The son of a soap manufacturer in a small way of business, Benjamin Franklin was born at Boston in 1706. His parents had intended him to go in for science. He was successively an apprentice to a candle manufacturer, a journeyman printer, the head of a big printing firm in Philadelphia, deputy to Congress, an ambassador, and finally President of the Assembly of the States of Pennsylvania. His political record was a great one. No one ever rendered greater services to his country than the diplomatist who signed the peace of 1783, and insured the independence of the United States.
It was towards the age of forty that Franklin began his study of electricity. Here is his own account of the memorable experiments to which he owed the greater part of his immense fame:—
"In 1746 I met at Boston a certain Dr. Spence, who came from Scotland. He performed some electrical experiments before me. They were not very perfect, as he was not a man of great ability; but as the subject was new to me they surprised me and interested me in an equal degree. Shortly after my return to Philadelphia, our librarian received as a gift from Pierre Collinson, a member of the Royal Society of London, a tube of glass, together with certain written instructions as to the way in which it should be used for experiments. I seized eagerly on the chance of reproducing what I had seen done at Boston, and with practice I acquired a great facility in performing the experiments indicated to us from England and in devising other ones. I say 'with practice,' because many people came to my house to witness these marvels."
After making several discoveries in regard to electricity, Franklin took it into his head to extract the fluid direct from the clouds. He had established the fact that a stem of pointed metal, placed at a great height—on the summit of a building, for instance—served as an attraction to lightning and guided it into the way prepared for it. He had been looking eagerly to the erection of a clock-tower which was being built at this time at Philadelphia; but, tired of waiting and anxious to carry out experiments which should solve all doubts, he had recourse to a more expeditious instrument, and one, as events proved, not less efficacious, for getting into touch with the region of thunder—a kite such as children play with.
He prepared two sticks in the form of a cross, with a silk handkerchief stretched upon them, and with a string attached of suitable length, and set forth on his mission the first time there was a storm. He was accompanied only by his son. Fearing the ridicule that is showered upon failure, he did not take any one else into his confidence. The kite was set flying. A cloud which looked promising passed without result. Others followed, and the excitement with which they were awaited can be imagined.
At first there was no spark and no sign of electricity. Presently some filaments of the string began to move, as though they had been pushed out, and a slight rustling could be heard. Franklin now touched the end of the string with his finger, and instantly a spark was given out, followed quickly by others. Thus for the first time the genius of man may be said to have come to grips with lightning, and begun to learn the secret of its existence.
This experiment took place in June, 1752, and made an immense sensation throughout the world, and was repeated in other countries, always with the same success.
A French magistrate, named de Romas, making use of Franklin's idea as soon as it was known in France, took it into his head to use a kite with raised cross-bars, and in June, 1753, before the full results of Franklin's experiments were made public, secured still more remarkable signs of electricity, having inserted a thread of metal throughout the whole length of the string, which was 260 metres. Later, in 1757, de Romas repeating his experiments during a storm, secured sparks of a surprising size. "Imagine before you," he said, "lances of fire nine or ten feet in length and an inch thick, and making as much noise as pistol shots. In less than an hour I had certainly thirty lances of this length, without reckoning a thousand shorter ones of seven feet and under." Numbers of people, ladies among them, were present at these experiments. They were not without danger, as may be imagined; de Romas was once knocked over by an unusually heavy discharge, but without being seriously hurt.
Franklin was the first to turn his experiments to practical account, attaching lightning-conductors to public and private buildings for their protection, and achieving marvellous results; the lightning being caught by the metallic stem and following it obediently into the ground.
From this time, lightning-conductors came into almost universal use, and their value was not long in being generally recognized. Curiously enough, France, which had been ahead of all other countries in the study of electricity, was not one of the earliest to go in for lightning-conductors. There were, indeed, signs of strong hostility to their introduction. It was held even that they went against the designs of Providence. In 1766, the Abbé Poncelet, in his work entitled "La Nature dans la formation du tonnerre et la reproduction des êtres vivants," in which he sets out to demonstrate that the force which produces lightning is the same as that which causes the earth to fructify, makes a strong protest against the construction of lightning-conductors.