Zhao Yu wanted to use the rare opportunity to persuade Jiang Wanzai to let him assist him in completing his plan, but when he found out that he hesitated, he gave up, he didn't want to take this risk, because once the plan was leaked, he would have no room for maneuver. And he had to quit halfway, the superweapon he designed has entered the final assembly stage, and if all goes well, it will be able to test launch tonight.

"Your Highness, how to tighten the bowstring of this crossbow, the lower official really can't think of it." As soon as Zhao Yu entered the garden, Zhou Xiang greeted him and said softly with a bitter face.

"Well, this is not difficult, I'll take a look first." Zhao Yu nodded. As he spoke, he walked quickly to the construction site, where more than a dozen craftsmen were gathered, and they were quietly talking about the bed crossbow standing in the clearing, because this bed crossbow was very different from anything they had seen before, and when they saw that the prince had arrived, they quickly got out of the way.

"That's good!" Zhao Hao tilted his head and looked at the big guy in front of him, and couldn't help but sigh.

"Your Highness, this crossbow has never even been seen by our old craftsmen who have been in the ordnance prison for several generations, and I really can't think of how to place this crossbow arm and Zhang Xian, so I can only ask Your Highness for guidance." Zhou Xiang was relieved to see that His Royal Highness was still satisfied, at least he didn't have to worry about manufacturing problems.

"Well, I'll take a look first." Zhao Hao said casually, secretly happy in his heart that this bed crossbow is not the other bed crossbow, not to mention that they have not seen it, and it is the first time he has seen a real object other than the picture, but whether he can do it or not is not at the bottom of his heart.

In fact, the correct name of the big guy who is six or seven feet tall in front of him is called a ballista, a serious eight-book foreign product, and it has been lost hundreds of years ago. These two things have a crossbow word, but the firing principle is different, and the power is naturally not the same, and the ballista can be said to be the pinnacle of projectile weapons in the era of cold weapons.

In the fourth century B.C., Western craftsmen found that with the development of armor and fortifications, the usefulness of individual bows and crossbows was correspondingly weakened, and they were unable to penetrate bronze shields, and certainly could not destroy masonry bunkers. Although attempts have been made to make huge crossbows, the firing power generated by the elastic deformation of the crossbow arms is close to the limit, and it is impossible to give more power to the arrows or projectiles. For the first time, the ballista invented by the craftsmen of Dionysus used the latest achievement in mechanical research, the torsion spring, that is, the torsion generated by two bundles of tensioned horsehair, leather rope or animal tendons as the power, driving the crossbow arm to drive the bowstring to throw projectiles or arrows.

The Greeks designed the ballista with a sturdy bracket on which the main beam rested on the bracket and two torsion spring sets on either side of the front end, each of which drove a crossbow arm with a bowstring attached to the center of which was a woven mesh bag for the projectile. There is a long dovetail groove on the upper side of the beam, a slider with a long guide rail can slide back and forth along the long groove, and the rear end of the slider is equipped with a set of delicate firing mechanism, which can easily lock and release the bowstring, and different grooves can be set to determine whether the stone bullet and long arrow are fired.

A winch is installed at the end of the beam, which can be moved by the user by pulling the handle or by dragging the rope. When the bowstring is pulled back and fixed by the firing mechanism, the weapon is in a state of readiness. In order to make it less laborious to operate the winch, metal racks are arranged on both sides of the beam, which not only allows the work of opening the bow in one go, but also ensures that the chute can stop at any point between the starting point of the stroke and the full tension point of the crossbow string, and through this setting, the projectile power of the weapon is adjusted to obtain the required range.

The ballista has great power, and the ballista with good performance can throw a stone projectile weighing more than 50 catties 300 meters away. The six-pound spherical stone was ejected four or five hundred meters away. In order to give the ballista a flexible orientation and elevation angle, the ballista was also designed with a base that could be rotated freely. In addition to this, the ballista is equipped with improvised sights, but its accuracy is also breathtaking, and it can even hit the same spot repeatedly, and there have been records of ballistas firing spears that have already hit in two pieces.

At that time, if the Chinese bed crossbow wanted to achieve the same power, the crossbow arm length should be more than two meters, and it was necessary to strengthen multiple bow arms, ranging from two bows to four bows. This requires increasing the number of people operating the winch shaft, five to seven people for small ones, and more than 100 people for large eight-ox crossbows, of course, if you want to move, it is not a labor-saving and time-saving job, and the operation simplicity of ballistas is much inferior.

The significance of the ballista is not only manifested in the siege of cities and land, it shows the unlimited potential of engineering technology for the first time to change the image of science in the eyes of people, and in turn greatly promote the development of science and technology and change the humble situation of engineering and technical personnel. Moreover, because of the emergence of artillery, the juxtaposition and equality relationship in the original infantry queue was completely broken, which in turn affected the transformation of social relations. Even many Western scholars believe that the emergence of the ballista had a non-negligible impetus to the collapse of the ancient Roman republic - a weapon that changed the social landscape and technology changed the world.

