But Zhao Kuangyi still didn't understand the importance of this instrument in Song Jiu's hand.

Guo Cheng sat down nervously.

Song Jiu asked: "Where are the two kings, Han Liu, Jin Sima, Sui Yang, and Tang Li?" ”

Among these surnames, although Yang of the Sui Dynasty is expensive, it is also a surname of Wang, the Sui Dynasty was too short, and Sima was not short in time, but the time of the Western Jin Dynasty was not long, and the Eastern Jin Dynasty Sima and the scholars ruled the country together, plus the compound surname, the influence is not far away. But the remaining two surnames, the influence is not low, the surname Liu is not necessarily the blood of Han and Liu, some Hu people have also changed to the surname Liu, and the surname Li is also the same, like Li Cunqiao, he is not a Han, but changed the Li family, and Li Tang is not the most expensive, the most expensive is Longxi Li and Zhaozhou Li, the five surnames and seven families and the Tang Dynasty have become a history, but the descendants scattered everywhere are still there. But it's too easy to find the descendants of these royal families. But whoever is looking for it, that's the real looking for a draw.

Zhao Kuangyi said: "Song Jiu, you have something to say." ”

"It matters," Song Jiu said.

Still starting from the sextant, Guo Cheng went to Lingnan and saw that the shadows were different, and he was thinking about one thing, the appearance of the compass, whether it was navigation or marching, came in handy, but it was still insufficient. For example, Kaifeng to Caizhou, almost southbound, and many plains, with a compass, open the road in the mountains, build bridges in the water, and will not lose your way to Caizhou. However, to the sea or to Qizhou, the theory of Qizhou is due south of Kaifeng, but the Dabie Mountain is separated, must be detoured, a few times around, is to know where the road is due south, if you don't ask the people no map and no guide, may not know where the army of Lu Road went.

Therefore, he wanted to invent a more advanced instrument from this shadow, which he could use to determine the direction. But this difficulty is too much, so I think about the movement of the earth, the angle of the sun.

Song Jiu only proposed the sun as a star, and did not say more, so the reference is still the sun. Guo Cheng thought about it. In the end, I came up with a way to use two mirrors, one is a fixed mirror that is transparent on one side and can be reflected on the other, and the other is a movable mirror that can be moved, and the projection of the sun is arranged in a straight line, so that the north and south of this position can be calculated by calculation, that is, the latitude.

However, in practice, the error is very large.

At one point, he was confused. When he was directly rotated, he returned to the capital and told Song Jiu about this idea.

Song Jiu is not very clear about the sextant, and the sextant in the previous life is also very complicated, but the relevant principles are a little known. Immediately find out the cause of the error, first of all, it can not be used on rainy days. Don't talk about the stars. Astronomy was not so mature in this era, and superstition was heavy. It doesn't matter if the reference object is the sun or not, does it rain every day?

The second is the time, which is most accurate in the afternoon, but the longitude is not scientifically understood at this time. For example, the noon in Mizhou is more than forty minutes earlier than the noon in Kaifeng, and this is nothing to do, compared to the hourglass, and the equipment in the actual workshop is studying the time. Although it didn't work out, the progress is not slow, and it may succeed next year. That is the bell, but Song Jiu didn't think of one thing, in the Song Dynasty, there was actually a primitive bell, which was studied by Su Song, just a hundred years later.

However, this clock is much more advanced than Su Song's, it is a real wall clock.

After Song Jiu pointed out some directions, he still handed it over to Guo Cheng for research and development, and also allocated some money as research and development capital, and named it Guo Chengyi.

After he finished speaking, Zhao Kuangyi was still puzzled.

Song Jiu said slowly: "Second king, I don't know much about other areas, but Jianghuai ships are berthed at the dock a lot, I occasionally talk to them, these years the country is peaceful, Jianghuai is rich, many families have two sons, three sons and four sons, these children will start a family in more than ten years." If it is about martial arts, I am afraid that our dynasty is not as good as the Tang Dynasty, but in terms of internal governance, the Tang Dynasty is far inferior to our dynasty. How many years did it take from Zhenguan to Tianbao, and the population quickly changed from two million households to more than nine million households. However, the territory of our dynasty is far inferior to that of the Tang Dynasty, and I have calculated that no matter how it is reclaimed, our dynasty will take back the Wu, Vietnam, Tang, and Northern Han dynasties, and the cultivated land will not exceed 9 million hectares. Orchards, vegetable gardens, mulberry, hemp and cotton, at least occupy nearly half. The remaining half of the land grain, if you do not compete for high-yield enclosure land, the yield of one mu of land is barely two stones, even if the competition is limited, the plan is to seed and cultivate the evolution, this half of the land grain will also deduct the miscellaneous grains used by livestock and poultry, the grain used in winemaking, how many people it feeds, 30 million households to the sky. ”

"Thirty million households, how is it possible?"

