Cao Cao looked at Guo Jia and couldn't help laughing: "The Son of Heaven once said Cao Cao, Cao Cao will arrive, I think we will change it in the future, if you want Cao Zhang, Cao Zhang will arrive!" ”

Guo Jia looked at Cao Cao and smiled: "It seems that Sikong still knows Ziwen Gongzi better." ”

Cao Cao instructed his subordinates, "Go and invite him in." ”

When the subordinates went out for a short time, they came with Cao Zhang and Ma Chao, and the two of them also held a few big paper rolls in their hands.

Cao Zhang respectfully saluted Cao Cao: "Meet my father!" ”

Ma Chao also stepped forward and saluted Cao Cao: "Meet Sikong!" ”

Then the two exchanged salutes with Guo Jia.

Cao Cao looked Ma Chao up and down, and asked Cao Zhang, "Ziwen, who is this?" ”

"He is Ma Chao Ma Mengqi, the eldest son of Yongzhou Thorn Shi Ma Teng, and he is also my sworn brother, I specially brought him to meet my father today!" Cao Zhang introduced Ma Chao to Cao Cao.

Cao Cao looked Ma Chao up and down, and praised repeatedly: "I have long heard that the son of Spur Shi is brave, and when I saw it today, he really looked dignified." ”

Ma Chao thanked Cao Cao: "Thank you Sikong for complimenting. ”

"Father, Brother Meng Qi made a great contribution in this campaign against Li Dao, so I specially applied to the Spur History to invite him to Xu Du as an official, and I can also help my father conquer the princes in the future. I took him to see his father today, and I also hoped that my father could arrange a proper position for Brother Meng Qi. ”

"Since Meng Qi is your sworn brother, it is most appropriate for him to follow you. As for the specific position, you think about it and tell me, I will go back to the table with Xun Lingjun, and ask the Son of Heaven for approval! Cao Cao nodded and agreed to Cao Zhang's request.

"Thank you, father!" "Xie Sikong!" Cao Zhang and Ma Chao thanked Cao Cao together.

Cao Cao looked at Cao Zhang and said with a smile: "Your sworn brother, you have already arranged your duties, tell me what is the purpose of your coming to see me." ”

"Father is wise, and the son really can't hide anything from you. It just so happened that Guo Junshi was also there, and I came here today to show my father a few new weapons that I thought of on the way back from Chang'an. ”

"New weapons?" Cao Cao's eyes lit up when he heard it, thinking that Cao Zhang really didn't disappoint him, and brought him another surprise.

"Yes, but it's just a prototype now, so I'll ask my father to look at it first." Cao Zhang said, unfolded the paper scroll in his hand, grabbed it with Ma Chao, and showed it to Cao Cao.

Cao Cao and Guo Jia stepped forward to watch the structure of a crossbow arrow presented on the drawing.

Both Cao Cao and Guo Jia showed great interest in the weapons drawn on the drawings. They carefully watched every detail.

Cao Zhang introduced them in detail: "This is the blueprint of the Divine Arm Bow, which can shoot farther and more accurate arrows, which is a huge advantage for our army. ”

The Divine Arm Bow is a crossbow arrow invented in the Northern Song Dynasty, with a range of more than 240 steps, far exceeding the range of any bow and arrow now, and is the standard weapon of crossbowmen in the Northern Song Dynasty army.

Through continuous memories and some of his own imagination, Cao Zhang tried to draw the design of the Divine Arm Bow.

Cao Cao's eyes flashed with excitement, and it was clear that he was looking forward to the potential of this new weapon.

Seeing that the two of them had finished reading it, Cao Zhang put away the drawings of the Divine Arm Bow and unfolded another drawing, this time painting a catapult.

Cao Zhang introduced: "I named this trebuchet a boulder cannon, and I added some devices when I designed it, which can better play the principle of lever counterweight, so that the thrown stone projectiles are larger and have a longer range, and if it is used in siege warfare, it can exert a greater killing effect." ”

Historically, it took up to six years for the Mongols to attack Xiangyang, and this new type of trebuchet played a major role on the battlefield, because his two inventors were Hui people from the Western Regions, so this weapon was named Hui Hui Cannon or Western Regions Cannon.

Cao Zhang once saw the photos of the return cannon in many documents, and he also tried to draw them.

Guo Jia looked at the "boulder cannon", his eyes widened in surprise, he knew very well that if this kind of catapult was put into battle, it would increase the chances of winning the city in the future.

Cao Cao's eyes also flashed with light, and he fell into deep thought.

Finally, Cao Zhang opened the third drawing, showing a large bed crossbow.

"This is one of my proudest achievements, the three-bow bed crossbow. He combined three large bows, which required thirty people to pull them apart, and could fire multiple arrows at the same time, with hard wood as the shaft and iron as the feather, which was extremely lethal and could deal with large-scale enemy attacks. ”

"And it can also be used for sieges, firing arrows directly into the walls of the city walls at close range, and our soldiers can climb up the ladder formed by the arrows." Cao Zhang said proudly.

What he took out was a weapon of mass destruction that appeared in the same Song Dynasty as the Divine Bow and Crossbow.

On the way back from Chang'an, he determined and carefully drew these three weapons after repeated scrutiny and research.

Cao Cao and Guo Jia were both attracted to these innovative designs, and they both saw how important these three weapons were to Cao's military strength.

Cao Zhang continued to say to Cao Cao: "Father, I want to apply to you to make these weapons and test them in the army. If we can succeed and put it into our army to form a certain number and scale, it will greatly enhance our combat effectiveness. ”

Cao Cao listened to Cao Zhang's words, but slowly reined in the excitement on his face, and turned into worry: "Although these weapons are powerful, they require a lot of resources and craftsmen to make and use, so they are not easy to do." ”

Guo Jia immediately understood what Cao Cao was thinking, and comforted him: "Sikong, are you worried that making these weapons will consume a lot of materials and money, right? I think the income from Cao Gong Paper and "Thousand Character Text" released in the past few months should be enough to support this experiment. ”

"The experiment was successful, and the funds needed to promote it in large quantities cannot be supported by just selling Cao Gong paper!" Cao Cao sighed softly, he was well aware of the power of these weapons, but without enough funds, no matter how good a weapon was, it would be difficult to exert its power.

"Father is very worried about it, and Erchen also thought that it would cost a lot of money to make these weapons, so he thought of several money-making plans to ask his father for approval!" Cao Zhang was prepared and immediately proposed his own solution.

Cao Cao and Guo Jia glanced at each other, and both of them had unconcealable smiles on their faces: Cao Zhang's work is always watertight, he can come up with a new weapon design plan, and at the same time, he can immediately solve the problem of funds, which is really a constant surprise for them!

"What's the way to make money, say it quickly!" Cao Cao couldn't help urging Cao Zhang......