Late Tang Dynasty: I

Chapter 371 Global Voyage
His Majesty the Emperor's thoughts affected the development of all walks of life in the Tang Dynasty all the time.

For example, looms and spinning machines have been updated several times in the past ten years, and the efficiency of weaving has also increased several times compared to the first generation.

For example, in iron smelting, the craftsmen of the Tang Dynasty invented a blast furnace that could be continuously filled to continuously smelt pig iron.

Unfortunately, there is no scientific chemical theory to guide, and the amount of filler depends entirely on experience. Sometimes good iron or even good steel can be smelted, but if you change the iron ore, all you will get is waste residue.

In addition, the temperature of the molten iron also depends on experience, and whether you can refine it well depends on luck.

But the progress is visible to the naked eye.

The changes in sailing ships are even more significant. Most of the ships in the Tang Dynasty were manufactured in the original Jingnan, under the supervision of Chengru.

His Majesty the Emperor wants to build the ship narrower and with a deeper bottom. When going to sea, ballast stones will be used. The sails will also change from square sails to triangular sails. The masts will be larger in the middle and smaller at the ends. There will be three masts, one big and two big. The small three-sided triangle sail, coupled with the cooperation of the helmsman, could actually use a "zig-zag" sailing method to sail against the wind, which directly exceeded the Tang people's knowledge.

Although it is conceivable that a sailboat can travel against the wind, this directly unlocks the shackles of sailing.

In the past, when sailing, a large ship would have to be equipped with dozens of sailors rocking the oars, but now there is no need for that.

As for adjusting the direction of the sail, how to steer, and how to make the ship travel faster, it was not something Li Ye could do. There were too many skilled craftsmen in the Tang Dynasty.

His Majesty the Emperor issued an edict ten years ago that those who can advance technology in all walks of life, whether it is shipbuilding, navigation technology, textiles, or iron-making, will not only receive generous rewards, but also be granted titles.

By now, the number of skilled craftsmen who have been knighted can be counted on one hand.

But Li Ye was still not satisfied.

A positioning technology stumped the emperor.

On the Khitan grassland, without a guide, the army was like a blind man. The vast grassland did not know how to move.

At sea, it's even more serious. The shortest distance to Japan is only a thousand miles. But even with such a distance, sailing to Japan depends not only on experience, but also on luck.

"Angle, angle!"

"Assuming that the position of the Emperor Star never changes, can we determine the position by measuring the angle of the North Star?"

Liu Wei's mathematics level has improved a lot, and Li Ye can already discuss some problems with him.

His Majesty the Emperor divided the right angle into ninety equal parts and determined it to be ninety degrees.

The north-south directions are called longitudes, and the east-west directions are called latitudes. Positions are determined using longitude and latitude lines.

The Emperor Star, namely Ziwei Star and Polaris, is almost aligned with the axis of rotation of the Earth, so from the northern hemisphere, Polaris is almost motionless.

This is easy to do. Observe Polaris from the point where a person is standing, and measure the angle between the observation direction and the ground plane. Isn't that the latitude?
At the North Pole, the North Star is directly overhead and the latitude is ninety degrees.

As for longitude, that would be more troublesome. There was no precise timer in the Tang Dynasty. It would be much simpler if there was a clock. For example, Chang'an in the Tang Dynasty was set as zero, noon was zero o'clock, and a day was set as 24 hours.

It's eight o'clock at noon where you are. Just divide three hundred and six by 24 and multiply by eight.

But the premise for this theory is that the earth is round.

At this time, people still thought that the sky was round and the earth was round.

Liu Wei has always been with the emperor. Li Ye told Liu Wei many of his ideas and listened to Liu Wei's ideas.

"Your Majesty, if the earth is round and sailing along the same latitude, if you can circle the earth, wouldn't it prove that the earth is round?"

"That's right!" His Majesty the Emperor woke up from a dream. He didn't need to know the specific longitude and latitude. As long as he knew the latitude, he could walk in one direction. If he walked to the end, wouldn't he be able to circle the earth?
Measuring latitude is not difficult, as long as you have eyes. Polaris is still easy to identify in the northern hemisphere.

As for navigation technology, the use of three-masted triangle sails can travel against the wind, what else can be restricted!
"Actually, there is another way to prove that the earth is round. That is to go all the way south. You will find that the North Star is getting shorter and shorter. Until you reach the equator, you will find that you can no longer see the North Star." "Your Majesty, I also think so. It makes sense. There are also solar and lunar eclipses. I also feel something is wrong. This solar eclipse is probably because the sun's light is blocked by the moon. And this time the dog eclipses the moon, I think it is probably because the earth blocks the sun's light and the shadow of the earth is illuminated. !”

His Majesty the Emperor was very happy and said to Liu Wei: "My dear, you understand!"

"I polished thousands of crystals in Bianjing, and finally got some results. When I get to Bianjing, I will surprise you."

"..."

…………

Wang Yanzhang's army entered the sea at Jinmen. The army went north along the coastline until it reached the mouth of the Yalu River. It was still two hundred miles away from the Han River.

"General, look!"

Wang Yanzhang saw two to three hundred sailing ships coming densely in front of him.

"Is he a naval engineer from Silla?"

Vice Admiral Du Jing shook his head and said: "According to the information provided by Yushan Guard, Silla's navy only has a hundred ships, and most of them are flat-bottomed boats on inland rivers!"

"Whose ship is that?"

"It can't be a Japanese ship, right? Has the King of Silla called for reinforcements?"

"possible!"

During the Han Dynasty, Emperor Wu of the Han Dynasty gave the Japanese King's Seal to the Japanese Kingdom. This saying continued until the Tang Dynasty.

The Japanese state has always sent envoys to the Tang Dynasty. Starting from Xuanzong, the Tang Dynasty has always recognized the Japanese state as a vassal state of the Tang Dynasty.

The military order Wang Yanzhang received was to blockade the Han River, not to declare war on Japan.

Army Commander Ma Ran Yuanhui said: "Let Zhu Youwu go and take a look. If they are Japanese ships, let them go back!"

"Alright!"

A light sailing ship sailed quickly towards the fleet on the opposite side. Before Wang Yanzhang could wait for the news, he saw several Japanese ships approaching. They surrounded Zhu Youwu's ship and beat him up. The Japanese soldiers fired their lit arrows. To Zhu Youwu's ship.

After a while, thick smoke billowed from Zhu Youwu's ship. You could see that the Japanese ship was using its iron claws to move the ship close to Zhu Youwu's ship. You could see that the Japanese soldiers were jumping onto the Tang ship one by one. The two armies were in close combat.

"How dare a mere Japanese pirate do this!" Wang Yanzhang sneered and said to Army Sima Ran Yuanhui: "Ran Sima, the military regulations of the army are that anyone who dares to attack the Tang army will be regarded as a traitor, and the general can suppress the thieves!"

Ran Yuanhui did not expect that the Japanese would be so bold and dare to fight directly without saying anything.

"Please general, please let these Japanese dogs see the military might of the Tang Dynasty!"

"Where is the flag bearer!"

"Humble!"

"Command the entire army to fight!"

"promise!"

The flag on Wang Yanzhang's flagship was waving, and all ships in the fleet turned their masts, sails, and rudders to adjust their direction.

The army rushed directly towards the Japanese fleet.

(End of this chapter)