A Condensed History of Air Conditioning

From hand fans to today’s high-end air conditioning technology, people have always found ways to deal with heat and humidity. And as mechanical cooling became more ubiquitous, some of the cultural practices for keeping cool were made obsolete. 

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Episode Transcript

Speaker 1 (00:01):
Welcome to Stuff You Missed in History Class from how
Stuff Works dot com. Hello, and welcome to the podcast.
I'm Tracy V. Wilson and I'm Holly Fry. It's August,
although by the time this podcast comes out it could
possibly be September. Not quite sure when this one's gonna

(00:23):
drop yet. And also, it's hot. That's what August means
usually for us, at least, yeah for us for sure.
I started working on this episode on one of those
days when I woke up and it was already eighty
two degrees inside my apartment. It is eighty six degrees
in my little studio right now. I am sitting with
a cold pack draped over my chair. So I decided

(00:45):
we should talk about the history of air conditioning. And uh,
sorry to our Southern Hemisphere friends who are always getting
the episodes in which I'm complaining that it's hot, and
so we're going to talk about ice or air conditioning
or whatever. When it's winter there. I could go there
and complain about winter while you're here and complain about

(01:07):
hot because I love the heat, but that cold is
not for me. Uh So, about a year ago, we
did an episode on Frederick Tutor who cut ice out
of ponds in Massachusetts in winter and then turned that
into a globally traded commodity. In that episode, we talked
about some of the ways that people had been making
ice and refrigerating things in warmer parts of the world

(01:29):
before the establishment of the ice trade and the development
of mechanical refrigeration. Things like people in the Indian subcontinent
using earthenware vessels as evaporative coolers to make kind of
a semi frozen slush, or using saltpeter infused water to
chill bottles of beverages. Similarly, people all over the world
had figured out ways to keep themselves at least relatively

(01:52):
cool for millennia before the invention of air conditioning. A
lot of these methods are still in use in one
way or another today. Most obvious starting point is the fan.
People have probably fanned themselves with their hands or with
relatively flat objects for about as long as people have existed,
but in terms of objects created specifically as fans, we

(02:14):
know that goes back at least five thousand years. We
have examples of hand fans from numerous ancient civilizations all
over the world. The earliest fans were fixed or rigid,
and made of all kinds of feathers, fronds, textiles, and
other materials. The first folding fans were probably developed in
either Japan or China. There are examples from both that

(02:37):
are about the same age, and both nations have their
own lore about the development of the folding fan, and
of course, fans themselves have their own history, with all
kinds of mythology and symbolism and etiquette and art and
culture woven in, and a lot of cultures, fans have
also had religious or ceremonial uses as well, And that's
on top of all the variation in the materials that

(03:00):
fans have been made of and how they've been designed
and constructed. We probably, if we felt inclined, could do
a whole episode just on fans. Only if we talk
about Star Trek and the fan dance, then I'm in um.
A lot of the earliest personal cooling methods were built
around the fan, people either fanning themselves or having a

(03:22):
servant or an enslaved person do it for them. In
places that were both hot and dry, people used fans
to force airs through damp and screens or mats, which
would both humidify the air and cool the air. As
water evaporated. In places where it was hot and damp,
people were more likely to use fans to move air
over ice, although that still made the room even more humid,

(03:44):
and depending on where that ice came from, it might
also make the room smell like gross pond water. After
President James Garfield was shot in one his doctors used
a variation on this fan and ice method to try
to keep him cool, and that used almost five hundred
pounds of ice per day. Leonardo da Vinci developed a

(04:04):
water powered fan in about fifteen hundred, and mechanically driven
fans powered by things like hand cranks were developed about
the same time. The first electric fan was developed by
Crocker and Curtis Electric Motor Company in eighteen eighty two.
That in eighteen eighty four, William Whitely developed the all
Weather Eye, which was a fan that attached to the

(04:27):
axle of a carriage, so when the carriage was moving,
the fan turned and it forced air over a block
of ice that was mounted under the passenger area, sort
of air conditioning the inside of the carriage. That's pretty ingenious.
There are also all kinds of architectural features all over
the world intended to keep people cooler. Before industrialization and

