From a small perspective, there are many examples of nature.

Once, Franklin was fascinated by doing electrical experiments, and once he designed an experiment of "electric turkey".

In the experiment, Franklin intended to kill a turkey with the current from two large glass jars. When he held the chain connected to the top wire in one hand and the chain in the other, a dazzling electric flame suddenly appeared, and at the same time he made a loud noise like setting off firecrackers. Franklin fell to the ground, shaking violently. Hands with chains curled up into chicken feet, eyes closed, and his face was bloodless. Ten minutes later, Franklin woke up. He slowly opened his eyes and told the people around him in a weak voice that he seemed to see God.

Scientists are human beings and make mistakes. Scientists are outstanding in that they can reveal the mystery of little-known truth from mistakes and failures. Franklin drew a conclusion from this setback: enough batteries connected in series can release huge current like lightning. The next step is to let lightning prove itself: I am discharging violently!

Kites and lightning

For some time, Franklin has been trying to test his hypothesis that lightning and electricity have the same properties. 1752 June, sultry summer came, and the sky was often overcast with thunderstorms. Looking at the unpredictable sky, Franklin was lost in hard thinking. Suddenly, he remembered the big blue kite he flew when he was a child. Suddenly, a bold idea appeared in his mind: with the help of an ordinary kite, he could easily enter the thunderous cloud area and complete his long-awaited experiment. So, he immediately began to work with his 2 1 year-old son William, and carefully made a big kite-a cross-shaped skeleton made of two pieces of wood, and then covered with a piece of silk to form its body and wings. Then, they fixed a metal wire on the top of the kite and tied a metal key on the end of the kite.

One day, the sky was overcast, and there was lightning and thunder. Franklin and William held kites in the sky. Time passed by, and the father and son watched anxiously, but found no signs of electrification. Suddenly, a dark cloud came, and Franklin suddenly found that the hemp fibers at the end of the kite string stood up and repelled each other, just like hanging on an ordinary conductor. He felt ecstatic and subconsciously reached for the key, which caused a strong electric shock. The heavy rain soon fell from the sky. When the rain wet the hemp rope, he saw a beautiful electric spark.

The experiment was successful, and mankind can proudly declare that lightning and electricity are the same substance. Franklin was overjoyed. However, in order to further study and sort out the research results and publish this news in their own newspapers, Franklin and his son kept this secret until June+10, 5438. 10 10 19, Franklin's first report on kite experiment was published in Pennsylvania newspaper.

Lightning rod and baby

At about the same time, Franklin also conducted another lightning experiment: a sharpened iron bar was fixed at the top of the chimney and extended upward for 9 feet. A metal wire extends from the bottom of the iron bar through the glass tube under the roof, leads down through the stairs and connects with the iron spear. On the stairs, separate the metal wires, tie a small bell at each end, and then hang a small copper ball between the bells with silk thread. Whenever Lei Yun passes by, the copper ball will swing the bell, and the spark on it can give the battery. This experiment once again proves that lightning is electricity and the principle of tip attraction and discharge, which proves that this principle can be used to protect human beings from lightning strike.

1760, Franklin installed this device on the spires of Pennsylvania college and government building, which may be the earliest lightning rod invented and actually used by Franklin. When he invited people to visit the lightning rod, people were surprised by this great invention. But a fat rich woman was puzzled: "What's the use of such a sharp iron bar?" Franklin replied politely, "madam, what's the use of a newborn baby?" There was friendly laughter around.