Like last year, this year's drought on the Loess Plateau was just as severe, with only a few rains in March and August during the rainy season.

If there is no rain, we can only hope that the snow will accumulate in the cold winter, otherwise the harvest will be dismal next year.

However, even if the wax moon in the Xiaoice era was extremely cold, there was still no snow.

Lao Huang said, this is called God is not beautiful, God does not open his eyes.

Qin Chuan knew that this had nothing to do with God, but something to do with human beings.

Since the Tang Dynasty, the trees of the Loess Plateau have been cut down to build palaces and tombs, and over the centuries, the Loess Plateau has become a bare wilderness.

Without transpiration from trees, the moisture content of the air would be low, and rainfall and snowfall would naturally decrease.

Fortunately, on Chinese New Year's Eve, the long-awaited snow finally arrived.

It was a heavy snowfall.

Qin Chuan and a group of subordinates had a Chinese New Year's Eve dinner, and when he was taking his two wives to set off fireworks made by Zhao Mancai in the inner courtyard, white goose feather snow suddenly fell in the sky.

It was as white as the white mink coat on Wen Suxin's body.

Qin Chuan hugged the big-bellied Wen Suxin with his left hand, stretched out his right hand into Li Yueru's coat, and smiled at the dark night sky with white snowflakes.

……

In the eighth year of Chongzhen, the first day of the first month.

Qin Chuan came to the third year of the Ming Dynasty.

On the morning of the first day of the new year, the heavy snow stopped, and the Guan Emperor army on duty at Black Mountain Fort hurriedly came out to clear the snow and clear a road.

Soon, Qin Chuan stepped on the road he had just swept out, and went to pay New Year's greetings to his father-in-law, Wang Jizong, Chen Zhan, Li Xuejing and others, and not long after, accompanied by this group of subordinates, he went to pay New Year's greetings to the battalions of Emperor Guan's army, and also allocated a sum of silver and red paper to each battalion head to seal red envelopes for the soldiers.

All the states and counties under the rule of Qinchuan are festive, although the people are still short of food and clothing, but no one is hungry, many people exchange the surplus grain for one or two catties of meat, and then ask the literate gentleman in the village to write a pair of Spring Festival couplets, at the beginning of the New Year, a few babies in front of the house to paste the Spring Festival couplets, build a snowman, giggle a snowball fight, the mother-in-law is at home to make meat dumplings, the house is steaming with the smell of meat, and the chimney is also full of vibrant black smoke.

In addition to festivity, there is also hope.

The people have hope, they know that General Qin can bring them a good life, hope that they haven't had for many years.

……

The snow continued to fall for several days, and by the fourth day of the Lunar New Year, it began to clear up, and the festive atmosphere gradually became busy.

The Guan Di army, which was stationed in the military forts of various prefectures and counties, began to resume their daily training, and the snow in several martial arts arenas was shoveled away, and soon slogans and shouts and curses sounded.

After more than two months of training, nearly 3,000 recruits and soldiers had been screened out, and finally 27,000 remained.

These soldiers have basically memorized the military regulations and adapted to the training of the Guan Di army, and although the formations and marches cannot be uniform, they have also practiced well.

Today, these soldiers have begun to practice military boxing, swords and shields, spears and spears, battle formations, javelins, muskets and other combat items.

After more than two months of full food, many of the originally thin and weak pawns have become stronger, and they run with 20 pounds of weight every day for five miles, and basically no one is left behind.

To this end, Qin Chuan reformulated the training plan, changed to five miles of weight and eight miles of weight, running in turns every other day, and added two compulsory training items, one is a 300-step obstacle run, and the other is a 50-mile rapid march with a weight, the former is practiced every other day, and the latter is practiced every seven days.

These two training programs are not only for recruits and soldiers, but also for all battalion leaders of the entire Guandi Army.

It won't be long before the Guan Di army is about to enter the grassland to fight, and Qin Chuan does not have enough war horses, so he can only rely on the two legs of the Guan Di army to fight the four legs of the nomads.

For long marches, the speed of infantry will be faster than that of cavalry, but for short marches such as running, supporting, pursuing, and escaping, cavalry must have the advantage.

Therefore, a fifty-mile rapid march must be practiced, and Qin Chuan didn't want to walk his dog on the grassland with the Mongolian cavalry.

Luo Zixi and Dong Lisan people have made no progress in the research of chemical fertilizers, and only experimented with the method of preparing sulfuric acid, nitric acid, hydrochloric acid and aqua regia in the laboratory, in fact, the alchemy and alchemy circles have long known how to make three acids, and Luo Zixi and others have only improved the preparation method.

Qin Chuan knew that chemistry was not an overnight thing, but it would depend on a large number of experiments and huge knowledge precipitation to gain something.

Therefore, he didn't urge Luo Zixi and the others at all, but only occasionally went to see the progress, condoled and comforted the three alchemy masters who were still unkempt, talked about the chemical knowledge he suddenly remembered, and ensured that the three masters had sufficient manpower and materials.

Luo Zixi, Dong Li, and Cai Ju were also very hard-working, except for eating and sleeping, most of the rest of the time was running in the laboratory, each with a few apprentices tinkering with various beakers, potions or powders.