(04:48):
the creation of air conditioning, most people lived in buildings
that were adapted to where they lived. They used local
materials and building techniques which were suited to the needs
of the climate and the landscape. The whole idea is
summed up as vernacular architecture. Vernacular architecture is absolutely full
of ways to deal with heat and humidity, and there

(05:09):
are so many that we cannot possibly name them all,
just like we cannot possibly name every variation on the fan.
But here are some examples. People on coasts oriented their
homes to catch the sea breeze through the windows. Porches
gave people an outdoor, semi sheltered place to go when
the house got too hot, and sleeping porches had bunks

(05:30):
or hammocks already there for when it was just too
hot to possibly go to sleep in the house. Thick walls,
high ceilings, and large windows have insulated buildings while also
allowing air circulation. Shady courtyards and fountains have offered respite
from the heat, and in places where it's hot in
the day and cool at night, Thick walls made from

(05:51):
mud or adobe absorb heat during the day and to
keep the inside cooler, and then release it at night
to keep the inside warmer. Then of course there's just
planting tree used to shade the buildings from the sun.
In the southeastern United States, one common design was the
dog trot house. This was a house with two halves
separated by a roofed breezeway in between, which usually also

(06:13):
connected a front and back porch. Usually the kitchen was
on one side of the dog trot while the sleeping
area was on the other, so you weren't heating up
your bedroom while you were cooking your food. Dog trot
houses were often built up on bricks or stones rather
than resting on a foundation or the ground, and that
allowed air to circulate under the house as well. And

(06:33):
sometimes these are also called possum trot houses. And the
same basic design is still used in some places today.
My sister in law lives in a house just like this. Yeah,
there are also, I mean there are historic ones that
still stand and newly built houses that are still following
that same basic design. I remember when I was in
college there was one at the botanical gardens next door

(06:54):
to the campus. Or we like to go sit around
and read. Step wells are a way of healing with
the heat and very arid countries, especially on the Indian subcontinent.
This is a pool of water very very deep underground,
which people would reach down an incredibly long spiral or
zigzag staircase. These pools had to be that deep underground

(07:15):
because that's how far down you had to go to
get to the water table. They were used as a
water source, but then also having such a deep, dark
underground shaft gave people a place to retreat out of
the heat. Sometimes step wells were designed to serve as
very large gathering places with intricate stairways and terraces, basically
lots of places for people to go down there and

(07:37):
chill out. A lot of these step wells fell into
disuse as human activity lowered the water table, either gradually
filling with trash or being taken over by animals. The
British Empire also destroyed a lot of them under the
idea that they were unsanitary, and this was kind of
ironic since it was extremely fashionable for British people to
complain about how miserable the heat was in colonial India. Today,

(08:01):
though some stepwells are being restored and reopened as water sources,
and the same principle has been used to design modern
buildings that require less energy to cool. Wind Catchers were
common and Persian architecture starting thousands of years ago, and
a lot of them are still standing and still working today.
This is essentially a windowed tower that's built to take

(08:21):
advantage of the prevailing winds. So exactly how the tower
is designed, how many windows it has, and which direction
it faces depends on where it's being built. When the
wind blows through a wind catcher, it draws hot air
up out of the house. Sometimes there's also a reservoir
of water or a very deep well inside the house,
so as the hot air moves out, moist, cooler air

(08:44):
is pulled up from below. A similar design was also
part of ancient Egyptian architecture. So Vernacular architecture is just
full of things like this, and people living in hot
places have also adapted their behavior, like the siesta during
the hottest part of the day a but as areas
have adopted air conditioning, these traditional elements have tended to

(09:05):
disappear as people instead designed buildings that are going to
be mechanically cooled and We're gonna start talking about that
in some detail after we first pause for a little
sponsor break. Modern air conditioning was developed in the United States,
and the United States has adopted it much faster than

(09:27):
the rest of the world, So the next stretch of
this show is going to be pretty US centric. The
first person in the United States to write down some
thoughts for creating a large scale way to cool places
was John Gory. In eighteen forty two, he wrote about
wanting to use mechanical condensation to quote counteract the evils
of high temperature and improve the condition of our cities.

