In Zhao Fujin's heart, Yanjingxing is the most daring and fanatical thing she has ever done. There she got acquainted with Yu Min and others, which greatly changed her impression of Fanren. It turns out that the Fan people are similar to the Han people, and the Fan people have their own writing, but they also speak Chinese, write Chinese characters, and even dress up, and they will learn the new style of Tokyo. The character is even more straightforward, and she is really tempered.

  It's just that after coming back from Yanjing, her heart is always empty, and she feels more bored than before she went to Yanjing, and she can't be interested in doing anything. It is said that she fulfilled her wish, and after visiting Yanjing City for so many days, she has tried delicious food and fun, and it shouldn't be like this.

  After returning from Yanjing, she rarely got into trouble with her palace maids in the palace anymore, and she wanted to sit there alone, sitting for a long time.

  Only that time the eldest brother of the prince came to her for help, speaking of Yanjing, talking about Wan Shengjun, and talking about Zhou Nan. Zhao Fujin suddenly felt an inexplicable joy in his heart. She just felt that she missed the happiness she had in Yanjing again, and she didn't think much about it.

  Until just now, Niangniang said that she was going to marry her, I don't know why, at that moment she suddenly thought of a fair-skinned face with a hint of a smile on the corner of her mouth, a pair of starry eyes, elegant and as deep as a mist, Zhao Fujin couldn't help but become flustered.

  She didn't know why, and in the end, she sent a ghost to ask her father to send Zhou Nan to Tokyo City. On that day, she was going to put on the most gorgeous clothes and makeup, and secretly stand beside her father, just to be able to sneak a look at him.

  But why look at him?! Zhao Fujin couldn't think of an answer, but although there was still half a month to go, Zhao Fujin was already feeling inexplicably cheerful now.

  The heavy snow covers the mountains, and they can't go out at all, but for the ten craftsmen of the Southern Dynasty in Sanssouci Village, it just allows them to concentrate on their work, and no one will disturb them.

  However, in three days, under the leadership of Shen Ding, ten craftsmen exhibited what they had learned and proposed improvements and supplements. Under the cycle of improvement, test flight, correction, and test flight again, several places have been improved. In the end, everyone was satisfied, so they brought the improved magic car to see Zhou Nan.

  Zhou Nan knew that he didn't have much time in the cottage, and in addition to chatting with Gao Yun and Yu Liyan every night in the past two days, he memorized the basic knowledge of physics, chemistry and biology that he remembered in the room.

  The process of memorization is a process that makes Zhou Nan feel blushing and ashamed from time to time - it's all because he didn't study hard when he went to school, and now he has to mistake people's children.

  For arithmetic problems, Zhou Nan is still self-aware, and his vague mathematical knowledge in high school will not be written out for others to laugh at. Zhou Nan just wrote down the basic knowledge of physics, chemistry, and biology as he still remembered, and as for how to get through, it depends on Lao Zheng Tou's own understanding. He is only responsible for instilling this knowledge in Lao Zheng Tou, so that Lao Zheng Tou can understand it first. As for how Lao Zheng Tou explained to the students, it depends on Lao Zheng Tou's teaching level.

  In Zhou Nan's time, this knowledge was nothing at all, and some even elementary school students understood it. But in this era, no one has ever summarized this knowledge, let alone thought about the truth. What Zhou Nan wants to do is to let more people understand the most basic principles of these natural science knowledge, so that they can confirm them one by one in practice when they do things. Zhou Nan believes that when the seeds of this knowledge are spread, more fruits will be reaped. There will certainly be people who, like modern scientists in the West, will gradually embark on the path of a theoretical science and technology system and develop the world's earliest modern scientific theories in China. Perhaps some of the principles and knowledge he wrote out cannot be confirmed by anyone now, but he believes that one day these principles of his will be confirmed one by one in the same way as Goldbach's conjecture and so on.

  Gao Yun and Yu Liyan also knew that Zhou Nan and Lao Zheng Tou had something to do, so they didn't bother him, and let Zhou Nan work hard in the room alone, except for occasionally going in to bring Zhou Nan a cup of hot tea or a plate of snacks.

  On the fourth day after Chinese New Year's Eve, Zhou Nan's own manuscript had already been completed, and he was about to take it to see Old Zheng Tou, Shen Ding and other craftsmen came in from outside the gate, and there was a divine car behind him.

  As soon as he saw Zhou Nan, Shen Ding said excitedly, "The big village master, the villains have improved a few places, please take a test ride for the big village master." ”

  Zhou Nan was not in a hurry to see Lao Zheng Tou, so he asked Shen Ding and others to let the god car rise into the air to see how the effect was.

  Shen Ding and the others skillfully unfurled the hot air balloon in the courtyard and began to burn the fire and inflate the balloon.

  Zhou Nan walked down the steps and watched carefully around the hot air balloon, and there were indeed many improvements made. The most obvious is that the long-necked iron furnace has been changed from the original one to two iron furnaces side by side, but the walls are thinner than the original iron furnace furnace and the furnace chamber is larger, so although it has become two furnaces, the weight is lighter. It is also equipped with a small blast leather bag, which is obviously the equipment used by blacksmiths to burn fires, and is now used on this stove, presumably the furnace fire will heat up faster and become stronger, and the hot air balloon will rise faster. Looking at Sun Rong's appearance of adding charcoal and blowing the wind at the same time, it was obviously not difficult.

  There is also a more obvious one, that is, the original hand-cranked fan blade has been changed to a larger fan blade driven by a foot-operated gear set. It is like stepping on a wooden wheel to drive a waterwheel. It is conceivable that if a person steps on the wooden wheel and drives the three-page fan blade to rotate, the effect of changing the horizontal direction must be much better than before. It's just that Zhou Nan didn't expect that in the era of the Northern Song Dynasty, there was already a gear device, although it was not made of iron, but a lot of hard wood was enough to use.

  Looking at Zhou Nan's stunned appearance, Shen Ding said proudly, "The master of the village doesn't know, in the city of the Southern Dynasty, there is a mechanism that uses the river water impact to drive the shaft, and the shaft then drives the stone mill, and the stone mill is used to grind the surface. The villain takes the mechanism and steps on it with his feet to drive the fan blades. Human legs and feet have a lot of strength, so it is naturally less labor-saving than hand cranking. ”

  Zhou Nan pointed to the wooden wheel used to step on it, which was as thick as a man's waist, and said, "This can be changed again, I'll draw it for you later." ”

  Shen Ding saw that Zhou Nan had a better way, so he nodded hurriedly and said yes, and said to Zhou Nan, "We have weighed these woods, and the ones used are the lightest woods." Like this fan leaf, it is made of sycamore wood from bamboo and wood. ”。

  At this time, the hot air balloon was full, bulging and swollen, and was swinging restlessly, as if it was about to break free from the ropes below and rise into the air.

  Shen Ding invited Zhou Nan to the hanging basket, and as Shen Ding signaled, someone untied the rope, and the modified hot air balloon rushed up at once. Like Song Chungui, please collect x Song Chungui.