# Chapter 190: Teacher (2)
As I mentioned before, the paper consumption at Area 51 and the research institute was enormous. The amount of paper used for writing various reports, proposals, and research records was no joke, and the cost of purchasing the necessary paper was also no joke.
"Damn it! We're going to spend the entire budget just buying paper!"
Sensing a crisis, Hyang mobilized craftsmen to create a paper-making machine that produced pulp using wood chips.
Rather than traditional hanji made from limited dak (paper mulberry) trees, the paper made from pulp using trees felled from the mountains surrounding Hanyang was cheap to produce.
"Well... the quality isn't top-tier, but..."
Hyang, holding the paper in his hand, muttered with a voice full of regret.
There was no problem writing documents with brushes or gold pens, but the yellowish paper still had a strong cheap feel to it.
"We could bleach it if we wanted to, but what about environmental pollution? I don't even know about that side of things..."
However, since the cost-effectiveness of this yellow paper was incomparable to traditional hanji, government offices began using yellow paper for anything other than important documents.
Thanks to this, as I mentioned before, ordinary people started calling this yellow paper "Aekji" (Paper of Misfortune).
* * *
Hyang, who received orders to produce textbooks for use in the 'Samin School,' was equally troubled.
"I can somehow manage to produce the paper... but the problem is printing..."
The issue of printing hundreds of thousands of copies of textbooks was quite a difficult problem even for Hyang.
"I don't like throwing manpower at it mindlessly. Isn't there some smarter method?"
Hyang wrapped his head around the problem for days, worrying repeatedly. Of course, he also issued orders to the craftsmen at the research institute and Area 51.
"Research a method to print textbooks in the shortest time possible!"
Following the Crown Prince's command, researchers and craftsmen also had to suffer through headaches.
While many people continued to worry, the one who found the answer was Jang Yeong-sil.
"Your Highness! Textbooks don't need to have type pieces changed one by one, do they?"
"That's true, but?"
At Hyang's answer, Jang Yeong-sil spread out the blueprint he had brought on the table.
"We carve pictures and letters onto a large cylinder, then roll it over the paper!"
Seeing the blueprint Jang Yeong-sil had drawn, Hyang, Jeong Cho, and Jeong In-ji simultaneously exclaimed.
"This is it!"
While primitive, it was a printing press and printing method suitable for mass production.
And Jang Yeong-sil was the one who came up with it.
* * *
Based on Jang Yeong-sil's blueprint, researchers and craftsmen at the research institute began producing a prototype.
- For convenience of production, the production method uses casting.
- For convenience of transport and management, the cylinder with letters carved on it is cut vertically for casting, then assembled.
Following this plan, researchers at the institute adjusted the size of the type and books. In this process, the most enthusiastic person was Jeong Cho.
"You know what part requires the most attention, right?"
"Yes! Letters must not straddle the boundary where the two parts meet!"
At the researchers' answer, Jeong Cho nodded with a satisfied face, but did not forget to emphasize once more.
"Listen well! These are textbooks to teach the pillars who will lead our Joseon in the future! You must make them with all your heart!"
"Yes!"
Having heard the researchers' answer, Jeong Cho left with a satisfied face to attend to other duties.
The researchers who politely saw Jeong Cho off returned to their seats and whispered.
"Why is that gentleman so concerned about this?"
"What did you do when you learned Mencius? Don't you know what's written in 'Mencius: Jinsim Chapter'?"
At his colleague's rebuke, the one who asked first became embarrassed.
The 'Mencius: Jinsim Chapter' contained the famous 'Three Joys of the Gentleman.'
- Parents both alive and brothers without wrongdoing is the first joy.
- Looking up, having nothing to be ashamed of before Heaven; looking down, having nothing to be ashamed of before people is the second joy.
- Obtaining the talented people of the world and teaching them is the third joy.
Connected to Samin School, the story of 'Three Joys of the Gentleman' circulated here and there. Hearing this story, Hyang muttered to himself.
