Makers of Electricity

by Brother Potamian; James J. Walsh

Fig. 13
Three Panes in Parallel

Later on, he arranged Leyden jars so that the inside coating of one could be hooked to the outside coating of another, the first of the series hanging down from the prime conductor of the machine, while the last one was grounded. "What is driven out of the tail of the first," he quaintly says, "serves to charge the second; what is driven out of the second serves to charge the third, and so on." This has become known as the "cascade" method of charging a battery, owing to the flow of electricity from one jar to the next (Fig. 15). Electricians, however, have discarded the picturesque "cascade" for the prosaic term of "series" or "tandem" arrangement.

Fig. 14
Three Jars in Parallel

Franklin also noticed that a phial cannot be charged while standing on wax or on glass, or even while hanging from the prime conductor, unless communication be formed between its outer coating and the floor, the reason given being that "the jar will not suffer a charging unless as much fire can go out of it one way as is thrown in by the other." (1748.)

Fig. 15
Three Jars in Cascade

Following his very ingenious Philadelphia friend and co-worker, Kinnersley, he varies the mode of charging by electrifying the outside of the jar and grounding the inner coating; for "the phial will be electrified as strongly if held by the hook and the coating applied to the globe as when held by the coating and the hook applied to the globe." (1748.)