Cold Open

It’s June 10th, 1752, in a field just north of Philadelphia, Pennsylvania.

As a storm brews in the dark clouds overhead, 22-year-old William Franklin strides toward a wooden shed at the end of the field. Walking briskly beside him is his father, 44-year-old Benjamin Franklin, who carries a ball of twine, a metal key and a kite—everything he needs to conduct his latest scientific experiment.

William takes the kite from his father and admires the craftsmanship. Unlike a common paper kite, this one is made of silk, a more durable material suitable for a flight through a thunderstorm. And at the top of the kite, a small wooden cross holds a thin handkerchief and a foot-long pointed wire. The elder Franklin wants to understand the nature of lightning and whether it’s caused by electricity. His idea is that the electrical charge from the storm clouds will travel down the wire, through the string and into the metal key tied at the bottom of the line.

An experiment like this has never been tried before, and it could be dangerous. But the Franklins are taking precautions. The kite’s handle is coated in sealing wax, and they plan to protect themselves from the storm by taking shelter inside the shed.

Reaching the far end of the field, William raises the kite against the growing wind. His father grips the handle and tells him to let go, then the kite catches a gust and lifts into the gray, electric air.

The Franklins take a position just inside the shed’s open door. William grips the top of the handle, his father at the bottom. A few minutes go by with nothing happening, and William hears his father begin to mutter in disappointment. But then, suddenly, the wind picks up, and the sky darkens further. The kite string becomes wet from the rain, and its loose threads begin to stand upright.

Benjamin Franklin tells his son to move his hand toward the key, just above his grip. Trusting his father, William tentatively moves his finger up the line.

And as he gets closer, small sparks jump off the key. For William, it’s a magical sight. His father’s experiment has worked.

Benjamin Franklin will one day become a Founding Father of the United States. But he will be far more than just a statesman or diplomat. He’ll devote much of his life to studying the laws of nature. His numerous scientific tests will cover meteorology, oceanography and many other fields, but none will be more famous than his experiment with a key and a kite performed on June 10th, 1752.

Introduction

From Noiser and Airship, I’m Lindsay Graham and this is History Daily.

History is made every day. On this podcast—every day—we tell the true stories of the people and events that shaped our world.

Today is June 10th, 1752: Benjamin Franklin’s Kite Experiment.

Act One: Streets of Philadelphia

It’s October 6th, 1723, at Market Street Wharf in Philadelphia, 29 years before Benjamin Franklin’s kite experiment.

The 17-year-old Benjamin steps off the boat from New York. After a few windswept nights at sea, he’s fever-ridden and weary. But as he looks up at his new home, he feels a surge of relief—and excitement.

Tired of life as an apprentice in his brother’s Boston print shop, Ben ran away from home earlier this year. After a brief and unsuccessful stop in New York, he took a boat to Philadelphia with just a single Dutch Dollar, some copper pennies, and the names of the local newspapermen in his pocket.

Philadelphia is a small town of about two thousand people and is far more rundown than either Boston or New York. Its main street is a dirt road blighted by vacant lots, and the town's narrow alleys and wooden shacks are packed with impoverished families.

Yet amid the squalor, Franklin sees the opportunity to carve an independent life for himself. Soon after his arrival in the city, Franklin finds work in the print shop of Samuel Keimer. The business is struggling but Franklin quickly distinguishes himself with his writing which wins the attention of the Lieutenant Governor of Pennsylvania. He’s so impressed that he befriends Franklin and offers to pay for him to visit London. There, Franklin can make new contacts in the printing business and source the latest equipment for print works back in Philadelphia. Franklin eagerly accepts, and he soon sets sail for the capital of the growing British Empire.

But when Franklin arrives in London, he finds no sign of the letter of credit he was promised by the Lieutenant Governor. Stuck on the opposite side of the Atlantic, Ben must find a way to support himself. He gets a job at a printing house and tries to hone his trade as a newspaperman while he saves up money to return home.

