The topic of today’s course is ‘Ocean Currents’.

In maritime navigation in the age of sail, ocean currents and sea breezes were almost equally important.

Just like Zhu Yuan's recent summary, when the Yuan Dynasty transported grain by sea, the early offshore routes were quickly abandoned. In addition to the fact that large ships were easily stranded due to tidal interference, another major factor was ocean currents.

In the offshore areas of northern China, there is a cold current from north to south all year round.

Therefore, the offshore route, from south to north, is equivalent to traveling against the current, and the difficulty of transportation can be imagined.

Let’s talk about ocean routes.

According to Zhu Yuan's estimation, the two "ocean routes" used by the Yuan Dynasty to transport grain did not leave the coastline for more than 500 miles, and did not even extend beyond the offshore continental shelf.

However, compared to offshore routes, after February every year, ocean currents from south to north and north to west begin to appear on the ocean surface, which is what he has heard from various classics and related people more than once before.

The sea opens in February'.

After this ocean current appears, even if the wind direction is unfavorable, just relying on the direction of the sea water, the fleet can be gradually transported to the Shandong Peninsula or the Bohai Estuary further north.

What Zhu Yuan wants to talk about is mainly the causes of ocean currents.

Such as wind power.

Such as density.

In addition, we talked about the nearby Zhoushan fishery, whose causes are also closely related to ocean currents.

These are actually the basic geography knowledge from the junior high school level in previous lives.

Zhu Yuan's goal is to let everyone know what is happening and why.

The more truths you understand and the unknowns are broken, the less instinctive fear of the ocean will be. No longer afraid of the unknown, the smoother the exploration of the ocean will be.

This class is still half an hour long.

Zhu Yuan finally admitted that what he said was not necessarily correct, and that people would need to spend more time in the future to verify and summarize, or even come up with a new theory.

However, Zhu Yuan also emphasized that many phenomena related to the ocean, whether it is tides or ocean currents, have clearly explainable causes. If you encounter them, you don't have to be frightened and confused, you just need to explore and discover.

At the end of the course, Zhu Yuan once again made a request to Liu Lian in class, asking him to organize a team to conduct corresponding summary of past data and current ocean current observations around the current grain transportation matters, and to make clear documents for everyone's reference.

Unlike tides, which can be calculated and involve ocean currents, long-term observations over several years or even decades are needed to summarize more clear patterns.

At present, it is mainly based on the various classics collected by the Maritime Operations Department during this period and the oral information of a large number of shipping people, and it is closely related to shipping.

Finally, it was announced that the class was over, but there was still no 'goodbye, teacher'.

Not polite!

Everyone dispersed, and Hua Gao and Wu Zhen came to the front of the hall together. It was the first time that Wu Zhen saw the globe that Zhu Yuan had brought as a teaching aid. It was novel and even looked at it with some inexplicable fear.

Own……

Actually lives on a ball!

What to do if you fall?!

Zhu Yuan did not disturb Wu Zhen and was talking to Hua Gao. He saw Mingzhou Guard Commander Tongzhi Chang Duan coming forward with a young man who looked somewhat similar to him.

These days, Chang Duan has been very cooperative with Zhu Yuan's various arrangements. However, Zhu Yuan could feel that this junior military attaché seemed to be deliberately keeping a distance from him.

Everyone has their own opinions. As long as you don't miss the point, you are not gold, so you don't need to be liked by everyone.

today……

Looking at the young man again, he was surprised.

Chang Duan stepped forward, clasped his fists to greet everyone, and then pulled the young man next to him and introduced: "My lords, this is the dog Chang Yao, who took the liberty of coming to listen to Hanlin's lecture today."

Young people about twenty years old wearing long gowns and black gauze respectfully saluted Hua Gao, Wu Zhen and Zhu Yuan one by one.

Hua Gao and Wu Zhen accepted it calmly.

Zhu Yuan still did not resist.

After all, he is Chang Duan's Shangguan. In this era, official status far outweighs his age. What's more, he is one generation older than Chang Yao, so it is natural for him to be worshiped by his juniors.

When Chang Yao stood up, Hua Gao spoke first, patted the young man on the shoulder, and said with a smile: "He is a young scholar. He is good at studying. Don't fight like me and your father again."

Chang Yao handed over his hand again: "I would like to listen to the governor's teachings."

Then he turned slightly to Wu Zhen.

The deputy governor had no instruction, so he turned to the globe again. The deputy governor was still worried about whether he would fall!

So he looked at Zhu Yuan.

Zhu Yuan also smiled and said: "I am not in good health and don't have much energy to answer your questions. If you have any questions, you can always ask Dr. Liu. In the future, the court will pay more and more attention to these new learnings. Do you know better?

There are only benefits."

During the conversation, Zhu Yuan also roughly judged that Chang Yao should still be white.

I didn't mean to solicit.

Chang Jue could allow his son to take the initiative to come over to meet him, which was already a closer gesture, so there was no need to add any extraneous details.

Chang Yao respectfully agreed again.

Chang Duan next to him also breathed a sigh of relief.

These days, Chang Duan secretly took some knowledge such as "Basics of Mathematics" home and asked his son to study it, because he also felt the importance of these knowledge.

However, Chang Duan was a military commander, but like Hua Gao, he did not lack the necessary political acumen.

In this regard, the young man in front of him rose too fast, his foundation was unstable, and he was too favored by his superiors. As the saying goes, flowers blooming brocade, fire cooking oil, climbing too high in a short period of time was not a good thing.

On the other hand, he also knew about the events in Jinling and realized that there might be discord between the young man and Zuo Xiang. He did not want to get involved. Therefore, when the news came out that Zhu Yuan had become his direct superior, he immediately

He gave up the idea of ​​letting his son become an official through the recommendation of the left prime minister, so as not to make it difficult for Chang to be a good person.

It just so happens that one thing has become increasingly clear recently.

There will be imperial examinations this autumn.

It would be a better way for his son to enter the officialdom through the imperial examination.

Today I quietly brought my son, who has been having a lot of doubts lately, to attend the class. Chang Duan originally wanted to be vague about it.

However, it was Zhu Yuan's previous treatment of Liu Laoqi's family that made Chang Duan see the meticulousness and thoughtfulness of the young Hanlin. Hua Gao and Wu Zhen happened to be there, so he felt that there was no harm in letting his son show his face.

Zhu Yuan's reaction made Chang Duan even more relieved.

As a young Shangguan, he should be able to see that his son has no official position, but he did not recruit him during the current employment situation. Not only that, he also mentioned the importance of these new knowledge, and took the initiative to open the door for Chang Yao to learn knowledge.

If you have any doubts, you can ask Liu Lian. Obviously, you can understand his thoughts and avoid him getting into trouble.
Chapter completed!