American Founding Father and polymath Benjamin Franklin created a number of practical inventions, including a new heating stove, crude swimming fins, a better urinary catheter, the armonica, a glass musical instrument, and, of course, his patented bifocals.
But the lightning rod, often known as the “Franklin rod,” which is a pointed iron pole attached to the top of structures to divert lightning energy away from the structure itself and toward the ground, dwarfs all of these creations.
Despite appearing straightforward at first glance, the lightning rod represented a fundamental change in how we understood electricity and lightning.
The affluent Franklin primarily withdrew from his lucrative printing firm in 1747 at the age of 41 and then set out to satiate his many interests, chief among them the nature of electricity.
He got right into experimentation and did everything from build a simple battery to shock a turkey to death, observing that the meat was “uncommonly delicate” in comparison to a turkey that had been killed traditionally.
His conception of electricity as the flow of a single “liquid” carrying “positive” and “negative” charges was one of his greatest contributions. It was the first theory to propose that electricity is just the buildup of charge from somewhere else.
Even though it was fundamentally flawed, it was quickly accepted by scientists all around the world and helped them get closer to a complete understanding of electricity.
Franklin opposed the prevalent practise of using electricity just for circus acts and parlour tricks at the time. He aimed to make it practical for the average person.
Franklin quipped that the many electrical shocks he received during his studies were helpful for “making a vain person humble,” as biographer Walter Isaacson highlighted in Burns’ documentary. However, there had to be more that was possible.
Franklin saw how very similar those electrical shocks were to lightning, which at the time was cloaked in superstition and was thought to be a tool of divine punishment from God. Franklin, though, proposed the theory that lightning was merely electricity.
This set him up to carry out the now-mythologized experiment that would make him famous all over the world. Franklin first planned to construct a “sentry box” on a tall structure or hill, manned by a lone experimenter who would raise an iron rod using a device to suck energy from a lightning storm in order to demonstrate that lightning was electricity.
Franklin came up with another experiment, one he was less confident in, and so performed it in secret with his son William. One of these boxes was intended to be built atop one of Philadelphia’s tallest structures, but construction was slow-going.
To demonstrate that the air during a thunderstorm becomes electrified, which would then transfer an electrical charge via the twine to the metal key at the bottom, Franklin and William flew a kite linked to hemp twine with a metal key at the end as a thunderstorm approached.
Franklin saw the twine’s strands standing on edge as the storm approached and that the key would give off a small electric charge when he touched it. Sparks erupted off the key as it began to rain. Franklin felt delighted.
He finally had a method to put his understanding of electricity to use! The danger from lightning at the time was lethal. Numerous bell ringers were killed when they were shocked, and hundreds, even thousands of churches — frequently the largest structures in most locations — had been struck by lightning.
Even in Italy, a building housing gunpowder was attacked, igniting a massive inferno that claimed hundreds of lives. The lightning rod was Franklin’s answer. It performed flawlessly. He refused to its patenting.
“As we enjoy great advantages from the invention of others, we should be glad of an opportunity to serve others by an invention of ours, and this, we should do freely and generously,” Franklin said.
While the majority of people lauded the lightning rod as a lifesaver, certain religious leaders argued that Franklin was trying to meddle with one of God’s most efficient ways of punishing sinners.
Franklin responded by saying, “Surely the thunder of Heaven is no more supernatural than the rain, hail, or sunshine of Heaven, against the inconvenience of which we guard by roofs and shades without scruple.”