Yang Zhen held the blooming bomb and weighed it for a long time. The whole body of the bomb was round and black, and the fuse hole reserved on the bomb body was plugged with a short cork.

Yang Zhen pulled out the short cork with a loud popping sound, and then exposed the letter tube inside, as well as the surface of the compacted black powder column in the letter tube.

Seeing this, Yang Zhen put the short cork back on, turned to Pan Wenmao who was following behind and said: "The most important part of the explosive bomb is the message tube. If the gunpowder column inside is not pressed firmly, it will burn too fast.

, easy to explode in the barrel.

"However, if the gunpowder column inside is pressed too hard, it will burn too slowly. After it is shot out and lands on the ground, it will not explode for a long time, but it will give the enemy an opportunity to take advantage of it. Has the burning speed of this message tube been tested?"

Pan Wenmao, who was following behind, suddenly heard Yang Zhen asking a question about himself and immediately followed him. However, when he was in front of Yang Zhen, he didn't know how to answer it correctly.

If the letter tube they made has a long burning time, it would be easier to say, for example, a quarter of an hour, a stick of incense, a cup of tea, etc., including a clepsydra and so on, and some have timing methods.

However, the burning time of this message tube was very short. It burned out in just a few breaths, leaving them too late to time it properly. Could he report to Yang Zhen that the burning time of this message tube was only between seven or eight breaths?

This is easy to say, but not easy to hear. After all, everyone is different, and the length of each breath is different!

Pan Wenmao, who had always been calm and unhurried, showed a rare look of embarrassment at this time. He smiled bitterly and scratched his head. For a moment, he didn't know where to start.

But after Yang Zhen asked the question, he looked at him, and everyone else knew that the question was very important, so they all stared at him, forcing him to answer as soon as possible.

Pan Wenmao gritted his teeth and said, "I've definitely tried it before. How could I not try such a deadly thing beforehand? It's just that the governor asked about the burning speed, but the humble official didn't know how to talk about it. A letter tube burned out.

, just between seven or eight breaths!”

At this point, Pan Wenmao looked at Yang Zhen, who was a little dazed, and then said: "However, I compared the fuse of the Flying General. Although the fuse on the Flying General is long, it only takes two or three to burn it from beginning to end."

It’s just breathing! So I believe that if you use this message tube, it won’t explode instantly!”

"It's not that I can't trust your craftsmanship, but it's a matter of great importance and you can't be careless. Let's do this. Before the official test launch, throw it into the fire and let it burn for a while and see how it goes from entering the fire to exploding.

How long will it take?”

Yang Zhenfang had just raised his question, and when he saw Pan Wenmao was a little embarrassed, he understood at that time that ancient timekeeping was really troublesome.

Although there is such a distinction as time and moment, there are different opinions when it is further subdivided. What is a stick of incense or a cup of tea? This timing method is too abstract and not accurate enough.

There are also different opinions on the scales of slightly more precise clepsydras, and the speed of hourglasses or water droplets also affects the accuracy of timing.

Relatively precise timing methods such as hours, minutes, and seconds, similar to later ones, were of course impossible to calculate in this era.

The burning of the message tube and the firing of the artillery are actually calculated in minutes and seconds. It is impossible to use such terms as a quarter of an hour or a stick of incense.

After Yang Zhen realized this, he actually knew that he had asked a rather rash question, and he also knew that Pan Wenmao might not be able to answer it.

But this issue was too important, and he had to figure it out thoroughly, otherwise wouldn't it be useless to use it for testing, destroying the artillery and demoralizing morale?

As for the seven or eight breaths mentioned by Pan Wenmao, it varies from person to person. Some breaths are long, while others are short, and it cannot be done accurately.

But after Yang Zhen had spoken, Yang Shen immediately asked someone to bring hay and firewood and pile them outside a trench bunker under the high hill. He also ordered all the soldiers on duty around the test site to retreat to a distant place and take cover.

After a while, the pile of hay and firewood crackled into flames, and soon turned into a blazing red fire.

Yang Zhen led everyone down from the high hill where the cannons were deployed, and jumped into the bunker dug by Yang Shen's troops. From a distance of more than ten steps, they watched Yang Shen run over with the projectile in his arms.

Throw the projectile into the burning fire and run back quickly.

At this time, there was no need for anyone to give orders. Everyone followed Yang Zhen and immediately crouched down in the ditch. Everyone counted the time silently in their own way.

From the moment the bomb was thrown into the fire, Yang Zhen silently counted the numbers in his mind at the normal counting speed of future generations, about one count per second: one, two, three, four, five, six.

, seven, eight, nine, ten...

