Benjamin Franklin is popularly known for flying a kite during a thunderstorm, thereby discovering that lightning is a form of electricity. This experiment led him to invent the lightning rod, a thick metal spike that reached above the roof and provided a low resistance way for the lightning pulse to reach the ground, thereby protecting the building.
He also proposed a 'one fluid model' of electricity, with electricity consisting of positive and negative charges. This allowed him to explain the phenomenon of static electricity. If two objects are rubbed together and one is made to hold a positive charge, then the other must be negative charge. In his own language, electric fluid is transferred from one object to another. Today we see static electricity as arising from an exhange of electrons.
