"Song Jiulang, if you want, please follow me."

Song Jiu was looking for this thing very hard, and he was almost ready to go to Tianzhu to find it, he was not a big person, and someone would harm him. said, "Please take me." ”

Leave the wharf, walk along the river embankment, almost to Layue, the willow forests on the river embankment are all withered, the river is gradually open here, the water surface is calm, like a silent and depressed landscape painting. It's just that the water and soil are not badly damaged, although the river is a little turbid, but it is slightly white, and the subtle waves hit the shore, and you can see a little snow. The sound of the waves is slight, like a mother's gentle lubilium. It should be said that the Yangtze River is very beautiful now, and I don't know if I can see the river green and blue in spring when spring comes.

The hobby of the previous life has flare up again.

But in this line, there is a place where Song Jiu wants to go, and he must go, Wulingyuan.

Down the embankment, there is a small boat moored on the riverside, the owner of the boy in Tsing Yi is on that boat, the three of them casually found a willow tree to tie the horse, with the boy on the boat, a very ordinary common boat, that is, a more luxurious passenger ship, there are sail masts, there are oars, and the ship's building, not big, the size of two small houses, standing on the deck. But the three of them got in, but the decoration was very extravagant, the walls were inlaid with precious wood, what kind of wood it was, Song Jiu didn't know, but he felt that the wood plank texture was very beautiful. There are also felt carpets on the ground, and there are several tables, as well as some other arrangements. In the center sat an old man with a slender face, about sixty years old, with a pretty fifteen-year-old girl in his arms.

is not too repulsive to this Song Jiu, in this era, it was not like this in the previous life, but it was only done publicly, and the other was not public. At most, Song Jiu won't do it, but people have changed, and God knows if he will be like this old man when he is old.

The old man was wearing a gorgeous brocade robe, with an elegant bearing, a very delicate appearance, and a handsome old man with a temperament.

However, Song Jiu was stunned for a moment, because he was very familiar with this old appearance, and hesitated: "Weng Weng, where have we met?" ”

"Song Jiulang, three years ago, in October, Tian Fuqing and I went to your Great Song City to attend the funeral of the Empress Dowager, did you see me at that time?" The old man said calmly.

"Three years ago?" Song Jiu was even more stunned, where was I in October three years ago? By the way, I was in Yunnan at that time, but it was not for tourism, but for business needs, and I stayed there for a long time. But this time, more than a thousand years of time and space have passed.

Song Jiu was stunned at first, and then reacted, no, he knew who the old man in front of him was, Han Xizai, who knew him, not a real person, but a painting, "Night Banquet Picture", but Han Xizai on the painting was obviously younger, looking like a person in his thirties, his eyebrows and beard were darker, not like the old man in front of him, with many wrinkles on his face, his eyebrows and beard were very thick, but some whiteness could be seen. The only thing that is the same is that I faintly see a hint of melancholy in my eyes.

According to the tour guide, the background of this painting is when Li Yugang succeeded to the throne, he was extremely suspicious, and he killed many ministers from the north. Song Jiu is not very clear about the affairs of the Southern Tang Dynasty, whether the process of killing is to kill as soon as he succeeds to the throne, or to kill him in the past, the former painting came out, and later this painting has not yet come out. In order to avoid trouble, Han Xizai indulged in lust, Li Yu was dissatisfied with Han Xizai's debauchery, and sent the painter Gu Hongzhong to sneak into Han's house and paint Han Xizai's actions, so there was a famous painting in later generations. But even if it is the way of knowledge, it cannot be said. Song Jiu asked hesitantly, "Are you a bachelor of Han Xizai?" ”

It's rude to say that, at least not by name.

Han Xizai was not angry, and said lightly: "Han is exact." ”

"Why did Master Han ask me out?" Song Jiu was thinking in his heart, the picture of that night banquet was really a bit similar. It doesn't matter if it's like it's not like it, you have to think about it. It can't be said to be a stone, before its role came out, it was at most a gem, the price was expensive, Han Xizai was also a big man in the Southern Tang Dynasty, it doesn't matter if he came, the Song Dynasty didn't get Ezhou for a long time, and it was also snatched from the Southern Tang Dynasty in the Later Zhou, even if Han Xizai had a heart, he couldn't fight back to Ezhou. The question is whether it's worth it?

"Song Jiulang, sit."

Song Jiu was only a little nervous when he saw Zhao Kuangyin, where would he be afraid of Han Xizai, so he sat down calmly.

Han Xizai smiled slightly and said, "Sure enough, it's a celebrity." ”

But this made Song Jiu embarrassed and said, "Master Han, don't praise me, let's get down to business." I don't have anything to do, your line of work will be made by your political enemies. ”

"Han is here on the orders of the lord of the country, who is making a fuss."

"The lord of the country?"

"Song Jiulang, your three arithmetic problems have stumped many of our arithmetic masters in the Southern Tang Dynasty."

"The trail, the small skill of carving insects, is not enough to worry about."

"Can you tell Han the answer?"

"Master Han, those three questions were asked for by the imperial court. If you Southern Tang Kingdom get the answer, I can still ask thirty questions, three hundred questions, or I can only get my reward of five thousand silks. That would be a lot of money for an individual, but what would it be for a country? ”

Indeed, in a sense, if Song Jiu does not publish the answer, it is possible that they will have no solution.

