The Flush Toilet
To be perfectly honest, Hwiyeom had never meant to rush the sewers like this.
His original plan had been to use the night soil collected from traditional privies to cultivate chojeon—saltpeter fields.
Saltpeter, or niter, was the most vital ingredient of black powder after sulfur. To obtain it, one had to spread manure and straw across the earth, turn the mixture, and let it ferment. White crystals of potassium nitrate would then rise like frost on the surface of the soil; that powder was saltpeter itself.
So how could he possibly introduce flush toilets that simply washed away the precious raw material?
Yet while he was developing a coal seam on land he had recently purchased, the diggers uncovered something unexpected.
Natural guano caves?!
He had sent the men in for coal. Instead they stumbled upon several caves thick with guano—bat droppings compressed over centuries into a mineral rich in nitrates and phosphorus. It made superb fertilizer and an outstanding ingredient for gunpowder. Before Fritz Haber’s ammonia synthesis, most of the world’s fertilizer had come from guano.
“Long live Sichuan!”
With coal, sulfur, and now guano in hand, there was no longer any need to hoard human waste.
Besides, the stench alone made me want to get rid of the old latrines the moment I had the chance.
A Tang clansman had to distinguish every poison by scent; sensitive noses made the reek of the privy pure torment. While that resentment was still simmering, the cholera outbreak at the Emei Sect—caused by latrine runoff fouling the drinking water—had erupted. Then the guano caves appeared. Hwiyeom decided to wipe the old pit toilets off the map.
At the very least, every latrine in the Family Head’s residence and in my research halls will be replaced. The collateral branches and the Council of Elders can fend for themselves.
He was installing flush toilets for his own comfort, not staff welfare, so he dismissed the discomfort of the branch houses without a second thought.
And so construction began on the Central Plains’ first flush toilets.
Hwiyeom first laid a water main that tapped the aqueduct spanning the Tang compound’s walls. Because it connected at the height of the ramparts, the pipe ran higher than a grown man’s head. It fed the rooftop of the new toilet building; from there a siphon carried the water through slender copper tubing into a cistern above the stalls. That cistern filled the flush tanks mounted high over each seat. A long chain hung from every tank. Once a user finished and pulled the chain, the stopper lifted, water rushed down the pipe, and the waste was washed away. When the chain was released, the flow itself sucked the stopper back into place and the water stopped. It was the same early flush mechanism once common in rural outhouses.
The outflow traveled through cement pipes buried underground and emptied into a ravine five li from the estate. Some might have called it filthy, yet in an age when night soil was either used as fertilizer or simply dumped in the nearest stream, no one found the arrangement particularly strange.
Compared with the reservoir and aqueduct that had supplied clean water, the sewers took far longer. Contaminated water had to be carried a great distance without leaks; there was no shortcut. From groundbreaking to the day the Tang compound opened the Central Plains’ first flush toilets, exactly one year passed.
The reaction was explosive.
“The privy doesn’t stink!”
“No more flies and maggots!”
“And it’s inside the building! No more groping for a chamber pot in the dark and knocking it over!”
Hwiyeom had demolished the old outdoor latrines and built indoor facilities in the Family Head’s residence, the council chamber, his mother’s rooms, and several public spots. Everyone had objected to the idea of a reeking toilet inside a building, but Hwiyeom had bullied the project through by sheer stubbornness. Now the same people sang his praises with one voice. These were nothing like the foul pits they remembered—dark holes roofed with planks, buzzing with flies, where a careless step could send a foot plunging into the muck.
White-glazed tiles lined the walls; blue-glazed tiles covered the floors. Modern porcelain seats sat in each stall, complete with washbasins and drains. Open a faucet and water poured from the rooftop cistern; one could finish business and wash one’s hands in comfort.
Word of the Tang family’s “clean toilets” rode the boasting of servants and kin into the streets of Seongdo. At first no one believed it. When the household staff kept repeating the same tale, curiosity began to stir.
The Council of Elders belatedly grew restless.
“Ahem! Young Family Head, perhaps our council hall might also receive one of those flush toilets…”
“Weren’t you the ones who said putting a filthy privy inside a building was unthinkable?”
“Cough—well—my own poor judgment led me to speak rashly. Now that I understand otherwise, even at this late hour…”
“I’ll think about it.”
When Hwiyeom refused to grant permission on the spot, the elders looked pitiable. Their habit of opposing for the sake of opposition, of carping simply to carp, had finally bitten them. Regret arrived too late.
During the year of toilet construction Hwiyeom continued his martial training, stabilized coal production, and founded a new bureau dedicated to mass-producing cement—the Construction Hall. Dang Un-sang quietly folded the ironworks and blast furnaces (already de facto Hwiyeom’s), their blacksmiths, the new Construction Hall and its carpenters, and the Poison Pharmacy with its physicians into a single organization.
He named it the Innovation Hall, meaning the place that would drive the Tang family’s transformation. Hwiyeom became its first director on his tenth birthday.
To safeguard the secret inventions born there, Dang Un-sang posted warriors of the inner household as permanent guards. No one outside the hall’s own craftsmen and physicians could enter; even direct blood of the main line needed permission from Dang Un-sang or Hwiyeom. The Council of Elders grumbled, but Hwiyeom’s results—and the reminder that the Tang family had always been fanatical about protecting its poisons and hidden-weapon techniques—silenced them.
