This barn is no different from the barn in the city. However, referring to the nearest well fence, the location is ridiculously different.

Who would build their barn outside the walls?

This barn building, which stands alone outside the courtyard wall, is obviously camouflaged by a mechanism. The "Wall Trap" and "Gatehouse Trap" that blocked it had been removed to block the path of the Knights of the Three Rivers. Leave this barn alone to hold its place. It is also unknown why it did not move synchronously, or because it was disturbed by the sound of drums.

Sneak closer.

Bai Yuwei took the Yanling knife in his hand and stabbed it with strength. The steel blade is divided into three points. Gently scrape, the ashes fall like rain. It's just outside the slab wall, smeared with mud, whitewashed chalk, and disguised as a warehouse. The inside is still wooden.

Dian Wei looked up at the cangshang pavilion. It's not hard to throw the oil bottle in.

"Don't storm and find the entrance." Su Yue, who was protected by Bai Yu's elite guards in the center of the formation, whispered.

"Hmm." Dian Wei made a look, and the white soldier immediately surrounded the warehouse building, searching up and down.

In a moment, a white guard found the entrance. There is a noticeable crack in the chalk coating around the entrance. Apparently it was broken when the door was opened and closed. It is not visible in the distance, but it is clear at a glance when it is near. The steel knife is inserted into the crack, the switch is switched, and the white jade is slightly picked open with the steel knife. Looking sideways, he was facing a yellow turban wrestler.

Before the Yellow Turban Lux could open his mouth to question, the white silk pawn had already flown in.

The wild goose knife swept across the area. There was a lot of screaming behind the door. Now that the war has begun, why hide your secrets! The white soldiers pounced one after another, slaughtering all the yellow turban thieves in the warehouse from the bottom to the top.

Seeing the yellow turban wrestler under the knife, he seemed to be dead. looked down at the yellow scarf costume on his body, and then grinned: "Well, I forgot that I am also a yellow scarf!" ”

"Quickly remove the corpse." The cabin was bloody and pungent, Su Yue covered his mouth and said.

The white spirit soldier then moved the corpse out and invited Su Yue and a group of good craftsmen to enter.

Sure enough, it is like the Chariot Building of the Thistle Country. The organ warehouse building is also divided into four floors. There is no animal power wheel at the bottom layer, but it is all driven by the joint efforts of more than a dozen yellow turban wrestlers. The middle layer hides a soldier, the upper layer has an arrow window, and there is an ambush with a strong crossbowman. They were all slashed and killed by the white elves.

The whole mechanism is extremely rudimentary. The only exception is in the top cabinet. Originally, there was a scout in the top cabinet. Embed on all sides of the "de-knotted bamboo pipe". The bamboo pipes are of different lengths, similar to the thirty-six pipes on the pipes. The difference is that both ends of the knuckle bamboo tube are covered with "thin cowhide" to form a "sound transmission bamboo tube". In the middle of the top pavilion, there is a peculiar shape of the "seven-stringed instrument", whether it is a musical instrument or not, it is unknown.

At this time, the bamboo pipe drum rumbled, but the "seven-stringed instrument" hanging overhead did not move at all and did not make a sound.

"The sound of the drums really disturbed the transmission of the Yellow Turban Thief." Su Yue said: "Let's wait for Zuo Zhonglang to stop the army." ”

"Hmm." Dian Wei then ordered people to garrison it.

Fight for a day, until the hour of dawn, when the drums cease. After clearing out several streets and alleys surrounding the urn city, Zuo Zhonglang ordered Huangfu Song to order a steady stream of soldiers to camp in the city. Yecheng is vast, and the yellow turban thieves are stubbornly defending. Street fighting is not a day's work. Steady and steady, slowly advancing, is also the right way. Huangfu Song was not blinded by hatred, he was a good general in the world.

When the drums fade away, the sound of the piano begins again. The sound of the piano was screeching, very rapid. The "Transsonic Bamboo Tube" that will stop will be agitated again. This time, the "seven-stringed instrument" finally spoke.

Among the seven strings, three strings occur in sequence, and then two strings resonate in unison. And so on and so forth.

This is the "code word" of the Yellow Turban Thief.

The principle used is actually extremely simple: the "resonance phenomenon", or "resonance effect".

