Chapter 167 - 113: Not Sure If It Can Be Considered a Success

Harano led people to set up camp at the Little River Bend, prioritizing the excavation of the Black Iron Sand there. After all, this place was outside his temporary territory; even though it was still a deserted wasteland and it was unlikely anyone would dispute his washing iron sand, it was ultimately not his turf, so he decided to get things out first and settle the rest later. And sure enough, within a few days, this year’s Meiyu Season also arrived. Fine drizzle began falling endlessly again—building houses and digging ditches was seriously affected—so he simply transferred the majority of the construction crew here: one team continued washing the Black Iron Sand that had accumulated at the river bend over the years, while another went to work building an "Iron Field" within his own makeshift domain. Building an Iron Field was very simple; there wasn’t much technical content involved. You just needed to turn a stretch of river channel into "steps." When water carrying Black Iron Sand flowed through, the continuous undulation of the current would slow the speed, causing the Black Iron Sand to naturally settle. Then manpower could scoop up the silt and wash it nearby. Of course, using a large chunk of magnetite to directly attract iron sand would be faster, but there wasn’t any natural magnetite to be found for now, so the process would just have to wait for future improvements to raise efficiency. For an entire Meiyu Season, all his time was spent on these Black Iron Sands—working every day against the wind and rain, his clothes never dry for more than half a day, constantly slogging through rain and mud. By the time Old Man Sun chased away the clouds and it was time to clock in on schedule again, efforts on both fronts yielded more than twenty thousand catties of Black Iron Sand—just over ten tons. For now, this would have to suffice. He transported the washed Black Iron Sand back to Wanjin, spread them under the sun to dry, hesitated a moment, and realized that the smelting technology would be hard to keep under his own control and he couldn’t guarantee the secrecy of future-era knowledge, so he decided to stick with the ancient Japanese method for now: the so-called "Tabei Method" of steelmaking. This was a matter of principle—he had to at least give it a try first. As for what the "Tabei Method" was... The Tabei is a large, wooden, man-powered bellows, typically over three meters tall; it uses foot-pedaling as a power source and can blow vast quantities of oxygen-rich air into the furnace. Any smelting operation using such a large foot-powered bellows can be called the "Tabei Method." Harano’s mind was made up. He strained to recall all kinds of details from NHK documentaries, trying his best to reproduce what he’d seen. Incidentally, his degree in chemical machinery at least brushed against metallurgy, and at the very least he knew what chemical reactions would arise during smelting; primitive mechanical devices weren’t a challenge either. In less than two days he produced a set of blueprints. With blueprints in hand, he set off to prepare fuel additives—namely, top-grade charcoal and limestone. For the former, he already had a charcoal kiln—also intended for a planned gunpowder workshop. It was quite capable of firing high-quality charcoal; good timber wasn’t lacking in this age, so he sent people up the mountain specifically to pick mature trees, those with exceptionally tight grain—the kind used for luxury crafts in later generations—oak, cork oaks. They chopped and fired batch after batch into fine charcoal, then picked the very best—setting a higher standard than even charcoal made for gunpowder. This was seriously good charcoal. The blocks had virtually no cracks, you’d have to hit hard to break them, and when broken, they would split into neat slabs with hardly any crumbs; the cut surface even shimmered with a metallic luster—absolutely top-notch charcoal. And as for limestone, that was no issue either. It was everywhere; just dig some up and pick through it carefully. At the same time, he selected premium wood and, with the help of carpenters, built two Tabei bellows—one on the left, one on the right—then laid a foundation in the open area between, dug a three-meter-deep pit, tamped the base, laid a layer of fine sand and crushed stone, a layer of charcoal above to absorb damp, then a thick layer of clay over the charcoal, and finally filled and leveled the pit carefully with boulders—where not even, he poured in lime powder to fill the gaps. This was meant to prevent ground moisture from seeping into the furnace, affecting the internal temperature. Once the foundation was in, he led people to pile a mass of clay on top, pounding it hard until it became a square, as compact as could be, then hollowing out the center into a funnel shape and carving out air inlets, slag ports, and other channels. At this point, the furnace was effectively built. He ordered his people to dry-fire the empty furnace, baking it thoroughly and setting its shape. Now—materials, furnace, bellows, fuel additives, and charcoal—everything was ready. They could begin smelting the iron sand. Harano was still very cautious; he checked everything several times, thought through the process again and again, and only when satisfied he’d missed nothing did he order people to start loading materials. A layer of charcoal, a layer of iron sand, a sprinkle of limestone, then charcoal again, iron sand, and another thin layer of limestone, repeating until the furnace was two-thirds full. Then they lit the furnace. The tabei bellows got to work, two men on each, calling out in rhythm, bobbing up and down, working the bellows like a seesaw, slowly blowing air in. The furnace didn’t hesitate: with the belly packed with high-quality charcoal and no shortage of oxygen, a bright red flame roared instantly, shooting toward the sky—then quickly shrinking back, the color shifting toward dark red, while the heat radiating out was astonishing. At least, astonishing to the human body. Harano, even standing a fair distance away, couldn’t take the heat and was forced to retreat several steps further. In these times, smelting