Qin Chuan was also tinkering with something, and he spent most of his time in the cannon factory every day, asking Chen Zhan for a blacksmith, and knocking on something every day.

After tinkering for many days, Qin Chuan suddenly called a large group of his subordinates to the artillery factory to observe his new invention.

In addition to Chen Zhan, Li Xuejing, Yan Sanqi and other officials from the Industrial Department, there were also other officials such as Wang Jizong and Wen Cheng.

After everyone entered the room specially vacated by Qin Chuan, there was a curved copper pipe in the middle of the room, one end of the copper pipe was connected to a small furnace, and two discs were connected in the middle, which were connected together with belts.

This thing doesn't look complicated, it's just weird.

"Ignition."

Seeing that everyone had arrived, Qin Chuan waved his hand, and the blacksmith who had been waiting on the side for a long time lit the small furnace, and then snorted and blew, and the flame rising in the furnace began to calcinate the copper pipe.

"General, what is this?"

Chrysanthemum pickers, who have always liked to take the initiative, asked out loud.

"Hehe, you'll find out later."

Qin Chuan smiled and sold a pass.

After waiting for a while, seeing that the heat was almost complete, Qin Chuan held down the disc and pulled it violently, and the disc spun up, and through the belt with another disc also rotated rapidly.

At each end of the copper tube connected to the disc, a piston began to move in and out of the copper pipe rapidly, repeating itself and making a harsh grinding sound.

Everyone involuntarily covered their ears and looked at this scene in amazement.

"Be careful, there's going to leak here."

"Lord Yue, please stand a little farther away, the interface of that section of the copper pipe is a bit thin, I'm afraid it will explode suddenly."

Qin Chuan had already stuffed two balls of cotton in his ear holes, and was pointing at the side.

When everyone heard this, they stood far away.

"General, why hasn't this thing stopped?"

Chen Zhan, who was already curious, looked at the strange thing without blinking, and asked Qin Chuan.

"Hey, hey."

Qin Chuan laughed proudly twice: "As long as the fire of that furnace is not extinguished, this thing will never stop." ”

"Huh?"

Chen Zhan was stunned.

"Really?"

"Absolutely."

Hearing Qin Chuan's words, Chen Zhan opened his mouth wide and looked incredulous.

Everyone around them looked incredulous.

The people present basically had some understanding of Qinchuan's industrial system, and they knew what it meant that the fire would never stop if it was not extinguished.

"That's right, this thing can replace human and animal power."

Qin Chuan laughed smugly a few more times.

"Not only that, but it can even spark a revolution."

"Ahem, that's the change."

"Industrial change."

"It's a machine, we can call it an external combustion engine for the time being."

"If this external combustion engine can be manufactured in large quantities, it can be invested in mining, manufacturing, construction, water conservancy, agriculture and other aspects to replace manpower storage, thus triggering an industrial change."

"I'm afraid you don't know what the industrial law change means, right?"

Speaking of this, Qin Chuan pretended to show a mysterious smile.

At this moment, the external combustion engine suddenly made a muffled "bang", followed by a "bang" sound of air leakage, and the disc and piston quickly stopped.

The copper pipe cracked and leaked.

"Ahem."

Qin Chuan cleared his throat in embarrassment: "This is just an experiment, the structure is very simple, the quality is not good, and problems are inevitable." ”

"The reason I asked you to come here is to let you brainstorm ideas to perfect this machine and slowly explore ways to manufacture it in batches."

"Come on, come on, the big guy can watch it up close."

As he spoke, Qin Chuan beckoned to everyone and motioned for them to come over.

Chen Zhan was the first to rush over, his face full of excitement.

Li Xuejing, Luo Zixi and others also showed fanaticism and rushed over.

They all know what it means to replace human and animal power with machines.

In fact, this is a later Stirling engine, also called an external combustion engine.

The Internet in later generations is a good thing, Qin Chuan once saw a video of others making a simple external combustion engine on the Internet, and he thought it was amazing at the time, because this thing is too simple.

Not long ago, when Li Yueru poured hot water for Qin Chuan to take a bath, she complained that the water vapor was hot and strong, and when she heard the word Jinda, Qin Chuan's first reaction was to think of a steam engine.

Soon the Stirling engine came to mind.

This thing is simpler than the steam engine.

However, when Qin Chuan tried to make a small, simple machine, he found it much more difficult than he imagined.

The working principle of this thing is simply thermal expansion and cold contraction, the primary problem faced by Qin Chuan is the sealing problem, the copper pipe must be sealed, otherwise the gas will slip through the gap after expansion and cannot push the piston.

Then there is the issue of lubrication, the piston and the inner wall of the copper tube must fit together without leaving a void in order to make efficient use of the expanding gas.

But without lubricating oil and rubber, there is a lot of friction between the piston and the inner wall of the copper pipe, so it makes a harsh and unpleasant sound.

As for air leaks...... It's that the seal is not done well, or there is a problem with the quality of the material.

Qin Chuan built this external combustion engine, and the sealing was so poor that there was a harsh sound.

Of course, he never thought about building a qualified external combustion engine, but just wanted to build a model for Chen Zhan and others to use as a reference.

He believes that the group of capable people under him will naturally find methods and raw materials for the production of external combustion engines.