In desperation, Su Hao could only throw down Cheng Yi and give Han Qian another lesson, which can be regarded as coaxing this little aunt and grandmother to smile. Lu Xiuer is a sluggish girl, and she can't taste the taste of this. She only knew that her brother's level was very high, and she taught Sister Cheng a lesson, and she also taught Sister Han a lesson, and now the two sisters have understood. It's just that after Sister Cheng understood, she was still thinking about those pieces of paper, and her mind was on those numbers. And Sister Han is just satisfied with the process of understanding, and now she has begun to ask her brother long and short questions to understand the situation of him going to the countryside.

"Master Su, listen to my father, you are going to Xuanfeng Township to look for coal deposits, I don't know what the harvest is?" Han Qian returned to her seat, lowered her head slightly, and asked Su Hao.

Su Hao didn't intend to hide it from her, so he said truthfully: "The harvest is very rich, I have found a few coal deposits, and I have also negotiated the price with the lord of the mountain farm." Now just wait for the scribe Dai to take care of the kiln, and then raise enough to start, and prepare some tools, and then you can mine. ”

"In this case, congratulations to Mr. Su." Han Qian said.

"In fact, this is also an errand for Han Zhi County, and mining coal, which is also the political achievement of Han Zhi County." Su Hao said.

"The little woman thanked Master Su for her father." Han Qian said.

Su Hao hurriedly said: "How dare you, Han Zhixian has entrusted the students with important tasks, and the students have nothing to repay." How dare you take the word thank you for doing such a small thing? ”

These two people are polite to each other, Lu Xiu'er felt bored when she heard it, she interrupted the conversation between them and asked Su Hao: "Brother, you just asked me to come downstairs and said that you want me to help with something, what is it?" ”

Su Hao then remembered his business, he spread out a large volume of maps he brought back on the table, and said to Lu Xiu'er: "It's a very troublesome thing, you see, this is the map we went to Xuanfeng Township to measure this time, there are more than 30 in total, I want to find one to draw them on a map, as long as you follow the drawing, but the lines should be thin, have you done this?" ”

Since Su Hao planned to mine coal in Xuanfeng Township, he naturally had to grasp the distribution of local mountains and rivers in order to arrange the location of mines and material yards, transportation channels, and so on. On the way to Xuanfeng Township, together with Ma Yu, he kept carrying out simple surveying and mapping and drew maps everywhere. However, these maps have a common disadvantage, that is, when they are drawn with a brush, the lines are too thick, and there are not many things drawn on a piece of paper, so they have to be divided into many maps to express them.

Su Hao has always wanted to compile these maps into a complete map. He tried it himself, trying to sketch it with a very thin ink line, but in the end he found that the work was too grinding. As a master who has a lot of opportunities, it seems a bit wasteful for him to do such a thing.

In a hurry, he thought of Lu Xiu'er, this kind of thing should be the most suitable for girls to do. However, Lu Xiu'er is less literate, let alone written, and it is difficult to do this kind of work, and Su Hao has no good solution to this.

Lu Xiu'er smacked her tongue when she looked at those maps, this kind of thing that required dancing and writing was what she was most afraid of. Han Qian and Cheng Yi also stepped forward to listen to Su Hao's explanation, and the two of them also frowned, feeling embarrassed.

Cheng Yi said: "Let Xiu'er do these things, I'm afraid it's a little difficult, the little woman is coarse and literate, but she is willing to serve." It's just that Master Su's drawings have too many lines on them, and I'm afraid that when I draw them on a picture, the ink will penetrate each other, and in the end, I won't be able to see anything clearly. ”

Su Hao nodded and said, "I am also worried about this matter. Because the ink penetrates, I had to draw on a large piece of paper. Now this is just a map of a township, and if you want to draw a map of a county or even a province in the future, won't you have to use a large piece of paper that is several zhang square? ”

Han Qian also thought of this question, and she asked, "Young Master Su, can this picture be drawn with the kind of charcoal you are used to?" If you want to draw such thin lines, I am afraid that you can only use charcoal. ”

Su Hao said: "Charcoal drawings are okay for temporary use, but if you want to use them for a long time, the charcoal traces are easy to erase." ”

"Just erase it and draw it again......" Han Qian blurted out, but halfway through speaking, she swallowed back the words that followed, and she also knew that this was unrealistic.

The crowd was worried, Deng Kui and Hao Tong came over from the backyard, and as soon as they entered the hall, they saw that there were so many people in the house, and they hurriedly saluted everyone. In these days when Su Hao went to Xuanfeng Township, Cheng Yi and Han Qian had come several times, and they had also met Deng Kui and Hao Tong, so everyone was not stranger to each other.

"Master Su is back?" Deng Kui and Hao Tong asked.

"You two didn't go out to play?" Su Hao replied with a smile.

