Reform and the Heavenly Army (6)
A startled shout rang out from the Gangnyeongjeon, echoing through the halls. It was Yi Yeon’s voice—low and husky, still rough from his recent voice change.
“Whoa! It’s grown this much?!”
Yi Yeon grinned, bright and satisfied, as he studied the horizontal line etched on one of the pillars. Seven months had passed since he became King Seonjo. Yet the difference between the original mark and his middle finger now surpassed it.
“The effects really worked.”
At forty, he had once seen a height-increasing workout online and tried it with all his might—only to discover that not even a single millimeter had grown.
“It even shrank me.”
So he hadn’t expected much this time either. He wondered how much room the loose clothes would have, but he had never measured himself since. Would the results be as impressive as he hoped? If not, the disappointment would be crushing.
But the actual growth was far beyond his expectations. The desire to be bigger burned even stronger.
“I want to be as tall as Shin Rip.”
A few days earlier he had measured Shin Rip’s height with a meter stick made for the modern system. It wasn’t nearly as impressive as he imagined. Stephen had looked almost the same height, so Yi Yeon had assumed Shin Rip was a giant. In truth, he was only 182 centimeters.
‘That’s exactly the size I want.’
Compared to his current standards he was still a giant, but he wanted to reach that mark anyway. Every time he stood next to Stephen for photos he had secretly placed his hand on the shorter man’s shoulder to make himself look bigger—something he found humiliating in Song Cha-jang’s case.
‘Even if I’m tall, I won’t pull that shoulder-patting trick anymore.’
Lost in middle-school hormone fantasies about height, Yi Yeon barely noticed Kim Yang-bo enter carrying a tray.
“Your Majesty, I have brought the egg yolks exactly as you commanded.”
“Really? Let me see.”
Yi Yeon recalled the twin-harmony tea his father loved in his previous life. He had ordered a skilled tea master to separate only the yolks from the tiny eggs now hatching on Inghwado and bring them over.
‘A little disappointing. If only I had added sugar, it would have been far more delicious.’
The bitter taste was softened by the egg yolks, but the sweetness was still missing. Still, it was better than nothing.
“Yang-bo.”
“Yes, Your Majesty.”
“Please tell Queen Insun about this tea as well.”
“Yes, Your Majesty.”
A child’s palate craved sweetness, but Queen Insun would surely appreciate the gentle flavor.
Left alone in the Gangnyeongjeon, Yi Yeon stared at the snowman he had built outside and murmured to himself.
“Soon the eggs will be hatching like salmon roe.”
The poultry business was proceeding exactly as planned. Over ten thousand chickens were already being raised on Inghwado, and Sim Tong-won’s people were said to be raising more than thirty thousand.
“The big crash is coming…”
Every egg produced across Han-yang and Gyeonggi Province was being collected and sent to the Inghwado incubator. The price of eggs had skyrocketed, and anyone who owned laying hens was treating them like golden geese. Disputes over chickens had become almost routine.
Everyone had gone chicken-mad, just like the tulip craze before it. But the end was approaching. A five-month-old chick could already lay eggs.
“I could distribute this to the people.”
Yi Yeon intended to tell the commoners about the height-increasing workout method.
‘I can’t be the only one who gets taller.’
To push the planned Hwaryeokgun forward, soldiers needed to eat well and grow fast. Even the heavier-than-a-cannon firearms required correspondingly heavy bullets. He had therefore arranged for regular supplies of high-quality protein—fresh egg yolks and older roosters that couldn’t lay.
He could never know the exact growth without measuring it. Asking the royal physician for a height chart would make him look like a useless king.
“I have no choice. I’ll ask Chohui.”
Yi Yeon had decided to use his legal younger sister, Heo Nanseolheon. Everyone knew she drew both beautiful calligraphy and pictures.
“Your Majesty, Princess Okhye has arrived.”
“Let her in.”
“Yes, Your Majesty.”
