Jia Changchao was a little dumbfounded, who was he, appeased the envoy, sentenced the famous mansion, knew Hebei affairs, came to this poor and remote place, Gaoyang County, which had never even heard of it before, was stumped by a child, Xu Deshan's question was actually simple, or a smooth sentence: A group of old men went to the market, and saw a bunch of pears on the road, one person has more than two, one person has two pears and two pears, and asked how many old men and how many pears?

Poor Jia Changchao, learning is the Confucian classics, when did he study the way of arithmetic, originally wanted to take the school exam Xu Deshan, just wanted to come up with a question that he had seen in the book, to see if Xu Deshan had seen it, and regarded arithmetic as a scholarly test, but Xu Deshan didn't, his real arithmetic was arithmetic, and he took the question out and called Jia Changchao to calculate.

Jia Changchao blushed and had a thick neck, he wanted to say that he wouldn't, but the question made by the child, if he said that he would not be a third-grade master, wouldn't he slap himself in the face, Jia Changchao thought hard, fortunately, Xu Deshan's question is not very complicated, and the number is not large, with Jia Changchao's wisdom, he tried one by one, and he came up with the answer in a moment.

"Three old men and four pears, right?" Jia Chang said.

Xu Deshan said with a smile: "Adults are amazing, I guessed the answer at once, but this question is simpler, it is calculated by country children, if it is changed to one person with more than ten, and each person with two less four, I don't know if adults can still calculate it?" ”

Jia Changchao froze when he heard this, and it took a long time to recover, and he shook his head and said, "I can't." ”

Xu Deshan said: "So, what I want to teach is how to solve this problem." ”

Jia Changchao didn't know how to evaluate Xu Deshan now, so he simply asked again: "Then what do you want to teach in engineering?" ”

Xu Deshan said: "The so-called engineering teaches physics and machinery, and in practice, it is to build houses and bridges, improve ordnance and weapons, and everything in the world can be used as long as you know the truth." ”

Although Jia Changchao still didn't fully believe Xu Deshan in his heart, hearing this, Jia Changchao's heart couldn't help but jump and asked, "You said that the world is lyrical, no matter how big or small, can be used?" ”

Xu Deshan said: "This is nature. ”

Jia Changchao said: "I have one thing, I don't know if your heavenly book can help me." ”

Xu Deshan said: "Let's hear it." ”

Jia Changchao said: "Can the river be controlled?" ”

Xu Deshan said: "This is nature, which river?" ”

Jia Changchao said: "Yellow River! ”

Xu Deshan suddenly stopped talking, and there was a death-like silence between the two, Xu Deshan's body couldn't move as if he had been immobilized by a spell, and Jia Changchao looked at Xu Deshan nervously, for fear that Xu Deshan would say a word.

The trouble of the Yellow River, since ancient times is the disaster of the land of China, almost every year there are major floods, especially in the eighth year of Qingli, the Yellow River in the Shanghu Sichuan of Lanzhou, to the north straight to the Daimyo's mansion, and then through the Wei River into the sea, along the way to destroy thousands of hectares of fertile land, countless dead and wounded, the imperial court in this river disaster to spend more than 10 million silver, but the big river, how can manpower be prevented, even now, the Yellow River flow is uncertain, along the way, waterlogging is frequent, has become the court in addition to Liaoxia the biggest heart disease.

Hebei Road, is the most serious place where the Yellow River floods, every year because of the Yellow River casualties, Jia Changchao consul Hebei affairs, such a disaster, so that Jia Changchao can not sleep at night, often personally go down to the river embankment to survey the terrain, convene skilled craftsmen, discuss the policy of river governance.

Mo said that it is Chinese, even in the world, there are only two ways to deal with big water, one is to dredge, the other is to block, and no matter which method is used, after a few years, countless manpower and material resources have been invested every year, but with little effect.

Jia Changchao is actually a bit similar to Fan Zhongyan and others, not the kind of pedantic people who only know the big truth, but people who can take thought as a signpost and act into practice, in the matter of governing the Yellow River, spending huge amounts every year, although the emperor did not blame Jia Changchao, but Jia Changchao felt deeply remorseful.

If you can't see the effect, you will fail, and there is always a reason for failure, Jia Changchao summarizes the gains and losses of governing the Yellow River every year, and the situation is different every year, but to sum up, it is nothing more than a few points.

The first is that although the Yellow River has been diverted now, it is still flowing erratically, and the river dries up every winter, and when the river surges in the second year, the flow direction may change again, so whether it is dredging or blocking, there is no way to start, and it is difficult to judge.

The second is the quality of construction, the manpower and material resources used today can be said to be the most historical, but every time the embankment is built, there is always an irresistible section in the face of the flood, and there are as many as two or three sections of the embankment every year, and every time the embankment bursts, the disaster caused is devastating.

