Lin Yuan hurriedly asked, "How can we let the fish come to us?" ”

Shen Wanqing said: "Isn't our sonar active sonar? We can use the sound waves emitted by sonar to force schools of fish to swim in our direction. ”

Lin Yuan asked, "What kind of sound waves can make the fish swim towards us?" ”

Shen Wanqing said: "Animals can predict the occurrence of earthquakes and tsunamis, have you heard of it? Once we went to the Seismological Research Institute to do counter-espionage work, and we heard from the experts of the research institute that there will be low-frequency sound waves before the earthquake, which we humans can't hear, but animals can perceive them, so I thought, if our sonar can simulate this kind of sound waves, wouldn't we be able to drive the fish over? ”

Lin Yuan said: "This method is really good, we can give it a try, do you know what the frequency of this sound wave is?" ”

Shen Wanqing said: "It seems that the frequency is relatively low, it may exceed the frequency range of our sonar transmission, it seems to be below 30 hertz. ”

When Lin Yuan heard this, he couldn't help but sigh and said, "Our towed sonar uses a frequency of at least 100 hertz, and if it is lower, the detection effect will be very poor." ”

At the moment of the stalemate, Lin Yuan suddenly said: "I thought that our towed sonar is equipped with a communication module, and the frequency of the communication module can be lower than thirty hertz. ”

Shen Wanqing asked, "Why does the sonar have such a module on it?" ”

Lin Yuan said: "This kind of module is used by us to contact the nuclear submarine, and the underwater communication of the nuclear submarine is done using low-frequency sound waves. ”

Lin Yuan gave an order, and the towed sonar immediately turned on the communication module, and tested it on the low-frequency sound waves, and finally at twenty-seven hertz, the fish began to be restless, their speed increased significantly, and three helicopters drove the fish in the core from three directions, like a big net, and drove the fish in the direction of Lin Yuan.

If you want to know the type of enemy ships and submarines according to the information of sound waves, you must conduct underwater acoustic reconnaissance on enemy warships and submarines in advance, record the shape of the echoes, and establish a database.

So it is impossible for the operator to read from the echoes what kind of fish make up the school, and if he can go down to the water, and he knows the biology very well, he will find out that the school of fish is the Pacific herring, which is a typical pelagic fish that lives in the sea at a depth of five to ten meters. When the sonar emits low-frequency sound waves, the sound waves penetrate through the layers of seawater and reach the bottom of the water, stirring up species such as small yellow croakers that live below 50 or 60 meters.

The upper and lower fish were crowded together, rushing towards the position of Lin Yuan's fleet, the sea water was darkened, and the experienced fishermen in the fleet had already begun to exclaim, they had never seen so many fish.

Lin Yuan ordered the fleet to disperse and began to lower the nets, and then the people on the water began to get busy, they lowered the nets into the water, and then pulled them up, they were full of large and small fish, these fishing boats have ingenious designs, there are special cabins for fish under the waterline, the outer walls of this cabin are with lattices, and the sea water can flow freely through the cabins, but the fish can't swim away.

The position of the fleet, the sea water is relatively shallow, when the fish swim here, it is very difficult to swim again, so many fish are trapped in the fish, which brings more convenience to the fishing, under the mobilization of Lin Yuan, more boats come from nearby, join the fishing army, some boats are really not loaded, so they go back to the shore first, unload the fish, and then come back to fish......

It wasn't until it was getting late that the fishing came to an end, and on the way back, Shen Wanqing asked Lin Yuan: "You don't plan to send a helicopter every day to do this, do you?" ”

Lin Yuan replied: "I have already thought about it, next time we will set up a purse seine net in the sea near here, drive the fish in regularly, and then let the fishermen catch it." ”

Shen Wanqing asked again: "But, can you transport so many fish?" If you can't finish it, won't it rot? ”

Lin Yuan smiled: "When you get to the shore, you will understand." ”

When they reached the shore, they saw that the fish were piled up on the shore, and many people were carrying the fish to the open field farther away by the fish pile, where there were many women and children, and they disemboweled, and smeared them with salt to prevent the flesh from rotting.

After the fish was smeared with enough salt, the fish and meat were transported backwards to the state capital where the famine occurred.

In the vehicle waiting area, Shen Wanqing also saw more than a dozen strange-looking big guys, in front of them was a boiler-like thing, and behind them were five carriages, very similar to trains, but they didn't take the tracks, Shen Wanqing pointed to them and asked Lin Yuan: "Is this a car?" ”

Lin Yuan replied: "This is a car, but it is powered by a steam engine, the speed is slower than a tortoise, and it can't run the carriage, when they were built, they were originally intended to be put on the battlefield transportation, but they are really muddy and can't support the wall, and they have to add water and coal after walking for a while, so they were abandoned, and now the transportation distance is relatively close, and the load capacity is large, so they are transported." ”

Shen Wanqing nodded and asked, "Then when will the car be built?" ”

Lin Yuan thought for a while and said, "Don't worry, as long as the Governor of the Northeast arrives, related industries can be built soon, such as petroleum, rubber, metallurgy, ......."

didn't wait for Lin Yuan to finish speaking, only to hear someone behind him shouting: "Lord Lin! ”

As soon as Lin Yuan turned around, he saw a person from far and near, and after a closer look, he found that this person turned out to be Xu Bin from Tianjin Machinery Bureau, and there was a large bruise on the corner of his eye, as if he had been beaten, Lin Yuan hurriedly pointed to the bruise and asked, "What's wrong with your eyes?" ”

Xu Bin pointed to the cars and said: "It's not all of them who are in trouble, there is a steam engine on the road that has no water, so we stopped to add water, who knows that there is a weaving factory run by the British on the side of the road......

Shen Wanqing asked on the side, "What is a weaving factory?" ”

Lin Yuan explained: "It is to weave textile raw materials such as silk and thread into finished products such as cloth or rope. ”

Xu Bin saw that Lin Yuan had finished explaining, and then continued: "When a few Britons saw our car, they bent their waists with laughter, saying that the batch of steam engines they eliminated recently were better than ours!" One of our young men was so angry that he went up to fight, and I stopped him in the middle, but neither of us did anything and punched me. ”

Lin Yuan and Shen Wanqing couldn't smile bitterly, Xu Bin asked: "I heard that Westerners have been able to make a small machine, which is oil-burning, loaded on the car, and the car runs fast. ”

What Xu Bin didn't expect was that Lin Yuan looked away with his eyes blankly as if he hadn't heard his words, Shen Wanqing stabbed Lin Yuan on the side, Lin Yuan came back to his senses and smiled "um" twice.

Xu Bin didn't care, he said goodbye and left, Shen Wanqing asked, "What were you thinking just now?" ”