ABSTRACT
Electricity Discovered: The Voltaic Pile to the Electric Motor Although the subject of electrostatics can be said to date back to the time of the Greeks, when it had been discovered that rubbing certain substances caused them to become charged, a practical device for the accumulation and storage of charge was not known until 1745 when Pieter van Musschenbroek, a Professor at Leyden, developed what became known as the Leyden phial or jar. At the time, the experience of shock was the only means of identifying the presence of charge, although electroscopes (initially balls of pith suspended by threads) came into use soon thereafter. In the period around 1750, Benjamin Franklin in America performed several significant experiments, including a demonstration of the electrical nature of lightning by means of kites flown into thunderclouds, and speculated on the nature of electricity. Joseph Priestley (the discoverer of oxygen) showed in 1766 that there was no electric force inside a charged vessel and deduced from this observation the inverse square law with distance for the force between charges. Later, more precise experiments were undertaken by Henry Cavendish and Charles Augustus Coulomb who both verified this law, the latter using a torsion balance.
