Chapter 37

Listen to the Yellow River! Li You sighed inwardly. The grand palaces of the Han and Tang dynasties had not yet been built, and the mountains of Longxi were still lush with towering trees, untouched by soil erosion. The Yellow River should still be clear, right? How I wish I could see this beauty that future generations will never be able to appreciate!

"General Ziyun! How did you discover the Xiongnu's weakness and come up with such a brilliant strategy?" The Han envoy continued on their journey, and Li You couldn't help but approach Chen Qingzhi to ask about his tactical thinking.

"I can't really explain it clearly!" Chen Qingzhi scratched his head in frustration. "After hearing the Xiongnu's strategy from my lord and the description of the ambush site from the deputy Tang Yifu, I had a vague feeling that this method would work! However, if it weren't for my lord having a mighty general like Pan Feng, my strategy wouldn't have been possible! General Pan Feng's bravery and strength are extraordinary; even compared to Yang Dayan of the Northern Wei, he would not be outmatched!"

Yang Dayan was a famous general during the reigns of Emperor Xiaowen and Emperor Xuanwu of the Northern Wei. He was called Yang Dayan because of his large eyes. Yang Dayan was known for his running speed and martial prowess. According to the *Book of Wei*, even if a three-zhang-long cloth was tied to his hair and he ran forward, the cloth would remain straight behind him without touching the ground. Throughout Chinese history, only a few generals like Mai Tieshuang could match him in this aspect!

Moreover, Yang Dayan was praised for his bravery, being called a "match for ten thousand men" like Guan Yu and Zhang Fei. When Chen Qingzhi was just starting his career, he followed Wei Rui in the Battle of Zhongli and faced off against the Northern Wei's Prince of Zhongshan, Yuan Ying, and Yang Dayan. The latter's exceptional martial skills left a deep impression on Chen Qingzhi. Now, by comparing Pan Feng to Yang Dayan, he was giving him the highest praise.

Since Yang Dayan was compared to Guan Yu and Zhang Fei, Pan Feng's martial skills must still be far behind them, right? He probably isn't as good as Yang Dayan?

Hearing Chen Qingzhi say this, Li You sighed. It seems that Chen Qingzhi's talent is innate and can't be learned. My hope of learning military strategy from him is probably slim!

Historical records also mention that Chen Qingzhi, in his youth, served as a personal attendant to Emperor Wu of Liang, Xiao Yan. One day, when Xiao Yan was bored, he asked Chen Qingzhi to play Go with him. Go, like military strategy, is a game where beginners rarely defeat experienced players. At just thirteen years old, Chen Qingzhi was no match for Xiao Yan. However, Xiao Yan made a mistake out of carelessness.

Chen Qingzhi immediately placed his stone in the only spot that could reverse the game's outcome! Xiao Yan was greatly surprised and immediately called for the old Go masters in his household to play against Chen Qingzhi. To his surprise, whenever the old masters made no mistakes, Chen Qingzhi would inevitably lose; but whenever they made a mistake, Chen Qingzhi would always seize the opportunity.

It seems this child has a natural talent for seeing the only path to victory in complex situations! Thus, Xiao Yan opened his private library to Chen Qingzhi, allowing him to study military strategy. When Chen Qingzhi came of age, Xiao Yan, despite his non-aristocratic background, entrusted him with important tasks. Chen Qingzhi did not disappoint, repaying his lord with one miraculous victory after another!

As Li You was lost in thought, Chen Qingzhi spoke again, "However, over the years of warfare, I have gained some insights. If my lord does not mind, I can share them with you after we set up camp!"

"That would be greatly appreciated, General Ziyun!" Seeing a glimmer of hope, Li You was overjoyed. "I will be waiting for you tonight!"

"Um, it seems that won't work tonight!" Li You seemed to remember something and said helplessly, "Today, I need to draw the maps of our journey over the past two days. I probably won't be able to seek your guidance until we cross the Yellow River!"

"Oh? My lord can also draw maps?" As a famous general, Chen Qingzhi naturally understood the importance of maps. Hearing that Li You had this skill, he became very interested.

"If you don't mind, perhaps you could help me with it later!" Li You thought, "At least I still remember some of my high school geography. In this era, I might be the only one who knows how to draw maps!" Li You finally found a sense of superiority as a time traveler in front of Chen Qingzhi.

At sunset, the envoy stopped advancing. Li You gathered everyone to record their contributions on the battlefield and announced that he would report their achievements to the emperor upon their return to Chang'an and request rewards for them. He then ordered Tang Yifu to arrange a feast to boost morale. The envoy's spirits were lifted! Afterward, he handed the arrangements for the night watch and the celebration to Tang Yifu and returned to his tent to prepare the map.

"Clear rewards and punishments, my lord truly understands the essence of leading an army!" Chen Qingzhi and Pan Feng followed him. Chen Qingzhi was curious about his mapping method, while Pan Feng was there to protect his safety.

Giving Pan Feng a jar of wine and serving tea to Chen Qingzhi, Li You crouched over the table, holding a brush, and began drawing the map on parchment! Since Cai Lun would not be born for another two hundred years, and silk was too fragile and bamboo too cumbersome, parchment became the best choice for drawing maps.

Li You first drew a compass in the upper corner of the map and then marked a scale in the lower right corner! These two methods amazed Chen Qingzhi, who exclaimed, "My lord's method is excellent!"

In ancient China, there were generally three methods for drawing maps: using mountains and rivers as a reference, using travel routes (waterways, roads, sea routes, etc.) as a reference, and using objective scales. None of these methods were mature during the Han dynasty or the Northern and Southern Dynasties.

There was no standard layout of north at the top, south at the bottom, west on the left, and east on the right, nor the concept of a scale! If someone unfamiliar with the area were to receive such a map, they would likely be completely lost. They wouldn't be able to extract useful information from the simplified drawings!

Moreover, the scales on these maps were extremely inconsistent. Some places that were hundreds of miles apart were only a few centimeters apart on the map, while others that were just a few miles apart were separated by a foot or more! As for the width of rivers and the height of mountains, it was even worse! Anyone who dared to march based on such a map would likely end up lost and face the same fate as the Flying General, who committed suicide after getting lost and missing the deadline!

With a scale, the general leading the army could obtain more precise distances through measurement. Although the data Li You drew and estimated by hand still had some discrepancies with the actual distances, it was much better than those primitive maps!

After completing this, he began drawing the map using the contour line method pioneered by Dupain in France in 1791. Seeing this, Chen Qingzhi couldn't help but exclaim, "Hmm, I seem to have seen such a map before!"