- How could the lightning rod terrify and offend people?
It's only a piece of metal connected with wire
to the ground.
Well, I'll tell you.
And along the way,
I'll tell you how the lightning rod was invented
because of a misunderstanding,
irritating lightning bells,
a Franklin chamber pot,
a terrible earthquake,
and how dangerous it was to ring church bells.
Ready?
Let's go.
♪ Electricity ♪
The lightning rod was invented in 1749 by Benjamin Franklin
because he got a little bit confused.
He'd been playing with electricity for three years
ever since a friend of his had sent him an article
about strange and fun electrical tricks he could perform.
Anyway, he became convinced as we are today
that lightning strikes were the same as the sparks
he was getting in his laboratory.
Now, Benjamin Franklin wasn't the first person
to have this thought,
but he was the first person
to think of experimental ways to prove it.
Franklin started by building a model
of an electrically charged cloud.
They couldn't exactly get a thundercloud in his room,
but he wanted something that he could hang off the ground
that could store a lot of charge,
irrespective if it looked cloud-like.
So therefore, he built a very light tube
and coated it with gold,
about 10 feet long and one foot wide.
He hanged up the tube with silk cords
and charge it up with his spinning static electric machine.
If he approach the charged cloud with a blunt instrument,
the cloud would discharge with a large crack and a flash.
If he approach with a thin taper needle,
the spark would be less dramatic.
He then turned the experiment around.
This time, he had one person hold a thin metal needle
close to the cloud before he even charge up the cloud.
When he run the static electricity machine,
the stick would get a steady stream of quiet sparks
and he could not charge up the cloud at all.
Extrapolating the nature,
Franklin decided that the pointed metal stick
could prevent clouds from becoming electric
and creating lightning strikes in the first place.
Franklin said that, quote,
"Rods of iron connected with wire
down the outside of the building to the ground
would draw the electrical fire silently out of a cloud,
and thereby secure us from that most sudden
and terrible mischief of lightning."
It was because of Franklin's theory
that you could safely drain the clouds of electricity
that Franklin came up with a way of proving
that lightning clouds were electric in the first place.
You put a metal pole with a kink in it
on an insulating stand in a little box
so that everything stays dry.
And when the electrified thundercloud passes by,
the pole will get electrified too.
As electricity tends to collect the points or kinks,
one could get sparks from the kink in a pole.
A man named Thomas Delabar actually successfully did this
in France in may of 1752.
Franklin planned on attempting this experiment
by putting a pole in the steeple of a church,
but this construction of the church was going slowly.
So months after Delabar did his experiment in France,
Franklin flew a kite with a metal pole in it
tied with a wire to a key.
Franklin and Delabar knew
they weren't getting struck by lightning,
but they mistakenly thought that the electricity
from the cloud was silently draining into the pole
to the key.
In fact, the electric charges were stuck in the cloud.
However, the charges in the metal rod or kite
were repelled by the cloud and moved by induction,
or moving charges in the distance
to the kink in the rod or the key.
Watching sparks stream from a pole
due to a distant thundercloud
seemed to verify Franklin's theory
that the pole stuck into the ground
will drain an electrical thundercloud of its electricity
and thus save people from lightning strikes.
In fact, at the end of his paper
about the success of his experiment in France,
Delabar mentioned that, quote,
"Perhaps no more than a hundred iron rods
would be necessary to preserve
the whole city of Paris from lightning."
Despite the fact that the original motivation
behind the lightning rod was flawed,
the lightning rod that we use today
is basically as Franklin originally designed it.
An iron rod placed on a roof
with a wire connected to the ground.
However, it never worked to silently drain electricity
from a cloud.
Why not?
Well it's because thunderclouds are farther up in the sky
than Franklin realized.
In order to bridge that gap,
the lightning cloud must have tremendous charge,
and therefore it strikes with tremendous power.
So if it doesn't work, why do we use it?
Well, it doesn't work
to stop lightning strikes from happening,
but it does work to save us from its terrible mischief.
This is because electricity easily flows through metal,
but has a difficult time flowing through glass,
or brick, or cement.
Therefore, when a lightning strikes
strikes a lightning rod,
the electricity safely and easily
flows through the wire and into the ground.
After a few years,
even Franklin started to see this advantage
of the lighting rod.
