A Man of Science and Engineering in Troubled Times Wandering in the Late Qing Dynasty

Chapter 81
Li Chun arranged the classroom discipline, and then said to Li Yu: "Mr. Lao."

Li Yu walked up to the podium, put the German textbook on the desk, and said, "I don't need to introduce myself anymore. I wonder what stage you have learned?"

Squad leader Wu Peifu said: "Back to the instructor, the former instructor has already talked about a function called normal distribution in error analysis in field surveying and mapping."

"Okay, thank you, classmate Wu."

Li Yu was a little ashamed. It always felt weird to call Wu Peifu a "classmate", although he is indeed a classmate now.

Li Yu opened the textbook, and there was a whole chapter on the introduction of normal distribution.

For battlefield surveying and mapping, error analysis is indeed too important, so not only the normal distribution model is discussed, but also the medium error, limit error, Bessel formula and many other contents.

Li Yu asked again: "Did the previous professor just start talking about normal distribution?"

Wu Peifu sat on the chair with his waist straight all the time: "Yes, teach."

Li Yu glanced at Sun Chuanfang, who was in the middle, and remembered that he had just entered the surveying and mapping class, so he asked, "Can Student Sun keep up with the progress?"

Sun Chuanfang said: "Teacher, don't worry. I didn't sleep last night. I have learned the latest chapters and previewed the normal distribution. It's just that there are many problems that are not clear."

Well, I really didn't expect a big warlord to love learning so much, it's so incredible.

"Student Xiaosun loves learning so much, it is very commendable."

Li Yu is now in his early 20s, so he is indeed older than Sun Chuanfang, who is only 17 years old now.So it seems that there is nothing inappropriate to call him "Student Xiaosun", but it always feels weird to accept it at first.

"Then let's start with the normal distribution function."

Li Yu is no stranger to the normal distribution function, after all, it is a content that must be learned in middle school.Moreover, the analysis of errors in undergraduate mechanical design is much more precise than that of battlefield surveying and mapping.

Whether it is the early 21th century or the [-]st century, error control is actually a very valuable technology, which is related to the advancement of many processes. In this regard, small Japan and some Nordic countries have done extremely well.

He didn't need to read too many textbooks. He was already familiar with the normal distribution. Li Yu drew the image of the normal distribution function on the blackboard, wrote down the formula, and listed the important properties item by item.

These methods of his are very common teaching methods 100 years later, but for now, they are actually an advanced teaching mode. The content of blackboard writing is much more flexible and concise than German textbooks.

If you follow the dozens of pages in the book and explain it mechanically, you may not be able to finish it in three days.

Education in Germany is still relatively rigid, or even education is too militarized.Otherwise, Einstein would not have gotten tired of the German middle school and went to Switzerland to go to school.

Since Beiyang is learning from the West, Li Yu does not need to use A, B, C, D to replace letters when he lectures to them, and directly uses abcd and mathematical symbols to represent them.

After the morning class, Li Yu had already explained the various properties of the normal distribution function clearly, and also explained the more complicated normal distribution function itself.

For the course of battlefield surveying and mapping, it is enough.

Li Yu put down the chalk, "I think today's lesson is over, if you have any questions, you can ask them."

Wu Peifu had already listened carefully to the lecture and took notes, and raised his hand first, "Excuse me, teacher, I read in the book about possible errors caused by the length of the ruler, and errors in reading numbers when surveying and mapping. What is the difference between them?"

Li Yu's eyes drifted to the notes he made, and he transcribed what he wrote on the blackboard very neatly, and even made notes in some places.

Wu Peifu used to be a scholar, but he was deprived of his fame again, but Wu Peifu did go to a private school since he was a child, and he also has calligraphy skills, at least much better than Li Yu.

Li Yu explained: "The damage of the ruler itself is naturally a systematic error, and the reading error is the accidental error we emphasized just now. Since it is a battlefield measurement, of course we must avoid systematic errors and minimize accidental errors as much as possible."

"Thank you for teaching." Wu Peifu immediately wrote it down in his small notebook.

Li Yu asked, "Are there any questions?"

A burly student said, "Professor, my name is Li Jinglin. I would like to ask, if the unit is wrong, what is the error?"

Li Yu thought about it: Li Jinglin, suddenly remembered, isn't this the Wudang Sword Immortal.

Li Jinglin will also be a great warlord in the future, but his fame comes more from his martial arts attainments.He is a master of modern martial arts and the successor of Wudang swordsmanship.And once studied under Yang Jianhou, the third son of Taiji master Yang Luchan, and learned Yang style Taijiquan, becoming one of the few apprentices with a foreign surname in the Yang family.

