When Hui returned, Sejong declared the end of the demonstration.
"Thus, I will conclude the demonstration. I will provide wine and meat for the soldiers who have worked hard, so let them enjoy the feast."
"Wow!"
"Your Majesty, may you live a thousand years! May you live a thousand years!"
As Hui shook his head and left his seat, he muttered,
"I can't stand it. I can't suppress my curiosity."
After leaving his seat, Hui continued to investigate by seeking out the cannon soldiers and musketeers.
"I'm sorry to detain you when His Majesty has provided a feast."
"That's not the case!"
"That's not at all appropriate!"
In response to Hui's apology, the musketeers and cannon soldiers waved their hands in denial.
"I won't make you feel bad, so please help me a little."
"That's not the case!"
"Just give us the order!"
"Thank you. First… what are the difficulties in using these muskets?"
The musketeers thought for a moment and then began to list the problems.
- They are hard to use. Except for the mounted musket, the others are used by attaching a pole to the muzzle. Even a strong soldier finds it difficult to fire more than two shots.
- The effective range for completely suppressing the enemy is too short. When a small charge is loaded into the mounted musket, it can fly 200 paces (about 240 meters), but it's hard to hit the target accurately. To compensate, they use a method called 'one shot, multiple arrows' by loading several arrows at once, but this requires the enemy to be within 50 paces (about 60 meters). To ensure a hit, they need to be within 40 paces, or even 30 paces.
"Hmm… I see."
While nodding and recording the soldiers' words, Hui looked at the mounted musket one of them was holding.
"Is this the mounted musket? Can I take a look?"
"Yes."
After examining the mounted musket handed to him by the soldier, Hui muttered to himself.
"Is this a problem with the center of gravity? How much does this mounted musket weigh?"
In response to Hui's question, Choe Hae-san, who was standing nearby, immediately answered.
"It weighs 3.8 catties (about 2.2 kg) and is 1.44 chi (about 44.6 cm) long."
"What about the length of the pole?"
"It's not precisely determined, but it must be at least 4 chi (about 1.2 meters)."
"Isn't the length a bit inconsistent for something like this?"
In response to Hui's observation, Choe Hae-san answered with a troubled expression.
"It varies slightly depending on which chi is used."
"Ah…"
Hui clicked his tongue at Choe Hae-san's answer. Indeed, the muskets the soldiers were holding came in various sizes.
This was a problem that persisted throughout the Joseon Dynasty. The standard unit of length, chi, was ambiguous. From what Hui had heard, units like the Huangzhong chi, Yeongjo chi, and Zhaoliqi chi were all in use.
"Isn't it essential to standardize the unit of length when manufacturing?"
"Because they are supplied through tributes…"
"Tsk!"
While clicking his tongue and looking at the mounted musket, Hui tilted his head.
'Even if the center of gravity is forward, it doesn't seem like the soldiers' size would make it impossible to fire two shots. What's going on?'
Unable to understand, Hui asked another question out of curiosity.
"How much gunpowder do you put in the musket?"
"1 tael (about 37.5g)."
"Choke!"
"Your Highness! What's wrong?"
Startled by Hui's reaction, the nearby soldiers, commanders, and Choe Hae-san rushed over. Hui waved his hands urgently.
"Nothing! Nothing at all! I was just surprised by the amount of gunpowder used!"
"Ah, yes…"
Hui's answer relieved the people around him.
'I've solved it! The culprit was the amount of gunpowder!'
Thinking he had found the root cause, Hui quickly tidied up his seat.
"I have all the information I need. General, I will send meat and wine through the eunuchs, so please distribute it to them."
"Your humble servant is honored!"
"Your humble servant is honored!"
The commanders and soldiers all expressed their gratitude at Hui's words. Hui waved his hand lightly.
"This is for those who work tirelessly for Joseon. Eat well and stay strong to defend Joseon."
"We will remember and act accordingly!"
* * *
On the way back to the palace after the demonstration, Hui talked with Choe Hae-san.
"Is the musket operated in pairs like that?"
During the demonstration, the musketeers worked in pairs. One soldier firmly held the musket's pole while another lit the fuse. After firing, a soldier waiting nearby handed over a pre-loaded musket, and the soldier holding the pole attached it to the muzzle and prepared to fire again.
Choe Hae-san answered Hui's question immediately.
"Basically, they operate in pairs."
"What about when they operate alone?"
"They either hold the pole with their right hand and light the fuse with their left, or they tuck the pole under their right armpit and hold it with their left hand while lighting the fuse with their right."
"It doesn't sound very convenient, does it?"
In response to Hui's observation, Choe Hae-san nodded.
"That's correct. That's why they operate in pairs, but the issue of requiring more manpower makes it difficult to expand the musketeer corps."
Choe Hae-san's disappointed expression was the same as one Hui had seen in a famous 21st-century advertisement.
-It's so good for men, but I can't say anything.
Hui nodded at Choe Hae-san's explanation.
"That's right. To properly fire a musket alone, one would need the strength of a demigod, not just a mere mortal."
"Yes! Yes, that's correct!"
* * *
Back in the palace, Hui opened a blank book and muttered to himself.
"The culprit was the amount of gunpowder."
In the 21st century, while in the United States to build a sailboat, Hui met many gun enthusiasts. Among them, a significant number were military history buffs, especially those who collected and fired classic firearms.
One of them had a collection that rivaled a museum, ranging from rifles of the American Revolutionary War to firearms of World War II. Not only did he collect firearms, but he also enjoyed shooting and even bought large quantities of black powder to make his own ammunition.
When Hui visited his house just before returning to Korea, he happened to see him reloading ammunition for a Henry rifle.
"Is this the gun from the Western movies?"
The gun enthusiast smiled and answered Hui's question.
