0:00:08 > 0:00:11At the dawn of the 19th century,
0:00:11 > 0:00:12in a cellar in Mayfair,
0:00:12 > 0:00:17the most famous scientist of the time, Humphry Davy,
0:00:17 > 0:00:21built an extraordinary piece of electrical equipment.
0:00:21 > 0:00:23Four metres wide, twice as long
0:00:23 > 0:00:27and containing stinking stacks of acid and metal,
0:00:27 > 0:00:30it had been created to pump out more electricity
0:00:30 > 0:00:33than had ever been possible before.
0:00:33 > 0:00:36It was in fact the biggest battery
0:00:36 > 0:00:38the world had ever seen.
0:00:38 > 0:00:41With it, Davy was about to propel us
0:00:41 > 0:00:43into a new age.
0:00:56 > 0:01:00That moment would take place at a lecture at the Royal Institution,
0:01:00 > 0:01:04in front of hundreds of London's great and good.
0:01:04 > 0:01:07Filled with anticipation, they packed the seats,
0:01:07 > 0:01:12hoping to witness a new and exciting electrical wonder.
0:01:12 > 0:01:17But what they would see that night would be something truly unique.
0:01:17 > 0:01:20Something they would remember for the rest of their lives.
0:01:20 > 0:01:23Using just two simple carbon rods,
0:01:23 > 0:01:29Humphry Davy was about to unleash the true potential of electricity.
0:01:35 > 0:01:39Electricity is one of nature's most awesome phenomena,
0:01:39 > 0:01:43and the most powerful manifestation of it we ever see
0:01:43 > 0:01:45is lightning.
0:01:48 > 0:01:52This is the story of how we first dreamed of controlling
0:01:52 > 0:01:54this primal force of nature,
0:01:54 > 0:01:57and how we would ultimately become its master.
0:01:59 > 0:02:02It's a 300-year tale
0:02:02 > 0:02:05of dazzling leaps of imagination and extraordinary experiments.
0:02:07 > 0:02:11Tens of thousands of volts passed across his body
0:02:11 > 0:02:13and through the end of a lamp that he was holding.
0:02:14 > 0:02:17It's a story of a maverick geniuses
0:02:17 > 0:02:21who used electricity to light our cities,
0:02:21 > 0:02:24to communicate across the seas and through the air,
0:02:24 > 0:02:28to create modern industry and to give us the digital revolution.
0:02:33 > 0:02:37But in this film, we'll tell the story of the very first scientists
0:02:37 > 0:02:41who started to unlock the mysteries of electricity.
0:02:41 > 0:02:44It's as though there's something alive in there.
0:02:44 > 0:02:47They studied its curious link to life,
0:02:47 > 0:02:51built strange and powerful instruments to create it
0:02:51 > 0:02:54and even tamed lightning itself.
0:02:55 > 0:03:01It was these men who truly laid the foundations of the modern world.
0:03:01 > 0:03:04And it all started with a spark.
0:03:20 > 0:03:24Imagine our world without electricity.
0:03:25 > 0:03:27It would be dark,
0:03:27 > 0:03:29cold and quiet.
0:03:30 > 0:03:35In many ways, it would be like the beginning of the 18th century,
0:03:35 > 0:03:38where our story begins.
0:03:43 > 0:03:46This is the Royal Society in London.
0:03:47 > 0:03:51In the early 1700s, after years in the wilderness,
0:03:51 > 0:03:54Isaac Newton finally took control of it
0:03:54 > 0:03:57after the death of his arch-enemy, Robert Hooke.
0:04:00 > 0:04:03Newton brought in his own people to the key jobs,
0:04:03 > 0:04:06to help shore up his new position.
0:04:06 > 0:04:11The new head of demonstrations there was 35-year-old Francis Hauksbee.
0:04:12 > 0:04:16Notes from the Royal Society in 1705
0:04:16 > 0:04:19reveal how hard Hauksbee tried
0:04:19 > 0:04:22to stamp his personality on its weekly meetings,
0:04:22 > 0:04:26producing ever more spectacular experiments to impress his masters.
