After admitting to himself that while he could build a waterwheel, he did not know much about how its rotational force was transferred to a millstone... Jin decided to change his approach.
"Are there any millstones left?"
"Yes. They're made of stone, so even though the watermill shed was crushed, the millstones were fine," Helga answered.
"All right, that's good to hear. Where are they?"
"For now, they've been placed in the corner of the plaza."
Four millstones had been in use before. Apparently, two were powered by the waterwheel, while the other two were turned by hand.
"Let's go take a look."
"This way."
Guided by Helga, Jin headed toward the plaza.
Located in the southern part of the village, the multi-purpose plaza served as a marketplace whenever peddlers visited and as a collection depot during the harvest.
Over in one corner, the four millstones sat stacked together.
"Huh?...Ah, were these two scorched by fire?"
Their colors were completely different. The two that appeared to have caught the fire were literally burnt brown.
The two hand-cranked stones were the ones that had been scorched.
Since the stones for the waterwheel had been located right by the river, they seemed to have escaped the flames.
"Reiko, set them down, please."
"Yes, Father."
Even though they were hand-operated millstones, each measured thirty centimeters in diameter and weighed over thirty kilograms.
Reiko effortlessly picked up the pair and carried them over, setting them down before Jin.
"Th-That's incredible..."
"That really is amazing..."
Reiko held one thirty-kilogram millstone in each hand.
The millstones here consisted of two short, cylindrical stone pieces stacked on top of each other.
Lifting the top piece would separate it from the bottom, so Reiko supported the lower half. However, she held each stone merely by pinching its bottom corner with her fingertips. It was little wonder Helga was flabbergasted.
Passing villagers stopped in their tracks, eyes wide in disbelief.
"The inside isn't scorched."
Since the grinding surfaces looked unharmed, Jin used "Forming" to shave off a thin layer from the exterior surfaces of the stones.
"Wow, they're so clean now."
"Amazing..."
The contrast between Kachea's and Helga's reactions simply reflected how much total time each had spent watching Jin work.
Regardless, though the millstones had become about two millimeters smaller, their original appearance was restored to perfection in roughly thirty seconds.
"Will you be able to get some work done with these two?"
"Definitely! Thank you, Jin-san."
Helga beamed with joy, while Kachea calmly chimed in.
"We'll need a milling shed, though."
Grinding wheat had to be done indoors; otherwise, the flour would blow away in the wind.
"We'll also need non-woven fabric masks."
Jin couldn't help thinking that he seemed to find himself in dusty, powdery environments quite often lately.
"Naturally, we don't have enough materials on hand to build a shed right away."
This was not Hourai Island, so he couldn't just go chopping down whatever trees were nearby.
Fortunately, there was still more than a month until the wheat harvest. That gave them plenty of time to prepare.
Milling shed, Jin jotted down as the third item in his mental notes.
Leaving them exposed to the elements would be a bad idea, so they decided to store the four millstones in the livestock barn currently under construction.
Since the animals had yet to arrive, the building was completely empty.
Jin added Livestock as the fourth item on his mental notepad.
Next, Jin and the others headed toward the eastern side of the village.
"Over this way were the river and the washing area, right?"
A reservoir had been built using water drawn from the Noshina River, where the villagers did their laundry and general washing.
"In the past, people would draw well water and just dump the wastewater all over the place," Kachea remarked.
"For the sake of the environment, wastewater needs proper treatment."
"Indeed."
When they arrived, the reservoir proved to be quite well constructed, having been built under the guidance of Avalon.
First, an upstream pond had been established, where they were beginning to farm a species of trout.
The tier below held the washing area, and downstream from that, two settling ponds had been excavated.
"Do they treat the water in the settling ponds at all?" Jin asked Helga, curious about the setup.
"Yes. Nothing is being done right now, but they said a Cleanup magi-device will be installed before summer."
"That should work well, then."
Relieved, Jin saw that there were no apparent issues on that front.
"Did they mention what to do with the sludge that accumulates in the settling ponds?" Jin asked, pursuing another point of interest.
"Um, I heard that before winter, they'll drain the water, and mixing the sludge with fallen leaves makes it good for the fields."
"Ah, I see."
Purified sludge would be rich in organic matter, so mixing in leaf mold might indeed make for good compost... or so Jin reasoned.
"Still, I have a feeling it might end up quite acidic."
"Ah, I think they also mentioned it'd be good to mix in crushed eggshells or leftover meal bones around that time."
"Would that do the trick?"
Bone meal was mostly calcium phosphate, so it ought to be slightly alkaline, Jin thought.
"If possible, it would probably be best to mix in plant ash as well."
Plant ash contained plenty of potassium and was undoubtedly strongly alkaline.
Using only leaf mold and bone meal would provide ample nitrogen and phosphorus, but Jin suspected the soil would lack potassium.
Incidentally, nitrogen, phosphorus, and potassium were known as the three primary fertilizer nutrients.
"Would ash from the hearth work?"
"I think that would be fine."
Since firewood was the only fuel used in the village, the residue was pure wood ash, meaning there would be no problem using it.
With that, Jin made a mental note of Agricultural guidance as his fifth item.
From there, Jin and the group walked upstream along the Noshina River, heading toward the northern edge of the village.
"The riverbank doesn't seem to have changed much."
Glancing over at the gravel bank where they had once searched for raw whetstones, Jin and the others looped around the village's northern perimeter.
"Were the fish all right after everything?"
"Yes, thankfully. Most of the game animals ran away, so we ended up eating nothing but fish for a while, though," Helga said.
Even so, it was a blessing that the river was bountiful enough never to run out.
Fish farming might actually be exceptionally suited to this place, Jin thought, adding Aquaculture guidance to his mental notes as well.