In the past, people always thought that the appearance of lightning and thunder in the sky was a manifestation of nature's great power. However, Franklin boldly suggested that this is a "discharge phenomenon" of nature. 1752 One day in July, he personally made a kite experiment to attract lightning.
That day, the sky was overcast with thunder and lightning. Franklin took his son to the suburb of Philadelphia. He made a white silk kite with a slender iron bar tied on it. The kite is tied with hemp rope, and the end of the hemp rope is divided into two branches, which are connected with a copper key and a small piece of silk thread respectively. He put the kite into the sky with silk thread in his hand.
Not long after, suddenly, a bright flash of lightning flashed and suddenly it rained cats and dogs. Franklin felt a little numb in his hands. When his finger approached the copper key, a blue electric spark immediately shot at his finger. He felt numbness in his arm and was almost knocked down. At this time, he shouted excitedly: "This is electricity, just like the spark in the laboratory!" " "
The kite experiment caused a sensation all over the world. Later, Franklin also invented the "lightning rod" to protect thousands of buildings and towers from lightning.