Three Things That Made the Modern Economy

Roman Mars:
This is 99% Invisible. I’m Roman Mars.

Roman Mars:
Tim Hartford is a master at picking up the perfect little story that explains some huge economic principle. In his long-running Financial Times column called “The Undercover Economist”, and in his books and in his radio shows, he’s been my go-to guy for learning about the economics and math behind the world at large. His latest radio series from the BBC is called “50 Things That Made The Modern Economy”. And with this project, Tim has made a podcast almost perfectly crafted to light up the pleasure centers of my nerd brain.

Roman Mars:
After he produced 50 fascinating stories about 50 everyday objects, he decided to come back for another season that premiered last month, with another 50 mini-documentaries of inventions that are so basic but so fundamental to how we live. We have three of the 50 things on our show today. Radar, which I’m sure you know about, but you have no idea how fascinating its origins actually are, the s-bend, the crucial innovation in pipes that made indoor plumbing possible, and bricks. You know what bricks are. Bricks are cool. You’re in for a treat.

Roman Mars:
Up first, the story of radar.

Tim Harford:
In Kenya’s rift valley, Samson Kamau sat at home, wondering when he’d be able to get back to work. He should’ve been in a greenhouse on the shores of Lake Naivasha, as usual, packing roses for exports to Europe. But the outbound cargo flights were grounded because the Icelandic volcano Eyjafjallajökull had, without sparing the slightest thought for Samson, spewed a cloud of dangerous ash into Europe’s airspace.

Tim Harford:
Nobody knew how long the disruption might last. Workers like Samson feared for their jobs; business owners had to throw away tons of flowers that were wilting in crates at Nairobi airport.

Tim Harford:
As it happened, flights resumed within a few days. But the interruption dramatically illustrated just how much of the modern economy relies on flying, beyond the 10 million passengers who get on flights every day. Eyjafjallajökull reduced global output by nearly $5 billion.

Tim Harford:
You could trace the extent of our reliance on air travel to many inventions. The jet engine, perhaps; or the airplane itself. But sometimes one invention needs another to unlock its full potential. For the aviation industry, that story starts with the development of the death ray.

Tim Harford:
No, wait. It starts with an attempt to develop the death ray. This was back in 1935. Officials in the British Air Ministry were worried about falling behind Nazi Germany in the technological arms race. The death ray idea intrigued them. They’d been offering £1,000 prize for anyone who could zap a sheep at a hundred paces. So far, nobody had claimed it. But should they fund more active research? Was a death ray even possible?

Tim Harford:
Unofficially, they sounded out Robert Watson Watt of the Radio Research Station. And he posed an abstract maths question to his colleague, Skip Wilkins.

Tim Harford:
“Suppose, just suppose,” said Watson Watts to Wilkins, “that you had eight pints of water, one kilometer above the ground. And suppose that water was at 98 degrees Fahrenheit and you wanted to heat it to 105 degrees. How much radio frequency power would you require from a distance of five kilometers?”

Tim Harford:
Well Skip Wilkins was no fool. He knew that eight pints was the amount of blood in an adult human. 98 degrees was normal body temperature. 105 degrees was warm enough to kill you, or at least make you pass out, which if you’re behind the controls of an airplane, amounts to much the same thing.

Tim Harford:
So Wilkins and Watson Watt understood each other, and they quickly agreed that the death ray was hopeless: it would take too much power. But they also saw an opportunity. Clearly, the ministry had some cash to spend on research. Perhaps Watson Watt and Wilkins could propose some alternative way for them to spend it?

Tim Harford:
Wilkins pondered: “It might be possible,” he suggested, “to transmit radio waves and detect, from the echos, the location of oncoming aircraft long before they could be seen.” Watson Watt dashed off a memo to the Air Ministry’s newly formed Committee for the Scientific Survey of Air Defense. Would they be interested in pursuing such an idea? They would indeed.

