After dinner, Chen Huaixiu invited the girls to come out and watch the stars.

Although, even in big cities in this era, there is not too much light pollution, and girls are accustomed to the starry sky. But the bright starlight fell on the surface of the sea, shining with infinite silver waves. This gorgeous and spectacular scene is the only one they have ever seen in their lives.

In March, the night breeze on the sea was only slightly cool, and there was finally no need to worry about getting sunburned, so several girls wrapped themselves in cloaks and enjoyed the beautiful scenery of the sea and sky on the deck, while smiling and saying their own words.

Even the eldest princess, who had not shown up since she got on the boat, came out of the cabin, leaned lazily on the recliner, and watched the stars in the sky blink while sipping wine, just like Zhao Lang's big eyes.

It's the third day of separation, miss him.

Zhao Hao is a smart person, and he knows that it is not a good idea to go to the girls or talk to his godmother at this time.

He would rather go to Zheng Ruozeng for advice on the use of the star board.

Seeing the two of them on the top deck, holding the plank and making a comparison, Zhang Xiaojing was very itchy. But she has been pestering Zhao Hao in the afternoon, how can she be embarrassed to get up again?

She had no choice but to withdraw her envious gaze and continue the topic of girls.

Xiao Zhuzi's eyes were looked at by Ma Xianglan on the side. Secretary Ma laughed secretly in his heart, he had just left Jiangnan, and Miss Zhang's mind was alive again.

It's not in vain that Sister Ma has been cheering her up for a while, Xiaozhuzi didn't give up, and finally adjusted her strategy and ushered in a turnaround.

In the opinion of the scheming Sister Ma, the Romance of the Three Kingdoms is naturally more durable than the struggle between Chu and Han. If you work hard and get a Warring States Seven Heroes out, then your life won't be too easy.

However, you also have to consider the ability of the childe to bear it. It's better to subtract one or less, and it's enough to make a Spring and Autumn Five Tyrant.

As for her, she is naturally a patriotic country that will never fight for hegemony and is harmless to humans and animals.

~~

"Ahh......h

Zheng Yiluan also put a cloak on his father.

"Don't worry." Zheng Ruozeng waved his hand, signaling him not to interfere with him. Then continue to demonstrate to Zhao Hao the use of the 'star board'.

A set of star-pulling boards is made up of twelve square ebony boards, the largest of which is about 24 centimeters long on the side, called 'twelve fingers'. Each piece is decremented by two centimeters, to the smallest piece that is two centimeters long, called a 'finger'. A rope about 72 centimeters long is threaded through the center of the plank, and it is very simple to make. Back then, Zheng He relied on it to measure the height of the stars and measure the direction.

Don't look at the appearance of this thing, but now the Ming Dynasty uses very little. Before, Zhao Hao inquired about Uncle Mi and Elder Niu Ma, and the three of them all knew about the existence of this thing. But it's useless to have a star-pulling board, it also needs to be used in conjunction with a star-pulling map, and none of them have ever seen a star-pulling map, so naturally they don't know how to pull the stars.

Zheng Ruozeng was also in Hu Zongxian's shogunate, under the pretext that he needed naval warfare to resist the Japanese, and only then did he find out a number of star-pulling maps from the cabinet library of the Southern Military Department, including the shipping route of the Yuan Dynasty's grain.

It was with these star maps that he was able to drive ships all over the sea areas of the Ming Dynasty and write the immortal thirteen volumes of the "Preparation of Sea Charts".

~~

"Astrology is actually quite simple." Zheng Ruozeng said as he looked up at the starry sky in the north, picked up the 'six fingers' board with his right hand, and straightened his right arm.

Then with your left hand, you can pick up the string that is threaded in the center of the plank and place it in front of your eyes.

"The eyes first look at the lower edge of the board, level the lower edge of the water, and then see if the upper edge of the board is level with Beichen." Saying that, he shook his head slightly and said, "It's wide, it's blocking Beichen." Change four fingers. ”

Zheng Yiluan hurriedly changed the 'four-fingered' board, and after repeating the above actions, Zheng Ruo saw the North Star appear on the edge of the board, and Fang said in a deep voice: "Beichen four fingers." ”

His second son hurriedly wrote down the new ship lamp...... After being able to blow the glass by yourself, this kind of portable and weatherproof kerosene lamp is not difficult to manufacture, but it still uses lamp oil as fuel. Especially the windy and rainy weather at sea is really a lighting weapon for the crew!

Zheng Ruozeng used the same method to observe the positions of Vega and Northwest Busi. He put on reading glasses and looked up a booklet, which was the 'Beiyang Star Atlas' that he copied from the Ministry of War.

Finally, he turned to the page he was looking for, and read slowly: "The black water is across the ocean, look at the four fingers of the North Star Flat Water, the East Vega Star has seven fingers of flat water, and the Northwest Busi Star has eleven and a half fingers. Childe, we didn't yaw. ”

Everyone breathed a sigh of relief when they heard this, this sea is boundless, and it is a far-sea voyage. Fifty boats are like a team of little ants, and no one can help but sweat, fearing that they will get lost in this vast sea, which is terrible.

Zhao Gongzi was not too worried, according to his shallow geographical knowledge, they had already entered the Kuroshio, that is, the range of the Japanese warm current.

Even if he gets lost, the most likely thing is that he was sent to Nagasaki, Japan, by the ocean current, just like Wang Zhi.

After listening to Mr. Kaiyang's explanation, Zhao Hao basically understood the principle of star pulling - in a word, the elevation angle of the North Star observed somewhere on the earth is the latitude of that place...... This is a very simple geometry proof question, and it does not need to be repeated.

