ch 20 #63

During one of Franklin’s initial experiments he noticed that a pith ball or cork would be repelled if touched together but at would be attracted to a charged object. He realized this because the two objects were initially charged differently, but once they touched they acquired the same charge. He later realized if he replaced the charged object with a bell he could make an "electric bell." Later he used the bell as a lightning detector that became known as Franklin’s Bells. When the bell was connected to a lightning rod it would ring when an electrical storm was nearby, which could be used as an early form of weather detection.

The Leyden Jar is a device that was invented by Pieter van Masschenbroek in 1975 to store electric charge. The Leyden Jar was made of a glass bottle with water to act as a conductor for electricity. It was made with a metal wire that passed through a cork which closed the jar. The design of the jar later added a metal foil coating part of the inner surface and a conductor foil wrapped around the outside surface. The jar is also now charged by an electrostatic generator connected to the inner electrode, with the outer plate being grounded. Additionally, the inner and outer surfaces store opposite charges that are equal in amount.