Tim Harford:
What Skip Wilkins was describing became known as radio detection and ranging and then as radar. The Germans, the Japanese, and the Americans all independently started work on it, too. But by 1940, it was the Brits who’d made a spectacular breakthrough. The resonant cavity magnetron, a radar transmitter far more powerful than its predecessors. Pounded by German bombers, Britain’s factories would struggle to put the device into production. But America’s factories could.

Tim Harford:
For months, British leaders plotted to use the magnetron as a bargaining chip for American secrets in other fields. Then Winston Churchill took power and decided that desperate times called for desperate measures. Britain would simply tell the Americans what they had and ask for help.

Tim Harford:
The magnetron stunned the Americans. Their research was years off the pace. President Roosevelt approved funds for a new laboratory at MIT, uniquely, for the American war effort, administered not by the military but by a civilian agency.

Tim Harford:
By any measure, Rad Lab was a resounding success. It spawned 10 Nobel laureates. The radar it developed, detecting planes and submarines, helped to win the war. But urgency in times of war can quickly be lost in times of peace. It might’ve been obvious, if you thought about it, that civilian aviation needed radar, given how quickly it was expanding. In 1945, at the war’s end, U.S. Domestic airlines carried seven million passengers. By 1955, it was 38 million. And the busier the skies, the more useful radar would be at preventing collisions.

Tim Harford:
But rollout was slow and patchy. Some airports installed it, many didn’t. In most airspace, planes weren’t tracked at all. Pilots submitted their flight plans in advance, which should in theory ensure that no two planes were going to be in the same place at the same time. But avoiding collisions ultimately came down to a four word protocol: See and be seen.

Tim Harford:
On June 30, 1956, two passenger flights departed Los Angeles airport, three minutes apart. One was bound for Kansas City, one for Chicago. Their planned flight paths intersected above the Grand Canyon, but at different heights. Then thunderclouds developed. One plane’s captain radioed to ask permission to fly above the storm. The air traffic controller cleared him to go a thousand on top, a thousand feet above cloud cover, see and be seen.

Tim Harford:
Nobody knows for sure what happened. Planes then had no black boxes, and there were no survivors. But just before 10:31, air traffic control heard a garbled radio transmission.

Transmission:
“Pull up. Pull up. We are going in.”

Tim Harford:
From the pattern of the wreckage, strewn for miles across the canyon floor, the planes seemed to have approached each other at a 25-degree angle, presumably through a cloud. Investigators speculated that both pilots were distracted by trying to find gaps in the clouds, so passengers could enjoy the scenery.

Tim Harford:
Accidents happen. The question is what risks we’re willing to run for the economic benefits. That question’s becoming pertinent again with respect to crowded skies. Many people have high hopes for unmanned aerial vehicles, or drones. They’re already being used for everything from movie making to crop-spraying. Companies like Amazon, expect the skies of our cities soon to be buzzing with grocery deliveries. Civil aviation authorities are grappling with what to approve. Drones have sense and avoid technology, and it’s pretty good. But is it good enough?

Tim Harford:
The crash over the Grand Canyon certainly concentrated minds. If technology existed to prevent things like this, shouldn’t we make more effort to use it? Within two years what’s now known as the Federal Aviation Administration was born in the United States, and today American skies are 20 times busier still. The world’s biggest airports now see planes taking off and landing at an average of nearly two a minute. Collisions are absurdly rare, no matter how cloudy the conditions. That’s thanks to many things, but it’s largely thanks to radar.

Roman Mars:
You’re listening to my personally curated selection of stories from Tim Harford’s “50 Things That Made The Modern Economy”. Up next, the s-bend.

Tim Harford:
“Gentility of speech is at an end,” thundered an editorial in London’s City Press in 1858. “It stinks.”

Tim Harford:
The stink in question was partly metaphorical. Politicians were failing to tackle an obvious problem. As its population grew, London’s system for disposing of human waste became woefully inadequate. To relieve pressure on cesspits, which were prone to leaking, overflowing, and belching explosive methane, the authorities had instead started encouraging sewage into gullies. However, this created a different issue. The gullies were originally intended only for rainwater, and they emptied directly into the River Thames.