The ancients discovered the phenomenon of resonance very early. "Zhuangzi Xu Wu Ghost" records the resonance of tuning: "For the sake of tuning, it is wasted in one hall and wasted in one room." The drum palace moves, the drum horns move, and the rhythm is the same. The husband changed the tune of one string, and the five tones were not appropriate, and the drums were all moving. ”

In this regard, Dong Zhongshu of the former Han Dynasty explained in his "Spring and Autumn Dew: The Movement of the Same Kind": "All things go to their differences, and from their sameness, so the same qi will be, the sound ratio should be, and its test will be clear." Try to tune the piano and make mistakes, the drum palace should be his palace, the drum should be his business, and the five tones are more than self-resonant, not a god, and its number is also. ”

This means that objects of the same nature can sense each other. The reason why the drum palace moves and the drum merchants should respond is because they have the same tone. This is a necessity, and there is nothing magical about it.

Regarding the use of the resonator, it has long been recorded in "Mozi Beixue". For example, dig a deep pit at intervals at the root of the city, and place a pottery urn in the pit, and cover the mouth of the urn with leather, so that the wise and discerning person can lie at the mouth of the urn. If the enemy digs tunnels to attack the city, not only can the sound be detected, but also the direction of the enemy can be identified according to the height difference of the "urn sound" of each urn.

Another example is the army of later generations, which made a military pillow called "empty deer" made of leather, so that the Conger soldiers can use the pillow at night. "Mortals and horses travel thirty miles away, and they are heard from the east, west, north and south." It is also recorded in "Mengxi Pen Talk: Instrumental Use" that the quiver made of cow leather "attaches to the ground pillow, and the sound of people and horses within a few miles is heard." At the latest, since the Song Dynasty, the people of the time have used "to knot long bamboo", buried directly in the ground, listening to the mouth of the bamboo tube, "buzzing like a drum". Qi Jiguang of the Ming Dynasty also used this method to prevent sneak attacks by Japanese pirates. Wait a minute.

However, not everyone has such insight.

Seeing that the "seven-stringed instrument" was playing on its own, Dian Wei, who was a cracked tiger and leopard, also widened his eyes. Bai Yuwei under his command was even more discussed.

Su Yue whispered with relief: "Don't panic. It's just a 'like-like' ear. It has been written in the book for a long time. Just find the source of the sound and you can find the mastermind behind the scenes. ”

"The sound came from heaven." Someone in the white felt said: "The violinist must be on a high place." ”

"There's no hurry. Find out the thief's 'string code' first, and then find an opportunity to break the enemy. "Su Yue has the rigor of the craftsmen of the great country.

"Hmm!" Dian Wei ordered people to be strictly guarded, and he wanted to spend the night in the enemy's formation.

Night is falling. When I couldn't see my fingers, I suddenly heard the wheels rolling around. The rails are also good for sound. The device that had been removed to resist the Han army was removed and returned to its position at night. The warehouse building that stood outside was surrounded by walls, gatehouses, and courtyards. If you raise the fire at this time and look at it again, the courtyard is deep and there are no flaws.

The surrounding traps and weapons all went to meet the enemy. Why does the single warehouse building stand still? Su Yue had already thought of what happened.

The warehouse building is high, and it is a "relay resonator". The 'string tone code words' from the Yellow Turban Qu Shuai will be passed on to the baton. Therefore, it will not move easily.

The so-called "drum palace palace moves, drum horn horn moves", the reason why it can achieve "palace business horn sign feather" and "the same rhythm" also shows the accuracy of the current tone. The people of the time sighed that "the etiquette and music collapsed". Collapsed, how can it be a sentence of futile emotion, can be generalized.

It was night, and the secret door of the warehouse building was suddenly knocked.

Dian Wei motioned for everyone to be on guard, and then asked in a low voice, "Who is outside the door!" ”

"It was under the order that food was brought in." Someone outside the door whispered.

"I'm not hungry today, I'll come back tomorrow morning." Dian Wei replied in a rough voice.

"So, let's go to the next place." The comer then departed.

"Can you show a flaw?" Su Yue asked in a low voice.

When the footsteps were far away, Dian Wei shook his head lightly: "No." ”