This edited article about Benjamin Franklin first appeared in Look and Learn issue number 557 published on 16 September 1972.
Benjamin Franklin experimenting with lightning by
John Keay
To set off into the country in the middle of a fierce thunderstorm might seem a strange thing to do, but for the purpose which Benjamin Franklin had in mind, conditions could not have been better.
He and his son went to a field outside Philadelphia, in the U.S.A., carrying a kite with a small pointed wire at the top to act as a lightning collector. Ordinary string was attached to the kite, with a length of silk ribbon joined to the end which was to act as an insulator. Where the string and the silk joined, he attached a brass key.
The kite was sent up, with Franklin holding firmly on to the ribbon. The silk had to be kept dry, so Franklin stood in a cowshed.
The storm was directly overhead. Franklin noticed that the fibres of the string were standing straight out, indicating that a “charge” of some type had collected on the string. With great caution, he moved his hand towards the key. A spark of electricity jumped to his hand. Franklin returned home soaked, but jubilant. He had proved that lighting was a discharge of electricity.
Benjamin Franklin was the tenth of the seventeen children of a poor soap-and candle-maker. Born in Boston, U.S.A., in 1706, he spent his early youth helping in his father’s business. Later, he was apprenticed to his brother James, who was a printer.
In 1723, Benjamin decided to go to Philadelphia to carve out a career for himself. He was hungry and penniless when he arrived. But with great determination and perseverance, he became the manager of a newspaper, and travelled to England to gain experience in his profession. By the time he was thirty, he was clerk to the Pennsylvania Assembly. He progressed from postmaster of Philadelphia to deputy postmaster for all the American Colonies. In twenty years, from his arrival, he rose to become the most important of Philadelphia’s citizens.
By 1746, he was wealthy enough to be able to spare time from business to take up the scientific research which fascinated him. Franklin was interested in the little-understood phenomenon of electricity. He had experimented with Leyden jars (ordinary glass jars covered inside and outside with silver paper) which were capable of storing a quantity of electricity until, on connecting the inner and outer coatings, the charge was liberated in the form of a spark. He thought that flashes of lightning were such sparks on a much larger scale.
In 1752, Franklin decided to put his theory to the test and the “kite” experiment took place.
As a result of his experiments in the field of electrical science, Franklin suggested that lightning conductors should be fixed to tall buildings to protect them during thunderstorms.
Although he led a busy life as a diplomat and politician, he continued scientific experiments in various fields. When he was sent to England on a diplomatic mission in 1757, he was welcomed as a distinguished scientist as well as a diplomat and was honoured by the universities of Oxford and St Andrews, Scotland.