The Great Qin Empire---Qin Li

Ying County is also called "Jinan City" because it is just south of Ji Mountain and northwest of Yunmengze. The copper mine Tongguan, the closest to Ying County and Jiangling, is located on Ji Mountain.

"In the land of Jingchu, gold (copper), lead, tin and other minerals are much richer than those in the Central Plains, but unfortunately most of them are still in the hands of Chu."

The day after inspecting the arsenal, Li You took Hei Fu and others to Ji Mountain to inspect the copper workshop of the official camp. After hearing the news, the copper official Yang Xi came to the fork in the road to greet them in person. Perhaps because he had dealt with Liehuo Mine more often, this person was a bit darker than Hei Fu...

As he walked, Yang Xi introduced his business.

"The largest copper mine is near Zuo Bingcao Shi's hometown..."

Hei Fu immediately remembered: "Could it be Tonglu Mountain?"

"Yes, it is the Tonglu Mountain in Edi, which is separated from Anlu by a river. It is said that people have been mining copper and smelting copper ingots there since the Shang Dynasty. After thousands of years of excavation by Zhou and Chu, there is still an endless supply!"

How much copper is there there? It is said that after a sudden rain, after the soil on the surface of the mountain is washed away, the mountain will reveal green or blue dots, which are the exposed copper veins.

Hei Fu, who had learned some chemistry in junior high and high school in his previous life, remembered that green should be the color of malachite, and copper was smelted from it.

Yang Xi even told Hei Fu and others that when King Zhao of Zhou went south to conquer Jingchu, he was trying to obtain the "US dollars" produced in Tonglu Mountain in Edi and take them back as trophies to cast ritual vessels.

"As a result, King Zhao of Zhou drowned in the Han River and never returned to Zhou." Yang Xi was quite gloating when he said this.

He also said that in addition to the Tonglu Mountain in the southern Hubei hills, there are many large-scale copper mines in Jiangnan (Hunan), Liudi (Anhui), and Gandi (Jiangxi). These copper and tin mines were the basis for the Chu State to dare to challenge the Central Plains during the Spring and Autumn Period. No wonder King Zhuang of Chu boasted shamelessly at that time: "The beak of the hook of Chu is enough to make nine tripods!"

At this time, after walking a few miles north from Ying County, the group had arrived at their destination, but saw that it was a small hill that was dozens of meters above the ground and stretched for more than ten miles.

"County lieutenant, left military officer, please look, it just rained yesterday, are there some stones on Ji Mountain with a faint green color? As the saying goes, if there is cinnabar on top, there is gold below, if there is cinnabar on top, there is copper and gold below, if there is green stone on top, there is lead, tin, and red copper below, and if there is ochre on top, there is iron below. Ji Mountain is a big copper mountain."

"But I heard that the quality of the copper mines here is not good, far inferior to Tonglu Mountain." Li You disliked this "copper mountain" and felt that it was a chicken rib.

"County lieutenant."

Yang Xi said with a smile: "Even if all the copper mines in the entire Nan County are added together, I am afraid that they are not as much as the reserves of Tonglu Mountain, and the copper ingots produced by Nan County every year are less than half of Tonglu Mountain..."

"If Tonglu Mountain can be seized, this lieutenant will not have to worry about the lack of copper and iron."

Li You sighed, but he also knew that the Chu people still had a lot of troops in the Jiangnan area, and there were two or three thousand soldiers responsible for guarding Tonglu Mountain in southern Hubei. The strategy of Qin State was to concentrate its army to attack the core areas of Chu State, Huainan and Huaibei, and did not intend to open another front in the south of the Yangtze River...

Hei Fu looked around on horseback and saw that the fir and pine trees on this small hill had been almost cut down, but with the shouts, trees on the hillside would fall to the ground from time to time, as if they had to cut down all the trees here.

"Isn't it stipulated in the Tianlu that cutting trees in spring is not allowed?" Hei Fu asked Yang Xi.

"The copper and iron officials are not included in this rule."

Yang Xi replied: "After all, they are military tools, and they cannot be extinguished all year round."

He added: "But as Zuo Bingcao Shi said, the wood in spring is wet and it is indeed difficult to burn. Therefore, more fuel is cut from Dahong Mountain and Jing Mountain in autumn and winter, and then sent here for storage. Now the trees are cut down only to dig the mines below."

Although the copper mine is not large, there are more than a hundred soldiers guarding it, and the walls are built for protection, and the entrance is strictly controlled.

The first place they entered was the residential area, which should be provided for the officials, soldiers, and prisoners in the copper official.

Hei Fu took a look and found that the living environment here was very bad. Most of the prisoners who were punished to work were prisoners who committed serious crimes, so their enthusiasm for work was not high. They came out of the house under the urging of the whip and walked listlessly towards the smelting area.

Li You and his group were also walking towards the smelting area. Before they got close, they smelled a pungent smell and felt a burning sensation.

From a distance, they saw more than a dozen oval furnaces erected in front of them. Not counting the convex rammed earth platform under the furnace, only the furnace body was counted, which was basically ten feet high. Each furnace was five feet apart, leaving a safe distance. Around the furnace body, there were also subdivided into various parts such as loading, blowing, copper output, and water supply.

At this time, flames rose from under half of the furnaces, and black smoke came out from above, covering half of the copper official.

Dozens of craftsmen and servants were guarding around the furnaces they were responsible for. Some people stood on tiptoe on the high platform, lifting baskets to put ore into the furnace; some people were bare-chested, pushing simple air bags to blow air into the furnace with sweat on their heads; the craftsmen squatted aside and nervously observed the fire, trying to grasp the time to open the furnace.

