This space should be a complete set of facilities for drawing water from the underground river, which is divided into two parts.

On both sides of the underground river below the aqueduct, there are two large indescribable waterwheels, which are not functioning now. But as long as it works, it will continue to pump water from the dark river into the canal.

Directly below the canal is a large ditch that has been dug by hand with the help of the topography, and inside the ditch there are box-like things nailed with varnish and tung oil. This wooden box is very large, three side by side, floating on the water. Three thick logs were erected upright, from the top of the box to the bottom of the canal. From my vantage point, I couldn't see what was underneath the canal, but I could imagine that there must have been something like a wooden frame reinforced on the back.

This entire set of water intake facilities is powered by the power of the underground river. Huge waterwheels are constantly drawing water from the river and feeding it into the canal. However, the canal itself has an angle, and when the water in the canal reaches a certain level, it will pour back along the angle. At this time, the ditch directly below the canal is also constantly filling water, and when the water is abundant, the floating wooden box produces a huge buoyancy, and the three logs that have been erected will be against the canal, so that half of the canal will rise as a whole, so that the inclination angle of the canal itself disappears, and a large amount of river water will continue to flow down the crack into Ta'er Lake.

The thought of this sent a chill down my spine, because the crack couldn't have been there forever, otherwise the lake would have backflowed all the time. I immediately turned around and walked the way I came, and when the beam of light from the flashlight spread out above, I saw two large stone slabs.

The slate is suspended and can be raised and lowered, and when the slate falls, it is equivalent to blocking the gap. When the slab rises, the gap opens and the lake flows back into the space inside the gap.

This whole set of facilities is very imaginative, and it is not easy for people to come up with such a solution in ancient times. But what struck me even more was that this huge water intake and discharge facility was actually fully automated, running by the hydraulic power of an underground river. When to drain water and when to irrigate, there are simple but very practical mechanisms that regulate it according to the hydraulic power. As long as the hydraulic power is reached, it can be operated.

It is conceivable that in those days, it would have taken a lot of manpower and material resources to build such a complete and huge drainage facility. It is not known who built this place, but based on the clay pot at the bottom of the lake, it can only be assumed that the builder was a Zhangxiong man.

As for the purpose of building here, it is probably easy to understand, the underground water source in the desert Gobi has little impact on the surface of the earth, and the surface water system has water to ensure the survival of vegetation and then form an environment suitable for human habitation. In this kind of place, as long as there is water, then it is worth the effort of manpower and material resources.

I was standing here at the canal, and my heart was pounding up and down. I speculate that when the Zhangxiong people lived here, they might have been able to control the whole set of drainage facilities in a regular manner. But without interference, there would be no regularity in the operation of this system, and now that the lake has been basically drained, if it enters the state of water intake, then the two huge stone slabs above the crack will fall and plug the crack.

If that's the case, it's going to be a plug in me.

"Xiaomao? Little? I shouted softly twice, but there was no response.

Under the light, I could see that the other side of the canal was still dark, which showed that the space ahead was still wide.

Although there was no response, it didn't mean that Xiao Mao wasn't here, he might be injured and unconscious, or he might have walked far inside and couldn't hear my shouts.

This place does not mean that there is no danger, but Xiao Mao rushed into the water without hesitation and let me stay on the shore, and now that he is in trouble, I must not be afraid of death. I took a breath and walked all the way from the canal to the other side.

My head was still dizzy, and all the uncomfortable symptoms caused by the fever seemed to be concentrated on me. The road behind the canal was about thirty meters in a winding way, and when I turned a corner, before I could look ahead, I heard someone shouting urgently.

"Chengfeng! Is that you!? ”

As soon as I heard this voice, the discomfort in my whole body seemed to disappear all at once. This is Xiao Mao's voice, for sure!

"It's me!" I could tell that the sound was coming from the front, and immediately quickened my pace and walked over, the road was uneven, some undulating, and I walked less than ten meters, and Xiao Mao's figure suddenly appeared in sight.

Xiao Mao squatted over there, maybe as soon as he saw the light transmitted by the flashlight, he knew that someone was coming. I hurried two steps, but felt a little strange in my heart. Xiao Mao should not have been injured, the water of Ta'er Lake is basically drained, and he can crawl out of the gap as long as he walks back the way he came.

However, for the whole night, Xiao Mao didn't go back, what was he doing?

"Xiaomao, you? What happened to you? I asked him as I walked forward.

