Speaking of rubber substitutes, Li Yan immediately thought of one thing. When he made his first bicycle in Chang'an, the craftsmen in the mansion once applied a special rubber to the wheels. The thing seemed to be wear-resistant, maybe it might be feasible?

Thinking of this, Li Yan hurriedly asked someone to call both Huang Cheng and Lao Wu, the two managers in the mansion. These two men were originally craftsmen from the wooden ware workshop and the iron ware workshop in his mansion. Because they helped Li Yan make a lot of new things, they were promoted to the manager. Among them, the bicycle was also successfully developed under the leadership of the two of them.

Yifan didn't know what Li Yan asked the two managers to do, so he looked at Li Yan with some surprise. After a while, the dull Huang Cheng and the old Wu head who was still strong rushed over and saw Li Yan and immediately bowed: "See the prince!"

"Get up, when I asked you to make that bicycle, you applied a thick layer of glue to the wheels. The glue seemed very tough. Is there any in the mansion now?" Li Yan asked the two of them to get up and asked impatiently.

When Li Yan asked about this, both of them were stunned. The more talkative old Wu head did not speak, but looked at Huang Cheng, who was very dull because the glue was made by Huang Cheng.

"Your Highness, that kind of glue was discovered by villains, but this kind of glue is not very sticky and has limited use on wooden tools. It is not always available. It can only be made when needed. However, it is not so easy to make that kind of glue now." Huang Cheng hesitated for a moment before answering honestly.

"Oh? Why is this?" Li Yan was very surprised when he heard this.

"Your Highness. That kind of glue was made by a villain from a kind of fruit tree sap, but that kind of fruit tree had just been introduced to my Tang Dynasty. It was only planted around Chang'an. This time I came to Dengzhou. Although the villain also brought some seeds, it was only a year before planting it and there was no way to get the sap." Huang Cheng said helplessly.

The sap sounds so much like a rubber tree, but Huang Cheng clearly said it was a fruit tree, but in Li Yan's memory, the rubber tree does not seem to produce any fruit?

"What is the name of that kind of fruit tree? Do it have any characteristics?" Li Yan asked hurriedly. The rubber tree is still far away in the American continent and it is impossible for it to spread to the Tang Dynasty. Therefore, Li Yan quickly denied the rubber tree's speculation.

"Your Highness, the villain heard that the fruit tree was brought by the Western Hu Shang, so he didn't know what its name was. However, after it was passed down to my Tang Dynasty, it was called honey fruit because the fruits they bear as sweet as honey. In addition, this kind of fruit is very strange and will bear fruit if it does not bloom, so some people call it figs!" Huang Cheng bowed and answered again.

"Sun, it turns out to be figs!" After Huang Cheng said this, Li Yan immediately remembered that he had eaten a lot of them when he was in Chang'an, but he didn't care at that time. After all, figs are very common in later generations and there is no big fuss about them. But he didn't expect that this thing had just arrived in the Tang Dynasty.

"Your Highness, we have planted a lot of fig trees in Chang'an's mansion. I believe your Highness has tasted figs. If you need it, you may have to transport them from Chang'an. However, this round trip will take almost two months!" Huang Cheng replied honestly.

In fact, Huang Cheng didn't know that since Li Yan presented his bicycle to Li Shimin, Huang Cheng's gum production method was also presented, and he would imitate the bicycles by the supervisor. With the promotion of bicycles, the demand for gum on wheels naturally increased greatly. Although many families in Chang'an City have begun to plant fig trees in large quantities, the time is too short to take saps at all. In this way, the mature fig trees are even more precious. The ones planted by Li Yan's mansion have been purchased at a high price, and the trees have been removed. However, this matter is too small. Li Yan and Huang Cheng, who are far away in Dengzhou, don't know at all.

"Okay, then you set off immediately and arrive in Chang'an immediately, make that kind of gum as soon as possible, and the more, the better. If it is not enough, let Mr. Wang find a way for you!" Li Yan immediately ordered. Mr. Wang is Wang Zihao, who is Wang Zihao. Xijun has entered his mansion, and Wang Zihao has become his elder. He doesn't respect him by calling him the name again, so he changed to Mr. Wang, and everyone in the mansion knows it.

"As for the order!" Huang Cheng also knew that His Highness was going back to Chang'an, but now he asked himself to leave first. Obviously, this matter is very important, so he did not dare to neglect it. After saying that, he immediately went back to the house to prepare, and left Dengzhou without even having lunch.

"Liulang, didn't you say you were looking for rubber? Why did you look for figs?" Yifan asked with confusion at this time. In fact, she wanted to ask just now, but she just couldn't get into the mouth.