For example, there is a question, the husband is a businessman, and the people in the house share wealth for the sale, the sea ship goes to the business to draw, in addition to the goods of the owner's family, there are 5,880 taels of agarwood, 1,430 bags of pepper (a package of standard weight of 40 Song Jin), ivory 212 (to the weight of ivory as a combination, an ivory is different in size, can have two in three in four), the Department of A, B, C, and Ding are Bo to the Bo, the fate yesterday to make up the book, there are mutual pretenses, A points to the official confession, A principal two taels, four bags of salt, 10 banknotes, B 800 taels of silver, three bags of salt, 88 banknotes, C Ben silver 1,670 taels, 15 degrees, Ding Ben Du 52 Dao, gold 55 28 baht, has been estimated a total of 424,000 guan, A borrowed B banknotes, B borrowed C silver, C borrowed Ding Du, D borrowed A gold, now the total allocation of each borrowed goods to the original owner's name, for the rate of equal distribution of the goods.

If this question is not translated, it will be difficult in later generations, but after translating, and then exchanging the value of degrees, banknotes, salt, gold, and silver, then this question is actually not difficult at all, but in the Song Dynasty it was one of the problems.

Because you have to make a quaternion quadruple equation.

But it can only be said that one is possible.

Another example is this question, there are things that do not know the number, the remaining two of the three or three numbers, the remaining three of the five or five numbers, and the remaining two of the seven or seven numbers, asking the geometry of things? This is the Great Extension Technique, also known as the residual law of Chinese mathematics. It can be found by a list of formulas, but if it is replaced by a column formula, it will be difficult, and even high school students will have a headache. But in ancient times, someone calculated it.

Originally, Song Jiu was disdainful of ancient arithmetic books, but Dr. Zhang was teaching, and he also looked at it, and found a binary quadratic equation, which should be more difficult. Then let Dr. Zhang calculate, Song Jiu sat on the side to watch how he used the calculation, he didn't understand it at all after watching it for a long time, and the answer really let Dr. Zhang figure it out. The answer is that it came out, and Song Jiu asked, how do you calculate, Dr. Zhang explained. As soon as the results were explained, Song Jiu felt that he was listening to Hawking's paper report.

However, Song Jiu's three questions are a bit complicated, and if you can get one question right, you will definitely not be able to get three questions.

Han Xizai said: "Song Jiulang, please use tea." ”

"Thank you, Master Han," Song Jiu took a sip of tea.

Han Xizai took out a small bag from his arms, opened the bag, and there were two stones inside, one slightly close to pink, and the other light yellow, this Song Jiu is not surprised, diamonds are not only colorless, but also various colored diamonds. It is estimated that there is colorless, because at this time people did not know its value, and it would not be brought to the Song Dynasty, and most of the colored diamonds brought were sold to the Chinese as ordinary gemstones. Song Jiu glanced at them again, and it seemed that they were relatively large, one could have more than ten carats, one could have more than twenty carats, and even close to the size of thirty carats. But it's not a diamond, and if you look at it like this, you still can't say for sure. So he said, "Mr. Han, can you let me give it a try." ”

"Please."

Song Jiu picked up the big yellow stone and used its tip to scratch it on the glass bowl with a knife, it was more luxurious to actually use real diamonds to scratch glass, but in this era, it was impossible to make artificial diamonds to make glass knives. Only real diamonds can be used.

It is also worth it, as long as glass can be produced, even if it is large-scale production, the price of glass will not fall for decades. Even if Song Jiu was lucky and found the best firing method, as well as the most suitable sand and other raw materials, to produce all kinds of exquisite glass, which could be dumped in West Asian or European countries such as Dashi.

It's not enough to have a diamond, you have to have some labor-saving tools to cut the glass.

But Song Jiu had a lot of strength, and although he was struggling at the tip, the glass bowl was pulled down by his force, and a crack appeared.

Exactly!

The hardness of other gemstones can't keep up.

And these two diamonds are not small, of course, for ordinary people, it is not big. It's impossible to cut it out, but with a little effort, you can make it into several parts, and although there is a loss, it can be processed into several glass knives, and if you are careful, you may be able to divide it into a dozen glass cutter heads. But when you think about it, with its hardness and current technique, it would be very nerve-wracking to want to divide it into several parts. And although Han Xizai took it out, it was not an ordinary person, it was Han Xizai who came in person, so it would be easy to get?

Song Jiu swallowed his saliva, now people don't know its value, but Song Jiu knows that no matter the size or color, they are all the best diamonds, although they are not hundreds of carats of stars in the world, with this size, if they are placed in the future generations, how much are they worth?

I played with it in my hand, and I was almost reluctant to put it down.

After watching it for a while, he handed it to Han Xizai, I heard that this person was good, Zhao Kuangyin heard his name, and wanted to keep him, and even deliberately detained him in the post house, and Han Xizai resolutely wrote a poem on the wall of the post house:

I am originally from Jiangbei, and now I am a guest from Jiangnan.

When I returned to Jiangbei, I didn't know each other.

The breeze blows me cold, and the bright moon is white.

It's better to go back, there are people in Jiangnan who remember.

I am a native of Nanyang, Jiangbei, Henan, but when I returned to the Song Dynasty, I couldn't see anyone I knew, so I might as well go back, at least there are still my wives and children in Jiangnan. then secretly and resolutely slipped back to the Southern Tang Dynasty, but this poem was written extremely tactfully, which made Zhao Kuangyin very melancholy.

Therefore, Song Jiu began to ask in the mountains: "Master Han, this is it, you can make a price." ”