Li Jinglin is a big martial arts idiot, and later he put forward the idea of ​​"nationalization of martial arts for the whole people", believing that martial arts can "strengthen the body, strengthen the country, strengthen the race, and strengthen the race".When the Nanjing Central Martial Arts Museum was established, Lao Jiang once invited him to be the curator, but he was rejected.

Li Jinglin and Sun Chuanfang are the same age in the class now, they are both younger generations, but Li Jinglin is obviously not as good at learning as Sun Chuanfang.

Li Yudao: "If the unit is converted incorrectly, it is the so-called 'gross error'. I think this is an unforgivable mistake in battlefield surveying and mapping. Otherwise, the map will be drawn incorrectly, and the battle will be impossible to fight. Put an end to rough mistakes. Where you can’t make mistakes, you can’t be sloppy.”

Li Jinglin scratched his head: "I'm usually easy to be sloppy."

Squad leader Wu Peifu said with a smile: "This is easy to say, I will definitely remember it after eating a few horsewhips."

Li Yu didn't know who else was important in this class, so he named another classmate: "What's your problem?"

"Teacher, my name is Cai Yubiao."

Uh... well, this person is also a bit famous.

Cai Yubiao later became an instructor at Baoding Military Academy. He was not keen on war, but devoted himself to education, including Mao Zedong and Deng Yanda, who were all his students.

Cai Yubiao asked more in-depth questions than others, and directly asked Li Yu about the extension of normal functions.Because what Li Yu drew on the blackboard is the standard normal function, which is a simple form.

Unexpectedly, Cai Yubiao likes to study.

Li Yu roughly gave him another calculation on the blackboard, but it wasn't really difficult, but it was a little more complicated and troublesome.

After Li Yu finished speaking, he said, "If you are interested, you can also write it down and deduce it yourself."

"Thank you for teaching." Cai Yubiao said.

When Li Yu did the calculation just now, even Wu Peifu stopped taking notes because he really didn't understand.For them, what Li Yu said just now is beyond the outline and belongs to the research content of mathematics.

The questioning session was almost over, and Li Yu said: "If you have any questions, you can do more research on your own, or discuss it with your classmates. If you really don't understand, you can of course come to me."

Li Jinglin felt confused all the time, and asked, "Teacher, do you have to take the test for all the things you talked about?"

Li Yu flipped through the exam syllabus and said, "All exams are compulsory."

Li Jinglin felt his head was about to explode, and he regretted entering the surveying and mapping department. He should have gone to the infantry department in the first place, it was really too difficult.

However, the surveying and mapping department belongs to the "rocket class" of the Beiyang Army's crash course, and it is the most likely to be promising in the future. If you want to become a master, you can only bite the bullet and get down.

At this time, the military school exams were all for real. Not many later generations could pass the exams just by living in college, and the punishment for cheating was much stricter than later.

Li Jinglin felt that there was no love in life. The surveying and mapping class had just begun, and he didn't know how many formulas and numbers were waiting for him. Thinking about it made him despair.

Li Yu smiled after seeing his painful expression: "If you really don't understand, you can read Wu Peifu's notes. He did a good job."

When Li Yu said this, all the students became interested, "Notes?"

They gathered around Wu Peifu one after another, and they found that his notes were much more concise and clear than those in textbooks.

It should be said that Li Yu's writing on the blackboard is very good, and Wu Peifu's transcription is also very good.The current German textbooks are like a holy scripture to them. German itself is a big obstacle, coupled with the unique thinking mode of Westerners in compiling textbooks, it is very difficult for these Eastern students to accept.

Not only the Beiyang Army Crash School, but when Western textbooks were first introduced in the early years, Japan was also troubled, and even went to China to find many books translated by the Westernization School and directly used them as textbooks.

So when Li Jinglin and others saw the notes written in Chinese, don't mention how comfortable they are.

Sun Chuanfang's eyes lit up: "Can you borrow me to copy?"

"I said it first, I copied it first!"

"How about one page per person?"

Wu Peifu said helplessly: "Who told you not to take notes in class, take it easy, don't tear it up for me!"

Seeing that they started to copy notes, Li Yu said, "We'll see you in the next class."

It was already noon, and not long after returning to the office, Li Chun brought Li Yu to the canteen in the camp.

Li Yu and the others entered the officer's canteen, and ordinary soldiers did not eat here.In fact, even if they were not separated, ordinary soldiers generally would not come to the officer's canteen to eat. The reason is very simple, the dishes are expensive and they cannot afford it.

