Franklin is probably most famous for his kite experiment. As the story goes, he and his son flew a silk kite on a long cord into a sky filled with black clouds.
A metal rod was tied to the kite. An iron key was tied to the end of the cord. Franklin and his son tied a silk string to the end of the cord and held on to that.
As the storm clouds got closer, the metal rod drew electricity, which Franklin called “electric fire,” from them. When rain got the kite and cord wet, that electricity ran—or was conducted—from the rod to the key. That’s because water is a good conductor of electricity. Then Franklin touched the key with his knuckle. He got an electrical shock. That proved his theory: Lightning was really electricity.