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The military equipment bureau of the Qin Dynasty gathered the country's top-notch skilled craftsmen. At this moment, most of them were listening attentively to the explanation of the Qin Emperor.
Qin Mu not only explained, but also conducted a small experiment himself.
He found two pieces of paper, each one foot long, and held one in each hand, letting the two pieces of paper hang naturally, with a distance of about two inches between them.
"If I blow air vertically downwards from the gap between the two pieces of paper, guess whether the two pieces of paper will float outwards?"
"meeting."
After Qin Mu asked this question, almost everyone thought that the two pieces of paper would definitely be blown to the sides by the airflow.
Seeing that they answered so confidently, Qin Mu didn't say much. He blew a long breath vertically downwards from between the two pieces of paper. What all the skilled craftsmen in the Military Equipment Bureau didn't expect was that the two pieces of paper did not float outwards as they expected, but instead stuck together inwards.
Not until Qin Mu blew out all the air did the two pieces of paper separate again and hang down naturally.
"You try it."
Qin Mu handed the pieces of paper to the curious craftsmen as he spoke. Everyone followed Qin Mu's example and blew air vertically downwards from between the two pieces of paper. The strange thing happened again. The two pieces of paper still did not float away and remained stuck together.
Some craftsmen did not believe it and took a deep breath, making their stomachs bulge, and then blew down hard. However, the harder they blew, the tighter the two pieces of paper stuck together.
In the end, everyone was convinced.
Qin took the paper back again, this time using only one. Instead of placing it vertically, he held it horizontally, with his thumb on top and four fingers supporting it underneath. Because the paper was soft, the parts that the four fingers could not reach still naturally bent down.
Qin Mu said: "Watch carefully, I will put it on the top of the paper and blow air horizontally. See what happens."
As a result, when Qin Mu blew a long breath, the part that was originally hanging softly where his fingers could not reach immediately floated up horizontally.
Now, all the skilled craftsmen no longer found it strange, but when Qin Mu asked them why this phenomenon occurred, no one could answer.
Qin Mu did not expect them to understand, so he patiently explained: "Let me tell you this, there is pressure in the air, and when the air is still, the pressure on each side will be very uniform. If the air passes through both sides of the paper at the same speed, then the pressure on the paper from both sides will still be uniform, and the paper will not stick together or float up;
But when we blow air, we artificially increase the speed of air flow on one side of the paper. Note that this is an iron rule: the faster the air speed passes through one side of the paper, the smaller the pressure on this side will be;
The pressure on the other side of the paper remains unchanged, so the relative value will be greater than the side where the air is blown, which will push the paper toward the side with less pressure. So you can see the paper floating horizontally.
I want to emphasize it again, theoretically, on the two sides of an object, the side with faster air flow will bear less air pressure.
If an object is placed horizontally, the smaller the pressure above, the greater the pressure, or lift, exerted by the air below on the object.
If you look closely at the wings of birds, you will find that when all birds spread their wings, they all have an upward arc. Why not a flat or downward arc? I tell you, this is the secret of how birds can fly in the sky.
When people heard this, they all held their breath. Flying has always been the dream of mankind. Thousands of people have paid the price of their lives in order to fly.
The emperor had long been regarded as a god-like existence among the people. In the eyes of the craftsmen, it was normal that he knew the secret of birds' flight. This was something that everyone was extremely eager to know.
Qin Mu looked at the pairs of eager eyes and continued, "Because the wings of birds have an upward arc, when the air passes through the wings of birds, the flow speed above the wings will increase, the pressure above will decrease, and the air pressure below the wings will provide an upward pressure for the birds, just like the piece of paper that just floated up. This is the secret of their ability to fly."
A young craftsman named Shi Qing couldn't help but ask: "Your Majesty, why do birds' wings curve upwards and the air speeds up when it passes over the wings?"
Qin Mu said encouragingly: "This is a very good question. We can make a model to test it right away."
There were many craftsmen in the Armory. Under Qin Mu's guidance, they quickly planed out a piece of wood with a small arc at the bottom and an upward arc similar to that of a bird's wing at the top.
