Chapter 54: New Weapons (2)
"Then how does one ignite the improved gunpowder?"
"By using the gunpowder that His Highness the Crown Prince created."
At Choi Hae-san's answer, Sejong pointed out a problem.
"Would that not become too troublesome? Since another gunpowder would go between the fuse and the main charge."
At Sejong's observation, the accompanying ministers all nodded.
Though most of them were civil officials, some had served in the Ministry of Military Affairs, and even those who hadn't had all heard at least once how cannons were used. And having seen it directly at the previous demonstration, they knew that a fuse was absolutely necessary to ignite gunpowder.
At Sejong's point, Choi Hae-san immediately provided an answer.
"Eul-sik gunpowder does not use a fuse. It uses a cap, no, a copper percussion cap (銅火帽)."
"Copper percussion cap?"
When Sejong expressed his doubt, Hyang quickly wrote the characters on a memo and held them out to Sejong.
"It is written like this."
"Hmm... Is there an actual object?"
At Sejong's words, Choi Hae-san moved a copper plate placed on one side of the table in front of Sejong.
"The small one is for handguns, and the large one is for cannons."
"Hmm..."
Sejong examined the copper percussion caps placed on the copper plate in detail.
The handgun version appeared slightly smaller than an index fingernail, and the cannon version appeared about the size of one joint of a thumb.
Sejong, who had been examining the problematic item, looked at Choi Hae-san.
"Is a demonstration possible?"
"I have already prepared it. This way."
Choi Hae-san guided Sejong and the ministers to a place slightly apart from where the table was placed.
The place Choi Hae-san guided them to was a space with a width of about 20 jang (approx. 60m) and a length of about 150 jang (approx. 450m).
"Truly desolate."
Seeing the place Choi Hae-san had guided them to, Sejong expressed his impression.
True to Sejong's observation, the space in question was truly desolate.
On three sides excluding where the people stood, earthen walls at least 2 jang high had been erected. And where the people stood, sacks filled with earth had been stacked up to chest height to create a wall. Inside the walled space, dug-out pits were scattered here and there.
Once Sejong and the ministers were positioned behind the earthen wall, Choi Hae-san spoke.
"Then I will begin the demonstration. Begin!"
At Choi Hae-san's command, the artisans waiting nearby moved a small table in front of the demonstration platform. On the table were copper plates and small wooden barrels.
"What is in the left barrel is Gap-sik gunpowder, and what is in the right barrel is Eul-sik gunpowder."
As Choi Hae-san's explanation continued, the artisans scooped the gunpowder onto the copper plates with spoons made of porcelain and inserted fuses. The artisans, confirming that the fuses were properly inserted, lit the fuses and stepped back.
Bang! Fizzle.
The Gap-sik gunpowder, whose fuse flame had burned, exploded with smoke, but the Eul-sik gunpowder only burned the fuse and that was the end.
"This time, we will use the modified handguns to demonstrate the copper percussion caps. Begin."
Once the order was given, the artisans brought two handguns. The artisans, who transferred gunpowder from the barrels containing gunpowder into the handguns, inserted paper wads and began tamping them with rods.
After tamping firmly, the artisans pulled back the hammers (擊鐵) protruding from the back of the handguns, then fitted the copper percussion caps. The artisans, having finished all the work, firmly clamped the gunstock under their right armpits, held the string connected to the hammer in their left hands, and stood facing the opposite wall.
"Fire! Fire! Fire!"
Boom-boom!
As the artisans, who had shouted the command loudly three times, pulled the strings simultaneously, the two handguns spouted flames simultaneously.
"Ohhh!"
"Hoh!"
When the two handguns spouted flames, the subjects exclaimed in admiration.
Sejong looked back at Hyang.
"So this is what you mean by not using a fuse? Hmm... There would indeed be fewer constraints than when using a fuse."
"That is correct."
"Truly, your efforts have been great."
Sejong looked at Hyang with a proud expression. However, Sejong immediately assumed a stern face and posed a question.
"You said the name of the gunpowder you created is Explosive Silver. Surely you are not using precious silver?"
"No, Your Majesty. We use mercury. Of course, mercury is also precious, but it is easier to obtain than silver, and since it is used only for the ignition role, the cost is less than expected."
"However. Then that is fortunate."
At Hyang's answer that the cost was low, Sejong's face brightened. After all, gunpowder was something that consumed enormous amounts of wealth.
With his expression much more relaxed, Sejong turned his head toward the demonstration grounds.
"I wish to know about the other gunpowder that the Crown Prince created. General."
"Yes, Your Majesty. Bring the Explosive Oil."
"Yes."