As soon as they entered the cafeteria, they saw Cao Kun commanding two soldiers to bring in several boxes, "Put them in the room, yes, right here, very good!"

There is also Zhang Xun in the room. He is sitting there in a very unrefined posture at the moment, and he has not completely sat down on his buttocks.

Cao Kun walked over and said with a smile: "Zhang Guandai, why don't you forget to practice your kung fu after eating? Are you doing horseback riding here?"

As soon as Zhang Xun gritted his teeth, his buttocks fell firmly on the chair, and he screamed in pain, but he still pretended to be calm on the surface: "Of course you can't forget to practice at all times."

Cao Kun smiled and said, "I brought something good today, let's have a drink together?"

Zhang Xun quickly shook his head: "No, no, no! I have to do rehearsals in the afternoon, and I can't drink or drink!"

Cao Kun picked up a bottle and took a sip: "Don't you drink soda?"

"Oh?" Zhang Xun took a look and found that what Cao Kun was drinking was not wine, but Watson's soda.

Yes, Watsons again.

There is definitely no problem with soda, Zhang Xun said: "Give me some!"

Li Chun and Li Yu sat at the table beside him, and Li Chun said, "Cao Guandai, can you give me a few bottles too?"

Cao Kun said casually, "Take it."

Li Chun picked up two bottles and handed them to Li Yu.

Li Yu looked at it, and there was really "Watson's Soda" written on the bottle.

On the side is a poster with the words "Orange Dew" written on it; on the other side is a brief introduction of Watson's Pharmacy and an advertisement about the "magic" of the soda in small characters.

Anyway, the advertisement at that time looked really shy, and it was embarrassing to read it.

Li Yu took a sip, and the taste was okay, it did taste like orange, but compared with the various drinks he had ever had, it was still somewhat inferior.

The most important thing is that it is really unexpected that Watsons has such a wide market, and even made soda and sold it to the new army.

In fact, before Coca-Cola became popular, Watson's soda was the hottest soda drink in the Qing Dynasty at that time.

Even after 100 years, Watson's soda has not completely disappeared, but its name has changed to "Arctic Ocean Soda", which I believe many people should drink.

Li Chun asked, "What do you think, sir?"

"It's better than drinking." Li Yu replied.

Li Chun said with a smile: "Everyone thinks so, they have to drink several boxes every day."

The food in the cafeteria was pretty good. After eating, Li Yu was about to go back to rest, and Li Chun said to him again: "Sir, if you are free, can you also take the course of ballistics?"

"Ballistics?"

Li Chun said: "Yes, the German teacher of ballistics is also on vacation. We originally wanted Japanese military officer Taga Zongzhi to take the class, but the effect is not very good. His Chinese is not very fluent."

Seeing Li Yu's distressed face, Li Chun immediately added: "There are also textbooks and syllabus, I don't think it will be a problem for Mr. Besides, our Beiyang Army respects teaching and learning, and the treatment is also high. Teaching and learning are treated according to the management and leadership." paycheck."

Li Yu said, "Guard belt?"

"Yes, teaching is the same as Cao Guandai and Zhang Guandai in terms of salary, 400 taels a month. And since you are also teaching two subjects, you can follow the standard of 800 taels."

Hey!That's a little motivation.

Li Yu thinks that he has been a student assistant for Yikuang for so long, and he only earned 200 taels. Now he earns 800 taels a month for teaching two courses. The gap is too big!Sure enough, Beiyang was extravagant. "Then please send me the relevant textbook."

Li Chunxi said: "No problem!"

The middle and high levels of the Beiyang Army still attach great importance to the Army Crash School, especially the "Rocket Squad" among them, who will be future reserve officers.

This has actually formed a tradition, so that the later Baoding Military Academy and Huangpu Military Academy received great attention, and the students were gradually trained to become a number of senior generals, and many famous figures came from the second school.

Sure enough, no matter in the 21st century or the [-]th century, talents are the most important.

Li Yu looked at the ballistics textbook given by Li Chun, and it seemed that he was learning and selling.

Fortunately, like surveying and mapping, current ballistics is not yet complicated, and it almost belongs to the field of applied mechanics in applied physics. It has not yet involved the dreaded aerodynamics and elastoplastic mechanics.

It's just that mathematics and physics knowledge in ballistics is indeed used more than in surveying and mapping. Of course, there are also some chemical combustion theories, explosion theories, and so on.

In other words: surveying and mapping is a basic compulsory course, while ballistics is an advanced professional course.

No wonder Li Chun told Sun Chuanfang that surveying and mapping was relatively difficult, and the depth of study was indeed higher than other subjects such as artillery, cavalry, ordnance.

(End of this chapter)