Han Jiang pointed to the whirring steam engine and said, "This thing, this thing burns charcoal here, and the wind comes out with a fan over there, it looks very interesting." However, it burns a lot of charcoal a day, but it is useless to carry a fan. ”

Du Zhongxiao said: "This is just a plaything, how useful it is to try to boil water like this." If it is used well, it will be of infinite use to replace the fan over there. Now I bring a fan, but it's hot, and it wasn't meant to cool off. ”

Han Jiang nodded: "I think so." If it's just blowing the wind and enjoying the coolness, this thing will be overkill. It's just that I don't know something, why does the boiling water turn here and there? The beauty of this thing is all in it. ”

Du Zhongxiao patiently explained: "When we boil water, the water becomes steam, and the area occupied is much larger than the original water. Use this steam to push against a plug inside, back and forth, and you can drive that side to turn. Brother Han is right, the magic is all here. ”

The principle of the steam engine is actually very simple, and it is impossible to understand, the difficult thing is how to use this simple principle to make practical machine work. The key is to use steam to realize the reciprocating motion of the piston, and the other is to transform the reciprocating motion into a rotary application and be able to work reliably. Achieving these actions is not as complicated as it seems, but it is difficult to increase power and efficiency.

Du Zhongxiao's textbook in his previous life, in fact, added a lot of legends when talking about these mechanical principles. Those legendary stories may not have been made up, but they did not happen in one time and one place, but only concentrated on one or two people in a short period of time. In fact, people are not so ignorant, and their first reaction when they see these new things is curiosity, just like Han Jiang now, rather than being surprised and afraid.

The development of the steam engine went through a long process, and in the early days it was not complicated and certainly not so practical. It was on the eve of the Industrial Revolution, faced with the needs of reality, that many people made improvements, and finally by Watt. Later, the various principles and structures learned in textbooks were finally formed in the process of improving the steam engine through summary and rational research. Du Zhongxiao had already learned various points of the steam engine in his previous life, and he took many detours in the process of making this model. In fact, in his previous life, when he was able to buy mechanical parts, he could easily make a principle machine. The size of this model is now enough to be used as normal mechanical power. In this era, all kinds of mechanical parts need to be made by hand, and it is far from the same.

Han Jiang nodded again and again, pointed to the various parts of the steam engine in front of him, and asked about the role one by one. His mind was nimble, and he was practical and saw the future of the machine. Although it looks like a plaything now, it can be useful if you change the rotating blade in the back.

After asking them one by one, Han Jiang took a breath and said to Du Zhongxiao: "Brother Du, this thing you did is much more useful than the method of steaming wine that was dedicated to the imperial court last year. It's a pity that there are no talented ministers in the court, so you can't show your talents in your chest. ”

Du Zhongxiao couldn't help laughing when he heard it: "Brother Han said it was funny." No matter how good this thing is, it is just a craftsman's talent, and what can it do. To contribute to the imperial court, you still have to study for the imperial examination, that is the right way. ”

Han Jiang nodded, and Du Zhongxiao said it well. In this era, it is possible to become an official if you donate technology, but it is only military capital, and there is no future. If you really want to have a future in politics, you still have to be admitted to the Jinshi, otherwise he would have been an official and come back to do something. Han Jiang's vision is good, this steam engine is much more useful than the method of steaming wine that Du Zhongxiao dedicated to the imperial court last year, but the actual benefits now are difficult to compare.