While overseeing the sewers, Hwiyeom finished designs for a new type of furnace and secured a site. Because both construction and structure had to remain top secret, he tore down a wall near the Innovation Hall, cleared the adjoining forest, and built there. Panic swept the branch houses and the Council.
The Young Family Head is building a furnace better than the crucible furnace!
Still smarting from the earlier crucible-furnace episode, the elders spared no effort to learn the new design. They sent spies to the site and tried to suborn the hall’s carpenters. Dang Un-sang answered with an iron fist: the Poison Bee Unit, the family’s internal auditors, was stationed on site day and night, backed by inner-household warriors.
“Hah! Clearly the main house no longer regards the branches as family! Even kin are barred!”
One elder finally snapped. Dang Un-sang’s answering smile was cold.
“Wasn’t it a branch member who sold the secret of the crucible furnace? This time I will guard security with every drop of blood. Should I find a traitor, I intend to pickle him in every poison we own.”
“…Ahem.”
The elder who felt the barb fell silent. Every ironworks in Sichuan was already converting to crucible furnaces. The change had spread so suddenly that the Tang family could not even identify the original leak, and so no one had been punished. Exact blueprints had never been recovered, and the Tang monopoly on coal still forced rivals to burn charcoal; their iron remained inferior. Yet the leak was real. Since no one of the main line would have sold the secret, Dang Un-sang’s warning—“It came from the branches, and we know you stand behind it”—left the other elders clearing their throats and shutting their mouths.
Looking at the structure this time won’t help them anyway.
Hwiyeom watched and smirked. What he planned to introduce was Henry Cort’s puddling furnace. Coal and coke burned in a firebox; the radiant heat reflected from a hemispherical roof melted ore on the far side of a bridge wall. Because the firebox could be enlarged and separated from the hearth, high temperatures were easy to maintain, and a spacious reverberatory chamber allowed great quantities of iron to be melted at once—ideal for mass production. Without knowledge of modern electric arcs, this was the most advanced furnace Hwiyeom could build. The design itself was simple. The real challenges were a ceramic lining that could endure and transfer the heat without loss, and a large, profitable structure whose skeleton would not warp like wood under heat.
Ceramic research was conducted inside the Innovation Hall, far from the construction site. The massive frame was poured concrete—cement, gravel, and iron reinforcing. An outsider staring at the worksite would learn nothing useful.
Without the secret of cement, they’ll just mix mud and lime around iron posts and call it concrete.
Hwiyeom quietly hoped someone would try to copy it and suffer a spectacular accident.
“That is exactly what happened.”
One morning Ye-eun delivered the report. Hwiyeom’s mouth fell open without his noticing.
“Who?”
“Jinpyeong Construction, owned by Elder Jong Ri-hyeok’s son-in-law. They built a furnace out of counterfeit gonguri—lime-and-mud plaster with bamboo reinforcement. That’s what we’ve decided to call concrete.”
“So the site was exposed. And then?”
“Because it wasn’t proper cement and they used bamboo instead of iron, the work went quickly. Yesterday they lit the furnace for the first time. Before the first iron even melted, the whole thing collapsed.”
“Idiots. It’s not even a jerry-built apartment.”
“Pardon?”
“Nothing. Still, even plain lime plaster should have held better than that. It’s stronger against heat than ordinary mud…”
“Apparently Jinpyeong Construction cut the expensive lime and padded the mix with flour.”
Hwiyeom’s jaw dropped at the self-inflicted wound.
“Amazing. Truly, they never disappoint. Are they the witch from Hansel and Gretel? Why are they building a house out of cookies…”
“Sir?”
“Never mind.”
The Poison Bee Unit paid Jinpyeong Construction a visit that same day. A little armed persuasion uncovered that the firm’s owner was indeed Elder Jong Ri-hyeok’s son-in-law and that the elder had supplied the puddling-furnace blueprints. Jong Ri-hyeok protested his innocence, but Dang Un-sang was not about to waste an opportunity for exemplary punishment.
If I let this slide with a light slap, they will only move more secretly and more carefully next time. Blind greed might even cause a larger disaster.
The Council of Elders had already once tried to drive Hwiyeom into a death trap during the Emei cholera affair. The anger of that day still burned in Dang Un-sang. Before the elders could unite and cry for mercy, he sent the Poison Bee Unit to seize Jong Ri-hyeok, broke his limbs, stripped him, and dropped him into a vat of strong acid. When the Council learned of it too late, they were stunned. Word that the Family Head had watched the thrashing elder melt slowly away, killing intent naked on his face, left them breathless.
What a savage clan.
To close every loose end, Jinpyeong Construction was annihilated that very day. The firm begged help from every power in Sichuan, even petitioning the Emei and Qingcheng Sects. Emei, long friendly with the Tang, simply called it “an internal family matter.” The officials of Seongdo, fattened by aggressive Tang bribery since the cosmetics boom, invoked the principle of non-interference in private clan affairs. Only Qingcheng tried to pick a fight, sensing opportunity—until the Tang produced a justification that, in the martial world, was absolute:
“We are punishing the leakage of a clan’s secret arts. Outside sects will not interfere.”
Even Qingcheng found no pretext to intervene against that cold, glittering blade of legitimacy.
While the entire Council and every branch house still reeled from the brutal death of one of their own, and with the puddling furnace nearly complete, the Sichuan Tang Family received a visit from the Pojeongsa couple.
“…What have you cooked up this time?”