Chapter 78

After the fourth period, lunch time arrived.

Along with Yuna and Sori, who were growling at each other, we lined up in the cafeteria with Ji Hye.

Everyone was busy chatting about the performance assessment that had taken place in the morning.

Ji Hye clapped her hands.

“You guys were competing with numbers in your class too! Our class had a new record of 9.3.”

“Seriously, it was so close, Ji Hye! In the end, I also got over 9!”

“So who came in first? Was it Namé again?”

“Ahem…!”

“…?”

Yuna proudly lifted her chin and snorted.

“You had Namé helping you the whole time.”

Sori glared at her sullenly.

Since the end of the second period, Yuna’s elevated tension showed no signs of dying down.

Having already had the necessary information once, Sori conveyed it to Ji Hye the same way.

“But injecting mana so accurately was really difficult!”

“Yeah, yeah, you’re amazing!”

“But how did Namé figure out those numbers?”

The structure of the model magic circle went beyond elementary school level content. It might even be suitable for middle or high school.

It was natural for Ji Hye to have questions.

“What we received was a magic circle that satisfies the harmonic mean. If the optimal solution for the north is 150 and for the south is 200, then the overall would be around 171.42.”

“What’s the harmonic mean?”

“Umm… how should I explain?”

If I said it’s the average of the reciprocals of the values taken as the reciprocal itself, they might not understand.

In this case, it was easier to explain with simple numbers.

“What’s the average of 1 and one-third?”

“Umm… uh… I feel like I should know this, but wait a moment!”

Ji Hye squeezed her head and finally came up with an answer.

“Three-thirds? No, that’s 1! Two-thirds?”

“Oh, our Ji Hye is smart!”

“Aah, don’t tease me when you know everything!”

She swatted Sori’s hand away as he stroked her head.

“This is how you find the harmonic mean. Answer one of my questions. What’s the reciprocal of 1?”

“That’s 1.”

“Then what’s the reciprocal of one-third?”

“Is it 3?”

“Now find the average of those two.”

“This one is easy. 2!”

“And then what’s the reciprocal of that?”

“Umm… one-half?”

“That’s correct. That’s the harmonic mean. Got it?”

“No, I don’t understand at all!”

I thought I explained it simply.

I guess I really don’t have a knack for teaching kids.

If I struggled with such simple math, I can’t imagine where to even begin with Adella later.

Anyway.

We received our lunches in order and went to the far corner of the cafeteria where we each sat down.

As always, Sori sat next to Ji Hye and Yuna sat next to me.

“Wow, bulgogi looks really delicious.”

Yuna smiled brightly as she set her tray down. Fortunately, today she piled her tray high with rice and meat dishes.

“Are you only going to eat that again today? Want me to share some of my meat?”

“No, it’s fine.”

“If you eat so little, you might get sick later.”

That would be because she could only eat a little due to being sick.

I put the bulgogi in my mouth while hoping Professor Cheon would bring good news about potions soon.

Unlike the usual chatter, today’s atmosphere was quiet.

Sori and Yuna rolled their eyes, seemingly thinking about the harmonic mean I explained earlier.

Unlike Sori, who was continuously trying to understand, Yuna, who had grasped a certain level of understanding, asked me again.

“I understand now, but I still don’t know what that coil magic does.”

“Are you curious about coil magic, Yuna?”

“No… Ah, yeah, actually I’m curious. Please tell me…”

Uncharacteristically, Yuna bowed her head and asked.

It seemed she really was curious about that magic despite her strong tendency to avoid admitting when she didn’t know something.

How could I explain it easily?

There’s a limit to just speaking it out loud.

“I’ll show you when I take the potion later.”

Surely the only good way is to demonstrate directly.

* * *

Formulas and theories are merely supplementary when explaining magic.

Ultimately, to understand magic, one needs a more intuitive observation of why such phenomena occur.

I took Yuna to the school backyard.

Right next to the fence that separated the middle school and elementary school, I placed a potion bottle I had brought from class.

“Why are we here?”

“I came to show you magic.”

“It’s scary because no one is around.”

Indeed, unlike the garden in front of the main building, the backyard was overgrown with weeds.

It helped create a creepy atmosphere.

But the reason I chose this spot was that people rarely passed through here.

“Did you bring a pen you aren’t using?”

“Yeah, this one is broken, so I don’t use it anymore.”

I took out all the contents of the four-color pen that Yuna handed and left only the plastic casing.

