roman period like they expected, they actually rose.  Despite all of the effort involved, Roman sanitation didn’t make its population any healthier than previous peoples.

A castle garderobe.  Made famous by the Game of Thrones TV show.  It has a hole in the bottom to allow excrement to escape.

A castle garderobe.  Made famous by the Game of Thrones TV show.  It has a hole in the bottom to allow excrement to escape.

The dark ages in Europe saw a lot of scientific knowledge and technology that was common among the Romans lost to the mists of time, and toilet technology was no exception.

By the medieval period toilets for the masses consisted of a mixed bag of chamber pots, communal outhouses, and holes in the ground.  The elite had something altogether different, however, the garderobe.  A garderobe was usually a tiny room in a castle that protruded from the side of the building and was open at the bottom, allowing gravity to do the job of waste removal.  You may have even seen a garderobe because one was featured in a certain scene in Games of Thrones involving a crossbow and the use of a toilet.

Christchurch Monastery Drainage Diagram 1167 a.d.  Unlike most castles at the time, Christchurch went to lengths to keep the sewage from contaiminating the site or water supply.

Christchurch Monastery Drainage Diagram 1167 a.d.  Unlike most castles at the time, Christchurch went to lengths to keep the sewage from contaiminating the site or water supply.

Most garderobes simply let the waste fall into a cesspit or the moat, or directly to the ground, but some castle dwellers must have thought that was pretty gross and used a drainage system.  Christchurch monastery was one of those.  They actually had a really elaborate drainage system that separated running water, drainage, and waste.

If you are wondering why garderobe sounds so much like wardrobe it is because it comes from the French words for guard, as in protect, and robe, meaning clothes and is what the modern term wardrobe comes from.  That is because clothes were often kept in the garderobe.  The ammonia smell in the room from all the urine was thought to protect clothes from fleas and other bugs by killing them  - which leads me to believe that that the smell of ammonia in the room must have been unbearable.  

Harington's Flush toilet is the forerunner of modern flush toilets.

Harington's Flush toilet is the forerunner of modern flush toilets.

The forerunner to the modern flush toilet was finally invented in the 1590s, during the reign of Queen Elizabeth the 1st in England by Sir John Harington.  Harington was the Queen’s godson and a bit of a trouble-maker.  During the 1590s he invented a flush toilet with a mechanical valve to seal off the toilet and a tank of water to flush it - 2 of the basic components that make up a modern flush toilet.  He called it the Ajax - which was a riff of the slang word for the toilet at that time - a jakes.  It took 7.5 gallons of water to flush it - an extravagant amount at the time since this was still before modern plumbing.  It also flushed into a cesspool below the toilet, and since this was also before the invention of the “s” bend all the fumes from the pit wafted back up through the toilet into the house, making it - less than ideal.

Despite these obvious short-comings of the Ajax Queen Elizabeth herself is alleged had one installed.

Harington introduced the Ajax to the world in 1596 in a publication called, “A New Discourse of a Stale Subject, Called the Metamorphosis of Ajax.”  While the book did detail the workings of the Ajax toilet and how to build one, it was also a discourse on obscenity and a thinly veiled critique of his peers - the members of the ruling class.

Perhaps unsurprisingly, the Ajax was not widely adopted.

Cumming's Design for the S bend finally made the modern flush toilet possible by keeping sewer gasses from escaping back up the pipe.

Cumming's Design for the S bend finally made the modern flush toilet possible by keeping sewer gasses from escaping back up the pipe.

Toilets finally became practical in 1775 when the inventor Alexander Cumming patented what is possibly the greatest contribution towards the modern toilet - the “S” bend pipe.

The problem that had plagued toilets prior to Cumming’s invention was the smell.  Sure you could flush away the excrement, but there was nothing stopping that stink from floating back up the pipe.  There needed to be a sealed barrier that would not let the gas pass back up the pipe, and Cumming came up with a surprisingly simple and elegant solution - bend the pipe.

A pipe with an S bend look a lot like an S lying on its side so one of the curved portions of the S is pointing toward the floor.  That part of the “S” captures a bit of water every time the toilet is flushed, and that trapped water acts as a barrier to the gas that tries to escape up the pipe, meaning that your toilet won’t smell like a sewer - at least as long as you clean it.

Thomas Crapper did not invent the flush toilet, but he did popularize it.  His toilet design is the classic that is often seen in old movies and cartoons.

Thomas Crapper did not invent the flush toilet, but he did popularize it.  His toilet design is the classic that is often seen in old movies and cartoons.

It wasn’t until the 1880s that the flush toilet went mainstream though, and it is thanks to a man named Thomas Crapper.  

First, let's get something out of the way - the word crap, meaning excrement, did not start with Thomas Crapper.  Crap had been in use since at least the time that crapper was in diapers and referred to the contents of diapers.  Crapper was just exceptionally well named for his eventual career.  

Crapper, also, I am sure it is obvious at this point did not invent the flush toilet, although he did patent several bathroom-related inventions, like the ball-cock.

Crapper is so well known for his contributions to the toilet because he was hired by England’s Prince Edward to install some of his toilets in several royal palaces, and because he displayed his toilets in showrooms, so when people needed a toilet they were already familiar with the Crapper name.

You are probably familiar with the Crapper toilet design because they are common in movies about the Victorian period and in a lot of old cartoons.  He mounted his water tank high up on the wall, with a pipe and pull cord leading down to the base of the toilet.

His design is still in production today.  If you want to buy one, his iconic design starts at 2209 pounds and can be bought at thomas-crapper.com

The toilets that most people have in their houses today are not significantly different than the toilets available in the 1930's.

The toilets that most people have in their houses today are not significantly different than the toilets available in the 1930's.

Throughout the 20th century, there were no major improvements to the basic toilet design.  Between 1900 and 1910 the toilet’s wash down method was improved when siphon-jet models were introduced.  Those are the little holes on the underside of the toilet bowl that are so difficult to clean.  At the same time, high wall mounted tanks were replaced with low tanks, and the opulent and difficult to clean toilets of the Victorian era were replaced with the smooth white easy to clean surfaces that we know today.

The economic pressures of the 1930’s made new more affordable close coupled two piece models more popular, and these are basically the toilets we have in our homes today.  Toilets have changed in style over the years, but the only significant technological difference between the toilets that we have today and those of the 1930’s is the amount of water used - we now have low-flush and dual flush models that conserve water.

 Of course, there are some pretty cool futuristic toilets out there now that for the most part have not made it into people’s homes, but that’s a story for another time.

 

Today’s show topic was requested by a listener and turned out to be a much more interesting show topic than I had anticipated.  You can find pictures of all of the toilets I talked about in today’s show on the show notes at hangyourhatpodcast.com.  The early flush toilets are really pretty cool looking.

If you have an idea for a show topic you can let me know about it by leaving a comment on hangyouhatpodcast.com, or by emailing me at hangyourhatpodcast@gmail.com

Hang Your Hat Podcast has just become a member of Patreon.  If you would like to help support the show please consider becoming a patron by going to Patreon.com/hangyourhat

If you are not up to becoming a patron buy would still like to support the show please leave a review on iTunes or wherever you get your podcasts, or just let a friend know about the show.

And as always, thanks for listening.

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