(09:51):
He speculated about a massive city that could use one
machine to cool off the entire place, as well as
to cool individual buildings. It's not clear whether he ever
made a working prototype of this air conditioner he had
in mind, but he did create a refrigerator that could
make ice. He had this working at the U. S.
Marine Hospital in Appalachicola, Florida, in eighteen forty four, and

(10:14):
he patented it in eighteen fifty one. That ice was
put to use in conjunction with fans to try to
keep patients with malaria and yellow fever cool. By eighteen eighty,
people were using fans and ice together to try to
cool buildings on a much larger scale. That year, New
York's Madison Square Theater was using four tons of ice

(10:35):
per day to try to cool the theater in the summer.
Before trying that it would pretty much just not had
shows in the summer. There's some overlap in the development
of refrigeration and air conditioning, and in the late eighteen
eighties people were also using refrigeration to try to cool
whole rooms. Pipes were used to carry a refrigerant from
a central station out to customers, and this central station

(10:58):
refrigeration was mainly used to cool whole rooms for things
like meat packing and cold storage. A few businesses did
try to put central station refrigeration to use basically as
air conditioning for people's comfort, though, in a restaurant called
Ice Palace opened in St. Louis, Missouri, that used central

(11:19):
station refrigeration to keep the whole building cool, and it
also decorated the place with lots of pictures of wintry scenes.
Over the next couple of decades, several people started designing
the systems that evolved into modern air conditioning. Alfred Wolfe
created cooling systems for a number of buildings in the
late nineteenth and early twentieth centuries. In eighteen eighty nine,

(11:40):
he created a ventilation system for Carnegie Hall or Carnegie
if you like that pronunciation, but most people except Carnegie
Hall as the pronunciation on that one. Uh. These included
racks for blocks of ice. In that same year, he
used chilling coils to cool the air in a dissecting
room at Cornell Medical College, which seems like an excellent
venue for air conditioning. In two he created a fan

(12:03):
driven system for the New York Stock Exchange that cost
one thirty thousand dollars and it could heat and cool
the building In cold weather. Steam boilers added heat and humidity,
and in hot weather, the air moved over coils that
were filled with a cooling brine to cool and dehumidify.
At about the same time, engineer Stewart Kramer was working

(12:24):
in textile mills in the South, especially in the winter,
that air in these mills would become very dry, which
was a problem. Cotton thread is a lot more brittle
and likely to snap when it's too dry. Wool is
a lot easier to work when it's properly moist. Plus
static electricity. When working with a bunch of textiles and
too dry air could be just unbearable. Kramer developed systems

(12:48):
that combined ventilation with humidification. They basically circulated the air
while also releasing a very fine mist of water. The
word that he coined for this combination of temperature and
humidity can role was air conditioning. Kramer was awarded a
patent for his air conditioning system in nineteen oh six.
Concurrently with Wolf and Kramer, Willis Carrier was working at

(13:11):
Buffalo Forge Company and the company made things like blowers
and bellows, and he had been made head of its
new experimental engineering department. Those three men that we've just
talked about, His is probably the name that at least
rings a bell, because Carrier is still associated with air conditioning.
We just got a new air conditioner installed and it
is a Carrier unit. So. Second, Wilhelm's Lithographing and Publishing

(13:36):
company in Brooklyn, New York was one of Buffalo Forge
Companies clients, and they were having a problem with humidity.
Variations in the humidity affected the paper that was running
through their printing presses. Sometimes this would cause the ink
to bleed or to smear or for the paper to
visibly work. But a bigger problem was that they were
printing in color. Colored inks went on to the paper

(14:00):
one layer at the time. Even a slight difference and
humidity affected the paper enough that the colors would be
out of register. Those layers wouldn't line up correctly. It
would not look like a cleanly printed color document. It
would look like overlapping out of the lines, messed up color.
I'm thinking about the various episodes we have done about

