Chapter 14: Weights and Measures / Metrology

Dragon Era Year 515

「Fire, red and hot—come to my palm.」

A voice rings out in the schoolyard before the sun is fully up.
The softly murmured alto belongs to a young boy.

「Good morning. Working hard again, Sig.」
「…! What— Oh, Sensei. Don’t sneak up on me.」

When I call out, Sig startles and turns to me with an abashed look.
I don’t know since when, but I recently noticed he secretly practices magic every morning, hiding himself away. His attitude in class isn’t great, but he may actually be the most earnest learner.

「I still don’t really get this “magic fire” thing.」

He shows me the little flame floating over his palm and mutters. It flickers before my eyes and then goes out.
His conjured flame isn’t very stable. Like me, he might mesh too well with fire, making control the hard part.

「But you can keep it going longer than before, right?」

At my words, Sig makes a complicated face. His form is far from human, but his expressions are easy to read. At the very least, he doesn’t look pleased.

「I am hard. I am fast. I am sharp. I am heavy. I am strong…」

Layering the spell over and over, Sig clenches his fist.
Controlling enhancement magic is difficult. But with him, that worry is entirely unnecessary.

He steps in and drives his fist forward.
The movement Yuuki drilled into him is incomparably smoother than before.

I catch it—one-handed.
In human form, not as a dragon.

「Hey, Sensei.」

He is getting stronger—that’s unquestionable. And yet…
His progress is all too slow.

「When will I be able to beat you…?」

I had no answer for him.


* * *


「Starting this year, we’re finally going to begin full-scale farming.」
「At last?!」

It was no wonder Yuuki shot back like that at my announcement.
It’s been about five years since we started the special class. We’d been dabbling in small-scale cultivation since the second year. The first time we managed to kill everything quite spectacularly, but from the second attempt on we succeeded, and the yields have been creeping up.

But there was a reason we hadn’t started agriculture in earnest.

「Doing it properly means we have to make big fields.」
「Ugh… we have to do that again?」

Remembering the earlier work, Yuuki grimaced.
Turning the soil, pulling weeds, picking out stones—tilling is brutal labor even for a tiny plot. We don’t have heavy machinery; we barely have farm tools.

「How large should we make it?」
「Exactly. That’s the first problem.」

I nod at Violet-san’s question.

How big, exactly?
Right now, I don’t even have a way to answer that question.
Because we don’t have a unit of length.
Not just length—volume and weight, too. We had no standardized weights and measures of any kind.

We speak in Japanese, so we can use words like meter or kilogram. But if asked how long a meter actually is, we’d be stumped.

If I remember right, the meter is defined by Earth’s size or the speed of light. Of course you can’t use that day to day, so there was a prototype meter bar kept under strict control.

At our level of civilization we don’t need that kind of precision. An approximate size suffices; feet, for example, are intuitively based on a human foot. Intuitive—but using that in this world poses problems.

Body size—indeed, body plans—differ wildly. Lizardmen never stop growing and just keep getting bigger; Lycos Centaurs, like wolves, touch the ground only with their toes, so where does a “foot” end? And mermaids don’t have feet at all.

And that applies not only to other species but to humans as well. Compared to Earth people in my memory, their individual variation is clearly larger. Giants like Dalga are rare, but there are oddly many very tall—and conversely very short—people.

「If only we had something whose length never changed.」

We could make a standard out of wood or stone, but stone is heavy and awkward to use, and wood would weather away quickly.

「We do.」

Nina looks at me as if to say, What are you talking about?

「Ideally something that won’t change in length over a hundred, two hundred years…」
「It hasn’t.」

Huh? Do we have something like that? I tilt my head.
Nina looks much the same, but even she has been growing, ever so slowly—she’s a bit taller than when we met, and more adult.

「For at least these five hundred years, you haven’t changed at all.」
「Huh? No, I have grown—」

I start to say it and finally realize: as a dragon I’ve gotten much bigger, but my human form hasn’t changed at all. Whether because it’s magic or because a dragon’s lifespan is absurdly long, I still look like a man of about twenty.

「Has my height really not changed?」
「Not at all.」

Nina says it flatly. If anyone would know, it’s her—she sees me almost every day.

「Then let’s try using me as the standard…」

If I remember right, my height in my previous life was about 175 centimeters. I may have shrunk a bit in my final years, but in my youth it stayed the same—and it’s a nice round figure, so I remember it well.

「Yuuki, could you mark a notch at my height?」
「Okaay. Onii-chan, don’t move.」

I stand by a post supporting the classroom roof and ask; Yuuki smoothly draws her sword. She makes a light hop and a single slash. A breeze brushes my bangs, and I hear a sharp rasp of wood shaving from above.

「Now to divide this into seven equal parts… uh, seven is hard.」

175 divided by seven gives 25 centimeters per unit—nice and handy—but dividing into seventh parts is trickier than you’d think.

「Ah, right. Violet-san, could you produce a vine this length?」
「Yes.」

Tilting her head, Violet-san extends a bramble vine from her fingertip. I cut it to my height, twist it into a loop, and draw a heptagram inside the circle.

It’s very hard to divide a line evenly into seven, but drawing a seven-pointed star is comparatively easy. In my occult-obsessed former life I drew them over and over. Never thought it would come in handy here.

