Entering this half-human-high tunnel, at first we can squat on the ground and climb forward on all fours, but after a few tens of meters, the cave is already low enough to allow us to lie on the ground and crawl forward. Our canvas was too full, and from time to time it was stuck by the raised stones in the hole, and we needed to stop to clean it, and the speed was suddenly much slower.

We followed the reminder of the curator Qi and kept a distance of more than ten meters, Sun Ping was in the front, Xiao Tian was behind, and I was in the middle. Sun Ping had heard Cao team chatter before, he was a veteran of the front line of Laoshan before, and he was a good hand at digging holes over the mountain, and with him in front, many obstacles along the way were cleared by him one by one, Rao is so, and it took us more than ten minutes to come to the place where the tunnel turned.

Here, the tunnel turns at a right angle of nearly 90 degrees, and after less than 20 meters, it turns to the other side, and the whole extends diagonally downward. I thought that the purpose of digging the tunnel in this way was to solve the problem that the height difference was too large and the slope was too steep, but during a short break, I shone a flashlight in all directions, and quickly rejected the idea.

At this point, we should be at a depth of more than ten meters underground, and the surrounding area is no longer a hard stone wall, but a deep black and flaky coal seam, but the coal seam here is very different from the coal seam I have seen before. One is that there are some large and small round holes on the surface of these coals, and when the sapper shovel is lightly knocked, the whole piece falls down, and then there is a layer of ash that falls together, obviously the inside is also hollow, and the structure is a bit like volcanic rock, which seems to have been burned a long time ago.

Second, not all the coal seams in the entire tunnel have become like this, about ten meters apart, there are two or three meters of hollow zone, but there is no law, it is obviously naturally formed.

Third, because of this special internal structure, there will be several thumb-thick steel bars as the support of the roadway at intervals of about ten meters along the way, and the top and bottom of the steel bars are connected by wooden seats.

Sun Ping, who was climbing in front, took advantage of our short rest in place and shouted to me, "Lao Chang, you see that there are some steel supports on both sides, and look at the rust on them, it should have been several years, and it is by no means a short-term temporary excavation." ”

The distance between me and Sun Ping is more than ten meters, and there is no barrier in between, but for some reason I think his voice is very far away, it seems to be separated by hundreds of meters, and even many words are not heard clearly, but it is clear to see the opening and closing of his mouth.

This time I came to Chengjialing Mine, and I didn't have much contact with Sun Ping, but I had the impression that he was a man who spoke with a lot of energy, how could his voice be so weak at this time? No, it should not be the problem of his voice itself, but the problem of sound transmission.

It was a strange feeling, as if the sound had turned into a liquid, and the hollow coal seams around it were like a huge sponge, slowly sucking the water away, and the sound was no longer traveling in a straight line, but undulating around the coal seam like a wave, so that the sound that came to me had become weak.

I used a lot of strength to shout to Sun Ping, "Old Sun, are you talking about those steel bars? Why is your voice so small?"

Sun Ping turned around in surprise, lay on his back in the tunnel, and then tried to half-sit up, and shone a flashlight at me, obviously, he didn't really hear my words, and he didn't expect me to be so close to him.

I managed to climb a few steps forward, less than five meters away from him, and then his voice became clear, and we simultaneously lifted the miner's lamp above our heads upward, so close, so small, the direct light of the miner's lamp was enough to blind us both for a short time.

"Chang, something is not right, we are talking so loudly, and we are so close, why can't we hear clearly?

I pointed to the coal seams with small pits around me, and under the illumination of the miner's lamp above my head, the coal seams on the four walls were no longer swarthy, some were glowing with blue-gray light, and some were dancing with brownish-yellow points of light.

"Lao Sun, the problem may be here, you see the surface of these coal seams, there are many small holes like honeycombs, and it is estimated that the structure inside is also the same, the sound waves hit the surface of these small holes, it is difficult to be reflected back, and is scattered into the hollow interior, just like the principle of the surface of the sound-absorbing wall. ”

"But the two of us speak in a straight line, so we shouldn't be affected by the surface of the coal seam, right?, why is it still like a piece of glass?" Sun Ping also began to scan the surroundings with a miner's lamp. As soon as we stopped crawling and focused on the seemingly monotonous walls of the tunnel, we felt more and more different from what we had imagined the mine to be.

"I also think this is strange, in this space, it seems that the sound waves will be affected by the coal seam, and it is no longer a straight line of propagation, it is estimated that Xiaolei's walkie-talkie is also because of this, so we can't receive the signal. ”

The Soul Bells in my jacket pocket didn't ring at all, and it seemed that the sound problem was more of a natural phenomenon and had nothing to do with ghosts. If the echo in the valley is the terrain that forms a trumpet-like resonance cavity that amplifies the sound, then what we encounter in the roadway must be the opposite, but I really can't think of what kind of terrain structure can absorb sound or delay the propagation of sound.