At Choi Hae-san's command, the artisans soon brought a small wooden box and carried it in carefully.
"Tilt the box to show the inside."
The artisans tilted the box so that Sejong and the subjects could see inside. In the middle of the box filled with sawdust sat a small porcelain bottle.
Choi Hae-san, who took the porcelain bottle out of the box, pulled out the stopper and tilted it slightly toward the empty ground.
Pop!
A single drop of Explosive Oil fell to the ground along the mouth of the porcelain bottle, and at that moment, a loud explosive sound occurred.
"Gasp!"
"Oh my!"
As the subjects were startled by the unexpected explosion, Choi Hae-san introduced it with a mischievous smile.
"This is Explosive Oil."
"Amazing! Amazing! Crown Prince, truly amazing! It is truly a weapon worthy of the name Explosive Oil! General, then how is its power?"
"It cannot be compared to the gunpowder our Joseon army uses. It would be fitting to say there is a difference of heaven and earth. Prepare."
"Yes, General."
The artisans prepared a demonstration that could compare the power of black gunpowder and Explosive Oil.
"This is a thickened handgun for testing power. The amount of gunpowder going in is 1/4 yang (雨, approx. 9g) for both sides. First is the Eul-sik gunpowder."
The artisan, who had tamped 1/4 yang of Eul-sik gunpowder into the handgun, fixed the handgun to a tripod that had been pre-installed on the ground. Then, he fitted an iron cap shaped like a large mushroom into the muzzle of the handgun, which was set up at an angle facing forward. The artisan, having pulled back the hammer and fitted the copper percussion cap, stepped back and shouted loudly.
"Fire! Fire! Fire!"
Bang!
Along with a loud explosive sound, the iron cap flew in a parabolic arc and fell to the ground.
The artisan began counting the units while retrieving the string connected to the iron cap.
"1 bo! 2 bo!..."
Choi Hae-san quickly explained to Sejong.
"Colors are painted at 1 bo intervals so you can confirm the distance flown."
"Is that so?"
"50 bo! (approx. 60m)"
"Now we will experiment with Explosive Oil."
At Choi Hae-san's gesture, the artisans began preparations for the second firing. The artisans' hands loading the Explosive Oil into the handgun were extremely cautious.
"They are being very careful, aren't they?"
At Sejong's question, Hyang immediately answered.
"It is an extremely finicky thing."
"Is that so?"
"Fire! Fire! Fire!"
The artisan who had finished preparations while they were conversing pulled the string connected to the hammer.
Boom!
Along with an even louder and sharper explosive sound than the Eul-sik gunpowder, the iron cap shot up into the sky and began flying far away.
The artisan who retrieved the iron cap that had flown quite far shouted the distance in a loud voice.
"110 bo! (approx. 132m)"
At the artisan's shout, Sejong's eyes widened in surprise.
"It flew more than twice as far?"
"That is correct. As much as its nature is finicky, its power is outstanding."
Sejong clicked his tongue at Hyang's expression as he answered.
"Tsk! Judging by your expression, it seems it's not something that can be easily used."
"That is correct. Given our Joseon's current circumstances, Explosive Oil itself is something that cannot be used."
"My goodness."
At Hyang's answer, Sejong could not hide his regret and clicked his tongue in disappointment.
"It is regrettable."
"I agree."
The ministers who heard Sejong and Hyang's answers made similar expressions to Sejong.
The Crown Prince's personality that they knew seemed to prioritize performance above all, but unexpectedly, he was also one who considered production costs.
However, that such a Crown Prince did not mention cost meant that the court could bear the production cost. Yet the Crown Prince had just evaluated it as "something that cannot be used."
"Just how finicky is it that you speak of it that way?"
"It is extremely finicky."
Hyang explained the reason to Sejong.
- First, production itself is impossible in spring or summer when the weather gets warmer. High heat is generated during the synthesis process, and there is a high possibility that it will explode or catch fire on its own from this high heat. For that reason, he himself could only attempt synthesis after winter began, and had to use large quantities of ice from the ice storage.
- One must pay very close attention during the synthesis process. Because highly concentrated acid solutions are used, protective gear must be worn to protect the skin of hands and face. Ventilation devices must also be absolutely present.
- If even a small amount of impurities enters, the risk of self-detonation increases enormously. For this reason, Hyang also had to go through numerous purification processes before and after synthesis.
- Storage is not easy either. It is extremely sensitive to shock, so if containers collide or shake violently during transport, it explodes immediately.
If lightning strikes nearby, it explodes immediately. As explained above, if impurity removal is not done properly, it self-detonates over time. Storage also requires keeping it in a cool place due to the self-detonation problem. In Hyang's case, he went so far as to dig a cave in Mokryeok-san (Namsan) to create a storage location.