0:04:32 > 0:04:35In November, he came up with this -
0:04:35 > 0:04:37a rotating glass sphere.
0:04:37 > 0:04:42He was able to remove the air from inside it using a new machine -
0:04:42 > 0:04:44the air pump.
0:04:44 > 0:04:49On his machine, a handle allowed him to spin the sphere.
0:04:51 > 0:04:56One by one, the candles in the room were put out
0:04:56 > 0:05:00and Francis placed his hand against the sphere.
0:05:01 > 0:05:05The audience were about to see something amazing.
0:05:11 > 0:05:15'Inside the glass sphere,
0:05:15 > 0:05:18'a strange ethereal light began to form,
0:05:18 > 0:05:21'dancing around his hand.
0:05:21 > 0:05:23'A light no-one had ever seen before.'
0:05:26 > 0:05:27That's fantastic.
0:05:27 > 0:05:30You see a beautiful blue glow, it's just marking out
0:05:30 > 0:05:34the shape of my hands, but then going right round the ball.
0:05:34 > 0:05:36It's as though there's something alive in there.
0:05:41 > 0:05:43It's difficult to really understand
0:05:43 > 0:05:47why this dancing blue light meant so much,
0:05:47 > 0:05:50but we have to bear in mind that at the time,
0:05:50 > 0:05:55natural phenomena like this were seen to be the work of the Almighty.
0:05:56 > 0:05:59This was still a period when, even in Isaac Newton's theory,
0:05:59 > 0:06:05God was constantly intervening in the conduct of the world.
0:06:05 > 0:06:07It made sense for a lot of people
0:06:07 > 0:06:11to interpret natural phenomena as acts of God.
0:06:12 > 0:06:16So when a mere mortal meddled with God's work,
0:06:16 > 0:06:20it was almost beyond rational comprehension.
0:06:21 > 0:06:25Hauksbee never realised the full significance of his experiment.
0:06:25 > 0:06:27He lost interest in his glowing sphere
0:06:27 > 0:06:29and spent the last few years of his life
0:06:29 > 0:06:32building ever more spectacular experiments
0:06:32 > 0:06:35for Isaac Newton to test his other theories.
0:06:35 > 0:06:39He never realised that he had unwittingly started
0:06:39 > 0:06:41an electrical revolution.
0:06:47 > 0:06:51Before Hauksbee, electricity had been merely a curiosity.
0:06:51 > 0:06:55The ancient Greeks rubbed amber, which they called electron,
0:06:55 > 0:06:57to get small shocks.
0:06:58 > 0:07:00Even Queen Elizabeth I marvelled
0:07:00 > 0:07:05at static electricity's power to lift feathers.
0:07:07 > 0:07:09But now Hauksbee's machine
0:07:09 > 0:07:13could make electricity at the turn of a handle,
0:07:13 > 0:07:15and you could see it.
0:07:17 > 0:07:21Perhaps even more importantly, his invention coincided
0:07:21 > 0:07:25with the birth of a new movement sweeping across Europe
0:07:25 > 0:07:28called the Enlightenment.
0:07:28 > 0:07:31Enlightened intellectuals used reason to question the world
0:07:31 > 0:07:35and their legacy was radical politics,
0:07:35 > 0:07:37iconoclastic art
0:07:37 > 0:07:41and natural philosophy, or science.
0:07:46 > 0:07:48But ironically, Hauksbee's new machine
0:07:48 > 0:07:52wasn't immediately embraced by most of these intellectuals.
0:07:52 > 0:07:56But instead, by conjurers and street magicians.
0:07:57 > 0:08:00Those with an interest in electricity
0:08:00 > 0:08:02called themselves electricians.
0:08:06 > 0:08:12One story tells of a dinner party attended by an Austrian Count.
0:08:12 > 0:08:15The electrician had placed some feathers on the table
0:08:15 > 0:08:19and then charged up a glass rod with a silk handkerchief.
0:08:19 > 0:08:23He then astonished the guests by lifting up the feathers
0:08:23 > 0:08:25with the rod.
