Existing comment:
Decorative panel from a fire engine, 1835
Franklin also researched static electricity that occurred naturally. To test a theory that lightning was electrical, he flew a kite in a thunderstorm in 1752 -- with a key attached to the kite string. Static electricity in the atmosphere -- not a lightning bolt -- charged the kite, string, and key. When a spark jumped from the key to Franklin's outstretched knuckle, he had his proof. He used the length, power, and pain of the spark to measure the strength of the electrical charge. |