Top Scholar

Chapter 640 Upgrading from a slingshot to a cannon
The imperial procession led the palanquin to the entrance of the Royal Mint, where Su Man, who also served as the director of the mint, along with two chief engineers and all the mint's employees, had been waiting for some time.

Amidst shouts of "Long live the Emperor!", Zhu Houzhao, supported by Zhang Yong, stepped down from the imperial carriage. However, his gaze passed over the welcoming crowd and landed on the three enormous waterwheels located close to the Changhe Dam.

"This thing must be at least two zhang tall, right?" Zhu Houzhao looked up at the slowly turning waterwheel and said with great interest, "My Zhengde silver coins were made from this thing?"

"This is my first time here since its completion. Please allow the two chief designers to explain it to His Majesty." Su Lu then pointed to Qiu Cheng and Lu Jingchang, who were kneeling on the ground, and introduced them to Zhu Houzhao.

The two men kowtowed to the emperor again, trembling with fear. They never imagined that such insignificant people as themselves would have the chance to meet the emperor.

"No need for formalities, no need for formalities, please tell me quickly, please tell me quickly," Zhu Houzhao urged impatiently.

"Yes." Lu Jingchang then explained to the emperor in the most straightforward language, "Your Majesty, these three large waterwheels have a diameter of 22 feet, and the wheel core is made of century-old hard jujube wood, with three layers of wrought iron rings on the outside, making them durable and resistant to impact."

"How heavy must that be? How can it still be turned?" Zhu Houzhao exclaimed in amazement.

"Your Majesty, each waterwheel weighs a full 20,000 catties," Qiu Cheng replied. "We have specially built a diversion channel on the riverbank to increase the water flow, and then used sluice gates to regulate the water level, so that even in years of severe drought, the waterwheels can run day and night. They each perform their functions, providing a continuous source of power for our mint."

"Our factory's silver coin production relies entirely on these three waterwheels. They not only greatly save manpower but also make it faster and better, increasing output by more than tenfold!" Lu Jingchang respectfully invited.

"Your Majesty will know exactly what they are used for once you go inside and take a look."

"Come on, let's go in and take a look!" Zhu Houzhao said with great interest, his hands behind his back, as he followed the two chief engineers toward the gate.

The mint's massive iron gates were incredibly heavy and usually kept tightly closed. They could only be opened when both chief engineers were present.

At each of the four corners of the factory area stood a watchtower three zhang high, with four imperial guards stationed inside each tower to keep watch both inside and outside, making the security extremely tight.

This was still too short a time; there hadn't been enough time for large-scale construction. According to Su Lu's plan, the Royal Mint would be built as a rammed earth brick wall, 27 feet high and 10 feet wide at the base. The wall would have passageways and loopholes at the top, allowing guards to move and defend against enemies.

A wide and deep moat will be dug around the high walls and filled with water from the Changhe River, so that he can feel at ease...

Upon hearing Su Lu's plan, Zhu Houzhao was not surprised at all; on the contrary, he understood. "Better safe than sorry. The capital is no peaceful place..."

"Your Majesty is wise," Su Lu praised, then said softly, "Besides external enemies, we also have to guard against traitors within our own ranks who leak secrets and steal from us, so we must strengthen our vigilance."

"Hmm." Zhu Houzhao nodded: "All the silver coins in the world come from here, so you can't be too careful."

As they spoke, Emperor Zhengde, surrounded by a crowd, passed through the heavy iron gate and entered the mint.

The factory was laid out in a neat and orderly manner, divided into five workshops according to the coin-minting process. The workshops were interconnected yet did not interfere with each other, with the roar of hydraulic machinery rising and falling in waves. The craftsmen performed their duties in an orderly and efficient manner, with a very reasonable division of labor.

This is all the work of Chief Engineer Lu Jingchang. The Ministry of Works' Baoyuan Bureau had been operating for over 120 years, accumulating rich experience in production management, which he directly adopted.