"Second king, I only say Tianbao, if there is no Anshi Rebellion, with the population of the Tang Dynasty increasing, how many years will it take to reach 30 million households. Moreover, because the Tang Dynasty was regulated by rents and yong, most of them were taxed on the basis of Dingkou, so the phenomenon of hidden households was heavier than that of our dynasty, saying that there were 9 million households, but in fact there were more than 15 million households. Besides, I'm heading. ”

Don't say that Song Jiu is confident in promoting the Song Dynasty.

In history, the Song Dynasty has reached more than 20 million households, and the cultivated land area is more than 5 million hectares when the Song Dynasty Zhenzong. However, because the Song Dynasty taxed the acres of land, and the hidden households also hid the fields, the actual amount was close to 7 million hectares at that time, and the Xining reform law reclaimed more cultivated land, which may be less than 3 million hectares in the household register, but may actually reach more than 8 million hectares. This is a terrible number, the Song Dynasty was at its peak when it was Tongguan Kaibian, reaching Xinjiang, and most of Qinghai, and also occupied a lot of Western Xia territory. The second is that not long after the Northern Han Dynasty was taken, Yinchuan and the North and South Hetao still had Song Dynasty garrisons, and there were garrisons, although they were mainly fetters, they could also be said to be the territory of the Song Dynasty. However, these two did not last long, and the real area was less than 3 million square kilometers. More than 8 million acres are almost 150,000 square kilometers, and the proportion of cultivated land development has reached more than 20 percent!

But this is the era of low production.

In fact, the phenomenon of annexation in the last years of the Northern Song Dynasty was serious, although many people were very rich, and a rich man in Shandong took out millions of dollars to do good deeds, exempting several states from arrears and all taxes paid in the year, but there was a serious inequality between the rich and the poor. Even if there was no southern invasion by the Jin, there was already the germ of a large-scale peasant uprising.

Can't raise so many people!

Maybe 30 million households is an astronomical number for Zhao Kuangyi, but it is not difficult to understand when comparing the population of Tianbao with the national policy.

"No wonder Wei Zheng said that it is more difficult to defend the country......"

"The second king, it's not difficult, it's just that our eyes have been staring at the country, staring at the past, and asking if the past is really so good? No. For example, Dayu controls the water, Yangzhou has not been developed, but it is the land of water, so it is the lowest in Kyushu. Yangzhou is full of war in our dynasty, that's it, who dares to list it as the lowest in Kyushu? ”

"Tell me, what's the connection with this little thing?"

Song Jiu continued to explain.

He knew a little bit about the sextant. But I didn't think about it at all. Guo Cheng was confused, but Song Jiu saw its meaning. Guo Cheng wanted to use it on land, and Song Jiu immediately thought of the sextant and the octant, but in fact it was a more backward octant.

Among the latitude and longitude, the first one you want to measure is time, and time is being studied in the workshop, not hourglass and water leak, this is the real clock. If the error is not large, the time of opening can be fixed, and the longitude is changing. The clock doesn't change. Then it is very easy to measure longitude, like Mizhou to Kaifeng through the shadow measurement of noon, and then look at the clock, immediately measure their different longitude, if you can measure the straight-line distance. Even from the difference between this length and longitude, the total length of this latitude can be roughly calculated.

The hard part is the latitude. Once Guo Chengyi's research is successful. Latitude is also not an issue.

First of all, there will be a drastic change in the cartograph, and the map will no longer be the sad and infuriating topographic map of the past.

The second is navigation.

Other voyages are not mentioned, everyone is very unfamiliar, but the Yanai people built these ships in the capital are well known, and more than 70 ships have been launched. Nearly three hundred voyages, the sea was too dangerous, two ships were sunk by wind and waves, this is the fleet. Some of them were rescued on the kind of raft that Song Jiu had made. Another ship was blown off course and disappeared. It's not one of them, the Gao family's boat has been blown to the mouth of the Qiantang River, the side sail is not good, the north wind is strong, only one day, and then sail west, to Hangzhou Bay. This is a compass, otherwise it will become Li Bai's friend of the Japanese country, and it can be blown to Guangzhou.

Whether the ship was blown to a strange place or sank is unknown, but it has never returned.

Blowing and sinking, helpless.

If it is blown to a strange place, it is also miserable, such as blowing to the island of Oceania, there is land and people, but can you ask those indigenous people wearing leaves, Harrow, fellow, where is this? Don't say that you don't understand, but they understand, and they know where the Tao is. I lost my bearings and didn't want to go home......

However, by measuring the longitude through the error of the clock and the length of the shadow, Guo Chengyi measured the latitude, that is, when he arrived in Antarctica, he measured the latitude and longitude, not too precise, and it could not be accurate, so he could find his way home. Since then, the vast sea will never again be an oversized labyrinth.

"Are you saying that if you succeed in researching the clock, and then have this Guo Chengyi, you can calculate the length of the earth?"