Tim Harford:
So that was the literal stink. The Thames became an open sewer. The distinguished scientist, Michael Faraday, was moved by a boat journey to write to The Times newspaper. He described the river water as, “an opaque, pale brown fluid … Near the bridges the feculence rolled up in clouds so dense that they were visible at the surface.”

Tim Harford:
Cholera was rife. One outbreak killed 14,000 Londoners, nearly one in every hundred. Civil engineer Joseph Bazalgette drew up plans for new, closed sewers to pump the waste far from the city. It was this project that politicians came under pressure to approve.

Tim Harford:
Michael Faraday ended his letter by pleading with “those who exercise power all have responsibility” to stop neglecting the problem, lest “a hot season gives a sad proof of the folly of our carelessness.” And three years later, that’s exactly what happened. The sweltering-hot summer of 1858 made London’s malodorous river impossible to politely ignore or to discuss obliquely with gentility of speech. The heat wave became popularly known as the Great Stink.

Tim Harford:
If you live in a city with modern sanitation, it’s hard to imagine daily life being permeated with the suffocating stench of human excrement. For that, we have a number of people to thank, but perhaps none more so than the unlikely figure of Alexander Cumming. A watchmaker in London essentially before the Great Stink, Cumming won renown for his mastery of intricate mechanics. King George III commissioned him to make an elaborate instrument for recording atmospheric pressure, and he pioneered the microtome, a device for cutting ultra-fine slivers of wood for microscopic analysis.

Tim Harford:
But Cumming’s world-changing invention owed nothing to precision engineering. It was a bit of pipe with a curve in it.

Tim Harford:
In 1775, Cumming patented the s-bend. This became the missing ingredient to create the flushing toilet, and with it, public sanitation as we know it. Flushing toilets had previously foundered on the problem of smell. The pipe that connects the toilet to the sewer, allowing urine and feces to be flushed away, will also let sewer odors waft back up, unless you can create some kind of airtight seal.

Tim Harford:
Cumming’s solution was simplicity itself: bend the pipe. Water settles in the dip, stopping smells coming up. Flushing the toilet replenishes the water. While we’ve moved on alphabetically from the s-bend to the u-bend, flushing toilets still deploy the same insight.

Tim Harford:
Rollout, however, came slowly. By 1851, a lifetime after Cumming’s patent, flushing toilets remained novel enough in London to cause mass excitement when introduced at the Great Exhibition in Crystal Palace. Use of the facilities cost one penny, giving the English language one of its enduring euphemisms for emptying one’s bladder: to spend a penny.

Tim Harford:
If the Great Exhibition gave Londoners a vision of how public sanitation could be, clean and smell-free, no doubt that added to the weight of popular discontent as politicians dragged their heels over finding the funds for Joseph Bazalgette’s planned sewers.

Tim Harford:
We still haven’t reliably managed to solve the problem of collective action, how to get those who exercise power or have responsibility, as Faraday put it, to organize themselves. There’s been a great deal of progress. According to the World Health Organization, the proportion of the world’s people who have access to what’s called “improved sanitation” has increased from around a quarter in 1980 to around two-thirds today. That’s a big step forward.

Tim Harford:
But still, two and a half billion people remain without improved sanitation, and improved sanitation itself is a low bar. It hygienically separates human excreta from human contact, but it doesn’t necessarily treat the sewage itself. Fewer than half the world’s people have access to sanitation systems that do that.

Tim Harford:
The economic costs of this ongoing failure to roll out proper sanitation are many and varied, from healthcare for diarrheal diseases to forgone revenue from hygiene-conscious tourists. The World Bank’s Economics of Sanitation Initiative has tried to tot up the price tag. Across various African countries, for example, it reckons inadequate sanitation lops one or two percentage points of GDP. In India and Bangladesh over 6%. In Cambodia 7%. That soon adds up.

Tim Harford:
The challenge is that public sanitation isn’t something the market necessarily provides. Toilets costs money, but defecating in the street is free. If I install a toilet, I bear all the costs, while the benefits of the cleanest street are felt by everyone. In economic parlance, that’s a positive externality, and goods which have positive externalities tend to be bought at a slower pace than society as a whole would prefer.