(14:22):
artists and there weren't getting printed cheaply, and I'm betting
probably these problems were part of part of how they
ended up such a mess. Uh So, Carrier developed a
system that moved air over a series of coils that
were cooled with compressed ammonia. Moisture condensed out of the
air and onto the coils, drying it out, which also
had the side effect of cooling the air off. He

(14:45):
ultimately developed a cooling, dehumidification, and air circulation system that
maintained a temperature of seventy degrees fahrenheit in winter or
eighty degrees in summer, and a relative humidity that was
a consistent This Wasrier's first attempt at indoor climate control,
and he went on to be awarded numerous patents within

(15:05):
the field. The first one was issued in nineteen o six.
That was US Patent number eight oh eight eight ninety
seven Apparatus for Treating Air. It described a process for
forcing air through a spray of water and then through
a set of baffles to remove any kind of pollutants
or impurities, before then heating or cooling it and adding
or removing humidity. In late nineteen o seven, Buffalo Forge

(15:28):
Company established Carrier Air Conditioning Company of America as a subsidy.
Willis Carrier was vice president and chief engineer. Among the
first clients were Flour Mills and Gillette. Too much humidity
was causing the razor blades to rust. In nineteen eleven,
Carrier gave an address on his rational psychometric formulae at

(15:49):
the American Society of Mechanical Engineers. This was also published
in the Society's journal, and the printed version started quote.
A specialized engineering field has recently developed, technically known as
air conditioning or the artificial regulation of atmospheric moisture. The
application of this new art too many varied industries has
been demonstrated to be of greatest economic importance when applied

(16:13):
to the blast furnace, that has increased the net profit
in the production of pig iron from fifty cents to
seventy cents per ton, and in the textile mill it
has increased the output from five to at the same
time greatly improving the quality and the hygienic conditions surrounding
the operative. And many other industries such as lithographing, the

(16:35):
manufacture of candy, bread, high explosives and photographic films, and
the drawing and preparing of delicate hygroscopic materials such as
macaroni and tobacco. The question of humidity is equally important.
While air conditioning has never been properly applied to coal mines,
the author is convinced that if this were made compulsory,

(16:57):
the greater number of mine explosions would be prevented. The
paper goes on to detail all kinds of formulas about temperature,
humidity and dew point, how they're inter related, how they
can be adjusted, and what the effect of those adjustments
would be. So that introduction to the paper and the
paper itself highlight a couple of things. One is that

(17:20):
initially air conditioning had a slightly different meaning than it
does today. Today, we most associate air conditioning with keeping
things cool and not too humid. Another is that, almost
without exception, it was not about the workers comfort. It
was about the products they were making and the temperature

(17:40):
and humidity needs of the materials and equipment that we're
working with in order to make them more productive and
to make the business more profitable. You can be hot
and sweaty, but the paper cannot correct. We're going to
get into how air conditioning finally became a household commodity
after we first pause for a little sponsor break in

(18:05):
the early nineteen hundreds, the general public didn't get to
experience much air conditioning in the United States unless it
was something that was being employed at their work to
make their work more profitable. The St. Louis World's Fair
used mechanical cooling at the Missouri State Building in nineteen
o four. Roughly twenty million people attended the fair, and

(18:25):
for a lot of them this was the first ever
experience they had with air conditioning. Home air conditioning was
still way out of reach. The first home air conditioner
was installed in nineteen fourteen at the Charles Gates Mansion
in Minneapolis, and it's not clear whether or not that
air conditioner was ever actually used because no one was
living in the mansion at the time. That same year,

(18:46):
Buffalo Forge Company decided to pull out of the air
conditioning business. Willis Carrier and some of his colleagues founded
Carrier Engineering Corporation the following year, with Carrier as its president. Still,
at this point, air conditioning was only focused on industry,
not comfort, and the availability of air conditioning meant that
factories were being open in places where the climate had