"Two kings, the latitude is not the meaning of the scriptures, the circle of the earth, the central latitude is not in our dynasty, it may be in the south of the city, the latitude calculated from our dynasty is not the length of the earth, only the length of longitude is about the same, but it is not easy to calculate. What can be calculated can only be the length of the latitude line where the capital is located, including Haizhou Longzhou, which is basically near this line, but it is certainly not the maximum latitude length of the earth, and it can only reach about half. If you add the error, the disparity is even greater. ”

"That's fine." Zhao Kuangyi is obviously interested, the boundlessness of heaven and earth is the concept of ancient and modern exchanges, and it is also good to be able to approximate the length of the earth now. After taking two steps, he asked again: "What does this have to do with population, Han, Liu, Tang and Li?" ”

"The ground is contained, that is, the load capacity on the ground is limited, the appearance of Guo Chengyi is conducive to navigation, and how much income navigation can bring to the country is not mentioned, but there is another advantage...... "Song Jiu found a pen and drew a map, did not draw North and South America, too far, only drew a map of Oceania and the South China Sea Islands, some countries and the Song Dynasty interacted, such as the Three Buddhas, these island countries began to have a preliminary civilization, and some were still very backward.

The South China Sea is difficult, like Mayi in the Philippines, which has received the light of China and has begun to have some civilizations, but even this civilization is still very backward. Song Jiu's meaning is that the population has increased to a certain point, and the tenant farmers who can't survive will be organized, and through some means of incentives, they will emigrate to the overseas islands, but there is no hurry now, but after the affairs of the Southern Tang and Northern Han Dynasty are settled, some bridgeheads can be organized overseas. Then select some children from the clan, as well as some descendants of meritorious heroes, and after large-scale immigration, govern overseas.

"No, is that still the people of the Song Dynasty?"

"Second king, the Tang Dynasty forbade the people to go abroad, and even did not allow them to go to the Bondage Land, where is Tang Li now? After the founding of the country, there were not many clans, but in the future, there will be more and more clans, how will the country be settled? Overseas, no matter how many people they have, they will not reach the number of China due to land restrictions, and besides, how can they threaten the Central Plains across the sea? It does not threaten the Central Plains, the branches are luxuriant, and those are the descendants of the Zhao family. Let me dare to say again, how long will I stand, and how about a thousand years? ”

Zhao Kuangyi was a little frustrated, Hugh said that in a thousand years, if there can be five hundred or six hundred years, it will be considered a long-lived dynasty.

Hooray, can you take it seriously.

"I'm not doing very well...... But fortunately, Zhou Gaomeng and Liu Chai are either here or not, and their descendants who are not there are still there, whether other dynasties can do it. But with the clan on the overseas side, no matter who it is, it has to be worried, and the clan will survive. This is one of them, there are many countries in this world, not my race, their hearts will be different, if the Han people migrate extensively, it is like the stars and the moon, guarding the country, guarding this civilization, since then, no matter what the country, there is more fire of civilization. ”

Zhao Kuangyi groaned.

But speaking of which, Song Jiu still values the significance of navigation, even if there is no southern invasion of the Jin people in the Northern Song Dynasty in the future, or under his leadership, it is enough to resist the southern invasion of the Jin people, and the population will inevitably explode to a terrible number. As for the stars and moons, don't count on them. The cohesion disappointed him too much.

Zhao Kuangyi thought for a while and said, "Take it with you, and we'll enter the palace." ”

"Entering the palace, I just came out of the palace."

"Then what's the matter, let's go into the palace again."

Zhao Kuangyi took them to the palace, Zhao Kuangyin was puzzled at first, Zhao Kuangyi explained: "Brother Huang, Liu Gang once castrated the two subordinates sent by Song Jiu and the Pan family to Guangzhou, and the Pan brothers have always hated it, so they sent Xiao Xiao to trick Liu Gang to gamble in Hezhou Shundian, owed a huge debt, and then extorted it, Liu Gang couldn't afford to repay, Pan Weide went up and beat him, Liu Gang's arms were discounted, and his subordinates went to Kaifeng Mansion to complain. I flogged Pan Weide fifty times, and was about to report to the imperial brother, how to deal with it, this kid came to intercede, and brought the student and this thing to bewitch me. ”

The eldest brother actually did this, and cold sweat broke out on Song Jiu's forehead.

Zhao Kuangyi continued: "Song Jiu, you re-explain. ”

Song Jiu had no choice but to repeat it one by one.

Zhao Kuangyi said: "Brother Huang, if he can do it, the younger brother is willing to be the first to go overseas and defend the Great Song Dynasty Jiangshan Sheji for the imperial brother." ”

can't take it seriously, but Song Jiu finally understood, and dared to say something unintentionally, which was used by Zhao Er as a gun to confess his heart. (To be continued......)