What are the inventions related to children?

100 years ago, there was a boy named Humphrey Potter in England who was hired by others to watch the steam engine. His task is to release steam whenever the lever of the steam engine falls. Children are naturally active, so it is difficult to sit by the machine for a long time and stare at the steam. Later, Potter finally had an idea. He installed some wires and bolts on the machine to make the valve open and close automatically. In this way, he can not only get away and have fun, but also improve the efficiency of the steam engine by 1 times. In this way, Potter discovered the principle of double pistons. A long time ago, there was a boy named jeffrey wright in America. He was herding sheep for a farmer. Every day, he drives the sheep to the pasture and watches them not to cross the surrounding wire fence to eat in the neighboring vegetable garden. One morning, the weather was pleasant and the breeze was blowing gently. White unconsciously fell asleep on the pasture. Suddenly, he was awakened by a roar. When he opened his eyes, he saw the farmer furious with him: "Damn guy! Sheep have trampled the vegetable garden in a mess, and you are still sleeping comfortably here! " The little shepherd boy knew that he was wrong and bowed his head and said nothing. Since this incident, White has been thinking about how to make a barbed wire around the sheep.

He remembered that there were roses in the west of the pasture, but the sheep had never been there. It turns out that they are afraid of thorns on roses. The little shepherd boy patted his thigh happily and said to himself, "There is a way. Just add some thorns to the wire and you can stop the sheep! " "

So he found some iron wires, cut them into 5 cm long pieces and tied them around the pasture as "thorns". After the completion, the sheep still want to try to cross the wire fence and eat the vegetables in the garden as before. However, the "thorns" on the barbed wire made them feel unbearable pain. After many pains, the sheep became honest and never tried to cross the wire fence again. Six months later, jeffrey wright applied for a patent, and then this barbed wire was widely used all over the world. Complaining about "little boy" perfume

A few years ago, a 9-year-old American boy, Blunden Clark, sprayed his father's perfume on his body in order to attend a class reunion. However, this move was criticized. Neighbors complained to Clark's mother that the smell of her son was too strong for minors to bear. In fact, all the perfumes sold in the market at that time were for adults. In a rage, Clark decided to develop a perfume suitable for boys. So he found all available materials, including detergent, children's soap and essential oil. With the help of my mother and a chemist, I finally made a perfume. The fragrance of this perfume is very light, just like fresh air. Clark happily named it "Little Boy" perfume. After four years' efforts, Clark set up "Blunden Company". After applying for a patent, he sold the product to a large American retail company. "Little Boy" perfume is favored by young customers and has been selling well since it was put on the market. Greed leads to the "Mpumba effect"

1One day in the summer of 963, a Tanzanian middle school student named Mpumba added sugar to his milk to make his favorite ice cream. At that time, several students were also preparing to make this delicious ice cream. He thought that if he waited until his hot milk was cold before putting it in the refrigerator, other students would have filled the refrigerator by then. In order to occupy space, Mpumba first put the cup with hot milk in the refrigerator. Unexpectedly, his hot milk freezes much faster than others' cold milk. However, at that time, his classmates and teachers were very dissatisfied with this discovery, and some even regarded it as a joke. In the face of everyone's ridicule, Mbamba did not give up easily. He came to Dar es Salaam University and asked Dr. Osbourne, a professor of physics. Experts have done the same experiment, and the results are exactly the same, which proves that this natural phenomenon really exists objectively. This discovery aroused the interest of many scientists in the world, and was later called "Mpumba effect".