Then he took a basin of water and paddled horizontally in the water with the planed board;
After careful observation, Shi Qing suddenly realized, "Your Majesty, I understand that air, like water, cannot tolerate gaps. Once there is a gap, they will rush to fill it. Because the wings have an upward arc, when flying, the wings will block a gap behind the upper part of the wing, so the air above will rush to fill the gap, causing the air above to flow faster.
According to what Your Majesty just said, the side where the air flows faster has the lowest pressure. Birds use the upward arc of their wings to make the air above the wings pass faster, so the air below lifts the bird up. Your Majesty, is what I said correct?"
"Yes, absolutely correct. If you don't understand this principle, the glider I want you to make won't fly. If you can figure out this principle and make it like a bird's wing, it won't be impossible for it to fly with a person."
The reason why Qin Mu spent so much time explaining these things to the craftsmen was that he hoped that the craftsmen would not only make the hang glider according to his drawings, but also understand the principles behind it;
Once you understand this principle, you can apply it to many things, not just making a hang glider. For example, when a sailboat is sailing against the wind, you can use this principle to sail.
Qin Mu hopes that through his own efforts, the people of Daqin can understand some basic sciences faster and more. Only with these basic sciences as a foundation can we talk about the great development of science and technology.
Holding the newly planed wood, he continued to explain to them: “Look at this upward arc. When moving forward, this arc will definitely bring resistance, but within a certain range, the greater the curvature of the upper arc, the greater the lift-to-drag ratio;
If the curvature exceeds a certain range, the drag will increase rapidly, and the lift-to-drag ratio will decrease. So what is the most suitable curvature? You can catch a swallow and measure its wings accurately to get an approximate curvature value.
But the wings of a swallow are very small, and if the measurement is not accurate, a slight error will lead to a huge mistake after magnification. So after getting the approximate arc value, you still need to test it repeatedly to get the maximum lift-to-drag ratio. "
Shi Qing volunteered and said, "Your Majesty, can you please give this project to me? I will do my best to complete the task assigned by Your Majesty."
Shi Qing was very young, only twenty-six years old. From his burning eyes, it was not difficult to see that he was extremely eager to be the first person to fly into the sky.
Interest is the best teacher, and from his performance just now, Qin Mu felt that he had a high level of understanding. So he said, "Okay, I will leave this research and development work to you, and I hope you will not let me down."
"Long live His Majesty. Long live His Majesty. Long, long live His Majesty!" Shi Qing was so excited that he knelt down and kowtowed repeatedly.
Qin Mu also told him how to reduce the weight of the hang glider, how to use the dive angle to increase speed and gain lift if it could fly, etc. Shi Qing wrote them all down.
In addition to the hang glider, Qin Mu also went to see the development of the flintlock. China had flint very early, and flint was made of flint, and flint contained a lot of phosphorus and manganese. It was easy to fly sparks when struck.
Installing flint on the gun to replace the traditional matchlock for ignition is a project that Qin Mu asked the Military Equipment Bureau to develop a long time ago. Several samples have been produced so far. I believe that as long as further improvements are made, it can be put into mass production.
In addition, Qin Mu also watched the first lathe manufactured by the Military Equipment Supervision Bureau.
The ancients were not unfamiliar with lathes. People knew how to use simple lathes to process things like jade very early on.
In ancient times, the manufacturing process of jade was extremely complicated. Rolling a piece of jade required drawing a pattern, sawing the material, making the embryo, making the inlay, polishing, engraving, etc. Jade is very hard and cannot be engraved by ordinary metal knives.
During processing, a foot-operated belt drive device is usually installed on a table or stool to drive a wheel to rotate. The wheels can be large or small, and drilling, hollowing, etc. are all completed in this way.
Although this tool for processing jade is relatively simple, it is undoubtedly the prototype of machine tools.
Now the Ministry of Industry has mined a kind of ore called heavy stone from the Dagengling area of Nan'an Prefecture in Jiangxi Province. After high temperature and a series of complex smelting processes, a kind of steel is obtained. It is extremely hard and can be used to make lathe drill bits for processing iron tools.