The third is sparse, don't look at the land of Hebei every year suffering from the Yellow River floods, but in the spring, and drought is frequent, although Hebei is not like Huguang is the world's granary, but here is the border farming, the important place to recruit soldiers and raise horses, this flood and drought, it will wear out most of Hebei's heritage, how to turn waste into treasure, so that the Yellow River irrigates the land of Hebei, is also a difficult problem.

Jia Changchao found that in order to solve these three problems, it is not enough to read and write Confucian poetry and books, and in solving practical problems, it may be that those craftsmen under his command are more able to put forward targeted opinions, although these opinions may be somewhat one-sided, some ridiculous, and some misunderstood, but these are some practical methods, which are much better than those literati who can only quarrel with their mouths.

The more he had such thoughts, the more Jia Changchao discovered the importance of craftsmen, although the court also had a scientific examination of this subject, and also sent a lot of people here, but Jia Changchao always felt that these people were still a little bit of meaning, until he saw the sketch painted by Xu Deshan, Jia Changchao subconsciously felt that Xu Deshan was the person sent by God to solve the flood of the Yellow River, so he traveled thousands of miles, worked tirelessly, and came to see Xu Deshan.

It can be said that Jia Changchao's hope for Xu Deshan is already stronger than when he entered Beijing to catch the exam and the Jinshi was unveiled, if Xu Deshan nodded even a little at this time, even if he fooled Jia Changchao, Jia Changchao would be able to sleep well for three days, but Xu Deshan did not, and kept silent, bowed his head and pondered, this situation, the depressed Jia Changchao held his breath and condensed, and he didn't dare to come out, he was even more nervous than when he saw the emperor in the previous court, for fear of saying a word from Xu Deshan's mouth.

After being silent for a long time, Xu Deshan sighed, almost not scared Jia Changchao half to death, Jia Changchao hurriedly asked, "Do you have a way?" ”

Xu Deshan did not answer, but bowed deeply to Jia Changchao, and Shi Li asked, "Dare to ask your lord's surname?" ”

At this time, Jia Changchao didn't need to hide his identity, and said directly: "I am Jia Changchao, and now I am sentenced to the Daimyo's Mansion and Zhihe North Road." ”

Xu Deshan sighed again and said softly: "Alas, it's still too small." ”

Jia Changchao didn't know why, thought about it, Xu Deshan may be saying that his official position is a little small, and he was a little dumbfounded, if you say that the grade of a Zhizhou is not high, forget it, but what is the concept of appeasing the envoy, although it is a foreign official, but it is a big official, a big official of the frontier, a huge Hebei Road, Jia Changchao is the one who said that counts, and the grade is equal to the governor of the political affairs, if such an official position is not big, then this child's eyesight, isn't it only the prime minister's privy envoy and the three envoys can be regarded as a big official.

Jia Changchao thought about it again, and felt that this child might be still young, and he didn't know much about his name, official position, and the meaning of the family behind him, and was about to explain to him, Xu Deshan said: "If you talk about the water of the Yellow River, it's not impossible to govern it." ”

Jia Changchao was stunned for a moment, and then the little heart began to thump uncontrollably, and hurriedly asked, "Do you really have a way?" ”

Xu Deshan said: "There is a way, there is a way, but it's a pity, you just sentenced the Daimyo's Mansion and took charge of Hebei Road, and my method is to gather the strength of the whole country to succeed." ”

Jia Changchao said: "How do you know that the current governance of the river is not a national force gathered, if you have any way, just say it and listen to it, if it is really feasible, I will personally report to the emperor and act according to your plan." ”

Xu Deshan shook his head and said: "Master Jia, I can understand your feelings, but doing things is one thing, and politics is another, if you act with your will, how can you and Fan Xianggong be demoted from the capital." ”

Jia Changchao was silent, because what Xu Deshan said, but a big truth, yes, it has been five years since the flooding of the Yellow River, but what has the court been doing in the past five years, all the ministers have their own words, and no one is willing to show weakness, the result is that everyone is pulling each other's skins, but there is no way to really control the river.

Jia Changchao was silent for a while, and said, "What is the solution, you can talk about it first." ”

Xu Deshan said: "I originally had two ways to treat the river, the first to treat the root cause, the second to treat the symptoms, now it seems that the first way to cure the root cause is useless, let's look at the second way to cure the root cause first." ”

Jia Changchao couldn't help but be blown by Xu De angrily again, and said that it is better to treat the symptoms than to cure the root cause, since you have a way to cure the root cause, why don't you say it, even if it is useless, it is good for everyone to refer to it, even if no one listens, since you know it yourself, you still say what to tease me for, is it very interesting, now it's okay, what else do you say to treat the symptoms, I can't listen to it at all.