Li Mansion, West Courtyard.

Li Zexuan rolled up the drawings, handed them to Yan Shaoning, and said, "Brother Shaoning, I understand your drawing method, but I still think my method is more concise and clear. ”

"Oh? Then Xiao Xuan, tell my brother and me, what is your way of drawing method. ”

Yan Shaoning saw that Li Zexuan was very confident in his drawing method, and couldn't help but want to know how amazing this method was.

"Little brother, this picture is drawn on a kind of parts of the three views and isometric side view, the so-called three views are from the front, side and top of the object, the outline of the object is drawn, such as this stone, Brother Shaoning, you look at it from the front......"

Li Zexuan picked up a stone for reference, explained the drawing method of three views to Yan Shaoning, and after a while, he packed the part that the professional teacher told him at the beginning and sent it to Yan Shaoning.

“…… Brother Shaoning, you see, with these three views, the craftsman can form a model of the parts to be made in his mind at a glance, and it will be easier to mark the size on the three views. ”

After listening to Li Zexuan's explanation, Yan Shaoning stood up, paced, pondered for a moment, and suddenly shouted: "Wonderful, wonderful, this drawing method is really wonderful, Xiao Xuan, you are simply a genius, your drawing does look clearer like this, and there are a lot of unnecessary annotations." ”

Yan Shaoning sat down again, rubbed his hands, stared at Li Zexuan and said excitedly: "I must tell my father about this drawing method, and let him promote this method, Xiao Xuan, are you willing to go to the prison, if my father knows your talent, he will definitely be willing to ask you for an official position in front of His Majesty." ”

Li Zexuan shook his head and said: "Thank you Brother Shaoning for your kindness, the younger brother has been away from home for many years, and he just came back a few days ago, and he doesn't want to be an official now." ”

The prison is almost equivalent to the Chinese Academy of Sciences in his previous life, and he is unwilling to let Li Zexuan work hard there every day to conduct research. Besides, he has been doing a lot of things about himself recently, and the Strange Pavilion is about to open, and the locust extermination plan will start in two days.

Hearing Li Zexuan's refusal, Yan Shaoning sighed: "Alas, that's really a pity. ”

Turning his gaze to the drawing again, Yan Shaoning was puzzled: "Xiao Xuan, what does this isometric side view do?" ”

"The main purpose of this view is to help the craftsman form a diorama of the object in his mind, because some objects with a particularly complex structure are difficult to imagine with only three views."

Yan Shaoning nodded thoughtfully.

At this time, Li Zexuan smiled meaningfully: "Brother Shaoning, you only noticed this drawing method just now, but you ignored the picture itself." ”

"Oh? Could it be that there is some mystery in this? Don't talk about it yet, I'll take a look. ”

Yan Shaoning began to examine the drawing again according to the three-view principle that Li Zexuan had just explained to him. After reading it, Yan Shaoning stood up, closed his eyes, and imagined a three-dimensional picture of this thing in his mind.

After a while, Yan Shaoning opened his eyes and said excitedly: "I understand what this thing is, Xiao Xuan, what are you going to do with this thing?" He could imagine a three-dimensional model of the thing, but he couldn't think of a use for it yet.

Li Zexuan said with a smile: "I named this thing a ball bearing, Brother Shaoning, do you think, if this thing is used in the transmission connection of the wheel and the wheel shaft, what will happen?" ”

Yan Shaoning himself has a lot of research on mechanical design, and after listening to Li Zexuan's little bit, he immediately understood, and he was even more excited than before at this moment.

"It's amazing, it's a genius design, and with this ball bearing, all the cars, whether horse-drawn carriages or wagons, will have very little resistance to move forward. Xiao Xuan, how did you come up with this? This invention is truly great. ”

Li Chengqian didn't understand machinery, and he hadn't said anything before, but when he saw that Yan Shaoning was about to blow this thing into the sky, he couldn't help but wonder: "Shaoning, this thing is really that good?" ”

Yan Shaoning was extremely excited at the moment, and when he heard the prince's question, he couldn't even think about affirming:

"Of course, it's not an exaggeration to call this the most useful invention of my Datang. Your Royal Highness the Prince, do you know, if all the cars of my Datang use this ball bearing as a transmission, then the same horse can pull at least fifty percent of the load-bearing cars at a time.

At that time, merchants can transport more goods at a time, and when there is a war, a grain truck can load more grain and grass, and in addition to the car, other machinery that needs to be transmitted, some can also use this ball bearing. ”

Hearing Yan Shaoning's analysis, Li Chengqian was also stunned, he didn't care if the merchants could transport more goods, but this could improve the efficiency of transporting grain in the battle array, it was really too crucial, in this era, one of the decisive factors in the victory or defeat of the war was the issue of grain and grass.

Only then did Li Chengqian realize that Yan Shaoning's previous praise was not too much at all, and he was also a little excited now.

"Brother Zexuan, this thing is very important, I wonder if I can let Gu take it back to the palace?"

Li Chengqian also knew that Li Tai was competing with him for favor recently, but he didn't have any other good way, he couldn't be coquettish in front of Li Er's eldest grandson like Li Tai, right? If he dared to do this, he would definitely be reprimanded by Li Er, saying that he did not have the prestige of a prince of a country.

There are some things that Li Tai can do, but he can't do because he is the crown prince. Seeing that Li Er was more and more fond of Li Tai, Li Chengqian was also anxious, but he could only be anxious.

At this time, seeing that this thing invented by Li Zexuan was so useful, and it could even be used in the military, Li Chengqian's first thought was that maybe he could use this thing to make Li Er appreciate him, and by the way, he could also ask for some benefits for Li Zexuan.

Li Zexuan was a little helpless at the moment, although this ball bearing is indeed extremely versatile, but these two people are not so excited, right? Hearing that Li Chengqian meant to present this drawing to Li Er immediately, Li Zexuan hurriedly said:

"Your Highness, this ball bearing is indeed very useful, but I don't know if it can be made yet, so I'm afraid it's too hasty to present the drawings to Your Majesty now."

When Li Chengqian heard this, he also felt that it made sense, and secretly said that he was still too reckless.

"What Brother Zexuan said is very true, then wait for you and Shaoning to build this thing and install it on the car, and then report it to your father, and then you will ask for credit to the two of you."

As soon as Yan Shaoning heard Li Zexuan's words, he began to frown and meditate, just now he was a little too excited, he didn't think about whether this thing could be made at all, he thought for a while, and hesitated:

"Xiao Xuan, I'm afraid this ball bearing is very difficult to make."

Li Zexuan before he proposed this ball bearing, he didn't know if it could be manufactured with the technology of the Tang Dynasty, although he was mentally prepared, but now when he heard Yan Shaoning's negative answer, there was still a little disappointment in his heart, but he also wanted to know where the technical difficulties were, so he asked:

"Brother Shaoning, I don't know where there will be difficulties?"

……