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Franklin is probably most famous for his kite experiment. As the story goes, he and his son raised a silk kite on a long cord into a sky filled with black clouds.
A metal rod was bound to the kite, and an iron key was attached to the end of the cord. Franklin and his son tied a silk string to the end of the cord, where the key was, and held on to that.
As storm clouds approached, the metal rod drew electricity (what Franklin called “electric fire”) from them. When rain made the kite and the cord wet, electricity was freely conducted (water is a good conductor of electricity) from the rod to the key. Franklin touched the key with his knuckle and received an electrical shock. This proved his theory that lightning was really electricity.
