In 637, there were no major incidents in the Central Plains, but the extortion of the Jin State tossed the Xian State for a while.

After Prime Minister Fan Tao replaced Chen Fangshi on the throne, the Jin State successively followed the example of the Xian State and implemented the Jin State version of the "Granting Land Law", which greatly increased the national strength of the Jin State, and secretly raised the Xian State alloy new coins, refining money and extracting gold and silver, but failed.

The people of the Jin Kingdom found that no matter how high the temperature of the Xianguo alloy new coin furnace was, it was not easy to melt, and even if it was melted, the gold and silver in the alloy coin were difficult to separate, and they tried for a long time, but finally had to give up.

He secretly purchased old coins from all over the world, in an attempt to blackmail the Xian king, exchanging the old coins for the ready-made gold and silver of the Xian Kingdom.

But in fact, due to the long-term depreciation of the old Xianguo copper coins, the Central Plains countries almost abandoned them, and the circulation is very poor, and the stock of foreign Xianguo old coins and copper coins is very small.

The Jin Kingdom suddenly took out millions of old coins and copper coins, and asked King Xian to exchange gold and silver for one to one, which was no different from robbers and robbers.

Moreover, the 300,000 Jin Guozhen Northern Army stationed in Beihai County was transferred to Yongxing City, in an attempt to force King Xian to submit, and also carried out 50 large-caliber breech guns, which were set up outside the capital county and released empty cannons every day.

However, the siege of the Jin army not only made King Xian nervous, but also made the Ligong faction nervous. After the middle of last year, the families of the children of the masters of the Ligong faction moved from the Changsun Kingdom to Yongxing, and the Ligong faction stranded in the headquarters of Yuke also moved to the Xianguo country, which was naturally the technology and financial resources of Bailiyan.

If the Jin army besieged the city, it would inevitably be killed and injured, so it invited the royal guests to mediate, but it was unsuccessful for three reasons.

One of them is that the strength of the royal guest is not as good as before, and speaking is based on strength. Second, the Jin Kingdom took possession, and the King of Xian did not repay his debts. Third, the Jin army only moved to Yongxing City to "assist in defense", and there was no substantive military action.

After a stalemate of two months, Bailiyan listened to Zong Botai's strategy and persuaded King Xian to send someone to lobby Zhiguo and ask Jin for gold and silver spot with Jin copper coins.

King Zhi readily agreed, so he asked Gongliangwen to send an envoy to the Jin Kingdom, asking for two million copper coins from the Jin Kingdom to be exchanged for the equivalent inch of silver, and the King of Jin categorically refused.

Although copper coins have an official exchange rate for gold and silver, they are in fact very complicated and cumbersome to exchange.

Because the output of precious metals is restricted by output, and the output of copper and lead is huge, it often requires a large amount of copper coins to be exchanged, and there will be no official phenomenon of exchanging a large number of copper coins for gold and silver, otherwise a precedent will be set for the powerful to take copper coins from the treasury first.

In this way, King Xian followed suit and categorically refused to be blackmailed by King Jin.

The king of Jin retreated to the second place in the name of the new and old currency of the Xianguo, and asked the king of Xian to exchange the equivalent gold and silver Tongbao again, but was rejected again, but at this time, the unexpected situation made Bailiyan change his attention.

The Ganggong faction searched for ore in the Xianguo to Jiangdong County, and found silver ore in the Lingshan on the side of Jiangdong County and the Jin Kingdom side of Jiangdong County, and the amount was considerable.

Bailiyan weighed it again and again, and felt that it was very profitable, so he discussed with King Xian and claimed back Jiangpu, Guo Ting, and Yancheng in Jiangdong County, which were close to Jiangdong County, in the name of exchanging new coins.

Jiangpu, Guo Ting, Yancheng three population less than 110,000, neither military stronghold, nor economic town, Jin State is not profitable, but Lingshan silver mine is located in the west of Guo Ting, a stone's throw away from Jiangdong County, take back the three places, undoubtedly Lingshan into the bag.

