After a while, everyone fell silent and continued shopping, but they all had a lot more thoughts in their hearts.

Cheng Aniu saw that there was a pen and paper seller on the side of the road, so he stopped to take a look, but the oldest worker came to him and patted him on the shoulder.

"Since the owner wants to teach, this pen and paper will definitely be given to us, so you don't have to spend that unjust money, and you will see what the owner does before speaking. ”

Cheng Aniu thought about it and felt that this sentence was reasonable, so he put down the pen and paper he had just picked up, which made the small boss who set up the stall very unhappy.

While the scholars and workers were spending their Sundays in various ways, Zhao Dagui himself took a box of pastries and a pile of materials to visit a scholar, Li Xinlan, the most powerful mathematician in the entire Qing Dynasty.

Li Xinlan has been living a very nourishing life recently, she doesn't need to run for life, and there are a lot of Western books to read, so she finally has the opportunity to get a glimpse of the corner of cutting-edge mathematics in this era.

In the past, although Li Xinlan was very talented, due to the limitation of knowledge, she could only use the most primitive mathematical tools to pursue the footsteps of Western mathematicians, otherwise she would not have created a mathematical tool like the Cone Technique to develop mathematical theories similar to calculus.

The innovation and theoretical value of the cone itself are very high, but doing such work before Newton and Leibniz created the calculus system is considered epoch-making, and now it is a bit of a repetition of the work of predecessors, and it is also a waste of Li Xinlan's genius.

Zhao Dagui really wanted to borrow Li Xinlan's mathematical ability in mechanical design and other things, but knowing the importance of theoretical mathematics, he would always resist the urge to let Li Xinlan go to the silk reeling equipment project team.

"Uncle Ren is very leisurely. When Zhao Dagui saw Li Xinlan, he saw him sitting in a corner of the library, holding a book and reading it with relish.

"How can it compare to Brother Zhao, who is worth millions, and there are a lot of people following him in everything he does. Li Xinlan said jokingly.

Zhao Dagui built a building in the concession, this covers an area of thousands of square meters, divided into three floors of the library is the most luxurious and expensive to build, invited British engineers to design and supervise, the outside is all made of high-quality green bricks, the wall is installed with huge and bright glass, the outside looks like a delicate Gothic building, the inside layout is also very elegant.

In addition to the lack of modern equipment such as electric lights, such a library is not inferior to the libraries of famous European and American universities in modern society by virtue of the exquisiteness of the decoration.

Of course, the most valuable thing in the library is the collection of books inside, more than 13,500 Western science and technology books, a large number of models, and thousands of Chinese books, which are among the best in the entire Qing Dynasty and even in Asia.

"Everyone is off on Sunday, I don't know what Uncle Ren reads?" Zhao Dagui looked at the book in Li Xinlan's hand and asked curiously.

"It's an artillery training textbook for Americans. Li Xinlan showed the cover of the book to Zhao Dagui, "I can't imagine that the mathematics level of Westerners is so high."

It's just the training of ordinary artillerymen, and it already involves the use of a lot of calculus knowledge, and if it weren't for the fact that I made up a calculus some time ago, I'm afraid I wouldn't be able to understand it.

Foreigners use people with such profound knowledge to do ordinary artillery, no wonder the military strength is so strong. ”

"It's not an ordinary artilleryman, people who can receive this kind of training, after graduation, they must have the rank of second lieutenant or above, and there is a great chance to be a colonel in the future.

However, I understand what Uncle Ren means, to such an extent, it can be called terrifying. Zhao Dagui nodded and agreed with Li Xinlan's words.

Many people think that modern people travel to hundreds of years ago, and they can rely on huge knowledge reserves to dominate and do whatever they want, but this is a big joke, except for the bug advantage of being familiar with history, the knowledge and ability of the vast majority of time-travelers are not much stronger than the ordinary elites of the steam age, let alone those real scientists who can leave their names in history.

In terms of mathematics, calculus was taught at the French Artillery Academy in Napoleon's time, and the level was very profound, surpassing the advanced mathematics of a university in science and engineering in the 21st century.

Zhao Dagui himself had read an artillery training textbook and found that many of the calculus problems were also very difficult for him, and only then did he understand that the regular artillery officers of this era would not be worse than the science students of the first-class universities in the 21 st century in terms of their mathematical foundation and IQ alone.

In this way, in the nineteenth century, the average time-traveler did not have much to praise except for preemptively registering other people's patents and plundering the style that should belong to others.

This point has also made Zhao Dagui always take it seriously.

In addition, it is understandable that the Qing army was beaten so badly in the Opium War, which was a real gap of the times.

"I know that Uncle Ren likes to eat peach shortbread, so I brought some with me when I came. Zhao Dagui took out the snacks he brought and put them on the table in front of Li Xinlan.

"Thank you very much. Li Xinlan happily picked up the dim sum and tasted it.

"By the way, I read Uncle Ren's recent translation of Euclidean geometry and calculus books, and I did a good job, but I changed the translator's name to Li Shanlan, I don't know why?" Zhao Dagui asked as soon as he remembered something.

"Oh, I recently chatted with Brother Wang Tao and others, and I felt that it would be better to have a pen name when I was away from home, so I changed my name to Li Shanlan.

Why, that's a good name, right?"

"No problem, no problem, anyway, if you change it or not, others will know it's you. Zhao Dagui nodded, but he was roaring in his heart, if you want to change your name, you should change it a few months earlier, so that when I first saw you in September last year, I would be able to recognize you.

The earliest "geometric original" in China was the fifteen-volume version brought by the Italian missionary Matteo Ricci to China, and Xu Guangqi later translated the book with Matteo Ricci, but only the first six were translated;

The last nine books were translated by Li Shanlan and the Englishman Willy Alice in the middle of the nineteenth century.

Later, Li Shanlan co-translated 20 volumes of "Heavy Learning" with Joseph Ai, and co-translated 18 volumes of "Talking Heaven", 13 volumes of "Algebra", and 18 volumes of "Algebra Calculus", and was the translator of China's first calculus work.

It can be said that Li Shanlan is the first mathematician in modern China, and even the only face in the mathematical world before 1900.

"I came here today because I wanted to ask Uncle Ren for some help.

In the past, Leibniz and Pascal invented a mechanical computer that could add, subtract, multiply and divide, and in 1833, the British scientist Charles Babbage also proposed the theory and design of the analysis machine.

I wonder how much Uncle Ren knows about this?"

"Oh, I've heard of Leibniz and Pascal's kind of computer, but I've never heard of an analysis machine.

Brother Zhao mentions these things, I don't know what to say?"