In order to increase the accuracy, it is also supplemented by observations of other constellations. Voyagers can record the data observed during the voyage to obtain a star map. In this way, latecomers can use the data of their predecessors to determine their own position.

This is the same principle used by the octane and sextant that were born in Europe nearly 200 years later. It's just that the latter is more precise.

Zhao Hao asked Pei Peijia to try to make an octave first, and also ordered him to use the data of Nanjing Qintianjian to try to compile the original "Astronomical Almanac". However, now, even the basic map mapping is not standardized, and the concept of latitude and longitude has not even been introduced, so it is natural that it cannot be counted on in a short time.

No way, there are so many classes to take. You have to eat the rice one bite at a time.

However, Zheng He went to the Western Ocean seven times, all according to the astrological technique and the compass, and the total voyage was hundreds of thousands of miles without getting lost. So for a long time, astrology is completely trustworthy.

Mr. Kaiyang also told Zhao Hao that from this, the third watch of Danyou needle can go to Tamluo.

"When it's almost dawn, you can see the mountains on Tamna Island." Zheng Ruozeng said: "Tamna Island is also the most important reference on this route. As soon as you see it, you can turn to the northwest with a single decant needle, and you can see the mountain head of Weihaiwei after thirty watches. ”

~~

Early the next morning, Zhao Hao had something in his heart, and he didn't lie in bed for the first time. When the sky was still bright, he washed and dressed under the service of Secretary Ma, ran to the deck, and set up a telescope in the direction of the bow of the ship.

After admiring the magnificent sunrise over the sea, he spotted a black spot at sea level.

Looking through the binoculars, I saw that the island looked like a burial bag, with a bulge in the middle. Zhao Gongzi has watched "My Name is Jin Sanshun", and he recognized it at a glance as Tamna. As for the protrusion in the middle, it is the legendary barbecue mountain...... Oh no, Hallasan is over.

North Koreans believe that standing on this mountain can get the Milky Way, hence such an exaggerated name.

Tamna is the Jeju Island of the future. However, the name 'Jeju Island' was privately changed by Gojong of the Goryeo Dynasty, but whether it is Yuan or Ming, the fathers found it too troublesome to change the name, and still used the original old name.

Although Li Joseon, who is now the first licking dog in the Ming Dynasty, wanted to change his name several times, but his father was annoyed and disagreed. So the name Jeju Island, Li Chao can only call it behind closed doors, and when communicating with his father's country, he still has to obediently use 'Tamna'.

It's the same as 'okay, Vincy.'

Zheng Ruozeng also appeared beside Zhao Hao, looking at the Tamna Island visible to the naked eye, and said gloomily: "This island doesn't look big from a distance. But in fact, one hundred and fifty miles from east to west and sixty miles from north to south, there are two Kunshan counties as big. And it has been a good place to raise horses since ancient times. ”

Zhao Hao nodded, indicating understanding.

"Originally, Tamna was an independent country that paid tribute to me from the Tang Dynasty, and was later annexed by the King of Goryeo." Zheng Ruo looked at the verdant island fixedly, and said quietly: "Later, it was occupied by Meng Yuan as a place for raising horses and exiled prisoners. When Emperor Taizu expelled the Tartars, Goryeo took the opportunity to go to the "Tamna Meter" and asked for Tamna to be handed over to them, promising to pay tribute to the Ming Dynasty according to the management model of the Yuan Dynasty's horse herding. ”

"In order to get Emperor Taizu to agree, they used a trick to reduce the circumference of Tamna by a factor of ten, and the population by a factor of ten. Emperor Taizu thought that this was just a small land hanging overseas, and the island was still under the control of Meng Yuan at that time, so he generously gave it to them. ”

"A vassal of my vassals, not my vassals." Zhao Gongzi muttered. In addition to its superior natural conditions, Jeju Island also has an excellent geographical location, which is located at the sea of Daming, Korea and Japan, and is an excellent transit point for trade between China, North Korea and Japan.

Emperor Taizu is so shrewd, how can he let the stick take this place?

Oh yes, people's old vermilion plates are not allowed to go to the sea, what do you want to do on an island?

"But fortunately, the current Li Dynasty is ten times more deferential than the original Goryeo, and it is the goods that lick the ditch for Daming. We can go to this island as much as we want, what do we like, there is no law binding us in the Ming Dynasty. Zheng Ruozeng, who left the land, showed his wild side.

He is the number one supporter and advocate of Zhao Hao's maritime strategy, believing that only by defeating the enemy at sea can the security of the Ming Dynasty's maritime frontier be completely guaranteed. Only by crossing the sea and teaching Japan a hard lesson, beating them down, and letting them be like North Korea, calling Daming dad every day, can the glory of the Celestial Empire be restored!

And Tamna is the forward base that Zheng Ruozeng planned for Zhao Hao. Whether you use this as a business base, you can earn endless silver from the Japanese. It is also used as a future military base, and it is excellent to raise horses and invade Japan here.

"When we sail back, let's go to the island and take a look around, and then think about it in the long run." Zhao Gongzi smiled and comforted, Zheng Ruozeng, who was not waiting for me.

"There's nothing to worry about, it's just horizontal! The more you cross, the more comfortable they are. Zheng Ruozeng stretched out his hand and clenched his fists, as if he was holding Tamluo in his hand, and said, "What kind of bird has they managed in such a good place?" Let's just let it go! ”

ps. There is one more, but there are more than a thousand words, wait a minute.