It has been more than a month since Li Er got the gunpowder formula, and he has always hesitated, and finally summoned Yuan Tiangang five days ago to let him start concocting gunpowder.

Today is the day to experiment with the effects of gunpowder.

There is a royal hunting garden behind the Daming Palace, Li Er only took Yuan Tiangang, Cheng Yanjin and Qin Qiong, and a few forbidden army guards, and ** except for Li Shimin, only Yuan Tiangang has seen it.

"Your Majesty, is this thing really that powerful?" Cheng Yanjin held the "Tian Lei Zi" made by Yuan Tiangang in his hand, looked left and right, and didn't think there was anything special, Li Er originally wanted other sergeants to try Tian Lei Zi, but Cheng Yanjin saw Li Er and Yuan Tiangang's mysterious appearance, and was curious and shouted to try it himself, don't look at the old Cheng coarse person, but his curiosity is not small at all.

Hearing Cheng Yanjin's question, Li Er didn't speak, Yuan Tiangang on the side smiled and said: "Lu Guogong has to be careful, Wang Zixin once said that this thing can open mountains and crack stones, fist-sized heavenly thunder can blow up boulders, and even bigger ones can blow up the three-meter-high city gate." ”

"So powerful?" Cheng Yanjin was not frightened by Yuan Tiangang's words, and wondered: "Isn't this just a bigger firecracker, there were a lot of firecrackers in my house during the Chinese New Year last year, so I heard a sound." ”

"Lu Guogong, don't be careless, this is not a firecracker, this is a thunderbolt, I think it's better to change a guard to try it."

"No, I'll just come here."

When we arrived at the place where the gunpowder was tested, a half-human-high stone had already been prepared about ten meters ahead, and a fist-sized hole was carved into the stone, just enough to put the heavenly thunder into it.

Li Er, Qin Qiong and Yuan Tiangang retreated to twenty meters away according to Wang Xiang's words, and Lao Cheng put Tianleizi into the hole and pulled the lead out.

Yuan Tiangang made a two-meter-long lead, Cheng Yanjin took out the fire fold and lit the lead on the ground, and watched the lead burn with curiosity.

"Lu Guogong, run back!"

"Lao Cheng, come back!"

"Bite the gold!"

Hearing that everyone was shouting about themselves, Cheng Biting Jin scratched his head and walked back, and looked back at the burning lead from time to time, feeling that Li Er and Yuan Tiangang were making too much of a fuss, and they had to run so far if they set off a firecracker.

"Boom!"

Cheng Yanjin had only run less than ten meters before he heard a loud bang behind him, his whole ears were buzzing, and before he could figure out what was going on, a wave of air pushed him behind his back and staggered, and there were a lot of gravel hitting his body, which was very painful, and he hurriedly trotted all the way to the place where Li Er and them were hiding.

"What the fuck is going on?"

Hearing that Cheng Yanjin could still complain about Li Er and Qin Qiong, they were relieved, they could see clearly just now, and a flash of fire suddenly erupted ten meters behind Cheng Yanjin, and after a loud bang, the big stone was suddenly blown to pieces.

The guards of the forbidden army who were guarding around heard the loud noise and ran over nervously, and they were relieved to see that Li Er and several adults were okay, Li Er waved his hand and asked the guards of the forbidden army to continue to go around to guard.

Seeing Cheng biting his back gritting his teeth, Li Er turned his body and took a breath, Cheng Biting Jin's back clothes were cut by those scattered gravels, and there were blood stains on his back, obviously scratched by the gravel.

Thankfully, he had run some distance and had some skin wounds on his back, if he had been standing next to a rock......

Li Er and Yuan Tiangang glanced at each other, their eyes were shocked, and Qin Qiong on the side also looked solemn and was afraid of Cheng after biting gold, these flying pebbles were almost comparable to hidden weapons.

"Your Majesty, do you still want to try?" Yuan Tiangang asked.

Li Er's eyes flashed with blazing flames, and he suppressed his excitement and said, "Try!" ”

He has seen the cracked stone of the mountain crack, but he has not seen the mountain yet. This time it wasn't a thunderbolt a little bigger than a firecracker, but an iron bucket half a man high, carried by two Praetorian guards, full of gunpowder! Wang Xiang said that using iron to fill gunpowder is the most lethal, and Li Er wants to see if it can open the mountain!

This time the target is not a stone, but a ten-meter-high stone mountain in the hunting garden, standing between a peach forest, although it is a stone mountain for ornamentation, but it is not an ordinary boulder can be compared, ten meters high, thirty or forty people can not surround the stone mountain in their eyes is already a behemoth, at least no city has such a tall and strong city wall.

Let the guards of the Forbidden Army carry the powder keg into a small cave under the stone mountain, and then pull out the lead, the lead on the powder keg is several times longer than the lead on the Tianleizi just now, but no one thinks it is long.

Cheng Yanjin suffered a loss, and he still had palpitations, so he naturally didn't want to light the fire again, and he hid far away with Li Er, and they all hid outside the peach forest, hiding behind a boulder.

Li Er summoned a guard and told him to go and light the fire, and reminded him to run back and hide it as soon as he finished lighting the fire.

The guard is not Cheng Biting Jin, so naturally he will not be careless, and he also heard the loud noise just now, and immediately ran back as fast as he could after lighting the fire, hiding behind the boulder, he was very curious about what the iron bucket that His Majesty asked them to carry over was for.

Soon his doubts vanished and turned into shock.

If you have to use one word to describe this movement, then you can only use the word "flat thunder" to describe it, and the earth seems to shake.

After the thunder on the flat ground, as far as the eye can see, the ten-meter-high stone mountain in the peach forest collapsed under the eyes of everyone, kicking up a cloud of dust!

It took half an hour for Li Er to wake up from the shock, and he wanted to go forward to check but was stopped by Qin Qiong.

"Your Majesty, let's send a guard over to take a look first."

After the guards confirmed that there was no danger, Li Er took Qin Qiong, Cheng Yanjin and Yuan Tiangang to the middle of the peach forest.

"Datang has this sharp weapon, what other city is there that cannot be broken!" Li Er gasped excitedly, Qin Qiong and Cheng Yanjin were also flushed with excitement, if they had this thing in their hands, it would be easy to lead the troops to attack the city.

"Your Majesty, look!"

Qin Qiong walked to a crooked peach tree and pointed to the piece of iron embedded in the trunk and exclaimed.

Li Er and Cheng Yanjin walked over and looked at each other, and then looked at the other peach trees nearby, there were many pieces of iron and gravel embedded in the trunk of the tree, and it was not easy for Cheng Biting Jin's strength to insert the sword into the trunk so deep, if these pieces of iron and gravel hit people's bodies...... I can't imagine it. Li Er finally understood why Wang Xiang said that using iron to fill gunpowder is the most lethal, if the bamboo tube outside Tianleizi is replaced with an iron sheet, once it is thrown into the crowd and explodes, the countless pieces of iron that are shattered are all sharp weapons for life! The same is true for adding gravel to gunpowder.

"Turkic." The corners of Li Er's mouth were slightly upturned, and a sharp light flashed under his eyes.

Yuan Tiangang sighed secretly in his heart, and couldn't help but think of Wang Xiang's strange face again......

On this day, many people in Chang'an City heard the earth-shattering thunder from the direction of Daming Palace, and some people even felt that the ground shook slightly, and then looked up and saw the scorching sun in the sky, and they all sighed that there was a vision in the sky, and the palace was even more chaotic.