electrical science; a science chained, yet really unknown and still feared though chained. It is the story of this servitude only that is capable of being told, and the first weak bands were a hundred and forty-six years in forging; from the Englishman Gilbert's "_De Magnete_," to Franklin's Kite. During all this time, and to a great degree long after, electricity was a scientific toy. Experiences in the sparkling of the fur of cats, the knowledge that there were fishes that possessed a mysterious paralyzing power, and various common phenomena all attributable to some unknown common cause, did not greatly increase the sum of actual knowledge of the subject. There was no divination of what the future would bring, and not the least conception of actual and impending possibilities. When, finally, the greatest thinkers of their times began to investigate; when Boyle began to experiment, and even the transcendent genius of Newton stooped to enquiry; from the days of those giants down to those of the American provincial postmaster, Benjamin Franklin, a period of some seventy years, almost all the knowledge obtained was only useful in indicating how to experiment still further. So small was the knowledge, so aimless the long experimenting, that the discovery that not amber only, but other substances as well, possessed the electric quality when rubbed, was a notable advance in knowledge. Later, in 1792, it was found by Gray that certain substances possessed the power of carrying; "conducting" as we now term it; the mysterious fluid from one substance to another; from place to place. This discovery constituted an actual epoch in the history of the science, and justly, since this small beginning with a wet string and a cylinder of glass or a globe of sulphur was the first unwitting illustration of the net-work of wires now hanging all over the world. The next step was to find that all substances were not alike in a power to conduct a current; _i.e._, that there were "conductors" and "non-conductors," and all varying grades and powers between. The next discovery was that there were, as was then imagined, several kinds of electricity. This conclusion was incorrect, and its use was to lead at last to the discovery, by Franklin, that the many kinds were but two, and even these not kinds, but qualities, present always in the unchanging essence that is everywhere, and which are known to us now by the names that Franklin gave them; the _positive_ and _negative_ currents; one always present with the other, and in every phenomenon known to electrical science.