0:08:26 > 0:08:29He then went on to charge himself up
0:08:29 > 0:08:32using one of Hauksbee's electrical machines.
0:08:33 > 0:08:39He gave the guests electric shocks, presumably to squeals of delight.
0:08:39 > 0:08:42But for his piece de resistance,
0:08:42 > 0:08:45he placed a glass of cognac in the centre of the table,
0:08:45 > 0:08:47charged himself up again
0:08:47 > 0:08:50and lit it with a spark from the tip of his finger.
0:08:54 > 0:08:57There was a trick called the electrical beatification,
0:08:57 > 0:09:01in which the victim sits on an insulated chair
0:09:01 > 0:09:05and above his head hangs a metal crown
0:09:05 > 0:09:07that doesn't quite touch his head.
0:09:07 > 0:09:11And then if the crown is electrified,
0:09:11 > 0:09:15then you get an electric discharge around the crown
0:09:15 > 0:09:17that looks exactly like a halo,
0:09:17 > 0:09:20which is why it's called the electric beatification.
0:09:24 > 0:09:27As England and the rest of Europe went electricity crazy,
0:09:27 > 0:09:30the spectacles grew bigger.
0:09:30 > 0:09:32The more curious electricians
0:09:32 > 0:09:35started to ask more profound questions,
0:09:35 > 0:09:39not only how can we make our shows bigger and better,
0:09:39 > 0:09:42but how can we control this amazing power?
0:09:42 > 0:09:46And for some, can this incredible electrical fire
0:09:46 > 0:09:49do more than just entertain?
0:09:59 > 0:10:03One of the first early breakthroughs would never have happened
0:10:03 > 0:10:05had it not been for a terrible accident.
0:10:09 > 0:10:12This is Charterhouse in the centre of London.
0:10:12 > 0:10:16Over the past 400 years, it's been a charitable home
0:10:16 > 0:10:19for young orphans and elderly gentleman.
0:10:19 > 0:10:24And sometime in the 1720s, it also became home to one Stephen Gray.
0:10:28 > 0:10:32Stephen Gray had been a successful silk dyer from Canterbury.
0:10:32 > 0:10:36He was used to seeing electric sparks leap from the silk
0:10:36 > 0:10:39and they fascinated him.
0:10:39 > 0:10:43Unfortunately, a crippling accident ended his career
0:10:43 > 0:10:45and left him destitute.
0:10:45 > 0:10:49But then he was offered a new life here at Charterhouse
0:10:49 > 0:10:53and with it the time to perform his own electrical experiments.
0:10:59 > 0:11:04Here at Charterhouse, possibly in this very room, the Great Chamber,
0:11:04 > 0:11:07Stephen Gray built a wooden frame
0:11:07 > 0:11:13and from the top beam he suspended two swings using silk rope.
0:11:14 > 0:11:18He also had a device like this, a Hauksbee machine
0:11:18 > 0:11:20for generating static electricity.
0:11:22 > 0:11:25Now, with a large audience in attendance,
0:11:25 > 0:11:29he got one of the orphan boys who lived here at Charterhouse
0:11:29 > 0:11:31to lie across the two swings.
0:11:33 > 0:11:37Gray placed some gold leaf in front of him.
0:11:49 > 0:11:52He then generated electricity
0:11:52 > 0:11:55and charged the boy through a connecting rod.
0:12:12 > 0:12:17Gold leaf, even feathers, leapt to the boy's fingers.
0:12:17 > 0:12:20Some of the audience claimed they could even see sparks
0:12:20 > 0:12:24flying out from his fingertips. Show business indeed.
0:12:29 > 0:12:32But to the curious and inquiring mind of Stephen Gray,
0:12:32 > 0:12:35this said something else as well -
0:12:35 > 0:12:37electricity could move,
0:12:37 > 0:12:42from the machine to the boy's body, through to his hands.
0:12:43 > 0:12:47But the silk rope stopped it dead.
0:12:48 > 0:12:51It meant the mysterious electrical fluid
0:12:51 > 0:12:53could flow through some things...