The appearance of this drill bit alone gave Qin Mu a new understanding of the smelting technology of this era. What was even more unbelievable to him was that the craftsmen in the Military Equipment Bureau actually said that similar drill bits for iron tools had existed in the Sui and Tang Dynasties.
Qin Mu didn't know much about minerals and didn't know what this heavy stone was.
He asked, and found out that Shang Xi, who had improved the smelting furnace last time, had improved the smelting method again. He made a crucible with graphite clay, then cut the iron into blocks, placed them in a closed graphite clay crucible, heated the outside of the crucible, and the iron melted into high-carbon molten steel, which was cast into small ingots and then forged into the desired shape.
The steel used for gun barrels today is also a high-strength steel that is smelted by cutting iron into blocks and placing them in a graphite clay crucible.
In addition to adding heavy stone powder, the smelting process of drill bit steel is more complicated and the cost is also higher. However, seeing the efficiency of the lathe drill bit in cutting iron, Qin Mu couldn't help but sigh that it seemed that he had underestimated the wisdom of the ancients again.
With lathes and drills, the Ordnance Inspectorate not only increased its efficiency dozens of times when processing things like gun barrels, but also unified specifications, facilitating mass production.
Qin Mu was filled with satisfaction. The Chinese were not lacking in wisdom, but they just lacked a fertile soil for displaying their talents.
Now just give them a piece of soil, and without any intervention from you, they will produce amazing results.
Whether it was the various processing techniques of the Military Equipment Supervision Bureau or the smelting methods that Shang Xi had repeatedly improved, they were all figured out by themselves, rather than being forced upon them by Qin Mu.
Qin Mu had just picked up a gun barrel with rifling cut out by a lathe drill when he saw Huang Lianshan, the commander of Yebushou, hurried into the Military Arsenal.
Huang Lianshan came to Qin Mu, bowed, and said, "Your Majesty, there is news from Mobei."
Huang Lianshan stopped talking after he finished speaking. Qin Mu said a few more words to the craftsmen, encouraging them to innovate. Then he walked out of the Military Equipment Bureau with a satisfied smile. As soon as he got in the car, he stopped smiling and asked Huang Lianshan, "What happened to Mobei?"
"Your Majesty, after the troops led by Qitate and Tuya entered Mobei, they joined forces with Zasaktu Khan Norbu to launch a fierce attack on the Tushetu tribe. Two months ago, the Tushetu tribe was defeated. The troops of Shiting went to Liuting, and Tushetu Khan led the remaining troops to retreat to the Burhan Mountains..."
What Huang Lianshan reported to Qin Mu was what happened in Mobei two months ago.
At this moment, in April, the spring breeze has just blown green grass buds on the Mobei grassland. At the foot of the Burhan Mountain at the source of the Onon River, the smoke of war has not yet dissipated. The battlefield is in a mess, with corpses lying side by side. The ownerless war horses licked their masters' corpses, raised their heads and neighed at the sky, looking extremely sad... ...
Burhan Mountain is the place where the Golden Family, which once swept across Eurasia, rose to power and is known as the sacred mountain of the Mongols.
But this sacred mountain did not protect Gunbu. The Tushetu Khanate, the most powerful of the three tribes in northern Mobei, was destroyed at the foot of Mount Burhan as the last smoke of war dissipated.
Tushetu Khan Gunbu and his son Chahundorji were taken before the three Zasaktu Khans Norbu, Qitat and Tuya. Norbu and Qitat swung their knives at the same time and chopped off one head each.
At the moment when the blood of the headless corpse spurted out, nearly 30,000 troops from the Zasaktu Khan and Qitat tribes cheered like a tsunami, and the echo of the towering Burhan Mountain.
Then, Qitate and Zasaktu Khan swore an oath of blood with Gunbu's blood, became friends, and with the Burhan Mountain as a witness, they joined forces and marched south, vowing to pacify the south of the desert and drink from the Yellow River!
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ps: Brothers, the end of the month is approaching, and the storm is about to come. The pressure this month is very high. Although I know it is not easy to get into the top six in the category, I am unwilling to give up. I stayed up until 2:30 last night and presented a big chapter of nearly 4,000 words. Please support me. Everything depends on my brothers and sisters. I beg for your monthly votes!
.(To be continued..)
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