With that, all preparations were complete.

“The model you saw earlier is a magic that generates heat using an electromagnetic coil. I’ll try to recreate it as closely as possible, even if it won’t be exactly the same.”

Before opening the potion, I inscribed the appearance of the magic circle on the ground.

It might be hard to understand just by looking at the appearance, but from now on, let’s channel my inner top instructor and explain it as simply as possible.

“This twisted wire is called a coil.”

“I know what a coil is! We learned it in science class in first grade.”

“Oh, then explaining it becomes easier. This part here is the formula that makes current flow through the coil.”

“Current?”

“I mean electricity.”

“It makes electricity flow? Why?”

“When electricity flows through the coil, heat is generated.”

“So the coil gets hot?”

“Yeah, it gets really hot.”

I skipped over the explanations of voltage, current, and resistance.

Right now, just the common knowledge that current makes the coil hot was sufficient for understanding the magic circle.

“If water gets hot, what happens?”

“Umm… hot water?”

“Make it hotter.”

“It turns into steam!”

“That’s right. From now on, we’re going to turn a liquid into a gas using the coil’s heat.”

First, I drew the inscribed magic circle on the ground and linked it with the pen.

Since the part that operates with electromagnetism was complicated, I boldly removed it and modified the magic circle to allow for regular current supply.

[Inscription: Heat Transfer – Coil]

I additionally recorded the pointer formation formulas to ensure the pen followed the principles written down by the magic circle.

“Yuna, you can think of it as a small coil being inside the pen right now.”

“Okay.”

“What do you think will happen if you drop a potion onto the hot coil?”

“Isn’t the potion going to turn into smoke? Or will the coil cool down?”

“Since the coil can’t cool down, I’ve put cotton in the middle. You’ll drop the potion one drop at a time onto that cotton.”

“Then it’ll turn into smoke!”

Yuna confidently said, and I affirmed her answer.

As soon as I opened the potion cap, I inserted the pen into the flask opening.

Covering the remaining space with clay left over from art class last week ensured that the residue wouldn’t oxidize.

An amusingly shaped structure was created, but it wouldn’t be easy to explain this magic any better than this.

“In essence, the key to this magic is resistance. Look closely. If I inject mana here, the total resistance is 0.5 ohms, okay?”

Tap, tap—

I tapped the pen twice to activate the inscribed magic circle.

As the magic circle on the ground started to glow, I put my mouth to the tip of the pen and inhaled.

The potion gets absorbed by the cotton, and the heated coil vaporizes it immediately, generating steam.

The gas that traveled from the pen to my mouth, then from my throat to my lungs, emerged as hazy smoke as I exhaled it.

“Hooouu.”

Just as expected. Consuming the potion this way definitely diminishes the bitter taste.

Furthermore, the mana in its gaseous state tends not to escape once it enters the body, so it’s no different efficiency-wise from consuming it in liquid form.

I wondered why I hadn’t thought of consuming it this way until now.

It was a moment that made me acutely aware of how essential creativity is in life.

“Wooaah! How did you do that, Namé? Smoke is coming out of your mouth!”

“Should we try increasing the resistance to double? Then the smoke will double too?”

“Is it going to be more than this?”

Yuna seemed excited, and her enthusiasm lifted my mood as well.

I changed the resistance to 1 ohm, then took the pen into my mouth and inhaled again.

“Hooouu.”

“Waah! The smoke! Cough cough…! Ugh, bitter.”

Yuna waved her hands as the smoke increased about twice compared to earlier, and it seemed she might have accidentally inhaled some through her nose while coughing.

“You shouldn’t try to inhale it on purpose. Why do you want to do that too? This doesn’t give you any benefits.”

“I almost died last time when I ingested it wrong…”

Yuna shook her head vigorously.

If she didn’t want to, there was no need to force her.

Before the fifth period started, I diligently exhaled the remaining potion to finish it off quickly.

As Yuna kept watching how the magic circle operated, she muttered.

“But it really looks like cigarette smoke.”

“Yuna, you’re really clever, aren’t you?”

“Huh?”

“This works on the same principle as cigarettes.”

“What?!”

I finished exhaling the last of the potion and completed my lunch dose for today.

The inscribed magic circle can be used for a long time, but it seems twenty times is its limit, so I couldn’t expect any more heat beyond that.

“This is called an atomizer. It’s the device found in e-cigarettes.”

Do kids these days not use e-cigarettes so they don’t recognize it?