(19:07):
not been very conducive to it before that. Industrial systems
did sometimes have a side effect of making things more
comfortable for workers, though. For example, the use of air
conditioning in tobacco processing kept the tobacco leaves at the
right humidity level, but it also really cut down on
the amount of dust that the workers were subjected to.
There are, also, of course, other cases where it was

(19:28):
the opposite, where this new air conditioning system would make
it feel to employees like it was cold and damp,
and they would want to open the windows, and if
they opened the windows, that would ruin the entire point
of having had this air conditioning in the first place.
It was in the nineteen twenties that people started experiencing
air conditioning that was specifically installed to make them more

(19:49):
comfortable while also still peeking all about UH profitability because
this was at movie theaters. There had been theater cooling
systems that combined ice, ba box and fans before this,
but they often weren't all that effective. They might wind
up with some parts of the theater being cold and
damp while others were hot and damp. Carrier Engineering Corporation

(20:10):
installed the first modern air conditioning system at a movie
theater at Metropolitan Theater in Los Angeles in nineteen twenty two,
and this was the start of three huge trends. Number one,
air conditioned movie theaters. Number two movie theaters heavily advertising
their air conditioning, and Number three, big movies coming out

(20:32):
in the summer when everybody would be going to the
movies to get out of the heat. By the start
of World War Two, most of the movie theaters in
the southern United States had air conditioning. In the US
isn't the only place where movie theaters were The first
public buildings to be air conditioned. The first public building
to be air conditioned in Hong Kong was King Cinema
that happened in ninety one. After movie theaters, the next

(20:56):
public buildings to be air conditioned in the United States
were mostly large department stores, especially in the South. Smaller
stores followed, and then came office buildings, with the first
air conditioned offices often being banks. The United States government
started air conditioning some of its buildings in the late
nineteen twenties. The House of Representatives chamber was air conditioned

(21:18):
in nineteen eight, and then the Senate in ninety nine,
and then the White House and Executive Building in nineteen thirty.
The Supreme Court was air conditioned in nineteen thirty one.
There had been some debate about whether these systems should
be installed, even though Washington, d c. Summers are famously
punishing in terms of the heat and humidity. There were
worries that people would see legislators and Supreme Court justices

(21:41):
as weak if they were going to work in comfortable
air conditioned buildings. Over these same years, Carrier and other
engineers were continuing to refine air conditioning technology. This included
more efficient compressors for the refrigerants and refrigerants themselves that
were safer to use that impressed. Ammonia that was being

(22:02):
used in the earliest air conditioners was extremely toxic. What
breathing ammonia air isn't good for me? Even so, by
the nineteen twenties, home air conditioning was still pretty rare,
unless a person was perhaps so wealthy that they could
afford to install one at their unoccupied mansion in Minnesota.
But that started to change as corporations started to develop

(22:23):
more compact and affordable models. Bridget Air debut a room
cooler in nine h H. Schultz and J. Q. Sherman
launched an early version of the window air conditioner that
was too expensive to actually be workable. The Thorn room
air conditioner came out in nineteen thirty two, and most

(22:44):
of today's window air conditioners still look a lot like it. Yeah,
the window air conditioning technology has not changed all that
much since this happened. Hotels had started installing air conditioning
not long after movie theaters did, but at first it
was only in the lobbies and the public spaces. The

(23:04):
first hotel with air conditioned guest rooms was the Detroit
Statler in nineteen thirty four. Even though window air conditioners
were starting to become a lot more affordable. The Great
Depression took a toll on the whole industry. One exception
was in the American Southwest, which was also struck by
the dust Bowl. At about the same time, people who
could find the money to do so installed air conditioners

(23:27):
to try to keep their relentless dust out of their homes.
In nine the Carrier Company went to the New York
World's Fair with its Igloo of Tomorrow, which both demonstrated
and educated people about air conditioning. That same year, Packard
debuted the first air conditioned car, but that was pretty
slow to be adopted. Only ten percent of cars sold

