According to Li Ke's estimate, if all these factors are taken into account, the average sea speed of a large modern sailboat with a pointed bottom can reach a speed of at least 15 kilometers per hour, which is about 8 knots.
Calculated at this speed, if you follow the charts and travel directly in a straight line in some sea areas, you can reach the Persian Gulf in about one month to one and a half months!
According to the theory mentioned by Li Ke before, if the land can be controlled within one month from the imperial capital, and combined with the ocean, the land area that Datang can control is not small.
Li Ke raised his head again and looked at the map hanging on the wall. Li Shimin and Li Chengqian were a little confused. They were all looking at the map like Li Ke. They didn't know what he was looking at. If they were just looking at the ocean, this road was indeed Far enough.
"Dad, I need your authorization." After a long time, Li Ke suddenly said.
"Authorize what?" Li Shimin was a little surprised.
"As long as the three of us know about this matter, we can't let the courtiers know, or let them know the real purpose." Li Ke spoke in a serious tone.
Chang Lin: "..."
Qi Julang: "..."
Fortunately, Chang Lin had already driven away the young eunuchs with ease.
"You said it." Li Shimin didn't take it seriously.
"The matter of trade with Sassanid Persia can be carried out privately in the name of commerce. This matter should not be known to the outside world." Li Ke said simply, "Furthermore, we, the Tang Dynasty, want to vigorously develop the maritime industry, and All Tang Dynasty shipbuilding technology is strictly forbidden to be passed on to outsiders, and anyone who violates it will be punished by the Nine Tribes."
For the first time, very harsh words came out of Li Ke's mouth.
The expressions of Li Shimin and Li Chengqian became serious, and Chang Lin and Qi Julang were both numb. You must know that when Li Ke asked Li Shimin to give up his rights before, he never said anything about killing the Nine Tribes, but now Li Ke has said it.
"Your Majesty, Your Highness... How about we leave first?" Sitting there, he hesitated for a moment and then spoke.
"No, you need to record these, it will be useful later." Li Ke directly stopped Qi Julang's movements.
Qi Julang: "..."
What else could he say, other than to sit here honestly.
"Why do you say that?" Li Shimin asked.
"Dad, you know, the main material transportation between my Xizhou and Chang'an currently comes from the Yellow River Basin, and the ships in the river are very important, so I spent a lot of money to have my people improve the ships."
"Currently, two very good ships have been improved for inland river transportation, as well as more advanced sails, making the ship travel between Chang'an and Xizhou faster! From this aspect, it can be seen that river transportation is very important to The importance of the Tang Dynasty."
Li Ke clicked on the Sui and Tang Dynasty Grand Canal marked on the map. The Grand Canal dug by Li Ke’s grandfather was not the Beijing-Hangzhou Grand Canal in later generations. The Beijing-Hangzhou Grand Canal in later generations was built by several subsequent dynasties. Li Ke’s grandfather Sui Yang The Grand Canal dug by the emperor started from Chang'an along the Wei River to the Yellow River, and then went down the Yellow River to the lower reaches of Luoyang. It was divided into two parts in the lower reaches of Luoyang, with one heading north until Zhuojun and Fanyangjun in Youzhou (later Beijing).
The other one used the Chasm and Hanhan ditch to extend to Hangzhou in later generations, today's Qiantang County of the Tang Dynasty.
What is the gap? The chasm is the famous Chu-He-Han realm! The word chasm has since become an adjective. In fact, chasm is an artificial canal dug during the Spring and Autumn Period and the Warring States Period.
In fact, it was only after he came to this era that Li Ke could understand how wise the ancient Chinese people were. The shock that comes from the culture. The more he understood it, the more his scalp became numb.
Many things can be traced in history.
For example, the Zheng family in Xingyang! Why Xingyang? Instead of Nanyang, Pingyang, Anyang, etc.?
Because during the Spring and Autumn Period and the Warring States Period, the divide between Jishui, Ru River, Huai River, and Sishui was connected, and the Yellow River met at Xingyang! Xingyang has been an important river transportation artery from the north to the south of the artificial canal since the Spring and Autumn Period and the Warring States Period!
This is why it is the Zheng family of Xingyang!
Although the gap in later generations has long since changed, only part of the river section has been preserved for future generations to admire! But in this era, it played an extremely important role. According to the actual exploration of the Tang Dynasty and the information learned by Li Ke, Honggou calculated according to the data of later generations. The flat-bottomed boat can carry at least a thousand tons of ships!
There is no need for Li Ke to elaborate too much on how much supplies a thousand-ton wooden ship can haul. Of course, the Tang Dynasty could not build such a large wooden sailing ship.
"And shipping! It's equally important!" Li Ke took a deep breath and clicked on two places on the map.
One is the Southeast Asian peninsula in later generations, that is, Vietnam and other places.
"The land in this place is fertile and the climate is pleasant. Rice can be harvested three times a year. If we get some of the improved rice seeds from the Tang Dynasty, the food that can be produced here will be more than enough to feed the three Tang Dynasties."
"And these grains are extremely cheap locally. We can rely on convenient sea ships to transport them directly from this place, and then transport them to various parts of the Tang Dynasty through the Yangtze River or Yellow River, and then through canals." Li Ke kept talking about the water system of the entire map. Gestures.
The living man next to him was quickly recording Li Ke's words.
Li Shimin and Li Chengqian were both a little excited when they saw it. They naturally knew how valuable it was.
"The point is, these places admire our Tang Dynasty very much. For example, silk, cloth, porcelain, and tea from our Tang Dynasty can be sold here at a price that is at least four to five times more expensive than in the Tang Dynasty. And this price is only We can buy grain at one-third or even one-fifth of the price of Datang and transport it back to Datang. We, Datang, can completely solve the food problem." Li Ke first gave an example.
Other things besides that were not mentioned at all. There are many good things in Southeast Asia. The rubber and lacquer trees that are to be loaded later are relatively expensive things in the Tang Dynasty. In addition, there are dense quantities in these places. Chinese medicinal materials.
And in places like the Philippines... there's gold! A gold mine where gold nuggets can appear!
"This river." Li Ke drew on the map. This was the Mekong River in later generations. It was called Lancang River in China. "I named it Lancang River."
Li Ke domineeringly drew out the entire river and said, "If our Tang Dynasty solves the problems in Tubo, Nanzhao and other places, on this river, we will improve the Wanhu hU boat (Hu, the volume unit of the Tang Dynasty) ) into the river, and with the size of the river's drainage basin, we can control all the land on both sides of the river."
If converted to a Wanhu ship, it is about a modern ship with a displacement of 600 tons. This displacement was very abnormal in ancient times.