0:12:54 > 0:12:57..but not through others.
0:13:05 > 0:13:10It led Gray to divide the world into two different kinds of substances.
0:13:10 > 0:13:14He called them insulators and conductors.
0:13:14 > 0:13:17Insulators held electric charge within them
0:13:17 > 0:13:21and wouldn't let it move, like the silk or hair,
0:13:21 > 0:13:23glass and resin.
0:13:23 > 0:13:27Whereas conductors allowed electricity to flow through them,
0:13:27 > 0:13:30like the boy or metals.
0:13:30 > 0:13:35It's a distinction which is still crucial even today.
0:13:38 > 0:13:41Just think of these electric pylons.
0:13:43 > 0:13:47They work on the same principle that Gray deduced
0:13:47 > 0:13:49nearly 300 years ago.
0:13:51 > 0:13:54The wires are conductors.
0:13:54 > 0:13:56The glass and ceramic objects
0:13:56 > 0:14:01between the wire and the metal of the pylon are insulators
0:14:01 > 0:14:03that stop the electricity leaking from the wires
0:14:03 > 0:14:06into the pylon and down to the earth.
0:14:09 > 0:14:14They're just like the silk ropes in Gray's experiment.
0:14:17 > 0:14:20Back in the 1730s,
0:14:20 > 0:14:24Gray's experiment may have astounded all who saw it,
0:14:24 > 0:14:28but it had a frustrating drawback.
0:14:29 > 0:14:35Try as he might, Gray couldn't contain the electricity he was generating for long.
0:14:35 > 0:14:40It leapt from the machine to the boy and was quickly gone.
0:14:40 > 0:14:42The next step in our story came
0:14:42 > 0:14:45when we learnt how to store electricity.
0:14:45 > 0:14:48But that would take place not in Britain,
0:14:48 > 0:14:50but across the Channel in mainland Europe.
0:15:06 > 0:15:09Across the Channel, electricians were just as busy
0:15:09 > 0:15:13as their British counterparts and one centre for electrical research
0:15:13 > 0:15:16was here in Leiden, Holland.
0:15:18 > 0:15:22And it was here that a professor came up with an invention
0:15:22 > 0:15:26that many still regard as the most significant of the 18th century,
0:15:26 > 0:15:30one that in some form or another can still be found
0:15:30 > 0:15:33in almost every electrical device today.
0:15:33 > 0:15:38That professor was Pieter van Musschenbroek.
0:15:38 > 0:15:40Unlike Hauksbee and Gray,
0:15:40 > 0:15:43Musschenbroek was born into academia.
0:15:45 > 0:15:48But ironically enough, his breakthrough
0:15:48 > 0:15:51came not because of his rigorous science,
0:15:51 > 0:15:54but because of a simple human mistake.
0:15:59 > 0:16:03He was trying to find a way to store electrical charge,
0:16:03 > 0:16:07ready for his demonstrations. And you can almost hear
0:16:07 > 0:16:10his train of thought as he tries to figure this out.
0:16:12 > 0:16:16If electricity is a fluid that flows, a bit like water,
0:16:16 > 0:16:22then maybe you can store it in the same way that you can store water.
0:16:23 > 0:16:26So Musschenbroek went to his laboratory
0:16:26 > 0:16:30to try to make a device to store electricity.
0:16:31 > 0:16:35Musschenbroek started to think literally.
0:16:35 > 0:16:39He took a glass jar and poured in some water.
0:16:42 > 0:16:46He then placed inside it a length of conducting wire...
0:16:48 > 0:16:52..which was connected at the top to a Hauksbee electric machine.
0:16:54 > 0:17:00'Then he put the jar on an insulator to help keep the charge in the jar.'
0:17:00 > 0:17:05He then tried to pour the electricity into the jar
0:17:05 > 0:17:08produced by the machine via the wire
0:17:08 > 0:17:10down through into the water.
0:17:11 > 0:17:16'But whatever he tried, the charge just wouldn't stay in the jar.
