Benjamin Franklin's famous kite experiment in 1752 was a landmark moment in the understanding of electricity and lightning. Although rudimentary knowledge of static electricity existed prior to Franklin, his simple but ingenious experiment demonstrated a practical link between lightning and electricity for the first time. This breakthrough laid the groundwork for innovations in electrical wiring that transformed infrastructure and enabled new technologies that still benefit us today.

Franklin's Interest in Electricity

Benjamin Franklin had long been fascinated by electricity. In the 1740s, he conducted experiments with static electricity, batteries, and Leyden jars. He coined terminology like battery, positive and negative charges, and conductor. By 1749, Franklin theorized that lightning was an electrical phenomenon, but he lacked evidence to prove it.

The Kite Experiment

On a stormy day in June 1752 in Philadelphia, Franklin set out to gather evidence for his lightning theory. With his son's help, he flew a kite during a thunderstorm, with a metal key attached to the top and a Leyden jar connected to the key's string. As hoped, sparks jumped from the key to Franklin's hand, proving that lightning was indeed electrical. This simple experiment demonstrated the electrical nature of lightning and thunderclouds for the first time.

Key Findings

The kite experiment yielded these groundbreaking insights:

These findings upended previous assumptions and paved the way for lightning rod installations, electrical wiring, and other innovations.

Developing Lightning Rods

Building on his experiment, Franklin installed the first lightning rod in 1752, attaching pointed iron rods to tall buildings. Lightning rods provided a safe pathway for electrical discharges to follow into the ground. This simple innovation protected countless buildings from lightning strikes and fires.

Lightning rods were a direct application of the experiment's findings, demonstrating that electricity from lightning could be safely channeled away from structures. Franklin promoted lightning rods in publications, installing them on prominent buildings to advertise their usefulness. Their success spread the practice across America and Europe.

Electrifying Homes and Businesses

After realizing lightning was electrical, Franklin explored other practical applications of electricity. He planned an experiment to electrify the inside of a home but lacked suitable wires to do so safely.

The availability of insulated wires was key for bringing electricity indoors. When sufficiently insulated copper wires were later mass produced, buildings could be electrified without risk of fires, finally implementing Franklin's vision.

Wiring enabled electric lights, appliances, telegraphs, and other devices to transform urban infrastructure and daily life through the 1800s. Franklin's findings thus catalyzed the wiring that electrified society.

Lasting Influence

The insights from Franklin's famous kite flight changed the prevailing understanding of electricity's nature and potential. The experiment was a seminal breakthrough that enabled him and others to develop new applications for electricity, especially wiring and lightning rods.

Franklin's simple kite flight launched the new field of electrical science. His empirical evidence electrified other scientists to study this phenomenon further and harness its power to transform technology and infrastructure. The experiment's legacy continues today in the extensive wired infrastructure underlying modern civilization.


Benjamin Franklin's ingenious 1752 kite experiment proved that lightning was electrical, leading to innovations like lightning rods and electrical wiring that still shape our world. His empirical evidence bridged lightning with electricity for the first time, opening new frontiers of knowledge and technology. The key findings electrified scientists and inventors for generations to come.