The Golden State: Where & How to Live, Secure, Visit, Enjoy and Thrive in California
Practical Electricity And House Wiring
Electricity And How It Is Measured
What Is Electricity?—Nobody knows what electricity is. Despite that fact, we do recognize electricity in many forms, and observe its many different effects. We do know that the spark and crackle present when a cat's fur is stroked, is the same force which makes possible the spark at the sparkplug in an automobile cylinder, the same force that makes it possible for electric lights to operate, motors to run, toasters to heat; it is the same force as the lightning in the sky. Despite all that, we still do not know what electricity is.
Electricity uncontrolled is a most powerful force; it causes fires, kills people, destroys property. Under control, it serves mankind in hundreds of ways. In this book will be covered the study of electricity as used in homes and farms. In order to properly serve the home-owner, electricity must at all times be under proper and complete control. It is controlled by the installation of wires and insulators, switches and receptacles, sockets and fixtures, and many other devices, all connected in proper combination and installed in proper fashion. So installed, electricity will provide countless advantages, with little danger.
Conductors and Insulators.—As commonly known as any other source of electricity is the ordinary automobile battery. When a pair of pliers or some other tool is accidentally dropped across its terminals, it causes sparks and if it is not quickly removed, the tool will heat. On the other hand, a piece of wood laid across the same terminals produces neither sparks nor heat. Why is one material affected, and the other not? The answer lies in the fact that some materials are conductors of electricity, permit an electric current to flow through them, while other materials do not permit such a flow. Materials which are capable of carrying an electric current are known as conductors; those that are not capable of carrying a current are non-conductors or insulators.
Not all conductors "will carry an electric current equally well. The poorer the material is as a conductor, the larger the size of the wire that must be used to carry a specific electrical load.
Silver is the best known conductor; copper is the next best, almost as good as silver. Other conductors are aluminum, iron, mercury and all metals in general. However, if one wished to use iron wire in place of copper wire, it would have to be about six times as large as the copper wire.
There are many kinds of insulators, such as rubber, various plastic compounds, porcelain, glass, dry wood, paper, and similar materials. As in the case of conductors, some insulators better serve the purpose than others; the poorer the insulating qualities, the greater the thickness of the material that must be used to insulate against any given voltage.