"Wait!" Xiao Mao squatted on the ground, motionless, and looked up and down: "I don't know if there will be danger." ”

"What the hell is wrong with you?" It wasn't until this time that I realized that Xiao Mao might have been in a squatting position for a long time, just squatting all the time, and couldn't even stand up: "Are you injured?" ”

"Don't walk around, you can take steps as I tell you to walk." Xiao Mao turned on the diving lamp and shone on the road under my feet: "Half a meter to the left, and then one meter forward." ”

I don't know what's going on at all, but since Xiao Mao said so, he must have a point. At the same time, I also began to be vigilant, because from the whole set of water intake and drainage facilities before, it can be seen that among the people who built this place at that time, there were people who were proficient in the machine, and it was possible that if they walked around here at will, they would touch some hidden mechanism.

I didn't dare to move a centimeter, according to Xiao Mao's prompts, little by little I walked forward, I was about ten meters away from him, and it took me a few minutes to walk.

"The stone under my feet is alive." Xiao Mao must have not slept all night, and he has been squatting here, this posture is very uncomfortable: "I don't dare to be 100% sure, but I think that if I let go, I may trigger some mechanism." ”

It wasn't until this time that I realized that the road under Xiaomao's right foot seemed to be a little wrong, obviously a little more concave than other places.

Xiao Mao probably didn't expect me to find here, he probably couldn't hold it anymore, no matter who it was, it was torture to stay here in one position for so long.

"What traps will be triggered?" I think the loose stone that Xiao Mao stepped on is similar to the principle of infantry mines, and it may be fine to step on it, but as soon as you let go, it will cause a chain reaction.

"I'm not sure, I've been afraid to move." Xiao Mao pointed to my back and said, "It should be there." ”

When I first saw Xiao Mao, I was so excited that I didn't bother to observe the environment here, after Xiao Mao pointed to me, I looked back and saw that there was actually an irregular mouth behind, about three or four meters wide and about four meters high. Directly above this entrance, there is clearly a large stone. The stone is suspended in the air and should be supported by something like a rope.

Xiao Mao felt that the trigger mechanism under his feet had something to do with the big stone, and if the mechanism was really completely touched, it might make the stone fall. The stone is very large, and once it falls, it will block the opening. In the absence of explosives, the mouth is blocked, and there is no hope of escape.

Because of this, Xiao Mao didn't dare to move here.

"What now?"

"Over there, there's something, it should be a half-broken terracotta figurine." Xiao Mao pointed to the left rear: "But it's too far away, I can't reach it." ”

I understand what Xiao Mao meant, he can't retract his feet now, unless something heavy is pressing on this stone, so that he can be freed.

I was very careful, and little by little I tentatively walked over. Xiao Mao saw it right, it was indeed a terracotta figurine that broke from the middle, and for some reason, it was left here.

This is a blood pottery, and the dark red veins can be seen from the surface of the terracotta figurines. Ever since I learned about the origin of this blood pottery, I thought it wasn't a good thing, but there was no other way to do it now.

I dragged half of the blood pottery, according to the distribution point that I had just walked over, and returned to Xiao Mao's side, and slowly pressed the stone under Xiao Mao's feet with the blood pottery, pressed a little, Xiao Mao's feet were pulled back a little, and finally, the blood pottery firmly pressed the stone, and Xiao Mao was finally freed.

Half of his body was completely numb, and he couldn't stand up. I quickly got him some water and food, and helped him rub his legs.

Xiao Mao rested for a long time, and the two of us began to talk about this place. The last time Xiao Mao came to Ta'er Lake, the team fished up a blood pottery from the lake, Xiao Mao felt that there was an article in the lake, and now it seems that the article may be in this space. I tried to take a photo, and the light spread completely in front of me, indicating that there was still a lot of space ahead.

"Go ahead and take a look."

"Let's be well prepared." Xiao Mao rummaged through my backpack, I have limited physical strength alone, and I don't have much to bring, Xiao Mao suggested going back to replenish it.

The two of us returned the same way, and went to the camp to rest for a while, Xiao Mao was safe, I was very happy, but the fever did not go away, and Xiao Mao did not let me go back immediately. I took my medicine, drank a lot of hot water, slept in the car with a blanket and sweated a lot. As soon as I sweated, I felt a lot more comfortable, and my body temperature dropped significantly.

I rested for the whole day, and by the evening I was refreshed a lot. Xiao Mao had already made out two backpacks, one for each person, and with the backpacks, the two of us returned to the crack under the lake.