I suddenly remembered the portable thermal imager that Xiao Du gave me, and the geological structure that may not be recognized by the naked eye can reveal the true face of Lushan in front of the machine?

The thermal imager resembles a large flare gun with a five-inch display at the end. Turn on the switch, the screen slowly lights up, and in the middle of the screen, is Sun Ping's body that almost fills most of the alleyway, in the middle is a white humanoid, and then light yellow, orange yellow, orange red, red, to dark purple, layer by layer.

I slowly moved the thermal imager away from Sun Ping, but found that in the tunnel that I thought it should be pitch black, there seemed to be a little bit of light, and it was still flashing. I couldn't believe my eyes, so I quickly adjusted the depth of field of the lens and shone behind Sun Ping.

The light spot on the screen is very dim, if you don't look carefully, you will only take it as the afterimage of Sun Ping's white light spot, and the position of the light spot is a little fluctuating, it seems to be moving, but the distance of movement is very limited, and it is also very slow. When I looked up, there was nothing in that direction except the deep black walls of the cave.

I turned around, and Oda also appeared on the screen with a white light, about a dozen paces away from me. When I re-focused the camera on the cave wall, two light patches appeared in that direction, and after a few seconds, they disappeared from the screen.

I don't think there could be any living creatures in such a small cavern other than a few of us, and the spots of light are too small and faint to make me feel as if the light is coming not from the tunnel, but through the cracks in the coal seam.

I put down the thermal imager, took out the porcelain bottle containing Tianmu water from my bag, unscrewed the wooden cork, and a faint mint smell came out, which lifted my spirits.

It's also funny, in the past, these potions and magic weapons at home were what we had to bring with us in this industry, I don't know when it began, and the Cao team went out to handle the case, and slowly didn't bring it much, just like the good things that the glass factory had in place over the years, with the passage of time, it gradually only existed in the memory.

On the contrary, Cao Team, a staunch materialist, has experienced countless strange events, but he has slowly learned to accept things that are beyond the cognition of ordinary people, and even began to have the strange dream that has been buried in the dark. However, now that I think about it, Team Cao's dream is indeed a bit weird, when he mentioned it before, I was misled by Zhou Cheng, and I thought it was caused by his excessive work pressure, coupled with too many strange things that had no results and could not explore the results, and could not enter a deep sleep. And at this moment, I am in a dark and small space, feeling difficult to breathe, my limbs are stiff, and I am extremely depressed, and I can already understand how painful and desperate Cao Team is to walk like this in his dreams every night.

"Lao Chang, are you not feeling well?" Seeing that I was stunned and thinking nonsense, and took out a white porcelain bottle and kept swaying, Sun Ping was a little anxious and asked.

"No, let Xiao Tian send you out first, there may be a little lack of oxygen here? ”

I waved my hand at Sun Ping and smiled, "Old Sun, the holes I have drilled are not necessarily less than those you have drilled in Laoshan, I'm fine, but I just remembered some things and got distracted." Do you think the temperature in this cave is a bit abnormal, hot and cold?"

Sun Ping saw that my expression was as usual, so he relieved himself, turned around with difficulty, and turned the miner's lamp back to the darkness in front of him. "Lao Chang, what you said is right, it's a little strange, we just walked in a few hundred meters, and the estimated depth is only twenty or thirty meters, but the hot and cold alternates three or four times, and the estimated temperature difference is at least four or five degrees, which has never been encountered before, who knows what caused it." ”

Sun Ping's speech, I have already wiped the Tianmu water in the porcelain bottle to my eyes, glanced at the compass in the bag, the pointer is quite calm, indicating that the direction of the roadway is a little north-northwest, but after more than ten seconds, the pointer seems to be pulled by something, and will jump up a few times, but soon return to stationary, this situation is indeed a bit suspicious.

(Qin Mugong said to Bole: "The son is old, and the surname of the son can make the horse seeker?") Bole said: "A good horse can describe the muscles and bones." The horses of the world, if they are destroyed, if they are lost, if they are lost, if they are gone, if they are gone. The sons of the ministers are all talented, and they can be told to be good horses, but not to the horses of the world. The ministers have the same salary as the people, there are nine square Gao, which is in the horse, not under the minister. See it. When Mu Gong saw it, he begged for a horse. In March, the newspaper said: "It has been gained, in the dunes." Mu Gong said: "Who Ma also?" and said: "Huang and Huang." "Let people take it, and make it happen. Mu Gong didn't say anything, but called Bole and said: "Defeated, the son makes the horse seeker! If Gao sees what he sees, the heavenly machine also obtains its essence and forgets its coarseness, forgets its coarseness in it, forgets what it sees in it, sees what it sees, does not see what it sees, and leaves it behind. Those who are like Ruogao are those who are more expensive than horses. "The horse is the horse of the world. --"Liezi")