Writing Delabar that, quote,
"Pointed rods erected on buildings
and connected with wire with the earth
would either prevent a stroke of lightning
or if not prevent it,
would conduct it so that the building
should suffer no damage."
Back in 1752, two months after his kite experiment,
Franklin constructed a lightning rod on his house
with a small gap with bells and a clapper
to warn him when the rod was electrified.
Supposedly Franklin's wife, Deborah
was not fond of the bell
and asked him how keep them from ringing all night
when he was off on his many travels.
Franklin also installed lightning rods without bells
in several buildings in Pennsylvania,
including at a church at the University of Pennsylvania
at the Pennsylvania State House.
By the next year,
he published in his Poor Richard's Almanac
the details of how the secure buildings for mischief
by thunder and lightning with a small iron rod.
In South Carolina,
a doctor managed to recreate Franklin's kite experiment,
but was restrained from installing lightning rod
by his nervous neighbors.
Why were they scared of a piece of metal?
Well, the fundamental reason was religious.
See, lightning was God's judgment on man.
It was the height of hubris to get in the way of God's plan.
Franklin tried to quiet their nerves by saying, quote,
"Shrewdly, the thunder of heaven
is no more supernatural
than the rain or sunshine of heaven."
And there are no qualms about roofs or umbrellas.
That did not quail the anxiety.
France's leading expert on electricity,
a man named Abbe Nollet,
he was mentioned a lot in the last video, said,
"It was as impious to warn off heaven's lightning
as for a child to warn off the chastening rod
of its father."
In 1755, a terrible and unusual earthquake hit Boston,
and a local reverend blamed it
on the lightning rods invented by the clever Mr. Franklin.
He said, "Oh, there's no getting away
from the mighty hand of God."
By the way, lightning rods and lightning
do not cause earthquakes.
Ironically, as churches tended
to be the tallest buildings at the time,
and with nice pointy crosses on top,
they were often the most struck by lightning.
Often leaving, say, houses of ill repute nearby untouched.
Ringing bells was supposed to help,
but just tended to be dangerous for the bell-ringer.
For example, in Germany,
over the course of just 33 years,
around 400 church towers were struck
and 120 bell-ringers were killed.
Over the following decades,
there were continual debate, riots,
and even battles in the courts
over Franklins heretical rod.
However, the debate against the lightning rod
was losing one because it worked and worked well.
Towers that were destroyed multiple times a year
never had any trouble again
once you added a little wire and a little metal stick.
Still, the debate over the lightning rod
went well into the 1780s.
Franklin never tried to make a penny
off of his many inventions
including the lightning rod.
That, combined with his wit and charm,
made him incredibly popular
among all levels of society.
He was fond over
and his image was put on every item imaginable.
Supposedly, the king of France got so irritated
with his mistress gushing over Franklin
that he gave her a chamber pot
with Franklin's image on the bottom.
20 years after Franklin's death,
John Adams, a man who personally disliked Franklin,
wrote that, quote,
"The invention of a lightning rod
was one of the most sublime
that has ever entered a human imagination."
And that Franklin's reputation was more universal
than of Leibniz, or Newton, or Frederick, or Voltaire.
And his character more beloved and esteem
than any, or all of them.
They were scarcely a peasant or citizen
who was not familiar with him
and who did not consider him a friend to humankind.
Franklin became a little distracted
from his electricity discoveries
in the 1760s and '70s by the American revolution.
In fact, all of Europe and America
seemed to be focused on politics and revolution.
Electricity parties went out of fashion,
and aside from a few more people accepting lightning rods
and a man named Coulomb,
discovering an equation for the force of electricity,
very little happened with electricity.
That all changed in 1791
when an Italian anatomy professor named Luigi Galvani
happened to put a dissected frog near electricity machine.
Then, due to Franklin's experiment,
he took the frog outside in a thunderstorm
and ended up inventing the battery.
That strange story is next time
on The Secret History of Electricity.
♪ Electricity ♪
Thanks for watching my video.
Please remember to give in a nice thumbs up.
Also, if you haven't seen it already,
I recommend watching the previous video
about the true story about Ben Franklin and the kite.
And make sure to check out the next video
about Galvani and the frog
and the invention of the battery.
It's one of my favorite stories
in the entire history of electricity.
Thanks for watching my video.
Remember to subscribe to my YouTube channel,
"Kathy Loves Physics,"
or my Facebook page, Kathy Loves Physics.
Have a good day.
(upbeat music)