"When casting gold, gold and tin, when the black turbid gas is exhausted, the yellow-white gas will be next, when the yellow-white gas is exhausted, the blue-white gas will be next. When the blue-white gas is exhausted, the blue gas will be next, then it can be cast."

This is the method of observing the color when smelting bronze, using high temperature to smelt the copper element inside. Whenever the red copper block comes out of the furnace and rolls into the big pit in front of the furnace, someone will immediately take water and pour it on it, and the water vapor will evaporate and turn into white mist. These copper blocks are then reheated and poured into earth molds to make copper ingots...

The newly refined copper ingots were sent to Li You by the craftsmen nervously, and Yang Xi also apologized, saying that because the copper mine in Jishan does not contain high copper, it often takes a lot of ore and smelting two or three times to get brass with higher purity.

Hei Fu looked around but didn't find a foundry. He asked and found out that the smelted copper ingots were not cast into weapons on the spot, but sent to the workshop area in the southwest of Ying County, where they were combined with copper, tin and lead sent from other places and matched in the right proportion before being cast into bronze.

Seeing Li You frowning and circling around each copper furnace to check the quality of the copper ingots, Hei Fu called Yang Xi over and asked, "Where is the place where the ore is processed? Take me to see it."

Yang Xi looked surprised. In the past, the county lieutenant sent people to inspect, and basically just walked around the smelting area and rarely went inside. So he smiled and said, "Zuo Bingcao Shi, the place where ore is processed is even dirtier. Not only is there sewage flowing, but there are also stone chips and dust flying everywhere. There is nothing to see."

Hei Fu didn't care and let Yang Xi lead the way. Sure enough, after walking more than a hundred steps inside, they were greeted by flying powder. When Hei Fu closed his eyes and opened them again, he found that they had entered the ore storage yard.

After hundreds of prisoners dug out the copper ore covered with mud from Ji Mountain, they used cattle and horses to transport it in baskets to the water flowing at the foot of Ji Mountain for cleaning, and then sent it to the ore storage yard along the downhill road. The yellow or green copper ore piled up like a mountain here.

The shaggy and barefoot prisoners in ochre clothes worked here. Most of them had their hair and beards shaved off. Some death row prisoners still wore wooden clamps around their necks, with their heads drooped and their backs hunched. However, they worked hard under the whip of the supervisors, using tools such as hammers and stone rammers to crush the whole piece of ore into pieces.

This is probably the most time-consuming and most difficult process in the entire smelting process. The ore is hard, and it takes a long time to smash it hard before it can be turned into broken ore that can be put into the furnace.

As he walked, Hei Fu felt his eyes brighten, because he saw that in a corner of the ore storage yard, there were rows of treading pestles. Many dusty, skinny prisoners were stepping on it, causing the stone hammer of the pestle to rise and fall continuously, pounding the already broken ore into even finer pieces... because the finer the ore powder, the easier it is to smelt.

Hei Fu immediately became interested and pointed over there, saying, "When did they start using the treading pestle to process the ore here?"

Yang Xi replied, "It was probably after the autumn harvest the year before last. This thing began to be promoted by the county governor's office in various counties and towns for pounding grain. At that time, the county engineer thought that the treading pestle could also be used for copper officials. Let those weak prisoners who couldn't lift heavy objects step on it to pound the ore finer. It was indeed more useful, but unfortunately it was still not enough..."

He pointed to the mountains of ore piled up around him and whispered, "Now the county lieutenant wants us to increase the copper smelting output, but no matter how many stoves are added, the prisoners still can't process the ore quickly."

It turned out that the copper content of the Jishan copper mine was low, so more ore was needed to smelt one pound of copper. Just processing the ore made the prisoners miserable, and more than a dozen people died of exhaustion every month.

Hei Fu nodded, knowing what to do, but he didn't show it for the time being. He glanced at the prisoners who were living in dire straits again, shook his head slightly, and returned to the smelting field with Yang Xi.

From a long distance, they heard the roar of Li You, the county lieutenant.

"No matter what you do, you must hand over twice as much copper as before in the next six months!"

Yang Xi hurried over, and he and a group of craftsmen complained: "Unless we are allocated hundreds of prisoners to smash the ore, we can reach the output required by the county lieutenant. Otherwise, even if we transport more ore from the mountain and build more stoves outside, it will be useless!"

At this time, Hei Fu interrupted and said, "County lieutenant, I have an idea that may solve this problem!"

"Oh?"

Li You, Yang Xi, and a group of craftsmen with gray faces all looked at Hei Fu, and everyone wanted to know what his idea was.

"I would like to recommend a man, a craftsman, to the county lieutenant, because I have seen him make a kind of equipment. If it is used to process ore, it can not only save twice the manpower, but also double the effect!"

Li You was overjoyed when he heard this and asked, "Is there really such a person? Who is he?"

Hei Fu said, "He is my brother-in-law. It is related to casting weapons and enriching the arsenal. I can only recommend the virtuous and not avoid relatives!"

"Brother-in-law?"

Including Yang Xi, all the craftsmen showed strange expressions.

Some people said in disbelief, "Left Military Officer, saving twice the manpower is too exaggerated. You can't brag about it just because he is your brother-in-law..."

They always felt that Hei Fu was taking the opportunity to place relatives in the county, and Li You also had a glimmer of doubt in his eyes.

"I'm not bragging." Heifu said, "Do you know, treading pestle has another name?"

The craftsmen looked at each other in surprise: "Anlu pestle?"

"Yes!"

Heifu clapped his hands and laughed, "To be honest, my brother-in-law is named Yuan, and he is the first person to make Anlu treading pestle! My brother-in-law once threatened me that as long as I give him manpower and money, he can transform the treading pestle that still needs human operation into a magical tool that can operate automatically without human hands!"

He began to brag shamelessly: "By then, not only can we save twice as much manpower, but ten times as much!"