The scene of thousands of ships going out to sea in turn lasted for a whole day.

By the time the last merchant ship departed, the setting sun was about to fall.

Li Zhi and others returned to Guangzhou City with the crowd.

It's going to be a lot more deserted for a while.

The sudden increase in goods allowed the foreign merchants to complete their tasks early.

They also left the city of Canton with the caravan.

Since Li Zhi still had to accompany Li Yuan in Guangzhou City, only Wang Qi and Chen Shuda accompanied him on the return trip.

As for Duan Lun, he had to go to the shipyards in various places to investigate.

Li Zhi accompanied Li Yuan to enjoy leisure time in Guangzhou City.

However, Li Shimin, who was in Chang'an City, was losing his temper in the court at this time.

Gao Changguo, who has always been attached to Datang, has been challenging Datang's bottom line one after another recently.

The cause is simple.

Because Gaochang Kingdom is the only way for the Tang Dynasty to trade with the countries of the Western Regions, the previous Gaochang Kingdom has always been able to enjoy the cake of Datang's foreign trade.

However, due to the arrogant personality of the king of Gaochang, the merchants of the Western Regions were always exploited when they crossed Gaochang.

Under such a premise, the Yanqi Kingdom next to Gaochang couldn't bear it in the first place.

So two years ago, they sent envoys to Datang to explain the situation, and hoped that Datang would help them open a trade route that did not need to go through Gaochangguo.

Now that all the countries in the Western Regions are subject countries of the Tang Dynasty, Li Shimin is naturally not easy to refuse.

So after weighing it, I agreed to the other party's request.

Gao Changguo was originally able to enjoy a big cake alone, but now he was robbed of a piece by his life, so he naturally didn't do it.

As a result, King Gaochang immediately launched a war against the Yanqi Kingdom and captured five cities.

It wasn't until Li Shimin made a statement to deter King Gaochang that he stopped the attack.

However, King Gaochang hated Li Shimin from then on, and he constantly stirred up the relationship between the countries of the Western Regions and the Tang Dynasty.

At the same time, these countries were prevented from paying tribute to the Great Donna.

When Li Shimin heard these things, he had already murderous intentions towards King Gaochang.

Unexpectedly, the king of Gaochang actually went to provoke the relationship between Xue Yantuo and the Tang Dynasty.

even relied on the fact that he had just formed an alliance with Desire Valley and threatened to use troops against Xue Yantuo.

How can our great Emperor Li Er endure this?

So he called all the civil and military officials and bluntly said that he must completely destroy Gao Changguo.

The generals below are all in good spirits at this time.

I only heard Wei Chi Jingde speak first: "Your Majesty, please let the humble man go and beat the old boy of Lu Wentai to death to vent his anger to the emperor." ”

Cheng Yanjin said: "Your Majesty, let the lowly post go!" ”

Hou Junji opened his mouth and said: "Your Majesty, the lowly post is familiar with the environment around Gaochang, so let the lowly post go!" ”

As a rising star, Su Lie couldn't be polite at this time.

I only heard him speak: "Your Majesty, the Dragoon Army has just been fully formed, how about letting the lowly lead the soldiers to train the soldiers?" ”

He Li also said at this time: "Your Majesty, Weichen is willing to go." ”

Li Shimin watched a group of generals under his command fight back and forth, and felt very satisfied.

It is very rare that these people, although they have all achieved fame, can still maintain such a high desire to fight.

The most important thing is that Gaochangguo is thousands of miles away from Chang'an, and you have to cross the desert along the way.

It is even more remarkable that these people can still talk about it so enthusiastically.

At this moment, Wei Zheng suddenly spoke: "Your Majesty, Gaochang Kingdom is far away from my Tang Dynasty, and we should send more soldiers and horses, and prepare a grain sketch to fight quickly." ”

When Su Lie heard this, he immediately came to his senses.

I only heard him speak: "Your Majesty, this battle is the most suitable for the Dragoons, Your Majesty only needs to prepare a little grain and grass for the ministers, and then you will be able to completely take down the Gaochang Kingdom." ”

Wei Chi Jingde said: "Your Majesty, the number of dragoons is too small to attack the city, so let the humble take people there!" ”

When the others heard this, they also opened their mouths to fight.

Li Shimin thought for a while and said: "This battle is not only to take Gaochang Kingdom but also to promote the prestige of our Tang Dynasty, so it must be resolved quickly."

Wei Chi Jingde, Cheng Zhijie, and Su Lie listened to the order. ”

Cheng Yanjin and the three of them stepped forward and bowed together.

Li Shimin opened his mouth and said: "Order the three of you to set off within ten days with 100,000 soldiers and horses, including the dragoons."

I will definitely take the Gaochang Kingdom to me. ”

Cheng Biting Jin and the three of them said: "The minister's decree!" ”

As the words of Cheng Yanjin and the three fell, a war against Gao Changguo began.

And a number of new weapons of Datang will also emerge in this war.

Li Su, who led the students to develop explosives, did not know at this time that with the start of this war, he would also usher in the first shining moment in his life.

At this time, he was studying acoustics and overcoming his fears to study electricity.

The new batch of books left by Li Zhi not only contains various knowledge of acoustics, but also some conjectures about the combination of sound and electricity.

These need to be studied and confirmed by Li Su himself.

Nowadays, Yan Lide and others have begun to try to use generators and electric motors as the power of some machinery.

At present, it is difficult to solve the problem of power stability.

Li Zhi can put forward some knowledge in the form of questions as their research topic.

However, it is not possible to make many things that cannot be achieved with existing technologies.

And he is usually too busy to have time to study with these people for a long time.

Therefore, a lot of things have become the homework left by Li Zhi to these people.

Let them learn and find solutions to their problems as they learn.

As long as the problem of electricity can be solved, Datang will officially enter the threshold of the second industrial revolution.

The steam engine, which is now widely used in textiles, mining, metallurgy and other fields, will soon be phased out.

For a long time to come, it is likely that only steam-powered trains and ships will be used.

And the steam train is what Yang Siqi is leading people to study now.

At this time, he was leading several students to build a model of a steam train based on the drawings left by Li Zhi not long ago.

Once the entire manufacturing process has been determined by building a model, they will start producing a prototype.

After the parts are machined, they are rigorously measured and then assembled.

If they find something that is not up to standard, they will immediately make changes.

Although there are drawings as a reference, it is difficult to guarantee that all parts can be successful at the first time.

The power of the steam engine as a machine is not very stable, so errors are inevitable.

Fortunately, this work is not in a hurry, and Yang Siqi and others have a lot of time to try slowly.

With the army attacking Gaochang Kingdom starting from Chang'an City, these people will all show their current value after this war.

All of them will go from being obscure to being truly important to the country.