Innovation and Revolution (4)
Yi Yeon stood before the farm implements that the mechanics had assembled and his mind drifted to Yi I. He had always assumed that, without a steam engine, none of this could have been possible. The thought planted a seed of doubt.
’Was he even human?’
Yi I was, undeniably, the greatest genius Joseon had ever produced. Still, this felt like too much. Every expectation had been shattered. When Yi I had brought the completed steam engine, Yi Yeon had told him not to come. His mother had worried about the rough seas of the season; the waves were dangerous.
’What if he fell overboard!’
No life jacket. Cold water. Even if the man could swim like a fish, he would drown. So Yi Yeon had demanded progress reports in writing. According to the letter, the inner diameter of the steam engine they were producing was thirty centimeters. That size should deliver at least one hundred horsepower. A big-boy engine with a sixty-centimeter diameter was rumored to exceed fifteen hundred, yet when Stephen and he had built one together, Yi Yeon had been astonished by how much more powerful it was than expected.
’A four-cylinder big-boy locomotive with cylinders eighty-one centimeters by sixty centimeters produced over six thousand horsepower. So it could haul that heavy train at a brisk one hundred thirty kilometers an hour.’
Plugging in Yi I’s numbers, the steam engine he had created should theoretically deliver two hundred thirty horsepower or more. The thirty-centimeter inner diameter gave it one-quarter the cross-sectional area of the big-boy model, and its length was only fifty centimeters—five-eighths as long. Yet the big-boy engine had been the king. Yi I’s was brand new. And during construction Yi Yeon had learned something: unlike internal-combustion engines, external ones like steam were not simply stronger just because the cylinder was larger.
’Temperature and pressure mattered far more.’
He had expected even the best-made model to top out at one hundred fifty horsepower. Three piston rings should have been more than enough to outdo a big-boy running hot, viscous coal. Yet it did not. The engine had not yet used hydraulics. It simply pressed a two-millimeter steel plate with pure mechanical force, sliced it into a shovel shape. At least two hundred horsepower should have been required. Torque was the force needed for cutting, and torque was power divided by rotational speed.
’How in the world…’
He was amazed. Huge. Anyway, it looked as though the engines now being produced could be installed straight onto the oar-sail ships. Eight hundred horsepower should pull a ship heavier than a thousand tons.
’Four engines, each smaller than the big-boy’s but still more than enough for thrust.’
’Maybe that was even better.’
Two engines side by side, like the horizontal opposition in famous sports-car engines, would eliminate vibration. The plan was to refit the oar-sail vessels. Extend their bows and sterns like cargo carriers, turning blunt shapes into sharp, elegant lines. The squares that had made them slow would vanish.
’The added weight would not matter; speed would soar. Cargo capacity would triple. Even on the open ocean they would move freely.’
The projected displacement of these modified ships was around five hundred tons. The current oar-sail vessels were only one hundred fifty, but the plan was to build reinforced hulls from ductile iron H-beams for the keel and clad the sides in zinc-coated steel plates. Add four steam engines, fill them with water, food, and coal, and the total would reach seven hundred tons. Even with people and weapons aboard, it would not exceed one thousand.
’Ten knots—eighteen point five kilometers per hour—should be easy.’
The British ship Britannica, at eleven hundred tons, had managed only eight point five knots with a seven-hundred-forty-horsepower engine. To go faster the square law of water resistance would demand enormous power, yet this felt sufficient. Some sailing vessels already reached twenty knots or more, but those would be outrun by steam turbines.
’The real problem was the crankshaft…’
That was the part that had to combine the power of all four engines into one shaft. The crankshafts were complex shapes. Still, if cast in ductile iron they could be made easily. The engine would receive the full force of four units, however, so the outcome remained uncertain. Ductile iron promised excellent tensile strength and ductility, but he could only hope it would work.
’For now, cast it and see. If it fails, we can forge and machine manganese-alloy steel.’
Such complicated problems had delayed any response to the Japanese raiders along the southern coast. This time Yi Yeon had decided they would be occupied outright. So he sent Kim Seong-il as an envoy. He had to make the daimyo of Tsushima understand that their backers were being watched and demand they stop.
* * *
Kim Seong-il stood before the daimyo of Tsushima and pretended to be furious. He slammed the tea tray onto the table with a loud crack. Cups leaped, the teapot lid flew, and the teapot itself rolled across the floor. The daimyo’s guards drew their swords with a metallic ring. Yet Kim Seong-il did not even blink. His eyes were fixed only on the daimyo.
He asked in a loud, commanding tone, “Do you actually believe that?”
The daimyo was speechless. He could not kill the envoy. Joseon’s envoy carried weapons that could be forged, and a completed trade deal that had brought him great wealth. He hastily waved the guards away.
”I am truly sorry. But I know nothing. I have no idea who those people are.”
The daimyo kept denying everything, so Kim Seong-il sighed. He had realized something. He had lashed out at Li Chengliang and expected the king to punish him severely. Yet the king had shown no punishment, only patience. That was far more terrifying. Gentle but unable to act, or so he had heard. The king had summoned him and asked, “I intend to send you as envoy to Tsushima. What do you think?”
”What?!”
He could not believe it. He had caused trouble and now they wanted him back as envoy. Had he not heard the raiders were rampant along the southern coast?
”I beg your pardon, Your Majesty. I truly know nothing.”
”Is that so?”