Tim Harford:
Contrast, say, the mobile phone. That also costs money. But as long as there’s somebody else I can phone, its benefits accrue largely to me. And that’s one reason why, although the s-bend has been around for 10 times as long as the mobile phone, many more people already own a mobile phone than a flushing toilet.

Tim Harford:
If you want to buy a flushing toilet, it also helps if there’s a system of sewers to plumb it into. And creating that system is a major undertaking – financially and logistically. When Joseph Bazalgette finally got the cash to build London’s sewers, they took 10 years to complete and necessitated digging up 2.5 million cubic meters of earth. Because of the externality problem, such a project might not appeal to private investors. It tends to require determined politicians, willing taxpayers, and well-functioning municipal governments. And those it seems are in short supply.

Tim Harford:
London’s lawmakers prevaricated, but when they finally acted, they didn’t hang about. It took just 18 days to rush through the necessary legislation for Bazalgette’s plans. What explains this sudden impressive alacrity?

Tim Harford:
A quirk of geography. London’s parliament building is located right next to the River Thames. Officials tried to shield lawmakers from the Great Stink, soaking the curtains in chloride of lime in a bid to mask the stench. But it was no use. Try as they might, the politicians couldn’t ignore it. The Times described, with a note of grim satisfaction, how members of parliament had been seen abandoning the building’s library, “each gentleman with a handkerchief to his nose.” If only concentrating politicians’ minds were always that easy.

Roman Mars:
We have one more story from season 2 of “50 Things that Made the Modern Economy” with Tim Harford after this.

[BREAK]

Roman Mars:
You’re listening to Tim Harford’s “50 Things that Made the Modern Economy” on 99% Invisible.

Voiceover:
I found Rome a city of bricks, and left it a city of marble.

Tim Harford:
That’s supposed to have been the boast of Caesar Augustus, the first Roman Emperor, just over 2,000 years ago. If it was, he was exaggerating. Ancient Rome is a city of brick, no less glorious for that.

Tim Harford:
Augustus was also joining a long tradition of denigrating or overlooking one of the most ancient and versatile of building materials.

Tim Harford:
The Great Roman architectural writer, Vitruvius, mentions them only in passing. Denis Diderot’s great French Encyclopedia of the Sciences, Arts and Crafts, published in 1751, and an inspiration for Adam Smith’s famous description of the pin factory. Well, Diderot doesn’t trouble himself to include any images of brick-making at all.

Tim Harford:
That’s because a brick is such an intuitive thing. People have been teaching themselves to build simple structures out of brick for many thousands of years, and grand ones too. The hanging gardens of Babylon were made of brick, so was the biblical Tower of Babel.

Tim Harford:
Come. Let’s make bricks and bake them thoroughly.

Tim Harford:
That’s Genesis 11, Verse 3.

Tim Harford:
They used brick instead of stone.

Tim Harford:
By Verse 5, the Lord is on the scene and things aren’t looking too good for the brick loving citizens of Babel.

Tim Harford:
As James Campbell and Will Price point out in their magisterial history of bricks, the humble cuboid is everywhere. The biggest manmade structure on the planet, the Ming Dynasty Great Wall of China, is largely constructed of brick. The astonishing Temples of Bagan in Myanmar, the Taj Mahal in India, mighty Marburg Castle in Poland, Siena’s Palazzo, and Florence’s Duomo, the bridges of Isfahan in Iran, Hampton Court Palace in West London – all brick. So is the best church in the world, Hagia Sophia in Istanbul, the best bridge, Clifton Suspension Bridge in Bristol, and the best skyscraper, the Chrysler Building in Manhattan. Brick, brick, brick. The architect Frank Lloyd Wright once boasted that he could make a brick worth its weight in gold.

Tim Harford:
This all started a long time ago. Bricks seem to have been with us since the very dawn of civilization. The oldest were found in Jericho, in Jordan, by the archeologist Kathleen Kenyon, in 1952. There’s something between 9,600 and 10,300 years old, and are simply loaves of mud, baked dry in the sun, then stacked up and glued together with more mud.

