Chapter 1
Section 1 of Little Masterpieces of Sciences, Invention and Discovery. For more information or to volunteer, please visit LibriVox.org. Read by Phil Schempf. Little Masterpieces of Sciences, Invention and Discovery, George Isles Editor. Franklin identifies lightning with electricity.
From Franklin's Works, edited in 10 volumes by John Bigelow, volume 1, pages 276 to 281, copyright by G.P. Putnam Sons, New York. Dr. Stuber, the author of the first continuation of Franklin's life, gives this account of the electrical experiments of Franklin. His observations he communicated in a series of letters to his friend Collinson, the first of which is dated March 28, 1747. In these he shows the power of points in drawing
and throwing off the electrical matter, which had hitherto escaped the notice of electricians. He also made the grand discovery of a plus and minus, or of a positive and negative state of electricity. We give him the honor of this without hesitation, although the English have claimed it for their countryman, Dr. Watson. Watson's paper is dated January 21st, 1748, Franklin's July 11th, 1747, several months prior. Shortly after Franklin, from his Principles of the Plus and Minus State,
explained in a satisfactory manner the phenomena of the Leyden file first observed by Mr. Cuneus, or by Professor Munchenbrock of Leiden, which had much perplexed philosophers. He showed clearly that when charged the bottle contained no more electricity than before, but that as much was taken from one side as thrown on the other, and that to discharge it nothing was necessary but to produce a communication between the two sides by which the equilibrium might be restored,
and that then no signs of electricity would remain. He afterwards demonstrated by experiments that the electricity did not reside in the coating as had been supposed, but in the pores of the glass itself. After the file was charged, he removed the coating and found that upon applying a new coating, the shock might still be received. In the year 1749, he first suggested his idea of explaining the phenomena of thunder gusts and of aurora borealis upon electric principles,
he points out many particulars in which lightning and electricity agree, and he adduces many facts and reasonings from facts in support of his positions. In the same year he conceived the astonishingly bold and grand idea of ascertaining the truth of his doctrine by actually drawing down the lightning, by means of sharp-pointed iron rods raised into the regions of the clouds. Even in this uncertain state, his passion to be useful to mankind displayed itself in a powerful
manner. Admitting the identity of electricity and lightning, and knowing the power of points in repelling bodies charged with electricity, and in conducting fires silently and imperceptibly, he suggested the idea of securing houses, ships, and the like from being damaged by lightning by erecting pointed rods that should rise some feet above the most elevated part, and descend some feet into the ground or water. The effect of these, he concluded, would be either to prevent a stroke
by repelling the cloud beyond the striking distance, or by drawing off the electrical fire which it contained. Or, if they could not effect this, they would at least conduct the electrical matter to the earth without any injury to the building. It was not until the summer of 1752 that he was enabled to complete his grand and unparalleled discovery by experiment. The plan which he had originally proposed was to erect, on some high tower or elevated place,
a sentry box, from which should rise a pointed iron rod, insulated by being fixed in a cake of resin. Electrified clouds passing over this, would, he conceived, impart to it a portion of their electricity, which would be rendered evident to the senses by sparks being emitted when a key, the knuckle, or other conductor was presented to it. Philadelphia at this time afforded no opportunity of trying an experiment of this kind. While Franklin was waiting for the erection of a
spire, it occurred to him that he might have more ready access to the region of clouds by means of a common kite. He prepared one by fastening two cross sticks to a silk handkerchief, which would not suffer so much from the rain as paper. To the upright stick was affixed an iron point. The string was as usual of hemp, except the lower end which was silk. Where the hempen string terminated, a key was fastened. With this apparatus on the appearance of a thunder gust
approaching, he went out into the commons, accompanied by a son, to whom alone he communicated his intentions, well knowing the ridicule which, too generally for the interest of science, awaits unsuccessful experiments in philosophy. He placed himself under a shed to avoid the rain. His kite was raised. A thundercloud passed over it. No sign of electricity appeared. He almost despaired of success, when suddenly he observed the loose fibers of his string to
move towards an erect position. He now presented his knuckle to the key and received a strong spark. How exquisite must his sensations have been at this moment! On his experiment depended the fate of his theory. If he succeeded, his name would rank high among those who had improved science. If he failed, he must inevitably be subject to the derision of mankind,
or, what is worse, their pity, as a well-meaning man but a weak, silly projector. The anxiety with which he looked for the result of his experiment may easily be conceived. Doubts and despair had begun to prevail, when the fact was ascertained, in so clear a manner, that even the most incredulous could no longer withhold their assent. Repeated sparks were drawn from the key, a file was charged, a shot given,
and all the experiments made which are usually performed with electricity.
