Yang Qiuchi asked: "Where was the fired granary guard on duty at that time?"

"Just in the second building, there is a small wooden house next to the granary, where the guards slept at night. There are also people on duty at the entrance of the granary courtyard, but they are only responsible for the vigilance between entering and leaving and outside."

The concierge took Yang Qiuchi to the wreckage of the north granary, roughly pointing to the second and third granaries that caught fire at that time, and the house guarding the duty. Yang Qiuchi stood there, touching his chin and pondered for a while, and said to the concierge with a smile: "You go back and do your business first, I want to take a look around here."

Yang Qiuchi asked Master Long to reward the concierge with two taels of silver. The concierge left with joy and thanks.

Yang Qiuchi walked to the ruins and ordered the guards to carefully move a layer of tiles on the second granary ruin that the gatekeeper said first caught fire, revealing the dark wood below. First observe the cracks carefully, and then use a small knife to scrape the scorch on it to see.

Yang Qiuchi ordered the guards to carefully clean up the tiles and bricks near the bottom of the log, squatted down and carefully cut off a layer of ashes on it, revealing a few pieces of unburned wood. He picked up one and looked at it, nodded.

After the inspection of this granary in the north, Yang Qiuchi asked the Jinyi Guards to move away the tiles on the third granary ruins. After careful inspection, they continued to check the granary ruins in other places, but the inspection speed afterwards was faster. By the time all the inspections were completed, it was already dark.

Song Yuner and others did not dare to disturb Yang Qiuchi, and watched him busy quietly. After he finished his work, he asked, "Brother, have you found anything?"

Yang Qiuchi patted the dirty hands and said, "It's not a fire, but arson on purpose!"

Ah? Everyone was shocked. Deliberately setting fire to burn disaster relief food? This is a death sentence.

Song Yuner asked, "Brother, are you doing it wrong?"

"It's not wrong. Come and see." Yang Qiuchi walked to the ruins of the granary that first caught fire and pointed to a piece of charred wood: "The fire was the first to burn here."

"Brother, you are so amazing. How do you know that so much charred wood is burned from here?"

"Did you notice that the wood here is different from other places?"

Song Yun'er walked to the wood and looked at it. It was a big round pillar. It looked like a pillar in the granary. After the granary collapsed, it fell to the ground. She found a small stick and poked the charred log, looking at Yang Qiuchi in confusion: "Nothing is different?"

Yang Qiuchi ordered Nangong Xiong to come to the ruins of other granaries in the south to carry a piece of charred wood, put the two pieces together, and asked, "What now? Have you found something?"

Song Yuner carefully looked at the two burnt woods, and it was covered with burnt cracks. She couldn't tell the difference and shook her head.

Yang Qiuchi pointed to the charred cracks on the surface of the wood and said, "The carbonization of the log on the surface of the granary that caught fire is relatively shallow - carbonization means the degree of burning of wood to black carbon - wood burning and carbonization. The depth of carbonization on the surface is enhanced as the fire gradually increases. The carbonization of the wood in this granary is obviously lighter than that of other granaries. From this, we can judge that this is the fire point."

"The cracks formed by burning wood around the fire point are shallow and thin. That is because when the fire at the fire point is ignited, the fire is relatively small and the fire is not large, and the log is thicker and cannot be fully burned, so it only burns the surface. The moisture in the wood is sprayed out by heat, which forms such shallow and thin cracks. As the fire becomes larger, the intensity of the wood burning increases, and the cracks formed become thicker and deeper."

"After the fire was ignited, the granary was hollow and the fire mainly burned the upper part of the roof, so the part below the pillar was not burned sufficiently. When the roof was burned through, the beams were burned, and the heavy tiles covered on it collapsed. Since there was no air, the pillar could no longer continue to burn, which retained the original appearance of the fire."

Yang Qiuchi pointed to the wood that Gong Xiong brought over again: "This one is different. This is only burned after the fire is very high. The temperature is very high, the fire is very fierce, and it burns very quickly, which will form such deep and thick cracks."

Song Yuner understood a little: "Brother, you mean that if you find this kind of wood with relatively small and thin cracks, it is the fire point, right?"

"In most cases, this is the case," said Yang Qiuchi. "Especially in the case of wind, the fire goes with the wind, and the fire burns more and more. The fire at the fire point is blown by the wind and extends in the wind direction. Therefore, the combustion degree of combustible materials near the initial fire point is relatively lighter than that behind. Because the combustion degree of the fire point and the wood in other places behind is different, their cracks are also different. You can find the fire point based on this."