Tim Harford:
The next big step forward was the simple brick mold, also originating from Mesopotamia, at least 7,000 years old and depicted with great clarity on a tomb painting in Thebes, Egypt. The brick mold is a wooden rectangle with four sides, but no top or bottom, into which clay and straw could be packed to make bricks faster and more precisely. These molds can’t have been easy to make. They predate the use of metal itself, but once constructed, they made mud bricks much cheaper and better.

Tim Harford:
Even in a dry climate, sun dried mud bricks do you not usually last. Fired bricks are much more durable, they’re stronger and waterproof. Making such bricks, by heating clay and sand at a temperature of about a 1,000 degrees centigrade, has been possible for many thousands of years, but at a price. Accounts from the Third Dynasty of Ur, dating back just over 4,000 years, notes that you could get 14,400 mud bricks for the price of a piece of silver, but only 504 fired clay bricks. An exchange rate of nearly 29 mud bricks for a single clay one.

Tim Harford:
Fifteen hundred years later, by Babylonian times, kiln technologies had improved and the price of fired clay bricks had fallen to between two and five mud bricks. That’s still too much for many people. Cheap and easy mud bricks are still perhaps the most popular material in the world for building houses. But as the economists Abhijit Banerjee and Esther Duflo observe, fired bricks can be an effective way for a very poor household to save. If you have a little money, buy a brick or two. Slowly, slowly, slowly, you’ll have a better house.

Tim Harford:
The brick is one of those old technologies, like the wheel, or paper, that seems to be basically un-improvable.

Tim Harford:
The shapes and sizes of bricks do not differ greatly wherever they are made.

Tim Harford:
That’s Edward Dobson in the 14th Edition of his Rudimentary Treaties on the Manufacturer of Bricks and Tiles. There’s a simple reason for the size, it has to fit in a human hand. As for the shape, building is much more straightforward if the width is half the length. That’s why if you get your nose close up to some buildings that seem vibrantly distinctive to their culture, the Minaret of Kalon Mosque in Uzbekistan, Herstmonceux Castle Castle in England, and the Twin Pagodas of Suzhou in China, you’ll find the bricks are all much the same. It’s precisely the uniformity of the brick that makes it so versatile. Many medieval buildings, such as Saint Alban’s Cathedral in England simply reused Roman bricks. Why not? Brick production still uses traditional methods in many parts of the world, but automation is gradually nosing its way in.

Tim Harford:
Hydraulic shovels dig the clay, slow conveyor belts carry bricks through long tunnel kilns. Forklift trucks shift precision stack pallets of bricks. All this makes the brick itself cheaper. Building sites have resisted automation. The weather and the unique demands of each site require well-trained workers. The bricklayer has long been celebrated as a symbol of the honest dignity of skilled manual labor, and bricklaying tools have barely changed since the 17th century. But, as in so many other professions, there are signs that the robots may be coming to bricklaying. A human bricklayer can lay 300 to 600 bricks a day. The designers of SAM, the Semi-Automated Mason, claim it can do 3000.

Tim Harford:
What of the brick itself? Various designs of interlocking brick, much like Lego, are catching on across the developing world. The result tends to be less strong and waterproof than bricks and mortar, but they’re quicker and cheaper to lay. And, if you have robot bricklayers, why not give them bigger hands so you can make bigger bricks? Adrian X is a robot arm which lays gigantic bricks that no human bricklayer could wield. Maybe we shouldn’t get too excited though. SAM, the Semi-Automated Mason, has a predecessor, the Motor-Mason, for which similar claims were made back in 1967.

Archive Tape:
The machine spreads the mortar as evenly as a skilled man who has spent half a lifetime doing it. In fact, it lays bricks five to 10 times faster than by the ordinary methods.

Tim Harford:
Perhaps the bricklayer will last a little longer yet. The brick certainly will.

Roman Mars:
Search for “50 Things That Made The Modern Economy” in your favorite podcast app, or click the link in the show notes.

Roman Mars:
You can download all 50 of them, right now, and just shotgun them. Just go for it.