"Come to think of it, I remember my high school Korean language teacher."
* * *
When Hyang was a high school student in the 21st century, the school he attended mainly scheduled Korean, English, and Math classes in the morning.
The reason was that core subjects should be taught when students' minds were relatively fresh.
However, when scheduling timetables, classes were sometimes arranged after lunch time.
Once afternoon classes started, many students couldn't overcome drowsiness and dozing off became a daily occurrence.
The Korean language teacher in charge of Hyang's second year class clicked his tongue whenever he saw that sight.
"The ancients spoke of 'Three Sorrows of the Gentleman,' and one of them is 'obtaining the dull-witted people of the world and teaching them'... You rascals! Attention!"
It wasn't until his third year that Hyang learned that 'Three Sorrows of the Gentleman' was a remark satirizing 'Three Joys of the Gentleman.'
"I thought it was real!"
* * *
As prototypes were made and printing tests using them were repeatedly conducted, the optimal form was gradually created.
Of course, since working with steel was difficult work, most experiments had to be conducted with cylinders made by connecting wooden boards.
"Success!"
"Then let's try with steel!"
"Yes!"
On the day of the experiment with the first prototype made by casting steel, even Hyang attended to observe.
*Squeeeeak!*
As the steam engine connected to the roller with carved letters moved with a loud noise, the large cylinder with carved letters began to slowly rotate and suck in paper.
As the cylinder continued to turn, papers with printed letters and pictures began to flow out in a line.
"Stop!"
"Stop!"
*Squeeeeak!*
The printing press stopped as the steam engine halted, and Hyang, Jeong Cho, researchers, and craftsmen examined the printed paper.
"It seems to have printed properly."
"Yes! It printed properly!"
When Hyang and Jeong Cho judged it as passing, researchers and craftsmen shouted with joy and clapped their hands.
"Wooooah!"
"Success!"
*Clap clap clap!*
When the researchers and craftsmen's shouts and applause subsided, Hyang spoke.
"Then let's make it with proper typesetting. Keep in mind that both sides of the paper must be printed, and the order must not be misaligned."
"Yes, Crown Prince Your Highness!"
The craftsmen and researchers, their morale raised, answered in loud voices.
Having achieved successful results, Hyang then asked Jeong Cho.
"It's a new device and printing method - what would be a good name for it?"
"Hmm..."
Jeong Cho, stroking his beard while thinking, soon seemed to have thought of an appropriate name and answered with a bright face.
"A large wheel turns and prints letters, so how about 'Yunjeon' (Wheel Turn)? Since it's a printing press, let's call it Yunjeon-gi."
"That sounds good."
'Wait... did actual rotary presses work this way? Ah, whatever!'
After briefly pondering, Hyang made an irresponsible decision.
* * *
"The textbook issue is resolved, but..."
Having solved the textbook problem, Hyang moved on to the next issue.
"If we have textbooks, we need notebooks too... Especially for studying mathematics, we need to solve equations... But..."
Stopping his words for a moment, Hyang sighed with a troubled face.
*Sigh...* "Paper is the problem. If we make notebooks with paper, pretty much all of Joseon's mountains will become bald hills. The one who insisted on afforestation projects making bald hills? I'd have nothing to say even if I get cursed at left and right."
While Hyang's arguments were strong, Joseon had traditionally put effort into forest management. The problem was that this was limited to pine trees.
Therefore, Hyang advocated for the necessity of systematic management including not only pine trees but also fruit trees.
Thinking Sejong and the ministers' agreement with Hyang's argument was reasonable, they established the 'Afforestation Office' under the Ministry of Works and began active management.
While thinking about trees, Hyang's thoughts veered off track again.
"Forests need to be lush to reduce drought damage... Wait? Come to think of it, the ratio of rain-fed fields in Joseon right now is surprisingly low?"
Hyang's consciousness was already drifting toward the problem of rain-fed fields.