iron was rare and could entail "family secret techniques." Naturally, Ah Man and the others ran over to see the spectacle. When the fire was finally lit, Ah Man immediately asked with concern, "How long until we see iron?" This wasn’t just smelting iron—it was smelting money. Of course she cared and hoped it would succeed soon. "About three days or so!" Harano replied softly, keeping his eyes glued to the furnace—worried the contraption would fall apart right in front of him without giving him any face—though, thankfully, the half-meter-thick furnace wall held strong and reassured him a little. Ah Man nodded half-understanding, but quickly asked, "So you just keep burning it like this? Do you need to throw a person in?" Harano was still focused on the furnace and, when he heard this, didn’t react at first. He asked in confusion, "Why throw a person in?" "With all this commotion and how important it is, shouldn’t you throw someone in? Like when building bridges or cities, you always need a human sacrifice, right?" Ah Man looked totally matter-of-fact, and those nearby didn’t react like it was anything odd—apparently this was common sense for the times. Harano was left speechless. What the hell is "human sacrifice"? You’re just smelting iron—how did that get involved? I really don’t get it! He looked around and saw there was quite a crowd come to watch, even Endo Chiyoda, the "Grand Steward," standing there with three young assistants, gazing at the roaring fire in amazement—never mind the rest. He hurriedly waved everyone away, gesturing for them not to hang around, saying they’d seen enough novelty for today and should get back to contributing to Wanjin territory. Once all the idlers were gone and there was no need to worry about saving face, he finally asked Ah Man, "What’s a human sacrifice?" "It’s a living offering!" Ah Man was no longer surprised by his lack of common sense. Watching the "marvel" of iron-smelting, she offhandedly explained, "If you’re building a bridge or a castle—big noisy projects—you might anger the gods, earth spirits, or vengeful ghosts, so ahead of time you bury a person to placate them. For example, there’s someone buried in one of the piers of the Yodogawa Bridge—he became enlightened and is now called... Ksitigarbha, Pillar-of-Human-Sacrifice." She paused, then added, "It’s the same when building castles—you always need a poor soul to be buried first. In most castles in Owari there’s a human sacrifice under them, otherwise, how could they be so stable?" Harano was left speechless again. Every time he felt like he was getting used to this era, it hit him with a slap in the face and another bizarre, psychologically-taxing anecdote. Or maybe he’d ended up in the wrong place—elsewhere, in the sixteenth century, this sort of thing probably wouldn’t still go on, or at least not as a common practice. He held his tongue for a while before shaking his head. "Don’t ever talk like that again. We’re not doing anything like that." "Fine, it’s your business, you decide!" Ah Man wasn’t fussed—it was Harano’s own business, after all. She didn’t know anything about smelting iron, just giving some suggestions and sharing what people usually did for big deals. "You go on back now!" Harano began feeling she was in the way—the furnace would need three more days of tending and he couldn’t have her lounging around the whole time. As for himself, of course he had to stay here. For now, he was the only technical person Wanjin had, and he also had to keep records and refine the process—just meant more work for him. After more than an hour, the color of the flame began changing again, gradually shifting from dark red to orange-red, becoming brighter—noting the rising temperature. With his head and face wrapped for protection, Harano moved closer to observe, supplemented his observations with what he knew, and judged that the iron, being heavy, had sunk to the bottom, while lower-melting impurities had started to separate and float up. He ordered the bellows paused, grabbed a large iron ladle, and quickly began scooping slag from the slag port at the furnace center. Once the slag was cleared, he had people pour more fresh Black Iron Sand, charcoal, and a bit of limestone in from above, sending in fresh air for a new round of smelting. This cycle repeated endlessly; the furnace temperature kept climbing, the flame finally turning golden yellow, scarcely visible even in daylight. By this point it was the third day, and finally the furnace surface cracked, its historical mission now complete—this kind of primitive clay furnace was single-use: each smelt meant making a new one from scratch. Harano’s eyes were bloodshot by now. He hurriedly told everyone to stop the bellows, waited a few more hours for the furnace to cool, then had people suit up and smash the furnace apart, clearing away any unburned charcoal. The process was easy. The furnace wall, once nearly half a meter thick, had burned down to barely more than ten centimeters after three days, and once all the junk was removed, all that remained was a big, porous lump of "sponge iron." The whole smelting process, to put it plainly, was that Fe3O4 and Fe2O3 reacted with carbon monoxide from the burning charcoal, the CO stripping away oxygen to become CO2 that rose up the chimney, and what was left without oxygen was just iron. But because the furnace never reached anywhere near 1500 degrees, the iron never fully melted into liquid, remaining half-solid, with most impurities burned away—which is why it ended up as a spongy mass full of holes. Or, in other words, a lump of low-grade steel-iron mix. Harano studied the mass of "sponge iron" carefully, ordered people to break it up while still hot and drop it into the cooling pool, then sorted it by color: most was inferior pig iron that would need laborious hammering to remove impurities before it could barely be used, a small amount was pure iron, and a little bit was low-temperature carbon steel accidentally formed when pure iron reacted with carbon monoxide—the so-called "tamahagane." This result... well, hard to say. Not great. Harano looked at the heap of messy iron and steel on the ground, not at all sure if this counted as a success.