Yu Hua looks forward to the school’s attitude towards portable lighting sources.

If you support me, the current misfortune can be barely maintained, if you object...

Yu Hua could only give up with pain.

After all, although portable lighting sources are a necessity for students, in fact, they violate the school's dormitory management regulations. The school has turned a blind eye to students' reading with kerosene lamps.

Attitudes from the school are crucial.

From a personal perspective, Yu Hua hopes that the school can support it, at least not object, although life is not just about being miserable at the moment.

But what Yu Hua wants now is to live in vain.

Those are hundreds of oceans, which can be converted into the RMB of later generations, and it will cost tens of thousands of yuan.

Fang Yu, who was directly abandoned, bit her lip: "..."

I could only watch Yu Hua go out under the call of Mr. Ren.

Helpless, but irritable, my whole mood suddenly became bad. Yesterday, the huge movement in the boys' dormitory had spread throughout the school. After a night of fermentation, everyone was extremely curious about Yu Hua's portable lighting source.

Especially girls!

Due to the limitations between men and women, girls cannot go to the boys' dormitory to watch it up close, let alone experience the taste of an independent electric light.

After the morning exercises today, Fang Yu, who was quiet and low-key in daily life, could not resist the curiosity in her heart.

I don't know when he will be back.

Sitting in the seat, Fang Yu was eager to see Yu Hua outside the window.

When he arrived in the corridor, Mr. Luo Wenguang looked natural and could not see any emotions. Yu Hua showed a ignorant and simple look, and greeted respectfully: "Hello sir."

"Yu Sheng, I heard you made an independent electric light?" Luo Wenguang looked at the tender and a little innocent Yu Hua and smiled.

"When I go back to the dormitory where the students are, students light kerosene lamps to read books and study every day. The kerosene lamps are dim, resulting in weakening vision. The students remembered the knowledge they had learned before physics. After studying for a while, they used the equipment on the market to create a set of portable lighting sources, that is, independent electric lights, so that the students in the dormitory can read books under the light of the electric lights, thereby reducing the damage to their eyes." Yu Hua heard Luo Wenguang's inquiry and immediately said something he had already compiled in his heart.

Focus on describing the disadvantages of kerosene lamps and emphasizing that dim light will lead to weakening of vision. The purpose of making this set of independent lamps is to be the students in the dormitory, not to make money.

There is no mention of making money by relying on portable lighting sources.

When Luo Wenguang heard this, he immediately became interested: "Oh? Will dim light lead to weakening of vision?"

This was the first time he heard this theory.

"Yes, for example, when you are usually in a darker environment, your eyes will become astringent and swollen in a short while, which will lead to weakening of vision over time." Yu Hua briefly explained and popularized common sense that is well known to later generations.

Common knowledge that most people in later generations knew was extremely novel in the Republic of China period when knowledge was scarce.

For example, the dim light causes vision to weaken. Many teachers and students have experienced it, but they have not summarized it into written level theoretical knowledge.

"I didn't expect that kerosene lamps have such disadvantages, so when reading books, you must read them in a bright environment?" After listening to the concise and straightforward description, Luo Wenguang recalled the past when he read books, and he was indeed as Yu Hua described, and sighed in his heart.

Yu Hua nodded: "Yes, but it is not good to have too high brightness. Too high brightness will reflect light, which will also cause vision to be weakened."

“Not bad.”

Luo Wenguang looked at Yu Hua and nodded and praised: "This view is very good and can be promoted to the whole school. Yu Sheng, how effective is the set of independent electric lights you have made and how long can it take to stabilize the lighting?"

"Using a 100-watt incandescent lamp, a dormitory is bright and has a moderate brightness, with a small impact on vision, can be stable lighting for about 3 hours, and a set of equipment can last at least three years." Yu Hua heard Mr. Ren's question and gave relevant performance parameters as he knew it.

Luo Wenguang nodded repeatedly and continued to ask: "Where is the cost?"

"Recharge once a day, it costs about 10 cents." Yu Hua replied.

"One cent a day, three hours a day, is much more efficient than the use of electric lights in school, and the service life is as long as three years. No wonder so many students last night were like crazy."

Luo Wenguang got the data and immediately calculated the monthly fee for portable lighting sources. He praised: "The independent lights you made are very good."

"Uh...sir, don't you criticize the students?" Yu Hua asked carefully when he heard Luo Wenguang's approval.

"criticize?"

Luo Wenguang was a little confused: "Sir, why should I criticize you?"

"The equipment made by the students violated the rules of turning off the lights and going to bed at half past ten in the dormitory. There was such a big noise last night, and I thought you would criticize me." Yu Hua said in a low voice.

"Who do you really abide by the rules of turning off the lights and going to bed after 10:30? It's late at night, all the kerosene lamps in the men's and women's dormitories are lit, and the school won't blame you for this." Luo Wenguang laughed and shook his head, looking at Yu Hua who was a little cautious, and said.

What are the rules for turning off the lights at half past ten years to sleep?

Ask yourself, have you followed it?

Since the establishment of Peking No. 4 Middle School, this regulation has been in vain and no students have followed it.

After the evening study of each student from No. 4 Middle School, they either go to the library or go back to the dormitory to continue to go to bed until twelve o'clock.

“…”

Yu Hua heard that he didn't know what to say.

"Sir, what about the independent electric light? Many students want to buy one." After taking a deep breath, Yu Hua raised the most critical question.

Luo Wenguang waved his hand and didn't care: "They want to buy it, you buy it, what's the point."

"Dong!" Before Fang Yu could finish speaking, a low and distant bell sound came from outside the classroom.

Class is on.
Chapter completed!