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MANAGERS AND PROJECTIONISTS
Electrical Action
IN order to arrive at a comprehensive knowledge of electricity, one must first understand the underlying principles which govern its action. It is absolutely imperative that the projectionist have at least a good working knowledge of electrical action, because he will be put in full charge of apparatus for generating and using current, which devices will operate safely and with high efficiency, or with low efficiency and perhaps unsafely, exactly in proportion to the expert skill and knowledge he is able to make use of in their adjustment, care and handling.
We will first try to convey an understanding of the one basic, underlying principle upon which all electrical action is based, always remembering that electricity and magnetism are two entirely separate and distinct things, notwithstanding statements of some authorities to the contrary.
POLARITY. — Polarity is the very foundation principle upon which all electrical action is based. Precisely what electricity is, no living man knows. Eminent scientists differ widely in their views as to the cause of the phenomenon. Some authorities claim it to be a "molecular bombardment," while others hold it to be something entirely different. With such arguments the. practical man has little interest. At best they represent little more than abstract theories. They have no importance as applied to the work of projection.
WTe may not know the precise nature of the thing which does it, but we do know that if we touch a "live" positive wire to a negative wire attached to the same generator, there will be a flash and a shower of sparks. We also know that by Connecting these two wires through certain devices, such as motors and lamps, instead of an uncontrolled flash and shower of sparks we can and do get light, heat or power. In other words we can make the electric force work for us in its passage from positive to negative.
So far as electric action is concerned, every electric circuit consists of just two wires — a positive and a negative. True, there may appear to be more, as in the three-wire system, but when analyzed we find that the additional wire or wires .merely operate to form additional complete circuits, which