Hao Tong shook his head and stopped talking. Deng Kui said the words: "Master Su, our brothers haven't seen you these days, I don't know what you're going to do?" ”

Lu Xiu'er glared at Deng Kui and said, "Brother Deng, you are pretending to be confused, didn't I tell you two years ago, my brother went to the countryside to look for a coal mine." ”

Deng Kui was exposed by Lu Xiu'er, but he was not annoyed, but continued to ask Su Hao: "Master Su, I don't know if what the eldest lady said is true?" ”

Su Hao heard that there was some displeasure in Deng Kui's words, and he didn't know what the reason was, he nodded and said, "Xiu'er is right, I went to Xuanfeng Township to find a coal mine, and it took a few years. ”

"Then what my Mr. Tu asked Master Su to do, I don't know when Master Su plans to start?" Deng Kui asked.

Only then did Su Hao understand that Deng Kui and Hao Tong were annoyed that he went out to make money, but he didn't take the matter of making guns to heart. In Su Hao's heart, he felt that the matter of making guns could not be rushed, and he needed to plan and then act, and the design of the gun, as well as the search for craftsmen, etc., all took time. But for Deng Kui and Hao Tong, this matter is completely different, they were left in Fengcheng by Tu Wenhuan for the purpose of helping Su Hao make guns. Su Hao didn't do it for a long time, didn't the two of them stay here for nothing?

Su Hao has the heart to say how he does things, and he doesn't need the two soldiers to take care of it. After thinking about it, it seems that he was a bodyguard for himself a little before he entered the house, and he hasn't entered the house yet. If he doesn't take the matter of making guns to heart, what qualifications does he have to let him protect himself?

"It turns out that the two of you are asking about this." Su Hao said with a smile, "You don't know, the younger brother went to Xuanfeng Township to look for coal, and what Mr. Tu told is also related?" ”

"What does the search for coal have to do with making that thing?" Hao Tong asked strangely, because Han Qian and Cheng Yi were present, it was inconvenient for him to say the three words flintlock pistol directly.

Su Hao said: "To make what Mr. Tu wants, you need to have good cast iron. And to smelt cast iron well, you need to have high-quality coking coal. Now there is a shortage of raw coal in the Fengcheng market, not to mention coking coal. The younger brother went to coal mining in order to be able to build a coking kiln and an iron-making furnace. Do you think this matter has anything to do with Mr. Tu's advice? ”

"This ......" The two soldiers were speechless, they didn't know much about industrial matters, but Su Hao's explanation seemed to make sense, so they couldn't refute it. It is reasonable to say that only good iron can make good guns, but in order to build a gun, it is a bit too far to start by digging coal.

"Master Su, this matter is very important, please ask Master Su to hurry up." Hao Tong said sneeringly, he originally planned to ask Su Hao Xingshi for his crimes, but now that he was blocked by Su Hao's words, he was also a little wilted.

"Don't worry, I've been thinking about this, and I'll talk to the blacksmith in two years to see if I need to prepare something." Su Hao said with a smile.

Deng Kui and Hao Tong couldn't help Su Hao, they nodded at Su Hao, and then turned around to leave. Su Hao's heart moved, and he called out to them:

"The two of you stay, the younger brother just has something I want to ask you."

The two of them stopped and turned around, Hao Tong asked, "Master has something to say, please speak." ”

Su Hao said: "I want to ask you, what is the map in the army drawn with?" ”

"What is the map drawn from?" Deng Kui and Hao Tong were puzzled by Su Hao's question, and Deng Kui replied, "Isn't the map just drawn with pen and paper?" What else could there be? ”

"With what?" Su Hao asked.

"Naturally, it's a brush." Deng Kuidao.

Su Hao pointed to the map on the table and said to them, "Take a look at how a map like this is drawn in the army." How can you use a brush to ensure that the handwriting does not penetrate each other? ”

Deng Kui and Hao Tong walked to the table, looked at the map drawn by Su Hao, and shook their heads: "Master Su, what kind of picture are you drawing, why are they all big traps and small circles?" This is not the case with the map in our army. ”

"This is not ......" Su Hao said to his mouth, and suddenly patted his head, he knew where he was wrong. The drawings he drew used the contour projection method, and this circle was full of contour lines on the ground. In the maps of the Ming Dynasty, the mountains and rivers were represented by pictograms, and it seems that such things as contour lines have not yet been invented in the West. Regarding the use of contour lines, he once taught Ma Yu, and in addition to Ma Yu, there is probably no other person in the entire Ming Dynasty who knows what this thing is.

"This thing is called a contour line." Su Hao had to explain to everyone, "Each line represents the same height, this circle is 5 zhang, if the drop of the mountain is large, a circle means 50 zhang, 100 zhang is also available." ”

"Contour line ......" The two soldiers stared at the map for a long time, Deng Kui hesitated and pointed to a place and asked Su Hao: "Master Su, you mean, this is a valley, the east side of the mountain is 15 zhang high, and the west side is 20 zhang. A gentle slope to the east and a steep slope to the west? ”

"Yes, dude!" Su Hao couldn't help but want to pat Deng Kui on the shoulder, he really deserved to be a professional soldier, and his understanding of the map was so good. I didn't know anything about the contour line just now, but in a blink of an eye, I was able to accurately read the map.

"Great! How did this come about? Deng Kui circled his eyes and asked Su Hao excitedly, "If you can grant this mapping method to the scouts in our army, the deputy chief soldier of my family is willing to give a thousand gold to thank him!"