"What do you mean?" Li Shimin asked, "What are you talking about?" ”

Xia Hongsheng shook his head and smiled bitterly: "My son-in-law told him that the earth under our feet, including the ocean, is on a circular sphere. If you start from one place and follow one direction without changing the same direction, you will eventually return to the place where you started. “

"This ...... I've heard from Qingque's mouth, it seems that the knowledge of geography is developed according to the theory of the heavens. Li Shimin thought for a while and said, "Could it be that we are really on a ball?" ”

"Well, it's like a spherical shape." Xia Hongsheng said: "If he can really do it, it will be excellent." The most important thing is that if he can really make a circumnavigation of the world, then he will definitely pass through the Americas, and maybe he can bring back the seeds of those high-yield crops from the Americas. Father-in-law, let's talk about the current situation first. The son-in-law felt that this was a good opportunity for Datang to make a move on Tianzhu. If Tianzhu is occupied, it will also be beneficial for controlling the Persian region in the future. After all, Tianzhu is not far from Persia. ”

"Tianzhu ......" Li Shimin frowned and thought: "An opportunity is an opportunity, Nibora helped Tubo fight against the Tang Dynasty, and the Tang Dynasty used troops against it, which is logical." Datang has nothing to do with Tianzhu, but it took the initiative to help Nibora to make a move against Datang, and it was also in line with God's will for Datang to fight back. It's just that...... The Tang Dynasty is now planning the Western Regions, as well as Persia and Great Food. Tianzhu has no impact on Datang for the time being. Attacking Tianzhu is not a trivial matter, and with so many lines to be carried out at the same time, I don't have the manpower to manage it, and I'm afraid that Datang won't have so much energy for the time being. ”

"Your Majesty, Tianzhu is actually easier to manage than Liaodong and Dongying." Xia Hongsheng thought for a while and said to Li Shimin: "Your Majesty doesn't know much about Tianzhu, Tianzhu implements a caste system, dividing people into four levels. The first class of Brahmins, mainly monks and aristocrats, had the privilege of interpreting religious scriptures and worshipping gods, as well as the right to enjoy voting, the main education, the audience Kshatriyas, who were responsible for monopolizing cultural education and reporting on the agricultural seasons and the right to interpret religious discourse; The second estate, the Kshatriyas, were the military and administrative aristocracy, the audience of Brahmin thought, who had the privilege of collecting all kinds of taxes, presided over the army, and were responsible for guarding the Brahmin class for the next generation; The third estate, the Vaishyas, were ordinary people, politically privileged, and had to provide for the first two ranks, the main business, in the form of alms and taxes; The fourth estate, the Shudras, who were overwhelmingly subjugated indigenous populations and consisted of servants and artisans, were the most populous castes and were considered the lowest. The four levels are very strict and must not be crossed. The more severe the oppression, the more intense the resistance will be once there is an opportunity to resist. As long as the Tang Dynasty breaks this strict caste system and gives support to the common people and lower-class slaves, it doesn't take too much, so that they can live a self-sufficient life just like our people in the Tang Dynasty, which is enough to trigger their rebellion against the first two castes and support the Tang Dynasty's rule over Tianzhu. In addition, Tianzhu is backward and not unified, and there is no obvious concept of the country, Your Majesty can let them get more benefits, can let them live and work in peace and contentment, they will definitely fully support Your Majesty, but it is easy to manage. ”

Li Shimin listened, bowed his head in contemplation, and was silent.

Xia Hongsheng saw that Li Shimin did not express his position, so he said: "Father-in-law, Tianzhu has an area of more than two million square kilometers, of which forty percent are plains that can be cultivated, and the plateaus and mountains up and down are rarely more than one thousand meters. It has unique natural conditions! ”

"Tropical monsoon climate? Alluvium? Tropical black soil? Li Shimin was confused.

"Uh......" Xia Hongsheng was speechless for a while. Why is it so difficult to communicate? Li Lao Er, you are lagging behind, if you change to the three brothers of the Li family, or even if it is Li Su and a few of them, you can understand this!

"It's all geography." Xia Hongsheng scratched his head: "I can't tell for a while, father-in-law, you just need to know that Tianzhu is the coldest time of the year, and it is equivalent to the temperature in early summer in our Central Plains." With such a temperature, you can cultivate and harvest all year round, and Champa rice can be harvested all year round! And the terrain is not high, it is very convenient to open up the field, plus the soil there is fertile, the arable land area plus the fertility of the land, the overall cultivation conditions are not much more than that of Liaodong, because the four seasons are like summer, and even more than that! If Tianzhu is occupied and agriculture is developed, Datang may really not have to worry about the lack of food anymore! If there is Tianzhu, then what is Linyi Dao, it is just a field equivalent to Tianzhu Dao! ”

Sure enough, after listening to Xia Hongsheng's words, Li Shimin raised his head suddenly, his eyes lit up, and he looked at Xia Hongsheng with a flash: "What the virtuous son-in-law said is true?" ”

"It really can't be more real." Xia Hongsheng nodded, pointed to the map and said, "Father-in-law, at this stage, for Datang, the usefulness of a Tianzhu is far greater than that of Australia. If Tianzhu returns to the Tang Dynasty, then the Indochina Peninsula is sandwiched between Tianzhu and Linyi Dao, and they are all barbarians, and the merger into the Tang Dynasty is also a matter of blink of an eye. When the time comes, the Tang Dynasty will play a role in the entire land from Linyi Road to Tianzhu, father-in-law, don't forget, in this piece of land, Zhancheng rice is at least three crops a year! In addition, Malacca at the southern end has also been returned to Datang. At that time, the maritime merchants of Datang set off from Guangzhou to the Persian Gulf, and the places they passed along the route were all within the territory of Datang! ”

Li Shimin's eyes lit up, like a tiger that had been hungry for a few days and finally met its prey, and kept looking between Tianzhu and Linyi Dao.

After a while, Li Shimin swallowed a mouthful of saliva, his throat moved, and his fingers stabbed from Linyi Road to Tianzhu: "Virtuous son-in-law, you said that in this piece of land, Zhancheng rice can be harvested at least three times a year!" ”

Xia Hongsheng nodded: "This is just farming, in this land, there are all kinds of precious mineral deposits, as well as countless forests that can make the best sea boats." ”

"Datang granary!" Li Shimin squeezed out four words from his mouth word by word, then smashed his fist on the map, closed his eyes, and took a few quick breaths.

When Li Shimin's eyes opened, there was only calm in his eyes.

"Someone!" Li Shimin shouted softly.

"Everyone!" Wang De immediately pushed the door in and bowed.

"Pass on the officials of the three provinces and the Ministry of War, enter the palace immediately!" Li Shimin said in a deep voice: "There is also the king of Hejian County." ”