When Zheng heard Professor Chen say that the entrance to the ancient tomb was here, he felt a little incredible, and said suspiciously: "The entrance of the ancient tomb is hidden in this shop?" It's a bit unlikely, that's it. ”

Professor Chen walked to the counter on the left side and looked at it, and said firmly, "The entrance must be in this store!" And I guess that entrance is hidden right behind the counter. ”

"Where will it be?"

Professor Chen ignored Zheng Suo, turned to Zhang Gong and said, "Old Zhang, you go out and compare the length of this room, and then roughly compare the length of this place to see which end has been reduced." ”

Zhang Gong smiled at Zheng Suo with a grimace, and then said, "Come on, Master Chen, please do it, the little one will be implemented for you now." ”

After a while, Zhang Gong came back and said to Professor Chen: "The right side has obviously been reduced by about two meters, so the problem should be over there." ”

"Well, you go behind the counter and take a look at the details."

Zhang Gong walked to the counter on the right, and saw that there was an aisle for the shopkeeper to enter and exit at the corner, and he opened the wooden planks on the top and side and went in. When he got to the back of the counter, he didn't look at the shelves directly, but first looked at all the back of the counter, and then lay on the ground and sniffed, after doing some seemingly funny movements, Zhang Gong stood up and said to Professor Chen with a smile: "The entrance has been found." ”

"Well, open it."

Zheng Suo, who had been watching from outside the counter, wondered, "You didn't do anything, how can you say that the entrance has been found?" ”

Zhang Gong said with a wicked smile: "The upper part of the nose is the eye, which is used for observation, and the lower part of the eye is the nose, which is used for smelling, and these are my best tools." ”

"And how do you judge?"

"There is a very musty smell here, but there is also a smell of sweat in it, which indicates that someone has just stopped over the river, and the smell of sweat may have been caused by strenuous or high-intensity exercise; Look at this section of the shelves, the color of the wood looks similar to the side of the shelf, but their materials are not the same, here from the counter to the shelves are made of oak wood, the original color is brown-red, with the passage of time, now it has been blackened, and such a section of the shelf is made of rosewood, the original color should be reddish-brown, and now it also looks black, but black and black are different, and it is easy to distinguish if you look closely. ”

"Lao Zhang, you are really amazing! Is that enough to make sure it's an entrance? So how does this entrance open? ”

"There is no back door and side door in this store, someone came in but disappeared, and there is no sign of anyone walking before and after the counter, only this place is suspicious, so it is judged that the entrance is behind this, and the entrance should be able to be pushed in."

After speaking, Zhang Gong put his hands in the middle of the shelf and pushed it back hard. With his exertion, the shelves moved slowly, and he kept moving forward nearly two meters before stopping.

Zhang Gong stood inside and gently took two breaths into the darkness, and then after making a few silent gestures to Professor Chen, he beckoned to Situ Fang, and then pointed inside.

Situ Fang understood that this was Zhang Gong who needed his help to explore the way, and there must be movement ahead. So he nodded and quietly walked to Zhang Gong's side.

It was pitch black inside, and after Situ Fang turned on the flashlight, he blocked the light with one hand to prevent the light from directly hitting the people inside, and then quietly walked inside.

Inside is a flat passage, after going straight for more than three meters, it is a 360-degree turn, and then there is a straight down passage, Situ Fang stood at the entrance of the passage and listened, and did not find any movement inside, and then the flashlight was illuminated inside, and the passage was empty, extending to the front.

After Situ Fang retreated, he reported the previous discovery, and when Zhang Gong heard that there was nothing found inside, he widened his eyes and said: "No, I can be sure that I must have heard a sound just now, and the sound is still obvious, it is the sound of several people walking." ”

"But I really didn't find anything inside, I don't believe you go and see, there is no turning in a passage that goes down, if there is a situation, you can see it at a glance."

After Professor Chen and the others went inside to take a look, they didn't find anything except that they felt a strong air flow gushing out, and the stone steps inside were very regular and clear, and they continued to the end of the darkness.

Zhang Gong dragged this section of the shelf out and returned to its position and said: "This is not normal! ”

After so many years of understanding, Professor Chen knew that Zhang Gong must have discovered something, if he was not sure, with his old naughty character, he would have laughed it off, so he asked, "What's not normal?" ”

"Let's not say if I heard the footsteps inside, you all went in just now, and you all felt the resonance of the air column, right? Do you feel the obvious surge of air, too? If the passage below had been like this, I should have felt a strong air flow the moment I pushed the secret door open, but it didn't happen, so why did it appear now? Is this a delay effect? Of course not! Even if the inner passage is long, it will only produce resonant sound, and will not produce enough airflow phenomenon, if you want to produce airflow, you need to have two points, one is that the inside is connected with the outside world, while the secret door is opened here, the air forms a convection and produces an airflow, and the air rubs against the inner channel to produce a whining sound, the second is that the temperature difference between the inside and the outside is large, and the temperature inside is much lower than the outside, but the airflow formed in that way can only move inward, if the inside temperature is higher than the outside, the formation is a hot airflow, Then the air flow will move from the inside to the outside, which obviously does not exist, after all, we do not feel the existence of the temperature difference; Now we know that there is a reservoir under this mountain, so if this passage goes all the way down, it is impossible to communicate to the outside, in the morning I read the weather forecast that there will be strong winds to cool down tonight, so I thought, this is definitely not a channel, the air flow that was not generated just now is because a certain channel has not been opened, this point I think Situ Fang must not have appeared when he went in, so when he went in again, there was an air flow, that is, the channel inside was switched! ”

Professor Chen saw that Zhang Gong's analysis was almost clear enough, so he asked sideways: "Old Zhang, could the footsteps you heard just now be the sound of the air rubbing against the cave wall?" ”

"No, the sound of air and the sound of footsteps are two different concepts."

"If there are multiple passages in there, where do you think it is most likely?"

"It should be done in two lanes, one should be at the place where the bend was just turned, and the other should be not far below, because it is not a minute from the time I heard the sound to the time Situ Fang entered, and the man couldn't have run very fast."

"If there is such a mechanism, then there must be a voice, right? But there's not a sound coming out of here, huh? ”

"If it's a mechanism trigger, relying on some form of kinetic energy, it will definitely make a noticeable sound, and if it's wood, it will only produce a faint sound, faint enough to be ignored."

"Okay, let's not discuss this tonight, let's go out first, and we'll have a positive contact with this tomorrow."