"The rubber thing is good, but we can't find it at all in the Tang Dynasty. We can only settle for the second best. We try it with fig rubber, but it should be similar." Li Yan seemed very unconfident when he said this. In fact, he didn't know that figs and rubber trees belong to the same family, and rubber can also be made in the saps they produce. Of course, the yield is not as big as rubber trees. As for the rubber made of yellow, the ingredients inside are almost the same as rubber.

Put the issue of steam engine sealing aside for the time being. Next, Li Yan carefully observed the operation of the steam engine and discussed the shortcomings and aspects that need to be improved with Yifan. In fact, the reason why the horsepower of this steam engine is so small is that in addition to the reason for the air leakage, there are also quite a few problems in the design. This is not about Yifan's ability, but when it was originally designed, it was only to make it run continuously. As long as this basic requirement is met, the horsepower matter can be improved step by step on this basis.

For this reason, after Yifan started to design the new steam engine after prototyping the steam engine, the purpose is to increase the power of the steam engine. With the foundation of this prototype, I believe that the new steam engine will be able to complete the design soon, but due to the limitations of process and sealing problems, even if the power is increased, it is estimated that it is very limited.

The process cannot be improved in a short while, and Li Yan, an amateur, can't help with this. The only thing that can be solved is the problem of air leakage. As long as the sealing material can be found, I believe that it will definitely increase the power of the steam engine by a large amount. Although it is still a huge waste, it is definitely no problem to be practical. At least it will not be like the prototype in front of them, it can only be used as a decoration.

Thinking of this, Li Yan was even more determined to solve the problem of air leakage. If the kind of glue made by Huang Cheng still didn't work, then he would publish the map from the Americas to Asia and offer a sky-high reward. I believe that there will be brave men under the heavy rewards, and someone will definitely dare to take the huge risk, although the hope for success is very slim.

After watching the steam engine, Li Yan stayed in the Academy of Sciences for another half day, went to other groups to check their progress, and helped them with whatever they could think of. Of course, Li Yan's level was completely the kind of slut, and he didn't help much. It was noon that he went back to his house to have dinner with Wen Xin and the others, but he had to go out in the afternoon because Wu Meiniang wanted to see him.

Wu Meiniang still lives in the house arranged by Li Yan for her. Although Li Yan has long relaxed the control of her freedom, in order to avoid unnecessary trouble, Wu Meiniang has always been living in seclusion. If it is not necessary, she basically doesn't go out much. Even if she goes out, she will dress up and call Yang Shi and his wife.

After not seeing each other for several months, Wu Meiniang naturally missed Li Yan very much. For this reason, she cooked herself, cooked a few authentic Guanzhong side dishes, warmed a pot of light wine, and sat at the table very well-behavedly waiting for Li Yan.

Li Yan pushed open the door and saw the scene in front of him, especially Wu Meiniang was wearing a regular dress and sat on the chair with a lazy look on her face. When she saw him come in, she smiled slightly, opened her red lips and said, "Husband, are you back?"

After only a few months of sight, Wu Meiniang became more charming and attractive, especially because the weather was hot and she was wearing thin clothes, which showed her convex and convex figure, making people unable to look away at first sight. In fact, Wu Meiniang is one year younger than Wen Xin, but her figure advantage is not a little bit better than her, but this is born and can't be learned no matter how hard she works.

Seeing her well-behaved appearance, Li Yan was just a heartbreaking little wife, and a little tenderness surged in his heart. In fact, Li Yan didn't have much thoughts about Wu Meiniang at first, but after spending time together, he suddenly realized that the other party had actually entered his heart, especially in the past few months since he was separated, besides missing Wen Xin and Xijun, the one he missed the most was Wu Meiniang in front of him.

"Mei Niang, thank you for your hard work during this period!" Li Yan quickly walked forward, picked up Wu Meiniang from the chair, and put it on his thigh, and then said softly. During this period, he was far away in Goguryeo, and all the information about intelligence was taken over by Wu Meiniang, which made her burden a lot heavier, so Li Yanhui said so.

"Hehe, no matter how hard Mei Niang works, she is not as hard as her husband's hard work for the country to kill the enemy on the battlefield!" Wu Mei Niang smiled mischievously. She knew that Li Yan was just a foil on the battlefield, but she still said so, obviously joking with Li Yan.

"Of course, I am very brave on the battlefield. Li Ji and Niu Jinda are very powerful in the army, but they were blocked by a small Anshi City. In the end, I rushed there and took down Anshi City in an instant. Even the city lord was blown to death, and the Goguryeo King..."

Li Yan naturally heard that Mei Niang was joking, but his skin was already thicker to a certain extent. He immediately followed her words and began to brag about his heroic appearance on the battlefield. He used bragging to tell his experience on the battlefield...!~!
Chapter completed!