Chương 213: 210. Fire Clay

"No, I don't mean to block it permanently," Kivamus explained with a small laugh.

"We will create a small barrier - maybe five to ten feet high in the path of the stream, which will make water gather upstream of it. Once the water has reached the height of the dam, it will begin flowing once again over the barrier, and it will resume the earlier path of the stream.

However, now the water flowing over the dam will be falling to the ground with a lot of force, which we can use to turn a water wheel - hopefully the same one we are using to remove water from the mine shafts - which is why I designed it to be easy to disassemble and in that particular... uh, overshot design." He shrugged.

"Anyway, I know there are fish in that stream, so we will make something called a fish ladder, which will allow them to easily move upstream and downstream of the small dam."

"Wait, wait..." Hudan interrupted with his eyebrows raised very high.

"How the heck are fish going to climb a ladder? No matter what you claim, I simply refuse to believe that it's possible!" Kivamus guffawed loudly at that.

"No, no, the fish are not going to climb like a human. Hahaha..." He explained once he had controlled his laughter, "It will basically be a thin slanted area of the dam on one side, perhaps a foot wide, which will have small steps on it just like a staircase. The fish can easily jump from the level of the river water downstream to the first step, which will only be a... few inches high, and then on to the second step and so on, until they reach the gathered water body on the other side of the dam.

It is just named a fish ladder," he added while trying to suppress his laughter again, "it doesn't mean the fish are going to grow legs and start climbing on a ladder... Don't worry, I may have some really unique ideas, but even I can't make fish do that." Hudan laughed as well along with others at that.

"Well... it still sounds difficult, but it is more reasonable than what I was thinking earlier." Kivamus nodded and explained further, "Unlike now, it won't require a couple of labourers to step on the side cleats to rotate the wheel, since the force of the falling water will be doing it instead. Assuming the barrier can be built high enough, the water can be made to fall right on top of the wheel - which we call overshot water wheel, and which has one of the highest efficiencies of water designs, from...

what I have read in the library. We will attach a long axle to the wheel this time, which will rotate with the power of the falling water with a good amount of torque... uh, rotational force. We can use that force to run a sawmill or to grind grain into flour - just like the ones which are built on the Kal river in Cinran. Even though the designs are a little different, both of the water wheels will perform the same tasks just as well."

"It's only a small stream though..." Duvas objected, still sounding sceptical.

"I have seen those water wheels in Cinran on the Kal River, and those are a lot bigger than the ones you have made for the mineshafts. Can this uh... overshot water wheel really produce the same power as them...?" Gorsazo grinned while looking at the majordomo.

"Are you really questioning another of his otherworldly ideas?" Kivamus groaned hearing that word. By this point it was already a running gag between him and his former teacher, since nobody else knew the real meaning of that word here, but he couldn't call him out on it, since it would require a lot of far-fetched explanation he wasn't ready to share to the majordomo. Duvas snorted in response.

"I know Lord Kivamus' ideas are often mystical, but it sounds difficult to believe that a wheel which is less than half the size of the ones used in Cinran will be able to produce the same power, not to mention we aren't even sure if we can even make a dam here on that small stream." Kivamus shrugged.

"I can't guarantee that it is going to work. There are a lot of ways it can go wrong, but I do believe it is feasible enough to make a dam there. As for the higher power generated by the smaller wheel, that is something I am a lot more confident about. The reason is that the wheel design in Cinran is called an undershot water wheel - where the flowing water just pushes the wheel from the bottom, that is, from under the wheel.

That design requires a large quantity of water to move the wheel - like a big river - but even then it is very inefficient. From what I remember, it can only capture around twenty percent - which is a fifth of the energy of the flowing water to move the wheel." Love this story? Find the genuine version on the author's preferred platform and support their work!