Just as no one can live to be a hundred years old, good things will be eliminated by new things that are constantly emerging, and ballistas will gradually disappear into the long river of history. But a classic is a classic after all, and in modern times it has been re-excavated by ancient weapons lovers and copied according to scattered ancient records. Although the replicators of later generations tried their best to use ancient techniques and materials to make finished products, they often could not achieve the effect recorded in the test firing, so some people thought that the ancients bragged, and more people because of the loss of ancient manufacturing processes affected the power of ballistas.

Zhao Yu also obtained the mystery from the exchanges and arguments of enthusiasts, but he was limited to financial resources and energy and was not able to try it out by himself, but he didn't expect that he would realize it after crossing. The medium-sized ballista in front of me was built according to the data in my memory, but it is still unknown whether it can be used and achieve the desired effect, and everything will not be known until the test firing......

The manufacture of the ballista is an extremely precise work, and the craftsmen distinguish the specifications of the ballista according to the size of the torsion spring, which in turn depends on the torsion spring, and all the components are designed around the spring, which depends on two formulas that the craftsmen have come up with. These two simple formulas contain an accurate understanding of the mechanical properties and ballistics of torsion springs, and are also the core secret of the manufacture of ballistas.

Zhao Yu ordered the craftsmen to weave the rope according to the thickness of their own requirements, and then fixed it on the bracket, and then clamped the crossbow arm made of hardwood between the ropes, and finally installed the cable and the crossbow machine, Wangshan, which is the same principle as the bed crossbow, and the craftsmen can complete it independently with only a little guidance.

"You can try!" After the assembly was completed, it was already dark, and torches were lit around, and Zhao Yu checked up and down again.

"You two Zhang Xian, hurry up!" Ni Liang is not there Zhou Xiang can only be used as a human crane by his small stature He can only be used as a human crane to hold it up and down and check it up and down but the weight of the prince is not light he wiped the sweat on his face and pointed at the two sturdy craftsmen and said. The two craftsmen hesitated, according to previous experience, two people would never be able to turn the winch of such a large crossbow, but as soon as they hesitated, they were reprimanded, and they could only step forward, but when they tried to turn it, it was not as difficult as they imagined.

"That's it!" Zhao Yu listened to the 'squeak' of the torsion spring due to the afterburner and the 'click' sound of the two pawls on both sides of the tail end of the chute sweeping backwards along with the chute and the cogs fixed on both sides of the bracket, and he was also very nervous, his palms were sweaty, and he was worried that the gun carriage would not be able to withstand such a large force and fall apart, and when the slider moved to half, he ordered it to stop.

"Reload and aim at the tree next to the wall and test fire." After checking again and finding nothing unusual, Zhao Yu pointed to a big tree with a thick bowl mouth about forty steps away from them and said.

"Yes, Your Highness!" Zhou Xiang agreed, this is a good time to behave, he asked a torch to be inserted in front of the tree, and then personally went into battle to pick up a pebble with a weight of about three catties and put it into the slot, adjusting the angle of the ballista.

"Your Highness, it's okay." If it is said that the most skilled person in practicing this kind of technical weapon is not the soldier who uses it, but the craftsman who makes the weapon, and Zhou Xiang has participated in the manufacture from beginning to end, and is familiar with the function of each part, so there is naturally no problem with the operation, and he reported to His Highness after the adjustment.

"Launch!"

"Yes!" Zhou Xiang let everyone disperse a little, slammed with a short hammer, turned the rotary trigger, and detached the buckle hook that held the rope sleeve on the crossbow string, only to hear the crossbow string relax and make a 'boom' sound, and didn't see how the stone bullet flew out at all, and heard the muffled sound of the stone bullet smashing on the object, and the big tree as a target stood there well, and it didn't seem to hit.

"Your Highness, I ......" Zhou Xiang saw that he had missed, and just wanted to plead guilty, and was about to try again, but found that the big tree suddenly fell down.

"Shot, let's take a look!" Zhao Yu was overjoyed when he saw this, shouted and jumped and ran over to check first.

"Your Highness, slow down, don't fall." Zhou Xiang is really confused now, saying that he is young, and His Royal Highness has made up this complicated big guy at a young age; Said that he was big, is this happy look just a child, he smiled bitterly and shook his head and chased after him!

"Your Highness, this crossbow is not small, but it pierced through the tree with only half a bow, smashed a big hole in the wall, and turned the stone bullet into powder." Of course, everyone refused to let His Highness step forward, and a craftsman stepped forward to inspect and replied.

"Okay, good, it's successful, cook meat and wine tonight, celebrate well!" Zhao Yu listened to the last bit of worry in his heart and dissipated, and he said loudly to everyone......

After being full of wine and food that night, Zhao Yu allocated some money from his already tight pocket to reward the craftsmen who tried to make ballistas. Zhou Xiang was then ordered to move the ballista to an open field behind the mountain outside the house, and let them test fire overnight to test the suitability of the weapon and collect data so that it could be put into use as soon as possible.