But the city of London gives him far more than a better understanding of typesetting or journalism. The British capital is a huge metropolis of 600,000 people, and the 18-year-old Ben Franklin becomes a regular in the city’s coffeehouses, theaters, and bars. He meets writers and scientists, who encourage Franklin’s growing interest in the natural world. He reads new books, the latest scientific journals, and daily newspapers, where he learns all about the work of scientists like Sir Isaac Newton.

But although he acquires some fascinating new friends, Ben fails to save any money. He can only afford the trip home when he’s offered passage by a merchant who wants Ben to open a new general store in Philadelphia. After carefully weighing his options, Ben accepts, and in 1726, he sails back to Philadelphia to enter the world of retail.

On his return, though, disaster strikes. His new employer dies suddenly, forcing Ben to close the general store after only four months. He decides to return to his old job at Samuel Keimer’s print shop. But now Ben has the knowledge and the contacts to make a real difference to the struggling printer. He uses his transatlantic network to secure the print shop a contract to print New Jersey’s paper currency. Then, he builds an intricate new press that can create bills so ornate that they’re almost impossible to counterfeit.

People begin to take notice of his work. Ben is just 22 years old, but in 1728, he’s offered the chance to open his own print shop. Finally, he has the independence he’s always craved.

But despite his growing success as a printer, Ben’s personal life is chaotic. In 1730, he has a son out of wedlock. To maintain his standing in the community, Ben decides he needs a wife. He begins courting Deborah Read, a young woman he first met as a penniless 17-year-old. Ever the scientist, Ben draws up a list of pros and cons for their relationship. He finds the balance is in favor, so on September 1st, 1730, the couple marries.

Deborah proves herself to be a capable partner for Ben in every way. She helps him fend off competition from his old employers and establish himself as the foremost printer in Philadelphia. Ben’s Pennsylvania Gazette becomes a successful newspaper, and his annual publication Poor Richard's Almanack, sells as many as 10,000 copies a year.

This business will make Ben Franklin one of the wealthiest and most influential men in Philadelphia. And with his newfound financial freedom, Ben will be able to turn more and more of his attention to his passion for science, and especially to one new and exciting area of research—electricity.

Act Two: Shock of the Lightning

It’s the summer of 1744, in a Public Hall in Boston, Massachusetts, a few years after Benjamin Franklin began studying electricity.

Now 38 years old, Franklin stares in puzzlement at the small boy on the swing in front of him. The boy lies on his stomach, suspended on a wooden platform that’s attached to the ceiling with silk string. His hair stands on end, while a traveling academic from Edinburgh in Scotland presents the boy to the audience with a magician’s flair.

Ben watches the routine carefully. The professor pulls out a feather and holds it to the boy's nose. He tickles him for a moment and then let’s go. But the feather remains attached to the boy's nose, as if it were glued there. As the crowd gasps and applauds, the professor announces that what they’ve seen is no magic trick. It’s the natural wonder of electricity.

Ben has heard of these travelling showmen, but this is the first time he’s ever seen their experiments in person, and he is determined to understand exactly how they work.

By now, Ben has read widely on the subject of electricity. Scholars have known about its existence for millennia. In Ancient Greece, Thales of Miletus brushed tree resin to generate static electricity. And, going even further back, the Ancient Egyptians documented electric fish that shocked their prey before devouring it. More recently, the English scientist Sir Isaac Newton speculated that an “electric spirit” permeates matter. But no one has yet been able to explain precisely how electricity works. And this becomes Benjamin Franklin’s next obsession.

To expand his research, Ben builds a sophisticated laboratory in his new house outside Philadelphia. There, he modifies glass jars to create an early form of capacitor that can store electricity. He works out how to build rudimentary batteries. And he even tests how far electric sparks can jump.

Through his experiments, Ben disproves a centuries-old theory that rubbing objects together creates electricity. Instead, he argues electricity is not created in this way—friction simply causes it to flow. Gathering a team of local scientists, Ben proposes a new law called the “conservation of charge,” and despite no formal training in physics or mathematics, Ben and his team are able to demonstrate the fundamental characteristics of electricity.

