Science Article

Photo in public domain

Benjamin Franklin flew a kite with a metal key on the string in a thunderstorm—a very dangerous activity. The key attracted charged particles, not, as the myth has it, a lightning bolt.

On a stormy summer day in 1752, Benjamin Franklin conducted an extremely dangerous experiment that both science and history books still describe—sometimes incorrectly. As the American scientist and inventor recounted in a journal article, he stepped outside into the storm and flew a silk kite with a key attached to the bottom of the twine. Contrary to popular misconceptions, Franklin didn’t discover electricity (a natural phenomenon observed since prehistoric times) and he wasn’t struck by lightning, which would have been fatal. His metal key attracted a small amount of charged particles from the base of the thundercloud, proving that lightning is static electricity. He assigned the terms positive and negative to describe these unbalanced charges. Other scientists of the day conducted similar experiments with iron rods rather than a kite and a key.