History of Electricity:

The Greeks were the first to discover electricity about 2500 years ago. They noticed that when an amber was rubbed with other materials it became charged with an unknown force that had the power to attract objects such as dried leaves, feathers, bits of cloth, or other lightweight materials. The Greeks called amber elektron. The word electric was derived from it and meant "to be like amber," or to have the ability to attract other objects.

This mysterious force remained little more than a curious phenomenon until about 2000 years later, when other people began to conduct experiments. In the early 1600s, William Gilbert discovered that amber was not the only material that could be charged to attract other objects. He called materials that could be charged elektriks and materials that could not be charged noelektriks.

About 300 years ago a few men began to study the behavior of various charged objects. In 1773, a Frenchman named Charles DuFay found that a piece of charged glass would repel some charged objects and attract others. These men soon learned that the force of repulsion was just as important as the force of attraction. From these experiments, two lists were developed.

It was determined that any material in list A would attract any material in list B, and that all materials in list A would repel each other and all material in list B would repel each other. Various names were suggested for the materials in lists A and B. Any opposite-sounding names could have been chosen, such as east and west, north and south, male and female. Benjamin Franklin named the materials in list A positive and the materials in list B negative. The first item in each list was used as a standard for determining if a charged object was positive or negative. Any object repelled by a piece of glass rubbed on silk would have a positive charge and any item repelled by a hard rubber rod rubbed on wool would have a negative charge.