Chapter 28
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Translator: Wjin
Chapter: 028
Chapter Title: Return (2)
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Outskirts of the Sternberg Estate, along the Sázava River.
The site resembled a battlefield turned massive construction zone.
Dust clouds billowed thickly as hundreds of laborers swarmed like ants, digging irrigation channels to divert the river water.
On one side, grunts pierced the sky as workers hauled ropes to erect the axle of a gigantic waterwheel.
"There! Pull harder on the ropes! The axle's tilting!"
"One, two, three! Heave!"
And at the center stood several bizarre structures towering like the Tower of Babel.
Enormous chimney-like towers built tall with firebricks and clay.
They were the medieval world's first modern blast furnaces: Sternberg Units 1 through 3.
I led the distinguished guests I'd brought from Prague toward them.
"Your Highness, what in the world is this?"
Hanush, master of the Prague Blacksmiths' Guild, wrinkled his nose and pinched it shut.
"Didn't you say you were building a forge? But there's no hearth or anvil in sight—just these monstrous chimneys. What, are you baking bread here?"
The artisans and apprentices behind him murmured. Their eyes held more contempt and doubt than curiosity.
"Country folk have some odd ways of building forges."
"That tall, and the fire just rushes up and out—how's the iron supposed to heat?"
"His Highness has been duped, clearly. Iron from those freakish towers?"
To them, a forge meant the clang of hammers and the whoosh of bellows.
But what I aimed to build wasn't a medieval workshop—it was a modern steel mill.
"Master Hanush."
"Yes, Your Highness."
"You've hammered iron your whole life. So you must know its properties well."
Hanush puffed up proudly.
"Of course! No famed sword in Prague has escaped my hammer."
"Have you ever made iron flow like water?"
Hanush blinked blankly at my question.
"Pardon? Iron... flowing?"
"Exactly as I said. Molten iron. Iron boiling and flowing like water or oil."
Hanush and the artisans exchanged glances before bursting into uncontrollable laughter.
"Pfft... hahaha! Your Highness, that's a bit much for a joke. Iron glows red and softens when heated, but it doesn't flow like water. That's alchemists' nonsense."
"Exactly. If there's a fire hot enough to melt iron, it'd be the flames of hell itself."
The Prague artisans were utterly convinced. And why not? Medieval bloomery methods couldn't fully melt iron.
At best, they'd extract half-molten lumps—what we call wrought iron—and smiths would sweat buckets hammering out impurities.
To them, liquefying iron completely was physically impossible, the realm of gods.
But not to me, coming from the 21st century.
"Oh? Quite sure?"
"Yes! Absolutely!"
"Then I'll show you. That hellfire you mentioned."
I nodded toward the top of the tower.
"Tomasi!"
"Yes, my lord! No—Your Highness! Sternberg Unit 1 is finally firing up! I've waited for this day!"
Tomasi had been one of those who shook his head at my blueprints at first.
But after prototype tests, he was now more devoted to this furnace than anyone.
"Charge it! Heat the base with charcoal, then dump in the fuel!"
At Tomasi's shout, workers on the wooden platforms atop the tower sprang into action.
"Fuel in!"
Whoosh—!
Workers upended sacks, pouring lumpy gray chunks into the furnace maw.
Hanush, watching, furrowed his brow.
"What is that?"
He sniffed.
"Not charcoal... but not coal either—the color's off. Full of holes like volcanic rock. You're not seriously using stones as fuel?"
"Close. It's called coke."
"Coke...?"
"Coal, distilled to its essence."
Medieval folk knew coal as "black stone" and burned it for fuel sometimes.
But they couldn't melt iron with it—sulfur in the coal made the iron brittle.
So I'd built a firebrick kiln beforehand, pyrolyzing coal in airtight high heat.
Driven off impurities and tar, leaving pure carbon lumps. That's coke.
Its heat output dwarfed charcoal.
"Distilling stone for fuel..."
Hanush looked incredulous.
"Your Highness, stones don't burn. No matter how hot, they can't outdo firewood."
"Just watch."
Tomasi kept shouting orders.
"Ore in! And limestone!"
Rumble—!
Red iron ore and white limestone powder cascaded onto the coke.
Hanush recoiled in genuine horror this time.
"What now? Dumping stone dust into a perfectly good hearth? That'll smother the fire cold!"
"Will it, though?"
Hanush couldn't know. This humble limestone was the magic powder to melt iron.
Silica impurities (SiO₂) in iron ore have sky-high melting points. Left alone, the iron won't melt—it just clumps like dough.
But add calcium oxide (CaO) from limestone?
It reacts, slashing melting points, turning impurities into slag that floats away.
To the chemistry-blind, though, it just looked insane.
"Blowers on!"
At my signal, the massive waterwheel by the river creaked into motion.
