Zhang Jun and his entourage said that they would go, and they passed through the city all the way, went out of the east gate, and went into the distance. Pen & Fun & Pavilion www.biquge.info

In addition to the three new people under the curtain, Hu Shuo and Zhou Tong were also in charge of personal guards, and there were also 20 cavalry escorts. The assassination turmoil has not stopped, and Zhang Jun does not want to be ambushed again because of lack of manpower.

Everyone rode fast horses, and under the leadership of Zhang Jun, they went all the way east along the post road, and soon left Guzang City behind, and slowly even the silhouette disappeared from sight.

After the initial excitement, all three became a little dull. Zhang Jun suddenly said: "I have an arithmetic problem here, I wonder if the three of you are interested?" ”

"Oh?" The fat man suddenly asked excitedly: "The lord is also interested in arithmetic?" ”

"How?" Zhang Jun said curiously.

"He's a fan of calculations on weekdays. It's a pity that Liangzhou is remote, and the spring breeze of the Central Plains culture is difficult to pass the Yumen. Song Pei sighed while teasing Suo Sanjie.

Even Jiang Wan looked at it curiously, obviously wanting to hear Zhang Jun's arithmetic.

Zhang Jun also no longer sells Guanzi, he said: "Today is expected to be on the island, set up two tables, three feet high, a thousand steps before and after, so that the back table and the front table are straight." In the past, the table walked one hundred and twenty-three steps, and people looked at the island peak with their eyes, and the end of the table was three together. From the back table, there are one hundred and twenty-seven steps, and people look at the island peak, and they are also three together with the end of the table. Q: What is the height of the island and how much does it go to the table? ”

After saying that, he looked at the three of them with a smile.

"The island is four miles and fifty-five steps high, and the table is one hundred and two miles and one hundred and fifty steps." Without waiting for others to speak, the fat man rushed to answer.

"Huh?" Zhang Jun looked at Suo Sanjie again, but he didn't expect that he was still an arithmetic talent. Immediately asked: "How did Quan Bin calculate?" ”

"It's not easy!" Suo Fatzi said proudly: "Take the height of the table and multiply the table as the truth; More is the law, except for it. The income is higher than the table, that is, the island is high. Those who seek the distance of the former table to the island, but the former table is multiplied by the table is real, and the law is more. In addition, the island goes to the table mileage. ”

Zhang Jun silently changed to modern mathematical terms in his heart and thought about it, which is really right! Immediately asked: "Quan Bin has done this?" ”

"Nope." Suo Fatzi said with a regretful face: "Where will there be islands in our western land, I just heard the legend of overseas fairy islands." Who's going to count the islands? ”

"My lord, who created this arithmetic problem, it is really unheard of!" Song Pei said in surprise.

On the side, Jiang Wan also nodded again and again.

Zhang Jun couldn't help but sigh in his heart, the level of science and technology in ancient China was not underdeveloped, but the lack of promotion. Either the broom is self-cherished and becomes the secret of a family name; Either it is considered heretic and destroyed by the ruler himself. Of course, even if neither of these factors occurred, then the problems caused by the difficulties of transportation in ancient times also directly affected the promotion of science and technology.

To give a simple example, iron tools and ox farming techniques appeared in the Central Plains as early as the Spring and Autumn Period and the Warring States Period, but it took a thousand years to promote it to the Cochin region. The technology related to whether you can eat and feed is still like this, not to mention the others?

He said: "This arithmetic problem was created by Liu Hui, a mathematician of Cao Wei during the Three Kingdoms period, and was included in the Pythagorean chapter of the ninth volume of his surveying work "Liu Hui's Nine Chapters of Arithmetic Notes". Because the first topic is to measure the height and distance of the island, it is also called the "Island Calculation". ”

"It's actually written by Cao Wei, why have you never heard of it?" Suo Fatzi said regretfully.

"This is inevitable, the world has been chaotic for more than 100 years, the roads between various places are cut off, and the sound is not connected, not to mention that Liangzhou is located in the west, in the eyes of the Central Plains, it is a wild place, and who will travel thousands of miles to bring this book?" Song Pei said regretfully.

"What Zeqing said is reasonable." Zhang Jun agreed: "In fact, not only Liu Hui's "Island Sutra", but also the works of two masters are rare to see. “

"Who?" Suo Sanjie asked anxiously.