Yi Yeon smiled with an uncle’s warmth when the six-year-old beauty stepped inside—exactly the smile he had once worn for his nephews in his previous life.
“Chohui greets Your Majesty.”
“How have you been, Chohui?”
“Thank you for asking, Your Majesty. I have been cared for by Her Majesty the Queen Dowager and lack nothing.”
“You still don’t call her Omama?”
“Forgive me, Your Majesty. The words have not yet entered my mouth.”
Yi Yeon felt a twinge of regret. If she had called her Omama or Mother, he would have asked her to call him “oppa.” But the timing was not quite right.
He couldn’t stop the smile tugging at his lips anyway. The sight of Chohui, dressed in the elegant attire of a historical drama, was simply adorable.
“I see. By the way, I heard you draw beautifully. So I came to ask a favor—would you mind?”
“Speak, and I will follow with all my heart.”
“You’re my sister, so that’s not necessary. I just need you to draw this so everyone who sees it will understand what it is.”
Yi Yeon unrolled the pre-drawn picture and placed it on the table. Chohui burst into a giggling laugh, like a nightingale.
‘Damn! I knew she’d do that.’
Yi Yeon had deliberately drawn a simple stick-figure animation: round head, eyes, nose, and mouth as dots, body and limbs as long lines to show motion.
Chohui realized her mistake and quickly stopped laughing, bowing her head. But her eyes were still curved like an upside-down crescent moon, and the smile remained on her lips.
“Forgive me, Your Majesty. Who drew this picture? It is so amusing.”
“Really?”
“Yes, Your Majesty.”
Yi Yeon wanted to say it was he who drew it, but he held back. Even before his little sister, he had to preserve royal dignity.
“I’m sorry, Chohui. This concerns the prestige of our country, so I cannot tell you.”
“Is that so?”
Chohui rolled her large, clear eyes in confusion.
“It is. Therefore, from now on, tell people that you drew this.”
“Your Majesty, that would be deceiving others, and I cannot do it.”
“It is an order.”
“I will obey, Your Majesty.”
Chohui bowed deeply. Though she had only been in the palace a few months, the bright child already knew the court etiquette.
‘Ugh! What have I done? I’m bossing around a six-year-old child…’
Yi Yeon felt a wave of self-loathing. He had assumed she was smart and simply ordered her around without explanation, and the words that usually belonged to his ministers had slipped out.
But he could not undo it. That was court etiquette.
‘Damn court etiquette. I should just abolish it right now.’
He had sworn to cancel the palace laws that imprisoned people within his own lifetime.
“Hmph. I’ll need your help anyway. I have a reason, little sister.”
“I understand, Your Majesty. If you give me a brush and ink, I will draw it immediately.”
Chohui smiled brightly, completely unbothered. Then her smile froze.
Yi Yeon had prepared paper and pencils, placed them on the table, and began sketching. After a moment he demonstrated erasing the lines with a sticky-rice cake eraser.
“Your Majesty, what is this object?”
“This is a pencil, and this is called an eraser.”
“Oh! It is truly marvelous. Did Your Majesty create these as well?”
Yi Yeon simply smiled and nodded. The sight of Chohui clapping her hands in pure delight was too adorable.
“Chohui, I’m giving you this. Please take good care of it.”
“I will not fail you, Your Majesty. I will draw the picture as beautifully as a person.”
‘Even I drew it as a person…’
Yi Yeon muttered to himself as he stood up. He watched Chohui pick up the pencil and start drawing, then nodded in admiration before heading to the Cheonchojeon.
“What did he want this time?”
As promised, Yi Yeon had summoned Yi I to teach mathematics. He had never imagined the level would be beyond the son of his mother’s friend.
Yi I was introduced to prime numbers—the fundamental building blocks of all mathematics—from the first-grade middle-school textbook. The method for finding them was Eratosthenes’ sieve, created by the ancient Greek mathematician and astronomer.