"However, when there is no wind, the situation may be the opposite. Because the fire point continues to burn, the combustion time will be longer than other places, and the combustion will be more sufficient and the combustion will be stronger. Other places may be extinguished by water in time due to rescue, and the combustion will be relatively light. In this case, the cracks formed are just the opposite."

Song Yuner nodded as if she had some insight and said happily: "I understand. You just asked the doorman if there was wind and what the direction of the wind is. It was just to judge the fire point."

"Yes." Yang Qiuchi smiled, "In fact, after analyzing the difference between the fire point and the burning marks of other fire points for a long time, it is not as easy as a more intuitive evidence to explain the problem."

"What evidence?" Song Yuner said.

Yang Qiuchi pointed to a granary that collapsed half of the granary in the north: "Did you notice it? This granary was not burned, but demolished."

When everyone saw that, although most of the granary was charred black, the half granary in the north was still relatively complete. I don’t know what happened, so I looked at Yang Qiuchi with doubt.

Yang Qiuchi said: "The remaining granary is the first granary counted from the north, which is in the north. As I analyzed just now, the second granary caught the fire first, but the north wind blew that night, and the wind was very strong. The fire spread along the wind and did not burn back against the wind."

"In addition, the distance between the two granaries is more than ten steps, which is quite far. Therefore, the granary in the upper wind is not burned except by fire. The granary in the other granary in the lower wind is burned. This is the best proof of the fire point."

Yang Qiuchi walked to the bottom of the log in the second granary, pointed to the carbon wood that had not been completely burned in the past few sections, and said, "Do you pay attention to these small pieces of wood that have not been burned? This is the most important evidence to prove the setting fire."

Song Yuner and others looked at Yang Qiuchi in confusion. How did the burnt wood that had not been burned for a few bars prove that it was a setting fire?

Yang Qiuchi said, "Think about it, how could there be such a small pile of wood on the corner of the granary house? What is it for?" Yang Qiuchi picked up one, scraped off the coke part on it, revealing the true color of the wood inside, and handed it to the little maid Yuechan: "When you were a child, you must have cooked it in the countryside. Look, what kind of wood is this?"

Yuechan took it with both hands, turned and looked carefully: "Young Master, this is a good pine tree with grease on it."

"What are you doing?"

"It's best to start the fire when cooking with this kind of dry pine wood with a lot of oil."

Song Yuner and others were all wealthy and had almost never been in the kitchen, so they were not familiar with the firewood used to cook and ignite. After listening to Yuechan's introduction, they suddenly realized that in a place where fireworks are strictly prohibited, such a small pile of fire-induced objects appeared. What was not used to set fire? It seems that this is the fire point that deliberately sets fire.

Master Jin heard Yang Qiuchi's analysis and immediately opened his eyes and nodded in praise. He remembered something and asked curiously: "Sir, what is your intention to find this fire point?"

Song Yuner rushed to say, "Hey! I don't know this, of course it's a judgment whether it's arson or a fire - am I right? Brother."

"Smart!" Yang Qiuchi praised, "Yun'er is right. Find the fire point and find the real cause of the fire based on the fire point."

Song Yuner turned her head a little proudly, but when she saw the charred granary wreckage, she frowned and asked, "Brother, I'm so confused about such messy things. How did you find out that this was intentional setting fire?"

"Didn't I say it? Any crime will leave traces!" Yang Qiuchi walked forward for more than ten steps, pointed to the ground and said, "Just just now, the doorman said that the room where the guards were on duty was located here. Since it was determined that the fire was burned down by the guards' fire for heating, the room was in the south, and the fire point we determined just now was more than ten steps away from the north. Logically, if the fire point accidentally caught fire due to heating, the fire point should be near the heating stove. How could this fire point run to more than ten steps away?"

Song Yuner thought for a while: "Can they move the stove there?"

"It's possible," said Yang Qiuchi, "but the pillar we just looked at was located in a corner of the granary. The ruins showed that other places were open spaces. It was more than ten steps away from another granary. In the cold winter, who would not keep warm in the room and run to the corner of the granary outside to keep warm? It's not in common sense."

Song Yuner smiled: "There are cases that are not consistent with common sense."

"But there are more cases that are consistent with common sense! Solving cases means listing the most likely situation as the primary investigative target. Moreover, when all the situations that are consistent with common sense are excluded, the truth is often the case."
Chapter completed!