According to most accounts, it was on June 15, 1752, that Ben Franklin tied a metal key to a kite and flew it in a thunderstorm.
He didn’t discover electricity.
Humans had known about electrical forces for more than a thousand years before that.
Franklin’s kite experiment was designed to capture the electricity in the air, which he suspected was carried by bolts of lightning.
Further, his kite wasn’t struck directly by lightning. That probably would have been deadly. Instead, he stood relatively safe in a shed as he flew the kite.
On the kite he had attached a wire, a key, a hemp string and a silk string.
The hemp string led to something called a Leyden jar.
That’s something designed to store an electrical charge.
Franklin knew the hemp string would get wet, but the silk string would remain rather dry.
As the thunderstorm approached, Franklin noticed the tiny threads of the hemp string were beginning to rise.
He raised his hand to the key and felt a tiny shock!
He had found what he was looking for.
The ambient electricity in the air surrounding the storm had travelled through down the string and into the Leyden jar.
Ben Franklin had captured lightning.
He understood that he could direct the electricity generated by actual lightning bolts to the ground.
Later experiments led to the development of the first lightning rods in 1753.
Since then, lightning rods have protected barns, churches and other structures from dangerous lightning strikes by transferring the energy of the lightning harmlessly to the ground.
None of which would be possible had not Ben Franklin first captured lightning