Some of Ben’s experiments prove dangerous, though. On Christmas Day 1750, he receives a terrible shock from two of his capacitor jars. But he’s not deterred, and for his next project, Ben begins observing the clouds in the sky.

He hopes to prove that lightning is a form of electricity. His hypothesis is that clouds contain negative charges at their base and positive ones above. Lightning bolts are simply the product of these differences seeking a balance.

To prove this idea, Ben proposes using a long metal rod that can reach high enough to penetrate the clouds. And if Ben is right, it should attract an electrical charge that can be captured on the ground.

But there’s no structure tall enough in Philadelphia. So, Ben has come up with another plan.

As a thunderstorm brews in June of 1752, Ben and his son William arm themselves with a ball of twine, a metal key and a kite. They head out onto a field near Philadelphia and conduct an experiment that will make Ben famous.

But he doesn’t publish his results immediately. It is only in October 1752 that he publicly reveals his kite experiment. Announcing it in his own publications, Poor Richard’s Almanack and the Pennsylvania Gazette, Ben says that his experiment proves that lightning is indeed a form of electricity.

This immediately captures the public’s imagination. Unlike the work of some of Ben’s contemporaries, it’s easy to understand—everyone has flown a kite before. So, people all over the world rush to acclaim Franklin’s discovery. The French King publicly applauds him, and the British Royal Society awards him their highest honor “on account of his curious experiments with electricity.”

In the eyes of many of the public, Ben is nothing less than a magician. To his fellow scientists, he’s a visionary. And although the next 30 years of his life will be focused more on the efforts to found a new nation than on breaking new ground in science, Benjamin Franklin’s desire to advance human knowledge will never fade.

Act Three: Up and Away

It’s September 14th, 1785 at Market Street Wharf, Philadelphia, 33 years after Benjamin Franklin’s famous kite experiment.

The now 79-year-old Franklin leans on his walking cane at the rail of a ship that’s just come into harbor. Looking down at the wharf, he can see hundreds of flag-waving Philadelphians who’ve gathered to welcome him home. It’s been 62 years since Ben arrived here as a teenage vagabond, alone and aching with fever. No one was there to greet him then. But this time, he receives a hero’s welcome. Church bells ring, cannons boom, and all the ships in port raise their flags in honor of his arrival.

For the past nine years, Ben has been in Paris as the first United States Ambassador to France. While he was in Europe, he worked tirelessly to secure French support for the Revolutionary cause, and without the soldiers, supplies, guns, and ammunition they eventually provided, the American War of Independence might have ended very differently.

But despite his important duties, Ben still found time for scientific endeavors. He witnessed the first human flight in a hot air balloon in 1783 just outside Paris, and he took part in the first major study that established the existence of the “placebo effect”. But after nearly a decade as America’s chief diplomat, Ben longed to return to the country he helped to create. So in 1785, he set sail for home.

As the ship docks, Ben thinks about his son William. William was just a young man when he helped his famous kite experiment. But the partnership between father and son didn't last. While Ben became one of the leaders of the American Revolution, William remained a steadfast loyalist to the British crown. This created a deep rift between them, and at the end of the war, William left America to go into exile in London. Ben has only seen him once since then, and fears they will never meet again.

Ben is correct, he will die five years later, at the age of 84, having never reconciled with his son. But he will always be remembered for helping found the United States of America, and for his contributions to science, which were feats almost as remarkable. Benjamin Franklin was a true polymath—a man with a ceaseless appetite for new discoveries and new knowledge, as he proved when he and his son flew a kite into a thunderstorm on June 10th, 1752.

Outro

Next on History Daily. June 11th, 1963. A Buddhist monk sets himself on fire in a dramatic protest in South Vietnam.

From Noiser and Airship, this is History Daily, hosted, edited, and executive produced by me, Lindsay Graham.

Audio editing by Muhammad Shahzaib.

Sound design by Gabriel Gould.

Supervising Sound Designer is Matthew Filler.

Music by Thrumm.

This episode is written and researched by Angus Gavan McHarg.

Edited by William Simpson.

Managing producer Emily Burke.

Executive Producers are William Simpson for Airship and Pascal Hughes for Noiser.