"For these reasons, Explosive Oil itself is absolutely something that cannot be used."
"Truly a damnably troublesome thing."
At Hyang's explanation, Sejong unconsciously uttered a curse. But this time, the ministers also agreed.
"Truly a damnably troublesome thing."
"The power is truly good, but... with such a nasty temperament..."
Leaving behind the regret about Explosive Oil, Sejong moved on to the next item.
"The next gunpowder to introduce is Cotton Gunpowder."
"Cotton Gunpowder? Did you name it Cotton Gunpowder because you used cotton cloth? Wait, you use cotton cloth for gunpowder?"
Sejong, recalling the explanation Choi Hae-san had given when he first saw it, made an expression of disbelief. The ministers were the same.
"Making gunpowder from cotton cloth?"
"Of course, cotton cloth does burn, but..."
While Sejong and even the ministers were muttering full of doubt, Choi Hae-san picked up a piece of cotton cloth placed on the table with tongs.
"Light it."
"Yes, General."
Bang!
"Oh my!"
"Oh dear!"
As soon as the artisan set fire to the cloth, the cotton cloth burned instantly with an explosive sound and turned to ash.
Seeing the ministers startled by the explosive sound, Choi Hae-san, who smiled faintly, spoke.
"It is made using well-woven cotton cloth and various types of acid solutions. As you can see, it has powerful firepower. And... there is something most important. Starting from that Explosive Oil, Cotton Gunpowder, and Deok-gap-sik gunpowder are all smokeless gunpowders."
"Smokeless... meaning no smoke comes out?"
"To be precise, less smoke comes out."
In the ensuing demonstration, Cotton Gunpowder showed power that was weaker than Explosive Oil but sufficiently stronger than black gunpowder.
"The last thing to show you is Deok-gap-sik gunpowder."
"Deok-gap-sik? What is the reason for naming it so?"
At Sejong's question, Choi Hae-san looked at Hyang. Following Choi Hae-san's gaze, the eyes of Sejong and the ministers all focused on Hyang.
Hyang scratched the back of his head and answered.
"Um... I thought that making it so that all soldiers using gunpowder can use it comfortably is also virtue (德), and I thought that being able to create it that way was all thanks to Father's virtue, so I named it that."
"Hmm?"
"It's a bit embarrassing, but it's quite a fine naming."
At Hyang's explanation, Sejong and the ministers nodded. But Hyang had to force a bitter smile.
'It's gunpowder I learned about through internet research, and since it's a German manufacturing method, I can never say I took it from Deok-guk, the name used to call Germany!'
Choi Hae-san continued his explanation.
"This Deok-gap-sik gunpowder is made by mixing Cotton Gunpowder with Explosive Oil and Glycerin in certain proportions."
At Choi Hae-san's explanation, Sejong's eyes widened as he pointed out a problem.
"You mixed in Explosive Oil? Didn't I hear earlier that Explosive Oil is of such an extremely finicky nature that it cannot be used?"
"Cotton Gunpowder and glycerin neutralized that nature."
"Is that so? But Cotton Gunpowder was white, so why is this gunpowder black?"
"Because it was coated with graphite, no, because the surface was wrapped in it."
In the ensuing power demonstration, Deok-gap-sik gunpowder demonstrated power fully equal to Explosive Oil.
Seeing that power, Sejong clapped his hands and was delighted.
"Truly excellent! Excellent!"
As Sejong was so pleased, Hyang had a proud expression.
'As expected, Deok-guk!'
However, this was Hyang's incorrect memory.
The combination Hyang remembered was not German-made but British-made. To be precise, it was the formula of Cordite MD.
Sejong, who liked the newly created gunpowder so much, looked at the ministers.
"Since such good gunpowder has been created, how about mass-producing it?"
At Sejong's proposal, Hwang Hee asked Hyang.
"How much is the production cost?"
"It costs about 30% more than the cost of producing the same weight of Gap-sik gunpowder. But even if you put in only half of Gap-sik gunpowder, it demonstrates more than that power."
At Hyang's answer, Hwang Hee nodded and advised Sejong.
"Though it costs much, it can be compensated by using less quantity, so it seems good to mass-produce it."
"The Right State Councilor's words are correct."
When the ministers agreed and supported it, Sejong looked at Hyang and Choi Hae-san.
"Prepare for mass production of Deok-gap-sik gunpowder."
At Sejong's command, Hyang answered with a troubled expression.
"Though it is shameful to say, given Joseon's current situation, mass production of Deok-gap-sik gunpowder is impossible."