As Hyang said, Joseon of this period had surprisingly few rain-fed fields. No, there was a significant ratio of rain-fed fields, but due to continuous flood control projects under Sejong's command, irrigation channels expanded, and rice paddies located on flatlands almost completely disappeared as rain-fed fields.
Therefore, the rain-fed fields Hyang pointed out were those often seen on the Korean peninsula in the 21st century - fields created by clearing mountain slopes. Those fields where even powerful water pumps in the 21st century couldn't properly farm.
However, in this period, such rain-fed fields didn't exist in large numbers.
Thinking about the reason, Hyang burst into a smirk.
"Tigers are helpful in times like this."
In Joseon's mountains during this period, tigers as well as bears, leopards, and wolves were common. Thanks to this, unless it was a situation of being eaten by beasts or starving to death, clearing such terrain almost never happened.
"For clearing to be necessary to that extent, the population of this land needs to exceed 30 million at minimum. We've just barely exceeded 5 million, so it's still far off, and we're doing variety improvement and diligently developing the north, so no worries... If all else fails, we can develop the North American continent... For that, we need to make steamships... Improvement of steam engines... The propeller form should start with paddle wheels?"
Hyang, wandering aimlessly following the flow of consciousness, suddenly slapped his own forehead.
"Damn! I went too far!"
Realizing he had strayed off track, Hyang hurriedly returned to his original point.
"Therefore, notebooks are impossible for now... Then..."
After thinking briefly, Hyang reached a conclusion.
"Blackboards are the answer. We needed large blackboards for mathematics classes for teachers anyway, so we can make small individual blackboards to distribute instead of notebooks."
Having concluded that blackboards were the only answer, Hyang let out a smirk.
"Pfft! Then checking homework is out of the question for a while?"
* * *
The manufacturing of blackboards themselves was simple, so a prototype was quickly completed. Also, chalk was made using limestone that was being quarried in large quantities for cement production.
"This looks quite useful!"
Sejong, seeing the prototypes of the blackboard and chalk, expressed great admiration. The ministers' reactions were the same.
"It seems it would be useful not only when teaching children but also when conducting meetings!"
"Not just meetings! It seems it would be good when carrying out work as well!"
With enthusiastic support from the ministers, mass production of blackboards and chalk was decided.
Once again, the world's first objects deviating from existing history were created.
* * *
As the ministers said, once blackboards were distributed, government work became a bit easier. Large and small blackboards were hung at the entrances of the Six Ministries' offices, in conference rooms, and in rooms where officials of each rank worked.
At the office entrances, the names of those on leave today and their reasons were recorded. In conference rooms, officials engaged in debates while writing on blackboards. And on blackboards hung in offices, who was doing what work was written, enabling smoother management.
Such blackboards soon came to be used by merchants in markets as well - they hung blackboards at shop entrances and wrote down the products they handled and their prices so customers could easily check.
As blackboards spread this way, the communal dining halls established in the Six Ministries' offices and the palace also began using blackboards. They wrote down the daily menu and hung it in front of the dining hall.
Thanks to this, various comedies also unfolded.
One day, at an office in the Ministry of Works.
"Say, Song Cham-bong."
"Yes, Chief Oh."
"Did you see what's for lunch at the communal dining hall today?"
"Rice, seasoned five-color vegetables, and tofu doenjang soup."
At Song Cham-bong's answer, Chief Oh's face crumpled.
"Damn it! I have to go out for lunch again today! Did the cook get served divorce papers by his wife or something? Why are all the side dishes just grass?"
At Chief Oh's complaint, Chief Go, who was nearby, made a joke.
"Then why not go to the dining hall at Gyeongbok Palace?"
At Chief Go's joke, Chief Oh shouted.
"This fellow! Do you want to see me die from choking while eating?!"
The communal dining hall at Gyeongbok Palace was where Sejong and ministers of third rank and above had their meals.
Thanks to Sejong's appetite, it was a dining hall where meat was never absent, and in principle, any official could go and eat there. However, among officials below third rank, there was no one who went all the way there to eat.