Screech—thunk!
The axle spun, and dozens of man-sized leather bellows inhaled in unison, then blasted compressed air into the furnace tuyeres.
A shockwave roar erupted.
No gentle forge whoosh—this was different.
Roooaaarrr—!!
Like a dragon awakened deep underground, bellowing rage.
Coke ignited, unleashing calorific fury beyond charcoal.
Onlookers at a distance felt their skin prickle from radiant heat.
"Gasp!"
Hanush and the Prague artisans staggered back in terror.
"Wh-what's that noise? It's exploding inside!"
"Fall back! It's gonna blow! That thing's blowing!"
Stones burning. Fiercely, like hellfire.
Utterly beyond their comprehension—pure terror.
The Prague men panicked.
But Sternberg's technicians stood firm.
"Temperature rising! Internal pressure normal!"
"Keep the air blasting! Don't stop!"
Jakub and Tomasi, faces smeared black with soot and sweat, clung to the furnace, tweaking the blowers.
As time passed, the roar grew fiercer; the tower walls glowed cherry-red.
Dazzling light and blistering heat that could blind.
Inside, tough ore succumbed to coke heat, liquifying.
Reduction reaction: perfect.
Time to cut the beast open.
"Tap it!"
At my order, Tomasi gripped a long iron rod and approached the tap hole at the base.
A small mud-plugged hole.
"Break it!"
Clang! Clang! Splat!
Tomasi hammered the plug mercilessly.
The moment the hardened clay shattered—
Flash!
Like the sun crashing to earth.
"Agh! My eyes!"
Onlookers screamed, shielding their faces.
Then, behind the glare—an impossible sight.
Gush—!
It was water, yet not.
Perfectly liquid molten iron.
The hardest metal, yielded to fiercest heat, flowing like water.
Cherry-red metal raced down pre-dug sand channels, filling spread molds.
"Uh... uhh..."
Hanush collapsed to his knees, legs giving out. Prague's top artisans gaped speechless.
"Molten iron... actual molten iron flowing..."
Not hammered into shape, but poured like water? Decades of smithing wisdom melted before their eyes.
Bathed in the glow from behind, I looked down at dazed Hanush.
"See it now, Hanush? The 'impossible' you mocked."
"Y-Your Highness... how...?"
"The handiwork of those stone lumps you laughed at: coke and limestone."
Hanush murmured blankly.
"...What is this truly? Magic? Did Your Highness borrow hellfire from the devil?"
I shook my head lightly.
"No magic. Chemistry."
"Chemistry...?"
"Yes. The science of change, for those seeking this world's truths."
I pointed at the flowing metal.
"Your hammer couldn't make a single suit of armor in a year of nonstop pounding. But look."
The outflow had already filled dozens of sand molds, cooling.
One tap yielded what a hundred smiths slaving a month could produce.
"I can churn out tons of this iron daily."
Hanush's eyes quaked.
His face mixed awe at an insurmountable craft barrier with helpless defeat—as a craftsman.
Dazed, he rose and staggered toward the glowing channel, braving the heat.
"Beautiful..."
He muttered like a man possessed.
"So... beautiful..."
Hanush's entranced whisper.
In that moment, the Prague artisans' eyes changed.
No more haughty guild pride. Only raw hunger for unknown craft burned there.
Hanush, still fixated on the glowing metal, asked:
"Your Highness, what must we do? What shall we forge from this miraculous molten iron?"
I thumped a cooling, solidified ingot in its mold.
"Sadly, this is useless trash as is."
"Pardon? Trash?"
I hefted a hammer and smashed a pre-made pig iron sample.
Clang! Crack!
Instead of denting, it shattered like glass, shards flying.
"Gasp!"
Artisans recoiled.
Iron not breaking, but shattering like glass?
Impossible by their logic.
"See? Too hard, and it shatters instead."
I tossed a shard to Hanush.
"This is pig iron. Loaded with excess carbon—impurities. Bloated like a greedy pig: hard but brittle. Won't scratch, but one hit and it explodes."
Like diamond: hardest, yet hammer-shatters.
Fine for pots or tools, but no swords, armor, or cannons.
"So we remelt this piggy iron, hammer off the fat."
"The... fat?"
"Exactly. Force out the impurities. Then it becomes true steel: strong yet tough."
"Steel..."
Hanush fiddled with the shard, swallowing hard. He nodded slowly.
"Then we hammer this molten iron into shape."
"Right. That's where your hands come in. My meisters excel at furnaces but lack finesse with iron."
I placed a hand on Hanush's shoulder.
"I'm not after swords or armor. Plates. Can you hammer this pig iron into perfectly uniform steel sheets?"
Hanush nodded firmly.
"Leave it to us, Your Highness. We'll deliver mountains of steel sheets to clad Prague's walls."