46.

The S-Bend

Gentility of speech is at an end,” thundered an editorial in London’s City Press in 1858. “It stinks.”1

The stink in question was partly metaphorical: politicians were failing to tackle an obvious problem. As London’s population grew, the city’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.2 However, this created a different issue: the gullies were originally intended only for rainwater, and they emptied directly into the River Thames.

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. 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.” The smell, he said, was “very bad . . . the same as that which now comes up from the gulley holes in the streets.”

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.

Faraday ended his letter by pleading with “those who exercise power or have responsibility” to stop neglecting the problem, lest “a hot season gives us sad proof of the folly of our carelessness.”3 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.”

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 a century before the Great Stink, Cumming won renown for his mastery of intricate mechanics: he served as a judge for the Longitude Prize, which spurred John Harrison’s development of the world’s best timekeeping device. King George III commissioned Cumming to make an elaborate instrument for recording atmospheric pressure, and he pioneered the microtome, a device for cutting ultrafine slivers of wood for microscopic analysis.

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

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.

Cumming’s solution was simplicity itself: bend the pipe. Water settles in the dip, stopping smells from 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: Cumming’s invention was almost unimprovable.

Rollout, however, came slowly: by 1851, flushing toilets remained novel enough in London to cause mass excitement when they were introduced at the Great Exhibition in Crystal Palace.4 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.” Hundreds of thousands of Londoners queued for the opportunity to relieve themselves while marveling at the miracles of modern plumbing.

If the Great Exhibition gave Londoners a vision of how public sanitation could be—clean and odor-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. Those plans weren’t perfect. At the time, it was wrongly believed that smell caused disease, so Bazalgette assumed it would suffice to pump the sewage into the Thames farther downstream. As it happened, that did largely solve the actual cause of cholera—contaminated drinking water—but it didn’t help if you wanted to fish in the estuary or bathe on a nearby beach. Cities that are currently experiencing infrastructure-stretching population explosions now have much more knowledge to draw on than was available in 1850s London.

But 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 has 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.5

Still, 2.5 billion people remain without improved sanitation, and improved sanitation itself is a low bar: the definition is that 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.6

The economic costs of this ongoing failure to roll out proper sanitation are many and varied, from health care for diarrheal diseases to foregone 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 1 or 2 percentage points off GDP; in India and Bangladesh, more than 6 percent; in Cambodia, 7 percent.7 That soon adds up: countries that have made good use of Cumming’s S-bend are now a whole lot richer for it.

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

The most striking example is the “flying toilet” system of Kibera, a famous slum in Nairobi, Kenya. The flying toilet works like this: you poop into a plastic bag, and then in the middle of the night, whirl the bag around your head and hurl it as far away as possible. Replacing a flying toilet with a flushing toilet provides benefits to the toilet owner—but you can bet that the neighbors would appreciate it, too.8

Contrast, say, the mobile phone. That doesn’t have as many positive externalities. It does have some: If I buy a phone, my neighbors with phones can contact me more easily, which benefits them. But given the choice, they’d surely prefer that I instead refrain from throwing excrement around. But most of the benefits of owning a phone accrue to me. Suppose, then, that I’m deciding whether to buy a phone or save that money toward a toilet: if I altruistically add up the benefits to myself and my neighbors, I might decide on the toilet; if I selfishly look only at the benefits to myself, I might prefer the phone. That’s one reason why, although the S-bend has been around for ten times as long as the mobile phone, many more people currently own a mobile phone than a flushing toilet.9

In Kibera, efforts to eliminate the flying toilets have centered around a small number of communal washroom blocks—and the distribution of specially designed toilet bags that can be filled, collected, and used for compost. It’s an ad hoc solution to the constraints of Kibera.10

Modern sanitation requires more than a flushing toilet, of course; it helps if there’s a system of sewers to plumb it into, and creating one is a major undertaking—financially and logistically. When Joseph Bazalgette finally got the cash to build London’s sewers, they took ten years to complete and necessitated digging up about 90 million cubic feet of earth.11 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 to accomplish. And those are in short supply. According to a study published in 2011, just 6 percent of India’s towns and cities have succeeded in building even a partial network of sewers. The capacity for delay seems almost unlimited.12

London’s lawmakers likewise procrastinated—but when they finally acted, they didn’t hang around. It took just eighteen days to rush through the necessary legislation for Bazalgette’s plans. As we’ve seen, whether it’s deregulating the U.S. trucking industry, reforming property registers in Peru, or making sure that banking doesn’t destabilize the economy, it’s not easy to get politicians to act with speed and wisdom. So what explains this remarkable alacrity?

A quirk of geography: London’s parliament is located next to the River Thames. Officials tried to shield lawmakers from the Great Stink, soaking the building’s 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.”13 If only concentrating politicians’ minds were always that easy.