He continued, remembering those huge wheels he had seen while travelling to Tiranat, "You all must have seen those water wheels in Cinran - they are huge, and for a good reason. It's because they need to be big enough to capture a lot of water to push against the paddles of the wheel to move it." Kivamus added, "On the other hand, the design I have made for the mine shafts - which is called an overshot water wheel - is a lot more efficient, even if it is smaller in size.

This design has a much higher efficiency of nearly eighty to ninety percent, since unlike the undershot water wheel which only uses the force of the flowing water, the overshot water wheel also uses the power of gravity to move the wheel. That's why even with a small size, this design can produce a lot more rotational force in the axle. This force can then be used for any task which is difficult to do manually."

"Then why doesn't everyone use this overshot water wheel design?" Hudan asked in confusion.

"It sounds like it would produce a lot more power, especially if the wheel was built as big as the ones in Cinran. It doesn't even sound that complex, so the local carpenters and craftsmen would certainly know about this design there even without someone like you telling them about it." Kivamus raised his eyebrows.

"Think about it. I just told you the answer earlier." When Hudan still looked confused, he explained, "The overshot design requires water to be falling on the top of the water wheel. How can that ever work in a flowing river in the plains, like in Cinran? We can only utilise the overshot design here because we will be making a dam - which simply can't be made in the plains region.

That's why an overshot water wheel is only feasible to make in hilly regions - whether by utilising a dam, or by putting the water wheel right under a cliff where water is falling from a height."

"Oh..." Hudan scratched his head.

"I didn't even think of that..."

"That's alright..." Kivamus looked at Duvas.

"While I didn't do any digging when I visited the coal mines and the stream, I am confident that there must be seat-earth under that soil, since the coal was also formed from some vegetation far in the past." Before he continued, Gorsazo interrupted with a frown, "Wait, you said the coal was formed from vegetation, like trees and plants? How is that even possible? They look completely different!"

Kivamus paused for a moment, not realising he had said something which would be difficult to explain, even if Gorsazo knew about his source of knowledge. He looked at his former teacher with his head tilted, hoping he would take the hint.

"Uh... that's what a book said in the library. We can talk about it later if you want, but it's beside the point right now." Gorsazo looked at the other two people in the hall, both of whom seemed curious.

"Ah... well, you are right. I have a teacher's mind, so I was just curious about it. You should continue what you are saying." Kivamus smiled with relief that Gorsazo hadn't pushed the point in front of others. Hudan asked, "Anyway, what will we even make the dam from? I don't think it can be made from wood, and I'm sure none of us here have any other ideas about it."

"Neither do I," Duvas agreed.

"It has been decades since I had visited that dam near Risalis, and even then I still have no idea what it was made from." Kivamus nodded, remembering from his memories of reading way too many things from the internet in his past life, "That is what I was getting to. So, basically, a common type of that seat-earth is fire-clay - which is basically another type of clay.

We will have to dig under the frozen ground to access this fire-clay, but it will be an excellent material to make the dam with some wooden support." Suddenly he realised another use of it, and grinned.

"Another good thing is that the fire-clay will also be a perfect material to make any refractory lining in a furnace - even a blast furnace - in the future." He knew that it would be a while until they could get to it, but the possibility of making a blast furnace in Tiranat in the future had made him giddy with excitement. Seeing that others were getting confused at this point, he summarised, "Leave the technical parts to me.

But the point is, we need to make a dam on the stream, and preferably before the snow melts, since there would be a lot of water flowing down the hills at that time from the melting snow which will move into that stream, so it can be used to fill the water reservoir very easily. Not to mention, it would be much more difficult to build a dam with a larger quantity of flowing water, unlike now when it is a much smaller stream.

As an added benefit, that reservoir will also increase the number of fish which can live there, apart from the pond we are digging in the south, which will also increase our supply of fresh fish for the village."

"Alright then," Duvas nodded, "I agree that making a dam soon is a good idea, but it won't be easy to dig under the frozen ground. We do have more than enough tools in the village now, but we don't have any labourers skilled in that. No, wait..." Kivamus grinned.

"Yes, exactly! You already realised what I am going to say!"