”Yes, Your Majesty. As you commanded, I have had no contact with the outside world.”
The king eyed him with open suspicion, but Kim Seong-il’s words were honest. He could not fear. Then the king clicked his tongue in disappointment.
”Tsk tsk! You are still so young and lacking in resolve.”
”…”
He had no answer. The daimyo was far older than the king, yet his temper made him hear such words often.
”What I meant when I said you should be patient was not to sever ties with the world, but to analyze and understand the incident you caused. Severing ties… Tsk!”
The king shook his head. Then he spoke decisively. “I have heard a hundred words are worth less than one glance. Go. Do exactly as you wish.”
”Your Majesty?”
”Go. Slap his cheek. Grab his hair. Topple the tray. See what happens.”
”Your Majesty! What do you mean by that?”
It sounded like a death sentence; Kim Seong-il could not help but ask in surprise.
”Hmph! He will not lay a finger on you. Feel what he feels.”
That was why the tray had been slammed down. To hit someone’s cheek, yank hair, or overturn a tray was improper etiquette. Yet it was true. The daimyo looked furious but was too distracted soothing his anxious guards to do anything.
’I would have killed them on the spot…’
That thought hit home. He understood now. Realized.
’I really was a blind, foolish fool…’
If he had studied under his master the way he had imagined, he would have known everything about the world. But that had been an illusion. The king’s words were true: one glance is worth a hundred lectures. Disappointment had made him sigh. Yet the daimyo bowed deeply and begged, “If you cannot trust me, I will send my successor as hostage.”
”What?”
The hostage idea came out of nowhere. He asked again, and the daimyo whispered something to the attendant. The servant returned carrying a toddler no more than two years old.
”This child is my successor, Yoshitoshi. Please deliver this message: forgive us and take him as hostage.”
The daimyo bit his lip, spread his arms, and bowed low. “Oh no! This will not do.” Kim Seong-il waved him off in shock. The daimyo only lifted his head slightly and spoke with sincere eyes. “Spare me. Please, envoy. I will die, but my child and the others must live. Take them as hostage.”
”What do you mean?”
He did not understand. “If I claim I did not send them, Your Majesty will not believe me. You would not believe me either, envoy.”
”That is true. The raiders could not reach Joseon without passing through this place.”
”Exactly. I am innocent, but the situation refuses to accept it. So I send my successor as hostage. There is no other way to persuade the Emperor of Joseon.”
”Ah…”
He had been wrong. The Japanese were different, just as the king had said. The daimyo’s eyes burned. His words were sincere, yet Kim Seong-il felt a chill.
’That was his teeth gnashing and heart rotting.’
”I understand. Since that is how it must be, so be it. But we must find out who those raiders truly are. Otherwise Joseon will have no choice but to suspect you.”
”Yes! I will find them.”
The daimyo bowed, hiding his face. Something felt off. Before, such gestures would have moved him, but not now.
The king’s warning echoed: trusting the enemy in diplomacy is the same as inviting death.
”Furthermore, you will report on the Japanese every day. If you do not, we will cut off trade at once.”
”Yes! I will obey.”
Kim Seong-il bowed and left. The world was completely different from what he had learned and experienced.
* * *
”D-do you even…”
Yi Yeon stared at the steam engine Yi I had built and could not speak. He had explained every known detail about steam engines, yet this surpassed them all.
”Your Majesty! Is there something wrong?”
”No. I am simply stunned at how well it has been made.”
”Your praise is too high, Your Majesty. There are still additional parts to add.”
”What else could you add?”
”A heat exchanger.”
”What?”
The combustion chamber of Yi I’s engine had been modeled on the Bessemer converter—or rather, Yi’s own converter. The only difference was that the walls were wound with brass pipes shaped like banana-milk containers. Yi Yeon examined it closely and felt his jaw drop.
Hot exhaust gases were routed through a screw-shaped turbofan. Fresh air was pulled in through a tunnel beneath the chamber. More than that, the engine used a rotary plate with a large handle to grind coal into a powder before sprinkling it. No more shoveling lumps into the firebox. Simply turn the plate, watch the metal thermometer on the fine hole, and the coal dust would feed itself.
Why build it that way? “The coal is smokeless, so it does not catch fire easily. Grinding it makes it burn better.” In addition, the device would automatically adjust the coal supply according to the preset steam pressure.
The engineer spoke so casually it seemed ordinary. Yi Yeon had been worried already. Smokeless coal had stronger heat than viscous coal, yet it was hard to ignite and could not be raised to full power quickly. Once lit, it burned steadily. Yi I had solved the problem by turning the coal to powder.
On top of that, he had added a turbofan. Yi Yeon could not help but stare in awe. But a new concern arose. Powdered flour could explode in dust form, so why coal? “When the chamber pressure rises, the exhaust tunnel opens automatically like a chick incubator.” The tunnel was routed through a water-filled pipe. That was why only white smoke had come out. Unlike viscous coal, smokeless coal does not produce black smoke.
Even this was astonishing. Adding a heat exchanger on top? Yi Yeon blinked in shock.
”Your Majesty once said that condensing steam allows it to be reused, which is more efficient, and that we should save water. I wanted to build it exactly as you described.”
”I mentioned it, but I never expected you to succeed. How did you make it?”
”Please look at the one we are building right now.”
”Of course I will.”
Yi Yeon followed Yi I with curiosity burning in his chest.
* * *