When he counted to ten, Yang Shen jumped from the ground into the trench bunker and landed not far from Yang Zhen. When he counted to seventeen, he heard a loud bang.

The ground shook for a while, and then sand fell like rain into the ditch, covering everyone's heads and bodies.

An unburned stick fell at Yang Zhen's feet. The end, which had been burnt black into carbon, was still smoking.

Yang Zhen stood up, stepped on it under his feet, twisted it on the ground, then raised his head, looked around at everyone, and said with a smile: "This time is enough, at least it won't explode in the barrel of the gun!"

Pan Wenmao, who was standing next to Yang Zhen ready to answer questions, breathed a sigh of relief and wiped the sweat from his forehead with his hand.

Although he had tried repeatedly beforehand, he was still afraid that something would go wrong at this moment and he would smash the ammunition factory's sign in front of everyone.

After the explosive bomb exploded in the fire, the dust settled and everyone followed Yang Zhen out of the trench bunker to see the crater formed by the explosion on the ground where the fire was originally located.

Perhaps due to the soft soil near the river bank, where the fire was originally built, after the explosion, a huge crater was formed that was more than five feet wide and about three feet deep, making everyone stunned.

Since there is no problem with the signal tube, it has been proved that the explosive bomb can indeed be detonated through the delayed signal tube of the new work. This situation has greatly increased the confidence of Yang Zhen and everyone present.

However, in order to ensure safety, Zhang Degui, Fang Guangchen, Li Lu, Zhang Chen and others persuaded Yang Zhen who wanted to ignite the fire himself. Everyone accompanied Yang Zhen back to the bunker, waiting for the test firing of the sky cannon hosted by Yang Shen to begin.

.

After Yang Shen issued the order, the soldiers at the artillery testing ground who had evacuated from hiding returned to their posts one after another.

Yang Zhen was behind the bunker under the artillery array, watching every move on the artillery array not far away.

But Yang Shen first ordered someone to stuff a large medicine bag into the muzzle of the cannon, and then another soldier used a long wooden pole to tamp it down.

After these things were done, Yang Shen ordered another person to come to the muzzle of the gun with a blooming bullet with a wooden holder, unplug the plug from the fuze port, and then slowly put the blooming bullet with the wooden holder together.

Stuff it into the muzzle of the cannon with a forty-five-point angle facing the sky.

The soldier who had previously used a long pole to pound the gunpowder package into the bottom of the cannon bore picked up the long pole again and slowly pushed the projectile inserted into the muzzle into the depth of the cannon bore.

Afterwards, the soldiers who loaded the powder, loaded the ammunition and pushed it into the bottom one by one evacuated from the muzzle. Yang Shen took a pointed wooden stick from the hands of the soldiers around him, inserted it from the fire door above the gunpowder chamber, and used force

Pounded it a few times.

Yang Zhen knew that this was piercing the powder bag that had been pushed into the artillery powder chamber.

Sure enough, Yang Shen pounded it a few times, then took out the wooden stick and saw that the tip of the wooden stick was filled with gunpowder. He took a medicine twister as thick as a little finger from the hand of the soldier beside him and stuffed it into the fire door.

Next, the soldiers on the artillery array quickly evacuated and took cover, leaving Yang Shen alone there, holding a lit torch in one hand and a red triangular flag in the other.

Yang Shen first waved the flag several times in the direction of the other side of the river, then stopped and looked across the river.

Yang Zhen looked in the direction Yang Shen was looking and saw a group of soldiers holding flags on the other side of the Xiaosha River quickly jumping into a bunker under the ground.

After all the artillery soldiers on duty on the river bank disappeared, Yang Zhen turned his attention back to the high artillery array where Yang Shen was located, and saw Yang Shen taking a torch to light the fuse exposed outside the fire door.

The medicine stick was instantly ignited, and thick smoke was rising. Yang Zhen counted again. This time when he reached five, he heard a muffled "bang" sound, and then the smoke filled the air.

Yang Zhen was not able to clearly see the moment when the bomb left the muzzle of the gun, but when he quickly turned his gaze to the air in front of the artillery array, he quickly saw the bomb flying over the Xiaosha River.

The mortar has a large caliber, a short barrel, and a low chamber pressure. Only when it is fired at a large elevation angle and almost upward, can it achieve a larger range. In other words, curved firing is the best way to launch the mortar.

Therefore, the shell fired by the mortar follows a high-throw trajectory, but because of the low bore pressure and low muzzle velocity, the projectile moves slowly.

This also means that people who understand the principle of mortar firing can capture the trajectory of the projectile with the naked eye.

Especially for the explosive shells flying through the air with smoke coming from the message tube, its movement trajectory is easier to be captured by those who are interested.
Chapter completed!