12 Chapter 2 Metal rod Positive charge Nagative charge Tin foil Wire Figure 3 Leyden jar. HQEW.net (2012). From Webster’s New World Dictionary of the American Language: College Edition (1959). All rights reserved. Rights now owned by Wiley. Reproduced here by permission of Wiley Publishing, Inc., Indianapolis, IN. inventors, in parallel but separate work, discovered what became known as the “Leyden” jar. Initially this was an attempt to capture the liquid of electricity, yes electricity was believed to be a liquid in many circles of the period, but in the end it proved much more important discovery.
The Leyden jar was a device used to store static electricity by lining the interior of a glass jar with a metal foil and adding another layer of metal-foil coating around outside and finally inserting a metal rod through the top and connecting it to the inner foil ( Figure 3 ). The jar was partially filled with water, which acted as a conductor, and when a static generator was applied to the electrode, a static electric charge could be stored in the jar thereby creating the first electrical capacitor (Buchmann, 2011).
It was not until sometime in the mid-1700s that the term “battery” was applied to this type of device and is believed to have been coined by none other than Benjamin Franklin himself, who had a strong fascination with the study of electricity. It is said that Franklin compared a group of