In the afternoon, in the palace garden, Yuwen Wen and his children were playing games. Yuwen Wen and Chen Ja and Chen Hua disguised as shopkeepers and clerks in the grocery store, while Yuwen Weiting, Yuwen Huiying and Yuwen Qiongying disguised as customers.

The grocery store that was temporarily built was quite decent, with all kinds of gadgets. The three school-age children were so confused that they were holding copper coins and preparing to buy things with great enthusiasm.

Yuwen Weiting, Yuwen Huiying, and Yuwen Qiongying are the same age. If they were later generations, they should have been a first-grade primary school student. Now they have learned some simple addition and subtraction, so they can play games of buying things.

Yuwen Weiting looked at the red oranges, swallowed his saliva, looked at the "shopkeeper" and asked, "shopkeeper, how much does this orange cost?"

"Three cents are apiece." Yu Wen Wen finished speaking and added with a smile: "Little Langjun, this orange is delicious, it costs three cents, and three are sold to you at a price of ten cents."

Chen Jae and Chen Jae on the side almost laughed when they heard this, but Yuwen Weiting's eyes lit up: One orange costs three cents, and one can buy three for ten cents, which is so cost-effective!

"I...I'll buy..." Yuwen Weiting took out the copper coins and was about to count them, but Yuwen Huiying pulled her hand: "Brother! You can't buy it!"

"What are you doing..." Yuwen Weiting struggled, unable to stop shaking his hands, trying to shake off his sister's hand: "I want to eat oranges!"

Yuwen Huiying is three days older than Yuwen Weiting, so she is an older sister. Girls generally develop intelligence earlier than boys of the same age, so the clever sister heard something was wrong and wanted to stop the stupid brother.

But the silly brother didn't listen and wanted to buy three oranges for ten cents.

Yuwen Qiongying, who was born one day later than Yuwen Weiting, also found that the situation was wrong, but she reacted very quickly, not just to pull, but to explain it with simple principles:

"Shiyilang! One orange is three cents, and three is nine cents. Why do you have to buy it for ten cents?"

"Ah?" Yuwen Weiting was stunned when he heard this, stared at Orange with wide eyes, then looked at the copper coins in his hand, then put them down and started counting his fingers.

After counting it a few times, I found that as my sister said, buying three oranges only costs nine cents. Then, it is not cheap at all for ten cents, so he has to give one more cent.

Thinking of this, Yuwen Weiting's eyes were so anxious that he looked at Aye and blurted out: "You are a profiteer!"

My son called me a profiteer, and this behavior was very unfilial, but now he was playing a game of buying things. Yuwen Weiting was "too deeply involved in the play", so Yuwen Wen would certainly not care.

He laughed and showed off his face as a profiteer: "Little Langjun, I'm not lying. I always marked the price clearly. Oranges cost three cents per and ten cents per three. These two prices are clearly told to you."

"You are willing to buy three for ten cents, that's your business, right? How can you say I'm a profiteer?"

Yuwen Weiting was blocked by this sentence and could not argue. Yuwen Huiying said first: "The shopkeeper is wrong. It is obvious that there is a problem with the price, so I deliberately took it out. This is fooling people!"

Yuwen Qiongying immediately echoed: "Yes, this is fooling people!"

Yuwen Weiting also agreed and nodded vigorously: "It's right, this is fooling people, the shopkeeper is a profiteer!"

"No, no, no, no, this is not fooling people. I am clearly marking the price and not lying to others. You can't understand it yourself. You don't know what you choose. You can't say that I am a profiteer. If I go to the government to go to court, my parents and officials wouldn't say that."

Yuwen Wen began to reason with his children: "Why do we need to learn arithmetic? It is to avoid losing money. Otherwise, if you buy an orange, you can't understand the price and can't count the money, you will spend money in vain. You said, isn't this a loss for not being educated?"

The three nodded, and their father's teachings made them realize the importance of reading and writing and being able to calculate.

......

In the evening, Yuwen Wen and his children finished supper together, moved to the study room, and urged a machine model.

This is a steam engine model. From the appearance, it is no different from other steam engine models.

Chen Wu brought some information over, saw the machine, looked at it carefully for a while, and asked, "Erlang, does this steam engine model burn gas?"

Yuwen Wen nodded: "That's right, it's burning gas, and electricity ignites, and its power is stronger than burning coal."

Because of the technology of using coal to make gas, gas lamps were used in the palace, and so were many workshops, so Chen Wu was familiar with gas.

"Water with wood is not as fast as coal, but with coal, but with coal, it is not as fast as gas. Do you know why this is?"

Chen Hua didn't know the answer to the question asked by Yuwen Wen.

He thought about it, drank a cup of tea, adjusted his thinking, and introduced the principle in another way.

Wood, coal, tincture oil and gas are all fuels and have one common feature, which is that they can burn.

Burning will release heat, which will boil water and melt the ore.

However, different fuels of the same weight have different "calorie values".

If one pound of dry firewood is fully burned, then the heat released when one pound of coal is two parts, and the heat released when one pound of tincture oil is three parts.

Of course, Yuwen Wen said this kind of calorie ratio quietly, but this is the truth. Chen Meng understood it, and Yuwen Wen continued to say it.

One kilogram of coal can be produced by passing through a gas generator, and three volumes of pure gas can be produced, and the heat generated by these three volumes of gas when burned is at least three times that of one kilogram of coal.

For example, if you use one pound of coal to boil water, the heat generated when you burn completely is one portion.

Then, make this pound of coal into gas and then burn into the same boiler furnace. The heat generated during combustion is three parts, the water will be boiled faster, and more steam will be generated in the same time.

Hearing this, Chen Wu suddenly realized: "So that's it. In the same time, the steam produced by the gas boiler is more than the steam produced by the coal-fired boiler, which can make the cylinder output more powerful."

"Yes." Yuwen Wen nodded.

Chen Wu asked again: "If this happens, it is better to convert all coal-fired boilers into gas boilers, and then use coal to make gas and burn gas. It's more cost-effective."

"Yes." Yuwen Wen looked at Chen Wu and smiled and said, "One three in three, three in ten in three are sold at a cheap price!"

"Ah?" Chen Hua was stunned. She heard something was wrong from Yuwen Wen's words.

Yuwen Wen continued: "A kilogram of coal is used to make three volume units of coal, and the heat generated by this gas is equivalent to three kilograms of coal. In other words, such a change directly turns one kilogram of coal into three kilograms of coal, which sounds good."

"But you ignore the cost. Let's put it this way, spend money to buy a pound of coal, and then spend money to turn this pound of coal into three-volume unit of coal. The total amount of money you have to spend can buy four pounds of coal."

"That is, the cost of buying one pound of coal and turning it into three pounds of coal can be at least four pounds of coal. Therefore, it is better to burn coal directly by using coal to make gas and then burning the boiler with gas."

Chen Wu was a little embarrassed when she heard this. This afternoon, she thought that Yuwen Weiting thought that "one for three, one for ten, three for ten, three for ten," was a fool. Now it seems that her idea is also stupid.

"However, it is good to burn gas and iron or even steel for blast furnaces. After all, the higher the temperature of the furnace, the ore will melt completely. The temperature required for steelmaking is very high. Why not use fuel with high calorific value?"

Yuwen Wen further explained that he let his beloved know that gas has a new place to use: "Also, coal is used to make gas, and this gas has a new purpose in addition to lighting and smelting, but it is amazing."

Chen Wu became interested when he heard this: "What is the purpose?"

"The way to burn." Yu Wen Wen smiled mysteriously, a little proud, "The way to burn is different, the effect is completely different."
Chapter completed!