Su Song stepped forward and smiled at Han Jiang and said, "Zihua, do you think this thing is of any use if it doesn't have a fan?" ”

Han Jiang said: "I heard people say that in the south of the Yangtze River, where the lake is open, there are boats loaded with wheels and stepping on wheels. If this thing is used to drive the treadmill on the ship, wouldn't it be possible to let the boat sail on the rivers, lakes and seas without manpower and wind. ”

Su Song clapped his hands: "Zihua is right. I discussed it with Brother Du many times, and I felt that the best use of this machine was to put it on the ship. Now the Bianhe River is transported, with no less than 100,000 van troops, and it costs countless people. If you use this thing to sail, how much manpower and material resources will be saved! ”

Du Zhongxiao said with a smile: "This matter is excellent when you think about it. But I don't know how much work it will take to load this machine on the ship. First, the machine is too weak now, and the ship it can propel is a plaything. Second, the machine is too large, and if it is loaded on the ship, it should not be loaded again. ”

Han Jiang said: "When things are first made, there are always such and such unsatisfactory things. As long as you recruit master craftsmen, you can always change it to use. ”

In fact, Du Zhongxiao's impression is that the steam engine is connected to the train. But there was no shadow of a train in this era, and when he discussed it with Su Song, the two agreed that the greatest use was on the boat. In particular, the Bianhe River is in good condition and is the most suitable for use. The prototype of the steamship was propelled by wheels, which is somewhat similar to the waterwheel used in Gangnam, and it has been around for a long time now, and it is suitable for inland rivers. The propeller with wider applicability has too high technical requirements and is not so easy to make.

When Han Jiang saw this thing, his first impression was also on the ship, of course, he was inspired by the impeller he was carrying now. However, it also shows that the use of things like steam engines on ships is the easiest use to think of in this era.

Du Zhongxiao is bent on being admitted to the sergeant and becoming an officer, and he won't spend too much energy on things like steam engines, at least for now. For more than a year, in addition to transforming the machine with Su Song, he also taught Su Song to draw by the way. For other things, I don't want to spend more effort. The initial improvement of this machine depends on the people of this era, not on Du Zhongxiao, who first has to consider his own future.

Su Song's family history has been exposed to astronomical knowledge, including astronomical machinery, since he was a child. In this era, it is extremely rare. Since the time of Taizong, private research on astronomy has been forbidden, and Su Song's family has been teaching astronomy, and I don't know how it was handed down.

Astronomical machinery is extremely precise, and Su Song is no stranger to machinery, nor is he unfamiliar with mechanical drawings. However, the previous drawings did not pay attention to the actual size, but were more like schematic diagrams, which were somewhat similar to the drawing methods of Du Zhongxiao's axonometric drawings in his previous life. Du Zhongxiao taught Su Song axonometric drawings by hand, including the principle of perspective, and then taught him three views, and now the two can basically communicate with drawings. Drawings are the language of engineers, and being able to communicate with drawings avoids a lot of misunderstandings in communication. In Du Zhongxiao's view, this is more important than making a more complete steam engine model.

Su Song was obviously more interested in these things than in the Confucian classics, and in just over a year he had learned to draw and was trying to compile a textbook for drawing. In his opinion, this is also helpful for painters at this time.

Han Jiang had been a magistrate, and was more interested in the practical value of the machine than Su Song and Du Zhongxiao. Circling around the machine, thinking about how to get to the ship. In addition to the boat, what other places can be used.

The other Guozijian students watched with great interest, but no one participated in the discussion. Han Jiang and Su Song are both sons of high-ranking officials, and they usually don't have much interaction with the people around them, and in the eyes of most readers, these craftsmen's things are only suitable for watching a lively look.

After a few turns, Han Jiang made up his mind and said to Du Zhongxiao: "After the release test, if there is nothing to do, how about you teach me to be a station?" ”

Du Zhongxiao was taken aback: "Brother Han, this price is expensive. Last year, I gave a steamed wine booklet, plus the reward money for the capture of the party's fine work, all of which were spent on it. Don't look at the black outside, there is a lot of copper inside, and it has to be refined by master craftsmen. ”

Su Song smiled: "Brother Du said that he was laughing. Zihua's family, where will there be a shortage of this money. ”

Du Zhongxiao smiled embarrassedly. The Han family and Lu Yijian's Lu family are the two major families at this time, and they are talking too much for a while. As long as they feel that the money is well spent, who cares how much the machine can use.