Lu Jingchang led Zhengde and his entourage into the silver smelting workshop and said respectfully, "Your Majesty, we use ready-made silver ingots and broken silver for coin minting, which saves a lot of work. We only need to melt and recast them."

Upon entering, a wave of heat hits you. A row of furnaces roars with charcoal fire. Bare-chested craftsmen feed broken silver into crucibles, add measured amounts of borax and tin powder, then cover the crucibles with heavy lids and let them slowly melt.

Some crucibles had already boiled. The craftsmen used long-handled iron tongs to remove the red-hot lids, then carefully skimmed off the scum with long-handled spoons. They then switched back to the iron tongs and worked together to lift the crucibles, pouring the molten silver into the molds to cast pieces of silver.

"This temperature is quite high." Zhu Houzhao was curious about sleight of hand and knew a lot about these things. "Besides burning coal, we also need to blow air, right?"

"Your Majesty is wiser than anyone else." Lu Jingchang hurriedly pointed to the small waterwheels behind the charcoal stove and said, "We use water-powered bellows. One of the three large waterwheels outside is dedicated to drawing water, sending the water from the Changhe River into the workshop, flowing down the stone trough on the ground, and driving these small waterwheels in the trough."

"Each waterwheel has a set of connecting rods and levers. Each turn activates a bellows, drawing in and expelling air to automatically supply it to the furnace." He then briefly explained the principle:
"Compared to manually operating the bellows, this method provides a more even airflow and a more stable fire, preventing the crucible from burning due to sudden fluctuations in temperature."

"That's interesting." Zhu Houzhao squatted down by the trough, watching with great interest as the small waterwheel spun around in circles, its ingenious mechanical structure causing the bellows to inflate and deflate, and the furnace fire to roar. Give him a stool, and he could watch until dark without getting annoyed.

Su Lu watched with him for a while, then walked to the mold and took a long strip of silver plate that had already been cast from Qiu Cheng's hand. "Oh my, it's quite heavy."

Qiu Cheng reported: "The weight to be put into the pot is exactly 25 jin. The requirement is that the loss of each pot should not exceed 1.5 qian. If it exceeds this, the next workshop will not accept it."

He then placed an equal-arm copper balance on the spot and weighed it, using small weights accurate to the centimeter, to obtain the accurate weight—24 catties, 15 taels, 8 mace, and 8 qian!
"Fire loss of one qian and two fen," the accountant in charge of weighing the goods said loudly as he recorded the information. "Qualified!" Su Lu did the calculation for a moment and exclaimed in surprise, "Fire loss of three ten-thousandths? That's too excellent!"

"To meet your requirements, we dare not waste a single bit." Qiu Cheng picked up the cleaned pot beside him: "Look, the pot is dry and the bowl is clean, not even a speck of silver can be seen. I was never this careful when I was melting gold at the Silver Workshop."

“That’s right.” Su Man laughed from the side, “We have to make up for any excess losses out of our own pockets, and we get a commission for keeping them under control, so of course we have to make sure every grain is accounted for.”

"Hehe, you're right, sir." Qiu Cheng chuckled sheepishly. He hadn't expected that this seasoned veteran would be so easily provoked into taking things so seriously. He then added, as if seeking praise, "..."

“This loss is already the limit in our dynasty. The Ministry of Revenue stipulates that there is a loss of two taels per hundred taels of silver, and local governments generally charge an even higher loss of 10%.” He paused, then added, “Of course, the loss from melting silver is not the greatest. We must be meticulous in every step to meet your requirements, sir.”

"Don't compare yourself to others, only compare yourself to yourself. Continuously break through your own limits and strive for excellence. That's the mark of a master craftsman!" Su Lu said solemnly.

~~
After a long while, Su Lu finally managed to coax and urge Zhu Houzhao to leave the 'men's speed bump' and head to the adjacent silver rolling workshop.