Seven is the only one-digit natural number that doesn’t divide 360 degrees. A week has seven days, the face has seven openings—eyes, ears, nose, mouth—so it’s magically significant. Not that it ever meant anything back on Earth.

Come to think of it, I’ve never really wondered—do magic circles actually help with magic in this world?

「What is that?」
「This makes it easier to get equal lengths.」

Answering Nina, I cut the loop where the star’s points touch the circle and bundle the pieces. The vine, divided into seven, comes out in nearly equal lengths.

Do the same on one of the cut lengths with a pentagram, and you get 5-centimeter units. With a compass and straightedge you can draw a perfect pentagram, but freehand is faster. Basic stuff.

Draw another pentagram on a 5-centimeter piece and you can make 1-centimeter units too, but the vine wiggles and the error would be large; we don’t need units that fine, so this will do.

「Hey, hey, Sensei—what’s that?」

Rin likely doesn’t really grasp what I’m doing; watching the cut pieces, she asks. The others look puzzled too—looks like almost none of them get it.

「Say you have ten Water Apples and three Hiiro yams—which is more, and by how many?」
「Water Apples by seven!」

Rin shoots up her hand and answers; I nod, yes, yes.
It’s a simple sum, but thanks to Nina’s steady teaching.

「Then between Violet-san and Nina, which is bigger and by how much?」

Asked that, Rin looks between Violet-san and Nina, furrowing her brow in thought.
Then her face lights up as if she’s realized something, and she points at Violet-san’s chest.

「Violet has two!」
「I will hit you.」

As Rin declares with full confidence, Nina balls her fist. Come to think of it, that area hasn’t grown at all… and with no mercy Nina’s fist comes down on my head.

…It hurts. A lot.

「Not that… I mean height. You can tell Violet-san is taller, but if asked by how much, you’re stuck, right?」
「Isn’t “about this much” good enough?」

Sig indicates the height difference between Violet-san and Nina with his hand.

「Oh! You’re giving that “about this much” a name.」
「Exactly!」

At Luka’s words, I shouted, so pleased I could’ve slapped my knee.

「Just like you count nuts one, two, and deer one head, two, you count length in centimeters. One of these small pieces is five centimeters; one of these medium pieces is twenty-five. My height is one hundred seventy-five centimeters.」
「One hundred seventy-five…」

Rin isn’t used to numbers that big; she repeats it blankly, not quite getting it.

「Hey. How tall am I?」

Sig is the first to ask.

「Violet-san, could you give me another vine?」
「Certainly. Just a moment.」

Violet-san picks up the 25-centimeter piece I cut, closes her eyes as if to focus with it in hand, then slowly grows bramble from her fingertip, shifting the piece back and forth in her hands a few times.

「How is this?」
「Wonderful!」

I can’t help but cry out at the vine she produces: it has thorns at 25-centimeter intervals. It’s extremely handy—and it proves she has fully grasped the concept of a length unit.

「Alright, stand in front of that post. Let’s see…」

I score the post at Sig’s height and measure with Violet-san’s vine. He’s a little above the fifth thorn; add a 5-centimeter piece and it’s almost exact.

「Sig is about one hundred thirty centimeters.」
「Onii-chan, measure me too!」
「What about me? Me?」
「I’d like to know mine as well.」

Everyone seems eager to know, and an impromptu round of measurements begins.

Nina is 155 centimeters. Violet-san is just shy of 170. With Luka it’s a bit tricky where to measure from to where, but standing, the top of her head is 160. Measuring Rin the same way gives about 100 centimeters, but if she straightens out and you measure to the tip of her tail, she’s 170.

「Yuuki is… 130 centimeters.」
「Huh? Same as me!」

When we measure Yuuki last, Sig stares wide-eyed in surprise.

「Huh, you’re right.」

Yuuki and Sig stand side by side and wave their hands over their heads to compare. Five years ago when we first met, Sig should have been a bit taller.

「Yuuki, how old are you now?」
「Fifteen!」

Already? She really has grown—taller, and her figure, once hardly different from a boy’s, has become much more feminine.

「You really have gotten bigger.」
「Yeah. These get in the way, honestly.」

Rin grabs those swelling breasts in a full handful; Yuuki answers without seeming particularly bothered.
Maybe the reason it doesn’t feel like she’s grown is her still-somewhat-childish personality. She still climbs all over me like a little monkey.

「Stop that. It’s improper.」

I can’t help scolding her, but in this classroom full of girls it seems I’m the only one feeling embarrassed. Even Sig, the only boy, doesn’t really get it—lizardman females don’t develop breasts, so the whole idea doesn’t click for him.

「Ideally we’d measure weight as well.」
「Weight?」
「It means how heavy something is.」

I answer Rin as she tilts her head.
That’s even harder than height, though. How do we make a scale? I honestly have no idea. Maybe draw water and use a balance scale… but I don’t really know how to make one either.

「Weight has numbers too?」
「Yes. Most things in the world can have their size expressed with numbers.」
「Then magic too?」

At Rin’s words I gasp.
It’s true that magic varies in strength. But it had never occurred to me to express it as a number.

After all, the kinds and strengths of magic vary too much by person. You can’t measure it all by a single standard like height… or—no, wait.

「Maybe… we can.」

An idea strikes me, and I say so.

If one standard won’t fit, then measure with several.