Open main menu

Page:Popular Science Monthly Volume 56.djvu/261

This page has been proofread, but needs to be validated.

the addition operated to upset the balance, so to speak, and the electricity escaped by a sudden (disruptive) discharge, or spark, or by the brush discharge already alluded to. With the Leyden jar, however, as fast as electricity was supplied to the inside coating it became "bound" there by the charge of opposite sign accumulating on the outside, and the limit of capacity of the jar was simply one of strength of the glass: if too much electricity was supplied, the stress of mutual attraction between the two charges relieved itself by destroying the jar.

Although Professor Muschenbroeck discovered the principle in the manner above referred to, it appears extremely probable that two other investigators, working independently, also did the same. One Cuneus and a monk named Kleist each claimed the honor of original invention of the condenser.

About 1747 the first gun was fired by electricity; this was accomplished by Sir William Watson, who also succeeded in kindling alcohol and gas by means of a drop of cold water and even with ice. The same experimenter reversed the ordinary procedure of causing the electric influence to pass from an electrified body to the one to be experimented upon, the latter being unelectrified, by electrifying the latter, and then producing the desired effect by approaching it to an unelectrified one.

A party of the Royal Society with Watson as chief operator instituted a series of researches on a grand scale to determine, if possible, the velocity of the electric discharge, and arrived at a number of conclusions which, however, were of a decidedly negative nature. The most important of these were as follows: That they could not observe any interval between the instant of applying the discharge to one end of the line and its reception at the other; that the destructive effects of discharge are greater through bad conductors than through good ones; that conduction is equally powerful whether occurring through earth or water.

Just previous to this there had been some brilliant experiments carried on in France, and the discharge had been conveyed through twelve thousand feet of circuit, including the acre basin of the Tuileries, but they had not been performed as systematically, or with the definite objects in view, as had the English experiments.

The following year the Royal Society continued its researches on a larger scale than previously, using 12,276 feet of wire, and found that even through that length the velocity was practically instantaneous.

Watson urged as a theory that electrical disturbances were caused by influx or efflux of a single electric fluid from the state of normal electrification, thus differing from Dufay in his opinion as to the