(23:48):
in the United States had air conditioning in nineteen sixty six,
but by two thousand it was Also in the nineteen thirties,
swamp coolers started to be manufactured to cool the air
in dry environments. Unlike most of the systems we've been
talking about, which used coils filled with some kind of
refrigerant to cool and dehumidify the air, swamp coolers cool

(24:10):
the air by adding moisture. Greyhound started air conditioning its
buses in nineteen forty, and in nineteen forty two, power
plants and the United States started implementing summer peaking to
handle the increased electricity demand caused by all this air conditioning.
The first really affordable window units hit the market in
nineteen fifty one, which put air conditioning on the way

(24:31):
to becoming almost ubiquitous in the United States. Even though
John Gory's first attempt at creating a cooling system was
all about patients in a hospital, hospitals were slow to
adopt air conditioning. By nineteen sixty two, only fifteen percent
of hospital patient rooms in the United States were air conditioned.
That same year, a Federal Housing Administration official was quoted

(24:54):
as saying, quote, within a few years, any house that
is not air conditioned will probably be obsolescent. I couldn't
find data about public schools, but just as a side note,
I was in public school in North Carolina from I
was almost never in an air conditioned classroom, Nor was
my college dorm air conditioned. I'm a few years ahead

(25:15):
of you, but by that point I was in Florida
and everything was air conditioned. So yeah, So the only
classrooms I remember being air conditioned were in one case,
being in a newly constructed part of the school that
was like brand new. We also had these things that
were called portable classroom units really trailers. The trailers were
air conditioned most of the time with like a little

(25:37):
window unit. Um, and that was really it. So we
had this whole system of if it was going to
be too hot for it to be safe in the classroom,
we had an hour early dismissal. Huh yeah, so uh,
that's the story of how hot it was. There would
usually be an oscillating fan mounted up on the wall,

(26:00):
and just the kids in the classroom seats would just
sort of sway back and forth trying to catch the
air from the oscillating fan for as long as possible. Meanwhile,
I was like the weirdy kid, like, can I stand outside,
it's cold here. Um. Central air conditioning debuted in the
nineteen seventies that was also in the middle of an

(26:20):
energy crisis. This prompted the US federal government to put
together its first federal energy efficiency standard for air conditioning.
So to be clear, when central air conditioning debut, there
were plenty of places that were having the whole building
air conditioned, but this was like a custom designed system
most of the time, rather than having a model for

(26:41):
central air conditioning that could be applied to a lot
of different homes. Like we said earlier, air conditioning was
adopted much faster in the United States than in the
rest of the world. In nineteen eighty, half of the
world's air conditioning was installed in the United States. This
means that the United States has also been using a
lot more electricity on air conditioning than the rest of

(27:02):
the world has, even as other nations have started adopting
air conditioning a lot more rapidly. In more recent years,
in the United States was using more electricity for air
conditioning than the entire rest of the world was, and
was using more electricity just for a c than the
entire continent of Africa was using for any purpose at all.

(27:23):
According to the Energy Information Administration's Residential Energy Consumption Survey
that was released in twenty eleven, seven percent of households
in the United States have an air conditioner or central air.
By comparison, eleven percent of households in Brazil and two
percent of households in India had air conditioning at the
same time. However, the popularity of air conditioning is spreading,

(27:46):
and it's already approached the saturation point in some other countries,
including China, South Korea and Japan. Fifty million air conditioning
units were sold in China alone. This has of course
led to environmental cons earns as a global adoption of
air conditioning starts to align with what already happened in
the United States. According to some estimates, electricity demand for

(28:09):
air conditioning could increase tenfold by the year twenty fifty.
That is on top of concerns about refrigerants and their
effects on the environment. Listeners of a certain age will
probably remember concerns about the chlorofluoro carbons like free on,
which were banned in the late nineteen eighties because of
their role in depleting the planet's ozone layer. And then
there's the fact that air conditioners pump hot air out

(28:31):
and cool air in, so the air just gets hotter
around any building where air conditioning is used, which then
requires more air conditioning. So in some places architects and
designers are looking at ways to incorporate some of those
elements of vernacular architecture so that it doesn't take quite
so much electricity and mechanical air conditioning to cool the
place off. The existence of air conditioning has also had