Inside the workshop stand four hydraulic silver rolling mills, which are connected to a large waterwheel outside via transmission rods. The heavy rollers rotate smoothly and at a constant speed under the power of water.

The craftsmen slowly fed the long silver plates into the rolling mill. The silver plates were repeatedly rolled by the rollers and gradually stretched into smooth and uniform silver sheets...

"Your Majesty," Qiu Cheng exclaimed with a complex expression, "these rolling mills are extremely hard after quenching. With the immense force transmitted through the waterwheel, they can roll silver plates into uniformly thick sheets. Each mill can produce two hundred silver plates a day, equivalent to the work of twenty skilled craftsmen!"
"Currently, only one machine is in operation; the other three are still being tested. But the entire silverworks bureau combined can't keep up with this one machine..."

“That’s normal,” Su Lu said calmly. “It’s progress that machines are replacing human labor. We should make full use of them, or we will fall behind.”

"Who could possibly surpass us?" With the pride of a master craftsman from the Celestial Empire, Qiu Cheng couldn't help but ask in a low voice.

"Europe," Zhu Houzhao said solemnly. Su Lu's subtle influence had not been in vain.

"Yes." Qiu Cheng and the others hurriedly replied respectfully, even though none of them knew where Europa was.

Inside the workshop, there were craftsmen who specialized in using copper gauges to check the thickness of silver sheets, demonstrating this to the emperor on site. He would insert the rolled silver sheet into the groove of the copper gauge, and it was considered合格 (qualified) only if it fit perfectly into the groove; if it was too thin or too thick, it had to be reworked.

The qualified silver sheets are then sent to the next blanking workshop, where craftsmen place them on a water-powered blanking machine. The heavy punch, like a nodding beetle, rises and falls powerfully with a fixed rhythm. Each fall is accompanied by a click, precisely cutting a round silver blank...

According to the process requirements, at least 440 silver blanks must be made from each silver sheet. Not a single scrap can be wasted; all of them must be collected and sent back to the workshop for remelting and reuse.

Zhu Houzhao grabbed a handful of silver ingots and exclaimed with a smile, "Amazing! They're all exactly the same, so perfectly round!"

“Mechanical stamping is not only faster, but also more stable. The edges of the stamped silver blanks are much neater, and they don’t need to be polished anymore; they can be sent directly for stamping,” Lu Jingchang said.

Su Lu glanced at him but didn't say anything. The real reason was that polishing inevitably causes wear and tear, so this step was definitely something that could be skipped whenever possible…

Then, the group arrived at the core stamping workshop, a crucial area, where guards were stationed at the entrance.

Two hydraulic stamping presses were set up in the workshop, each with two craftsmen working alongside them. One craftsman was responsible for embedding the silver blank into the die ring with a serrated pattern. The other craftsman would then take the blank into the gap when the punch rose, remove the previous finished piece with his left hand, and immediately put down the silver blank with the die ring in his right hand.

As soon as he removed his hand, the water-powered plunger fell with tremendous force, and with a muffled thud, it instantly pressed the silver blank into a complete Zhengde silver coin.

The two workers repeated their work, taking the finished product off and throwing it into a wooden box to the side, and then continuing to press the next one.

The two machines clattered back and forth, spitting out silver coins one after another with the help of four workers.

Zhu Houzhao reached out and picked up a handful to examine it closely. He saw that the patterns and edges on both sides were clear, regular, and perfectly shaped, exactly the same.

"Your Majesty, a Zhengde silver coin has been made." Lu Jingchang reported, "Finally, it was sent to the packaging workshop for inspection. The defective ones were picked out and melted down, while the qualified ones were packaged into boxes and sent to the silver treasury."

"Good, good, good, this is really fun... Uh, this is truly an eye-opener!" Zhu Houzhao praised with satisfaction, "I finally understand why Scholar Su wasn't afraid of forgery. Who could afford to forge this? Nobody has the ability!"

"Great job! You'll be richly rewarded!" He then waved his hand generously and gave the reward.

(End of this chapter)