Even the prodigy Yi I took a moment to grasp why prime numbers mattered, but afterward he made progress at lightning speed. One glance at the formulas and graphs on the blackboard was enough. The foundations were being drained faster than Yi I could count.
Yi Yeon entered the Cheonchojeon with his heart pounding.
“Your Majesty.”
“Yes? What brings you today?”
“Forgive me, Your Majesty. I have come to confirm the practical applications of the equations of motion and differential calculus you taught me.”
“Really?”
Yi Yeon leaned forward eagerly. It was wonderful news.
He had heard of ballistics but never the formulas or their uses, so he had planned to have Yi I create them. When Yi I instinctively drew back, Yi Yeon coughed and spoke.
“Tell me what you wish to verify.”
“Yes, Your Majesty. You once said that the speed of a projectile moving through the air can be found by differentiating the distance traveled, and the acceleration by differentiating again. You also mentioned considering wind as a variable. Therefore, to launch an object precisely, the wind variable must be incorporated into the equation. Otherwise the target will be missed. That is why… I have made formulas in that manner. Please check if they are correct.”
Yi Yeon swallowed hard.
‘Damn. I’m being completely drained.’
The formulas looked intricate even at a glance. He had to pretend to examine them.
“Let me see.”
“Yes, Your Majesty.”
Yi Yeon studied the formulas for a long time, head throbbing. Then something caught his eye.
I found a flaw!
Yi Yeon cleared his throat and said, “There is a question mark here. What does it mean?”
“That is the speed at which the object falls to the ground. The value cannot be known, so it is marked that way.”
“Hm…”
Yi Yeon nodded as if he understood and searched for an excuse.
‘Damn! I need to explain gravitational acceleration first. How do I do this?’
The “?” in Yi I’s formulas represented the symbol “g,” the value of gravitational acceleration. To explain it, Yi Yeon had to start with how to measure that value and how to apply it.
‘I don’t know! Just give a rough explanation.’
This time Yi Yeon decided to use his classic theatrical style.
“When I was a child, I saw an apple fall and wondered if a stone would fall at the same speed. So I climbed a high place and experimented.”
He glanced at Yi I. Fortunately the prodigy’s mouth watered and his Adam’s apple bobbed, showing he wanted the answer quickly.
‘I need to draw this out.’
Even though the story was complete, a little delay would make it seem deliberate. Too easily told and he would be questioned again.
‘Explaining one second was genuinely hard.’
Yi Yeon himself had never truly understood why it was one second. Yet Yi I had peppered him with questions about it. He had no choice but to give a rough answer.
“Do you know why we divide a year into twelve months? Because the moon appears twelve times a year.”
“Yes, Your Majesty. I have heard that.”
“But why is the length of a month irregular?”
“This servant also wonders about that.”
“I heard the moon’s orbital period is twenty-nine and a half days. So the first month has thirty days, and the next has twenty-nine.”
“Ah…”
Yi I’s delighted gasp made Yi Yeon feel proud. He had used future knowledge, but knowing that the genius Yi I still bought the story felt good.
But the next question shattered his confidence.
“Your Majesty, what is orbital motion?”
“It means the moon circles the Earth.”
“What?!”
Yi I’s shock was genuine. Only then did Yi Yeon realize he had made a mistake.
‘Damn! We’re still in a time before that concept existed.’
The term “Earth” had led him astray. In 1543 Copernicus had proposed the heliocentric theory, but it had not yet reached Joseon.
Yi Yeon had no choice but to continue with nonsense.
“We know this place is round like the sun or moon, so we call it Earth. Then I thought, perhaps Earth circles the sun and the moon circles Earth. Do you know why I thought that?”
Yi Yeon knew the perfect way to stop further questions: end with a question. He had used that trick before, but it could not stop Yi I’s insatiable curiosity about new knowledge.
“Forgive me, Your Majesty. This servant does not know. Yet I am curious why Your Majesty thinks that. Please teach me, my inadequate servant.”
Yi Yeon grimaced.
‘I’m going to lose my mind…’