"That's a Winchester, and this is its predecessor."
"How much gunpowder do you use?"
"30 grains."
"Choke!"
"Your Highness! What's wrong?"
Startled by Hui's reaction, the nearby soldiers, commanders, and Choe Hae-san rushed over. Hui waved his hands urgently.
"Nothing! Nothing at all! I was just surprised by the amount of gunpowder used!"
"Ah, yes…"
Hui's answer relieved the people around him.
'The problem is the lack of proper aiming devices, which forces them to use point-blank firing. To be effective at point-blank range, they have to load a lot of arrows or shot, and to ensure the projectiles have enough power, they need more gunpowder. This leads to soldiers being overwhelmed… It's a vicious cycle. Sigh~.'
Sighing, Hui came to a conclusion.
"We need to start by making proper individual firearms. First, though…"
* * *
The next day, Hui immediately sought out Choe Hae-san.
"General, I have a question."
"I will answer to the best of my ability."
"Are the fuses for the muskets all the same thickness?"
"Are they not?"
"Can you get some of those fuses now?"
"Please wait a moment."
After seeking Hui's understanding, Choe Hae-san called for someone and gave an order.
A short while later, the person who received the order handed the fuses to Choe Hae-san.
"Your Highness, here they are."
"Can you light a candle for me?"
"Yes? Yes."
Hui took the fuses and, as soon as the candle was lit, placed a fuse against the flame.
Sizzle!
As the fuse caught fire with a pungent smoke, Hui immediately blew on it.
"Puff!"
Fizzle!
When Hui blew on the burning fuse, it sputtered and went out. Hui repeated the same experiment with other fuses and got similar results. Seeing the results, Hui nodded.
"Indeed… General, do you understand the problem?"
Choe Hae-san nodded in response to Hui's question.
"Yes. The fuses are too susceptible to wind."
"Was there no report about this issue?"
"No. If the fuse goes out in the wind, it can be immediately replaced and relit."
Choe Hae-san's dismissive answer made Hui's expression sharp.
"In the heat of battle, where time is of the essence? Immediately contact the Military Equipment Bureau and have them find an appropriate thickness for the fuses."
"Understood."
Two weeks later, a report from the Military Equipment Bureau was submitted to Sejong through the Ministry of War.
"Upon the order of the Crown Prince, we investigated and found that the diameter of the touchholes in various cannons and muskets was 7 li (about 2.1 mm). When firing, the flame would often go out, but when we increased the diameter by 1 li, the flame did not go out.
However, there was no adjustment for the range and depth of penetration of the arrows or shot. We request that the diameter of the touchholes in all cannons and muskets be set to 8 li from now on."
After reviewing the report, Sejong gave an order to the Minister of War.
"The report is correct. Adjust the diameter of the touchholes in all cannons and muskets to 8 li."
"Understood!"
After giving the order to the Minister of War, Sejong smiled contentedly.
"Indeed, the Crown Prince."
Hui didn't know, but changing the thickness of the touchholes was something that Wang Munjong had also done in actual history.
* * *
While Sejong only knew about the fuse issue, Hui was busy behind the scenes.
"Recently, the Crown Prince hasn't been seen."
In response to Jeong Ch'o's statement, Yi Ch'ŏn added,
"He has been in the annex for five days, searching for something very important in the Western books and conducting experiments."
"Experiments?"
"Yes. He has obtained various acids and mercury through the Military Equipment Bureau and the Board of Deliberation."
"Is that so?"
In response to Yi Ch'ŏn's answer, Jeong Ch'o turned his gaze toward the annex built in the Donggung Palace.
At Hui's request, two annexes were built right next to the Donggung Palace. The larger of the two was the main hall where Jeong Ch'o and others worked, and the smaller one was designated for Hui's experiments. This small building had become the most desired place for the researchers and staff of the study.
"Crown Prince, Your Highness!"
At the eunuch's announcement, everyone who had been chatting stopped and straightened up. A short while later, Hui entered, carrying a long wooden stick and a roll of blueprints.
"Everyone, please take your seats."
"Yes."
Once everyone was seated around the large table in the center, Hui began the conversation.
"Have you all eaten?"
"Yes. What about Your Highness?"
"I have eaten. You're in the prime of your youth, so you need to eat well."
After exchanging light banter to ease the atmosphere, Hui checked on the progress of the work.
"Jeong Dae-gam, how is the revision of the calendar?"
In response to Hui's question, Jeong Ch'o bowed slightly and answered.
"Significant progress has been made. We have identified the discrepancies between the Ming calendar and our seasonal divisions and are creating formulas to correct them."
"What about solar and lunar eclipses?"
"We are also working on the formulas for those."
Hui's face brightened at Jeong Ch'o's answer.
"Good work. When can I expect the results?"
"We can complete it by the end of this year."
Hui frowned at Jeong Ch'o's answer.
"By the end of the year is too late. I want to see the results before the Mid-Autumn Festival."
"Before the Mid-Autumn Festival?"
At Hui's order, Jeong Ch'o's face turned black. He and Jeong In-ji were already working overtime like it was a daily meal. They had managed to set a deadline for the end of the year, but the Crown Prince wanted it even sooner.
"If necessary, recruit more officials who are skilled in mathematics. If two people find it difficult, three can do it, and if three find it difficult, four or five can handle it, right?"
"There are no volunteers…"
In response to Hui's words, Jeong Ch'o spoke with a troubled expression. A rumor was circulating among the officials working in the palace and the Six Ministries.
'If you go to Jiphyeonjeon, the king will make you work hard, and if you go to the research institute, the Crown Prince will make you work hard.'
"I've said before, bring them in using my name. Why are you so hesitant, even though you hold a high rank?"
Hui's not-so-subtle reprimand made Jeong Ch'o bow his head.