Zhang Jun also did not sell Guanzi, and said: "The former official Cao Wei scattered the cavalry and the servant of Shangshu, and the doctor and Sikong of Jin Guanglu, and Pei Xiu, who was the prince of Julu County, Pei Jiyan made the "Yugong Territory Map" and proposed the six bodies of cartography. ”

"Cartographic Six-Body?" Song Pei said: "What's the explanation? ”

Zhang Jun began to elaborate: "One is the 'fraction', that is, it is used to reflect the proportion of area, length and width (today's scale); the second is 'quasi-hope', which is used to determine the mutual orientation relationship between landforms and features; The third is 'Daoli', which is used to determine the distance of the road between the two places, the fourth is 'Gaoxia', that is, the relative elevation, the fifth is 'Fangxi', that is, the undulation of the ground slope, and the sixth is 'Straight', which is the conversion of the height and fall of the field to the distance on the map. ”

He also praised: "This is exquisite, it is really unprecedented." ”

Jiang Wan and Song Pei's faces were unclear, but Suo Sanjie was heartbroken, and said: "I don't know if such a masterpiece still exists in the world・・・・・・ he hurriedly said with concern: "What about another person?" ”

Zhang Jun said: "There is another person named Jia Tan, who studied under Pei Xiu's cartographic six-body and spent nearly 17 years to draw a "Hainai Huayi Map". ”

"Ahh Song Pei exclaimed: "I never thought that there were such people in the world, and I didn't know them for 17 years. He added: "The lord is well-read and strong, and Zeqing also admires it very much." ”

"Huh." Zhang Jun smiled modestly and did not say anything. But in my heart, he said, "Because I had a professional course called historical geography in my last life." And you're afraid you won't be able to see this person, because this person lives in the Tang Dynasty! “

When it comes to ancient Chinese mapping techniques, they are definitely not lagging behind. Not only is it leading the world, but many of them are world firsts.

Let's talk about Pei Xiu first, the six bodies of cartography he founded are now the most scientific and perfect cartography theory in the world, and there is no one! In addition, in addition to the things that were impossible in ancient times, such as latitude and longitude lines and projection of the earth, he mentioned almost all the main factors that should be considered in modern cartography.

Speaking of this Jia Tan, he used Pei Xiu's cartography method, organized painters at the age of 55, and spent 17 years to draw the huge map of China in the Tang Dynasty. This map is about 10 square meters of abbot, which is 10 times larger than Pei Xiu's "Topographic Abbot Map". Its main feature is that it pays attention to the research of history and geography, and the ancient and modern place names are annotated in different colors, thus creating a precedent for the evolution of China's map. ”

So Zhang Jun also despises those travelers who traveled to ancient times to draw maps, don't talk about it, wash and sleep, let the ancients slap their faces in the face and lose the dead.

Putting aside what they were thinking, everyone had gradually come to the geographical range preset by Zhang Jun. He pulled the reins, stopped his horse, pointed with his horsewhip, and said, "What we are going to survey and map today is a distance of ten miles to the east from here, and the range is about one mile. ”

The people also stopped, and looked along his horsewhip, and saw the hills undulating and the bushes overgrown・・・・・・

"Ten miles?" The fat man wailed: "Lord, you are not wrong, we people, how can we measure ten miles!" ”

"Hehe, it's okay." Zhang Jun pointed to the marching tent that was being unloaded from the pack horse by Hu Shuo, and said with a smile: "If you can't finish it, you can rest on the spot, when will you finish it, and when will you go back?" ”

"Lord, I don't know what your specific arrangements are?" Song Pei asked.

Zhang Jun said: "Zeqing and I, together with the soldiers, are responsible for the measurement; Quan Bin is responsible for the calculation; Ru Qing was in charge of recording and simple painting. How? ”

"Hmm!" Song Pei nodded and said, "Obey the lord's arrangement." ”

"Talk less, do more." Zhang Jun patted the fat man on the shoulder and said, "Be serious." ”

"Yes!" Suo Sanjie said busily.

As for Jiang Xiaohuang, he prepared pen, ink and paper, Zhang Jun nodded approvingly at him, and he also responded with a smile.

When everything was ready, Zhang Jun took the lead in climbing a small hill and said: "A mountain bag, a path, a village, and a well must be recorded and not omitted." ”

"Yes!" The crowd roared into orders.

"Alas・・・・・・" Zhang Jun looked into the distance and said in his heart: "Ten miles seems to be a little farther・・・・・・"