Chapter 458 (1/2)

Li Hong looked at Long Ma's treasure. He continued to cram for his map and carefully smoothed the folds on it. His heart was filled with respect and admiration for the empress of this generation in history.

He knew better than anyone that such a map appeared in Wu Mei's eyes, how shocked she was.

After all, the maps of this period were all based on mountains and rivers. County maps and city maps first drew the center of the city, then drew the mountains, rivers and other places in the jurisdiction according to the general orientation of the city center, and finally filled the nearby villages and other places to the corresponding foot of mountains and rivers A regional map.

This kind of map drawing depends on the cartographer with simple directional equipment and simple ranging equipment step by step. Due to the lack of positioning technology and the lack of coordinate system such as longitude and latitude, the error of the map drawn will increase with the increase of the map, and the area is not proportional to the area, so people can only follow the Walking on the map is like being led forward. If not, you will lose your way and don't know where you are.

As for the military map, it is more important than military map in this area.

As for the current waterway map, with the increasing importance of the Sui and Tang canals in this period, the map of waterway drawn by the people of Tang Dynasty is that the drafter stands at the bow of the boat, first draws Luoyang at this end, and then along with the progress of the ship, the drafters draw down the cities, mountains and rivers along the line one by one. After arriving in Hangzhou, they draw Hangzhou at the end of the map State, then this waterway map came into being.

This kind of map has no practical reference function at all. It is just like a cartographer drawing what he has seen and heard after playing around.

There is no direction and proportion to speak of. If you are in a good mood, you should paint this place better. If you are not in a good mood, you should draw a few strokes of this place. The map it makes is more like an artistic painting than a professional map.

When Li Hong was ten years old, he once incited Li Chunfeng. The astronomical telescope made for Li Chunfeng at that time made him crazy for a year. He had to rely on the telescope for food and accommodation every day.

At the same time, the students of hongwenguan began to use the ”plan Li plan Fang” and the ”six body drawing” made by Pei Xiu of Jin Dynasty, and began to redraw the map of Chang'an city. Only when the real coordinate system and the accuracy of longitude and latitude were missing, and the problem of the curvature of the earth was not taken into account, or did not know it at all, for a long time, The map of Chang'an has been drawn.

It's just that the map, in addition to the imperial city and other places nearby, is more accurate, and other places are no longer accurate.

What's more, in the process of drawing, they found that the more outward the map was, the more distorted it was. Even as if it had been pulled away from it, it became distorted and could not draw a satisfied map.

Fortunately, the students of hongwenguan didn't feel discouraged because of this. Looking at the prince's disdain, these people began to plunge into it. It is said that Dayu left behind the ”rope on the left, the rule on the right, four seasons, to open Jiuzhou, tongjiudao, beijiuze, dujiushan”.

Some books, such as Zhoubi Suan Jing and Jiu Zhang Suan Shu, were borrowed from Guozijian by hongwenguan's students. Shangguanyi of that time repeatedly told them that it was OK to borrow them, but they should not be damaged.

If you plunge in, you are bound to let the prince's Royal Highness look at them in a different way. They are just nodding and saying that they are like wolves. In their minds, they only have how to draw a perfect map, and how can they have the mind to put shangguanyi's advice in mind.

But fortunately, when shangguanyi saw those books again, she was very relieved. Fortunately, there was nothing damaged. There was only one book, which was obviously written in the handwriting of his Highness the prince, with four words: ”a group of idiots!”

When the students of Hongwen school, one by one, looked like defeated cocks, hung their heads and saw Li Hong, they saw a round wooden ball in front of his royal highness.

Some of the words on it were handed to those who did not understand it, such as ”Gao Yi”, ”those who didn't understand it”, ”those who didn't understand it, handed it to someone who didn't understand it”, ”and handed it to someone who didn't understand it.

After that, Li Hong personally selected more than a dozen Hongwen school students from these observation days, and asked them to take the paper and the wooden ball to find Li Chunfeng, and agreed that within ten years, if we could understand thoroughly and draw a satisfactory map, everyone would be given the title of official of the Tang Dynasty!

The students were naturally overjoyed by this promise, but when they heard what the prince said ten years later, everyone realized that this matter of mapping was not as simple as it had been since the time of their research.

When they came to Taiyi mountain with paper and the wooden ball in their arms, Li Chunfeng watched for a long time, but did not understand.Yuan Tiangang looked around with the ball and joked with the students: ”who painted it? What is this? ”