On the way home, Gu Qing walked all the way across Zhuque Street and the gate of the mansion. Cheng Yaojin was standing at his door, "Boy Gu, are you going to go to sea?"

"Yes, yes." Gu Qing nodded awkwardly.

"I'm giving you a lot of money." Cheng Yaojin said.

"That's natural." Gu Qing nodded again, "Uncle Cheng, don't worry, guarantee that there is a lot of money to be paid."

"I heard from my eldest son yesterday that you are short of money?" Cheng Yaojin's words meant something.

"Things are not." Gu Qing smiled bitterly and stepped back secretly.

"Really not?" Cheng Yaojin asked again.

"It's really not." Gu Qing nodded vigorously, "Serious."

"Go to do things well," Cheng Yaojin said, "Go back. I'm not happy recently and can't hear the word "silver and money."

"Boy will say goodbye now."

In Bizhai, Dongshi, Di Renjie was instructing the fat monk to send his eyes to Goguryeo these days and watch the actions between Goguryeo and Japan.

The center of gravity of the Qing Gang separated from Guanlong and headed towards the East China Sea step by step.

Gu Qing was walking home, and a servant blocked the road, "Do you dare to ask if it's Shangshu Ling Gu Qing?"

"Who are you?" Gu Qing said in confusion.

"The head of the Li family in Zhaojun dragged Xiaomin to deliver the letter."

After the other party finished speaking, he handed a letter and left.

Gu Qing opened the letter as he walked and read it. It was written on it. It was written with Li Ran's words. He didn't say much, but he was hinting when Di Renjie would go to the Li family in Zhao County to propose marriage. He also said that the Li family in Zhao County had prepared eight thousand civil servants and was willing to build a large port for him.

To build a large port and return sea boats, it takes a lot of manpower and material resources. To go to sea before spring, the monsoon is a very critical factor. It is not easy to build a steam engine in this era.

Another very important thing to go to sea is the compass. With a compass, you can ensure that you don’t lose your direction at sea. In the Age of Discovery Compass is the lifeblood of the navigator.

When he returned home, Gu Qing began to prepare for making a compass. In fact, the prototype of the compass appeared very early in the history of the Central Plains, and there were many statements. It was first recorded in Guiguzi's book, and the term Si Nanche appeared, and there was a spoon and a compass in the situation.

Later in the Kaiyuan period, there was a master of geography. The three needles of geography were also the prototype of the compass. The origin of this geography was also mentioned in the historical materials of the Ming Dynasty. It was only in the era of scientific enlightenment that compass was often used on the compass of geography.

This is thus covered with some mysterious colors. It is actually very simple. It is just a magnetic needle and it is not so magical.

Li Zhi looked at Gu Qing polishing the magnetic needle and asked, "Gu Qing, how magical is the compass you are talking about?"

"This thing is not magical, it just points to the direction." Gu Qing said while polishing the magnet, "because it is easy to lose its direction on the sea, and the sea has no references."

Grind a magnetic needle and Gu Qing put it in a water bowl.

Li Zhi watched the thin magnetic needle float on the water, "It's moving, this needle has moved!"

"The magnetic poles attract and repulse each other. To be larger, the land under our feet is a large magnet, with magnetic poles in the north and south, which will be emitted on the magnetic needle."

Li Zhi was curious and held the water bowl. No matter how he turned the magnetic needle, he would point to the north and south ends. "Gu Qing, it's so magical."

"It's very slow, and the direction deviation is a bit large." Gu Qing said thinking, "It seems that you still have to be a compass, otherwise there will be problems with the direction."

"Is there anything I need to help?" Li Zhi was excited as if he had discovered a big secret, although he couldn't understand why the land under his feet was a big magnet.

"Please keep quiet when you are your Highness, King of Jin."

"Yes!" Li Zhi stood aside and looked at Gu Qing expectantly.

Half an hour passed, Gu Qing was still busy himself, and Li Zhi stood for half an hour, looking at Gu Qing's eyes from expectation to confusion, and then became angry.

"Gu Qing!" Li Zhi stomped his feet, "Do you keep me quiet when you ask me for help?"

"Your Highness King Jin, you have realized it!" Gu Qing said earnestly, "Please continue to keep quiet."

Li Zhi stomped his feet and slammed the door and walked out of the door.

"I am so arrogant at such a young age. I am the same as my father and I." Gu Qing said to himself that he was busy in his hands.

It is not difficult to make a compass, but the difficulty is sensitivity and accuracy. The pointer should be small, light and flexible.

Another failure was made. Gu Qing sat down decadently, and there were a lot of parts on the table. Why is this compass so difficult to make?

Wu Mei brought some buns over, "Husband, it's been more than three hours."

Gu Qing took the bun and bite it. It was stuffed with sauerkraut. Wu Mei liked to eat sour food while pregnant.

"The boy who came from his stomach was not making a fuss." Gu Qing pulled Wu Mei and let her sit beside him.

"I'm so obedient." Wu Mei covered her mouth and chuckled, "Just just saw His Highness King Jin go out in anger, my husband must have bullied him."

When he was holding Wu Mei, Gu Qing whispered, "It is a blessing to suffer losses. It is a good thing to suffer losses when you are young. Only after you suffer losses will you know what to do in the future when facing the same situation. Eat one's thorns and one's wisdom!"

"You can always tell a bunch of inexplicable truths." Wu Mei and Gu Qing's table were filled with parts.

"That kid looks unhappy." Gu Qing sighed.

"So for your husband, His Highness King Jin is in a blessing and does not know how blessed you are. If your husband bullies him, will he still thank your husband?"

"It's not that good." Gu Qing nodded vigorously.

Wu Mei covered her mouth and smiled Gu Qing and stood up and said, "Xiao'er should wake up too."

"By the way!" Gu Qing grabbed Wu Mei, "I wrote to the Li family in Zhaojun. What do you think Di Renjie's marriage is like..."

Wu Mei knew that Gu Qing respected her views very much. In fact, there was no need to ask about her wives and concubines during the matter. The head of the family was the leader, but she still said, "Di Renjie is not young, it's time to start a family."

"This kid is only sixteen years old, is it too early?" Gu Qing hesitated.

"How could you be a teacher like this?" Wu Mei whispered, "I have been adults at the age of sixteen. Di Renjie has been in contact with the young lady of the Li family in Zhaojun for many years. My husband cannot be a person who breaks up his marriage."

"Okay, as the old saying goes, it's better to demolish ten temples than to destroy a marriage." Gu Qing hesitated again and again, "After having dinner tonight, I'll ask the boy what he thinks."

"I'll ask," Wu Mei said, "You men always go straight and say something."

After Wu Mei said that, she walked out of the laboratory, carefully closed the door for Gu Qing and went to the bedroom to take care of her son who had just woken up.
Chapter completed!