In order not to make the Jin Kingdom suspicious, Jiangpu to the north of Guo Ting and Yancheng to the south were recovered. The negotiations lasted for three months, and the Jin State was not allowed to keep secrets, and finally returned the three places to the Xian State with a huge sum of 1.3 million gold and silver treasures.

After the silver mine was in hand, the news was pressed for four years, until four years later, the Xian army returned to defense, and the Lingshan silver mine was developed.

Facts have proved that in the following 100 years, the Lingshan silver mine has become one of the top five huge silver mines in the Central Plains, with extremely high quality and purity, and in one fell swoop has reversed the passive situation of only one small silver mine in Xianguo.

After this intimidation, King Xian once again asked to cast a cannon, and Bailiyan also realized that the performance of the artillery is one thing, and whether there is or without it is another, and it is necessary to solve the problem first, so he began to use his free time to tackle the artillery steel.

Yongxingcheng carbon steel still belongs to the primary carbon steel type, which is an iron-based steel with carbon as the main added element, and the early low-pressure breech cannon is not a big problem, but it is still subject to the bottleneck of casting and smelting technology, and the early carbon steel chamber has low pressure and poor high temperature resistance, resulting in large wall thickness and weight.

Then 250,000 pieces of gold and silver Tongbao were allocated for mold and trial production work.

Due to the lack of manufacturing and theoretical experience, Bailiyan blindly tried to make a light picture, eager for quick success, during which there were four explosions, and the delay fuse was simply used, which did not cause casualties, but the accident also accumulated a certain amount of experience for casting artillery.

Due to the limitation of the performance limit of carbon steel itself, Bailiyan must make trade-offs between range, weight and performance on the premise of ensuring high strength and safe use.

Continuing to increase the firing range meant that the chamber pressure had to be increased, and before the advent of cannon steel and the forging of large components, carbon steel could only increase the chamber pressure by increasing the wall thickness, thus increasing the weight of the gun itself. Even though the range is far exceeded, it is not conducive to deployment and maneuver, and it is better to use a copper cannon with copper-nickel-white copper.

For this reason, it is necessary to give up a certain range and reduce the wall thickness to make it more practical, as long as the range is guaranteed to be enough to cover the Changsun artillery and traditional long-range delivery combat equipment, it will be considered a large part. Before the technology matures, the blind pursuit of advanced technical standards is obviously more than worth the loss.

In addition, many explosions have made Bailiyan determined to do a physical and chemical analysis, and it can be roughly determined that the carbon steel smelted in Yongxing has a carbon content of about 0.3 percent to 0.35 percent, and the standard carbon steel contains a small amount of sulfur, silicon, and a trace amount of manganese, but also found a very strong phosphating reaction.

Too much phosphorus and sulphur can be harmful to steel, as phosphorus can make steel brittle and lose toughness.

The steel ingots in Yongxing City are mainly used to produce cold weapons and armor, and after smelting, they enter the forging workshop and return to the furnace to be heated and beaten repeatedly, and the phosphorus and sulfur elements in it are basically discharged under repeated high-temperature hammering, so there is no problem.

However, with the current technology, the cast cannon steel does not have the operability of repeated forging and repeated heating.

In the final analysis, he is not omnipotent, his previous life is just a doctor, at best he is a modern person with scientific thinking ability, and he will put into action the massive social basic experience information and ideas beyond the times in the current existing technical conditions.

In most cases, he still knows what it is, but he doesn't know why, and when it comes to the technical threshold of going deep into the professional field, he, as a doctor, is stretched.

In the end, there are only some trade-offs to be made between the quality of steel and the thickness of the gun's walls while ensuring the range of the artillery.

At the same time, in order to solve the problem of casting and molding, under the joint efforts of Bailiyan and Cheng Jiyuan, the master of the left door of the Ligong faction, after long-term accumulation of technical experience, it has the technical reserves for the construction of large-scale blast furnaces.

