I've always been fascinated by the story of Benjamin Franklin flying a kite in a thunderstorm to prove lightning was electricity. As a scientist and inventor myself, I wanted to dig deeper into the details of this groundbreaking experiment that unlocked the secrets of harnessing one of nature's most powerful forces. In this article, I will take you on a journey through Franklin's background, the context surrounding his experiment, how he designed and conducted it, and the enormous impact it had on the understanding and application of electricity. Strap in - we're going back in time to witness a seminal moment in scientific history!

Benjamin Franklin's Scientific Background

First, it's important to understand Benjamin Franklin's scientific knowledge and mindset leading up to his kite experiment in 1752. Franklin had been interested in electricity for over a decade by this point. He had already conducted experiments with static electricity, batteries, and Leyden jars. Through hands-on tinkering, Franklin had realized electrical charge could be transferred from one object to another and could produce sparks. However, the nature and origin of this "electrical fire" remained a mystery.

Franklin theorized this electrical fire was related to the flashes of lightning witnessed during thunderstorms. Other scientists had already suggested lightning was an electrical phenomenon, but no definitive link had yet been proven. Franklin was determined to experimentally test this hypothesis. Being a printer by trade, he was skilled in designing experiments and building apparatuses to carry them out. As a self-taught scientist, he brought an ingenious and open-minded perspective.

The Context Surrounding Franklin's Fateful Kite Flight

Franklin's kite experiment didn't happen in a vacuum. By the mid-18th century, many leading scientists like Franklin were investigating electrical phenomena through experiments. There was burgeoning interest, but no consensus explanation for observations. The field was ripe for major discoveries and theories to synthesize the piecemeal knowledge.

Additionally, lightning was a fearful force of nature, commonly associated with wrathful gods. Preventing damage from lightning strikes was a pressing concern. Lightning rods were beginning to be installed in Europe to redirect lightning, but the mechanics were poorly understood. There was a clear need to demystify lightning and improve control over its devastating effects.

Designing & Conducting the Kite Experiment

Benjamin Franklin carefully considered how to best test his hypothesis of lightning being electrical. Flying some type of rig aloft during a storm was an obvious option. After much thought, he settled on using a common rectangular kite with a metal tip. This was attached to a silk string with a metal key tied about a foot from the bottom. Franklin proposed that electricity from lightning would be conducted down the kite string and stored in the key, which could be touched to draw off sparks.

In June 1752, Franklin and his son went out during a thunderstorm to fly the kite. Just as hypothesized, sparking was observed on the key after rain soaked the string to act as a conductor. Leyden jars were used to store the charge from the kite. Franklin described receiving sufficient electric shocks from the key to produce convulsive twitches. He concluded lightning must be an electrical discharge from the clouds. This linked the strange electrical phenomena people created on the ground to the lightning flashing through the heavens.

Impact on Understanding & Applying Electricity

The results of Franklin's kite experiment electrified the scientific community and the public at large. He published his account in a series of letters, gaining widespread fame. His empirical evidence that lightning was electrical energy provided the first unifying theory about electricity's nature and manifestations. Researchers realized they had been witnessing different aspects of a single fundamental force, which could now be systematically studied for emerging technologies.

Franklin's kite findings paved the way for practical applications of electricity. Most importantly, it led to the lightning rod being improved and deployed more widely to protect buildings. Franklin himself helped advance lightning rod installations. Additionally, the electrical nature of lightning was essential knowledge for myriad later technologies like telegraphs, electric motors, radio, and power grids. Ben Franklin ushered in the Electrical Age with that fateful day he went flying a kite in a storm.


In quaint yet ingenious fashion, Benjamin Franklin's kite with metal key unlocked centuries of mysteries surrounding electricity in one fell swoop. By empirically showing lightning was an electrical discharge, he linked the heavens and the earth. Franklin's thirst for hands-on discovery and lightning rod to safely channel nature's power changed the course of history. Whenever I see a lightning bolt shoot across the sky, I can't help but think of Franklin's epic kite experiment that launched the modern understanding and harnessing of electricity.