On the silent night, the cunch outside the window also seemed extremely loud. Shangguan Wan'er, who was holding the pen, naturally heard it. At this time, she also looked up at Zhang Zong, and her big eyes were full of doubts.

"This..." Zhang Zong hesitated for a moment, then said, "Wan'er, stay in the room, you must not come out without my instructions!"

"Wan'er understands!" Shangguan Wan'er was extremely smart, so she naturally could see that Zhang Zong knew who the person outside was, but she didn't ask a question. In fact, she grew up in the palace and knew that she shouldn't talk too much about something she shouldn't know, otherwise she would only cause a big disaster to herself.

Zhang Zong was also very relieved about Shangguan Wan'er. He stood up and walked out of the door, walked through a winding path to the palace wall of Furong Garden. Sure enough, he could see Li Hong on the wall at a glance. Since he climbed the high platform left by Taiping last time, he seemed to have become addicted and never let Zhang Zong climb over the wall to Furong Garden again.

However, compared to the novelty last time, Li Hong smiled bitterly this time. Seeing Zhang Zong spread his hands and complained: "Coal, why don't you keep such a good thing for me?"

Zhang Zong had long guessed that Li Hong saw that he must be doing it for coal, so he also replied with a smile: "Crown Prince, you should know why I gave coal to the eldest princess. After all, if you were asked to go to the palace, I am afraid that the queen would never let anyone go!"

Li Hong naturally knew that Zhang Zong saved Shangguan Wan'er, but he couldn't help but complain: "A little palace maid, you gave the coals to your aunt. If I had known, I would have given you one hundred directly!"

When Zhang Zong heard this, he shook his head and said nothing. He was destined to be with Shangguan Wan'er, and the matter started because of him, so he came forward to rescue him. It would not be possible if he were someone else, such as the Ni Nirvana Master I met today.

Li Hong complained, but he also knew that what Zhang Zong said was the truth. If he went to the palace to save people, it would be impossible to rescue them, because he was not like Princess Chengyang, who was a woman. In order to save people, the eldest princess could play tricks and even rob people out of the palace by tearing them apart. But the prince could not do this, otherwise his image as the crown prince would be ruined, which would also cause extremely serious consequences.

"Coal, you don't know how much fuel Changan lacks every winter, especially cheap and easy-to-use fuel. In the past, when it was cold, the prices of firewood and charcoal would soar. In the winter, seven or eight out of ten people died in Chang'an City were frozen to death."

Li Hong said again at this time, and at the end he liked the expression of distress. After all, such great political achievements were given to Princess Chengyang for nothing. But these political achievements were of no use to Princess Chengyang, and it was nothing more than to exchange for some rewards.

"Prince, some things are indispensable. The previous printing technology is already the most suitable political achievement for you. If you suddenly come up with too many new things, it will make people suspect that someone has made plans behind you. And now for the prince, too many conspicuous political achievements are not a good thing!" Zhang Zong said calmly again.

Li Hong was stunned when he heard Zhang Zong's answer, especially Zhang Zong's last words made him look thoughtful. Before, he only wanted to use political achievements to stabilize his position as the crown prince, but Zhang Zong's words suddenly woke him up. No matter what era, the crown prince is just the crown prince. Although he can make some political achievements, he cannot threaten the person above the crown prince's head, otherwise there will definitely be no good ending in the end.

"I understand. If it weren't for your reminder, I almost made a big mistake!" After a long time, Li Hong said with a long sigh that he had only been fighting for power and profit with his mother for a while, but he ignored his father's attitude. After all, the emperor had the final say in this country, so he was actually a little bit careless.

"With the wisdom of the prince, even if I don't say it, the prince will sooner or later find out the problem." Zhang Zong flattered Li Hong's flattery, and then continued, "In addition, although the merit of offering coal is not the prince, the prince can find merit from other places, and it will not cause suspicion!"

"Oh? Zhang Zong, what you mean..." Li Hong's eyes lit up when he heard Zhang Zong's words and asked.

"Our Tang Dynasty is so big, there is more than one coal mine. The coal mine in Xianyang is actually not particularly large, but it is closer to Chang'an, so the mining cost is low. However, the coal mines in other places are even larger, and some even exposed to the ground can be mined directly. As long as the prince sends people to find several large coal mines, it will also be a great achievement!" Zhang Zong said with a smile.

The popularity of offering coal is too great and is not suitable for Li Hong. In comparison, finding a few large coal mines is not so conspicuous. The difference between them doesn’t seem to be big, but it is actually very subtle.

For example, from Li Zhi's perspective, the coal mine was presented by his own sister, and he would also personally ask people to find the coal mine. If his son finds a few more large coal mines, the family will be kind and filial, and Li Zhi will only think that Li Hong's son is particularly capable.

"Yes, why didn't I expect this!" Li Hong's eyes lit up when he heard this, but then he showed a embarrassed look and said, "But you also said that our Tang Dynasty is so big, where can I find a coal mine?"

"Crown Prince, don't worry. I know where there is a large coal mine. I don't know if you have a map of the entire Tang Dynasty in your hand. I will mark it for you. If you send someone to search for the area I marked, you will definitely gain something!" Zhang Zong said with a smile.

"God helps me!" Li Hong also shouted excitedly when he heard this, and then he asked someone to pick up the map.

After taking the map, Li Hong also handed it to Zhang Zong, and Zhang Zong also marked out several coal-producing places he knew, such as in later generations, Pingdingshan, Henan and other places. Although the location may not be accurate, as long as Li Hong sent more people to search carefully, he would always find some.

Then Zhang Zong handed over the map, and Li Hong looked carefully as if he had found a treasure. At this time, Zhang Zong spoke again: "Prince, the coal mine is hidden underground. If it is too deep, it will be very difficult to mine. However, some coal mines are open-pit, and the reserves are huge and easy to mine. In addition, if the coal is burned into coke, it can also be used to refine steel, and the quality is no worse than that of steel made of charcoal!"

"Open-pit coal mine? Which one is an open-pit coal mine?" Li Hong asked even more excitedly when he heard this.

"The Shuozhou north of Taiyuan and the coal mines next to the Shanyu Protectorate are almost all open-pit." Zhang Zong said again, but then he explained that the so-called open-pit does not mean that coal is directly exposed to the ground, but that coal is buried shallowly, and there is no need to build a mine cave, but directly mined open-pit, so it is not easier to find than other coal mines.

Although the information provided by Zhang Zong was vague, it was enough for Li Hong. He immediately put the map carefully and prepared to send someone to these places to search carefully tomorrow. Even if one of the ten places could be found, it would be enough for him.

After the main talk, Li Hong thanked Zhang Zong for the perfume he asked Xue Shao for last time, but at this time he suddenly turned his head and looked at the study room with the lights on behind Zhang Zong, and then asked again: "The maid of Taiping has become your maid now. She shouldn't know about you and me yet, right?"

"No, but with her intelligence, even if she didn't see the prince, she could still guess it." Zhang Zong said helplessly at this time. Although Shangguan Wan'er's move in brought him a lot of convenience, there were advantages and disadvantages. She would sooner or later know about her meeting with Li Hong.

"That's true, but I have met this little maid a few times before. She is Shangguan Yi's granddaughter, and she was rescued from the palace by you and your aunt. It is estimated that there will be no connection with the palace anymore. I think with her intelligence, she should know what to say and what not to say. If it really doesn't work, please tell her a few more words." Li Hong nodded first, and then said without caring.
Chapter completed!