Due to the use of multiple molten iron ladles and multiple risers cast at the same time, the artillery of Changsun Kingdom has a low yield of artillery, many defects, and frequent explosion accidents after delivery, which is largely due to its inability to cast and form at one time, and at the same time, a large number of harmful substances such as sulfur and phosphorus exist, the furnace temperature is not enough, and the iron is the common result of poor fluidity in the molten state.

For this reason, Changsun Guo has spent great efforts in the past two years to make seven or eight hundred catties of iron furnaces, so that only two risers are needed to cast more than 1,000 catties of small-caliber artillery, and only five risers are needed for more than 4,000 catties of cannons.

In order to solve the problem of metallurgical steelmaking expansion in the future, Bailiyan allocated 500,000 yuan of gold and silver Tongbao and 1.2 million stone grain to build Yongxing West City on the opposite bank of the Yongxing City River, and popularized a large number of 1,000-kilogram blast furnaces.

And in 638 Shengyuan, another 5,000-kilogram blast furnace was built, and water conservancy and wind blowers were used for the first time, which also means that the eve of Yongxing City's entry into industrialized steelmaking is about to open.

So far, Yongxing City's steel production broke through the one million mark before 637, and with the completion of the 5,000-kilogram blast furnace in 638, Yongxingcheng's steel production theoretically produced more than two million kilograms per year.

Due to the limitation of coal and iron mining technology and output in Xianguo, the production capacity of 1.3 million jin has not been expanded, and the output of about 1.3 million jin will continue to be maintained in the short term.

Soon after the completion of the west city, all the coking, 500 and 300 jin iron furnaces in the south of the city were moved to the west of the city, and a new glass workshop was opened in the west of the city to research and produce optical glass, chemical utensils, and glass syringes.

It is worth mentioning that in 635, Bailiyan ordered people to go to the country of Changsun to touch the rubber trees and determine the existence of rubber resources, but unexpectedly, unlike the rubber trees on the earth, rubber is obtained by cutting the trunk.

The rubber tree discovered by Changsun Guo is more like a coconut, and the white rubber is taken from a fruit that is larger than a durian, and the fruit is a rubber emulsion inside.

After stealing the seeds, they were cultivated in Beihai and Dongyuan counties, and successfully grew seedlings, but a few years later, it was found that due to the influence of climate and latitude, the quality of the gum tree fruit in Xianguo was far less than that of Changsun country, but it was better than not.

In the summer of 638, the school held the second mathematics enrollment examination and recruited another 300 people.

In 635, the first batch of more than 190 students in the junior and intermediate classes completed their graduation at the beginning of the year after three years of study, and 37 of them were awarded the title of master of mathematics and arithmetic with excellent ability.

On the day of graduation, Bai Liyan distributed a set of advanced mathematics textbooks to each person.

With the great changes in the situation in the Central Plains, he has no time to continue to personally promote research in the field of higher mathematics, and can only hope that this batch of seeds cultivated in three years can be brought to the regular in the future.

Before the autumn harvest, the workshops in the north of the city were completed one after another, and the blast furnace rose from the ground, in order to control the smelting time, Baili Yan made a time hourglass, and indirectly controlled the temperature and metal metallographic by controlling the smelting time.

At a time when the technology is simple and there is no metallographic laboratory, controlling the smelting time and supplementing it with a simple smelting agent is undoubtedly an effective means to control the metallographic structure of metals.

After the autumn, the grain harvest in various places is abundant, the price is stable, the cotton of Zhiguo and the soybeans of Song are successively transported into Xianguo, and a large number of rape are harvested in Xianguo, and the capital county and Xincheng area are thriving.

By 637, the National Money House had achieved a basic profit, with an increase in gold and silver deposits, and a return of gold and silver Tongbao deposits.

At the same time, the circulation of new money and the absorption of old money in various places went smoothly, and the branch of the money square was opened to various places one after another, and the branch money fang was directly supervised by the salt lord, the tax department and the tax undertaking department, and was only responsible to the imperial court, regardless of the place, so as to curb the collusion of local magnates and officials to exploit the place.