(28:55):
a huge impact on so many things, including arc at
extra human behavior and demographics, everything from fewer premature deaths
during heat waves to the existence of computers since their
components can't really be manufactured without temperature and dust control.
The advent of air conditioning has been credited with people

(29:16):
retiring to the South, particularly to Florida. It's also been
credited with leading to more industrialization and urbanizing parts of
the American South. There is still some debate about correlation
versus causation, but in general, air conditioning has been cited
as one element in a massive Southern population boom in

(29:36):
the last fifty years. As one example that ties all
of this together, during the post World War two Baby Boom,
huge numbers of white, middle class Americans were buying houses
in the suburbs. Many of those newly designed houses were
built to be cooled through air conditioning. Particularly popular in
the region of the southern US that's known as the
Sun Belt was the ranch house, one story flat, often

(30:00):
with a large picture window in the living room but small,
narrow windows elsewhere. It had none of the vernacular design
elements that we talked about earlier meant to help a
building stay cool, because it was meant to be cooled
with a C. And then there's another trend that wraps
back around how air conditioning really started out to help industries.
According to research by economist William Nordhouse, around the world,

(30:23):
as a general trend, the hotter the average temperature, the
less productive people are. In the past, this trend has
been used to prop up racist stereotypes about people from
the hottest parts of the world, But really there's just
a lot of data that being hot makes it harder
to be productive. Just as one example, this summer that

(30:46):
we're recording this podcast, the Harvard th H. Chan School
of Public Health published a study about how students who
lived in non air conditioned buildings in Boston performed more
poorly on cognitive tests than their peer who had air conditioning. So,
at least in theory, air conditioning or some method of
cooling makes countries with a really hot climate more productive

(31:09):
than they could be without it. So it's still about
productivity and profitability as much as it's about people's comfort.
The two are kind of um inseparable, really part of
how it all works. Um, do you have icy cold? Listener? Mail?
Kind of I got h It's a very brief mail
that we got from Nina. Nina says, thought you might

(31:31):
be interested to read this update on Ann Lister as
she's recently been honored. She's got that in quotes with
a blue plaque in Yorkshire and there is a link
to an article from the BBC. So this is a
plaque that was unveiled at Holy Trinity Church on July.
That is the church where Ann Lister and and Walker
went to church on Easter and had a communion together

(31:55):
and like that was a symbol of their marriage to
each other. This plaque describes this as a quote gender
nonconforming entrepreneur celebrated marital commitment without legal recognition to a
walker in this church established an eighteen thirty four. So
this has led to a furro or about the fact
that the plaque describes and Lister as gender nonconforming but

(32:18):
not as a lesbian. And one of the things that
we talked about in that episode is that like the
word lesbian wasn't really being used in that sense, but
the way she wrote about her own experience is clearly
something we would describe as a lesbian today and a
lot of times she's noted as the first modern lesbian.
So the trust that established this plaque released an apology

(32:41):
afterwards saying we recognize that this has hurt people and
we apologize. UM. So there is a commemorative plaque now there,
but the commemorative plaque is controversial. If you would like
to write to us about this or any other podcast,
where a history podcast at how stuff works dot com.
We are also all over social media at the name

(33:02):
missed in History. That's where you'll find your our Facebook
or Twitter or Instagram, and our Pinterest. You can come
to our website, which is missed in History dot com,
where you will find show notes of all the episodes
that Holly and I have done together, a searchable archive
of every podcast every You will also find a link
to our brand new te public t Shirts store, where
you can find shirts that have little uh some of

(33:25):
them inside jokes about some of our favorite episodes. Some
of them are shirts with our logo on. Also other
products like mugs and notebooks, et cetera. So you can
come to our website at missing history dot com to
do all that, and you can subscribe to our show
on Apple podcasts, Google podcasts, and wherever else you want
to get a podcast for more on this and thousands

(33:50):
of other topics, visit how stuff works dot com.