0:17:17 > 0:17:20'Then one day, by accident,
0:17:20 > 0:17:24'he forgot to put the jar on the insulator,
0:17:24 > 0:17:28'but charged it instead while it was still in his hand.'
0:17:33 > 0:17:37Finally, holding the jar with one hand,
0:17:37 > 0:17:39he touched the top with the other
0:17:39 > 0:17:42and received such a powerful electric shock,
0:17:42 > 0:17:44he was almost thrown to the ground.
0:17:44 > 0:17:48He writes, "It's a new but terrible experiment
0:17:48 > 0:17:53"which I advise you never to try. Nor would I, who've experienced it
0:17:53 > 0:17:56"and survived by the grace of God do it again
0:17:56 > 0:17:58"for all the kingdom of France."
0:17:58 > 0:18:02So I'm going to heed his advice, not touch the top,
0:18:02 > 0:18:06and instead see if I can get a spark off of it.
0:18:11 > 0:18:15The sheer power of the electricity which flew from the jar
0:18:15 > 0:18:18was greater than any seen before.
0:18:20 > 0:18:22And even more surprisingly,
0:18:22 > 0:18:27the jar could store that electricity for hours, even days.
0:18:30 > 0:18:35So in honour of the city where Musschenbroek made his discovery,
0:18:35 > 0:18:38they called it the Leiden jar.
0:18:40 > 0:18:44And its fame swept across the world.
0:18:44 > 0:18:48And very rapidly, from 1745 through the rest of the 1740s,
0:18:48 > 0:18:52the news of this - it's called the Leiden jar - goes global.
0:18:52 > 0:18:55It spreads from Japan in East Asia
0:18:55 > 0:18:59to Philadelphia in eastern America.
0:18:59 > 0:19:06It became one of the first quick, globalised, scientific news items.
0:19:08 > 0:19:14But although the Leiden jar became a global electrical phenomenon,
0:19:14 > 0:19:17no-one had the slightest idea how it worked.
0:19:18 > 0:19:20You have a jar of electric fluid,
0:19:20 > 0:19:24and it turns out that you get a bigger shock from the jar
0:19:24 > 0:19:29if you allow the electric fluid to drain away to the earth.
0:19:29 > 0:19:33Why is the shock bigger if the jar's leaking?
0:19:33 > 0:19:38Why isn't the shock bigger if you make sure all the electric fluid
0:19:38 > 0:19:39stays inside the jar?
0:19:39 > 0:19:43That was how mid-18th century electrical philosophers
0:19:43 > 0:19:45were faced with this challenge.
0:19:49 > 0:19:54Electricity was without doubt a fantastical wonder.
0:19:54 > 0:19:56It could shock and spark.
0:19:56 > 0:19:59It could now be stored and moved around.
0:19:59 > 0:20:03Yet what electricity was, how it worked,
0:20:03 > 0:20:04and why it did all these things
0:20:04 > 0:20:09was nothing less than a complete mystery.
0:20:21 > 0:20:25Within 10 years, a new breakthrough was to come
0:20:25 > 0:20:28from an unexpected quarter,
0:20:28 > 0:20:31From a man politically and philosophically at war
0:20:31 > 0:20:34with the London establishment.
0:20:34 > 0:20:38And even more shockingly for the British electrical elite,
0:20:38 > 0:20:42that man was merely a colonial.
0:20:42 > 0:20:43An American.
0:20:47 > 0:20:49This painting of Benjamin Franklin
0:20:49 > 0:20:51hangs here at the Royal Society in London.
0:20:53 > 0:20:57Franklin was a passionate supporter of American emancipation
0:20:57 > 0:21:00and saw the pursuit of rational science,
0:21:00 > 0:21:03and particularly electricity,
0:21:03 > 0:21:06as a way of rolling back ignorance, false idols
0:21:06 > 0:21:13and ultimately his intellectually elitist colonial masters.
0:21:13 > 0:21:19And this is mixed with a profoundly egalitarian democratic idea
0:21:19 > 0:21:21that Franklin and his allies have,
0:21:21 > 0:21:25which is this is a phenomenon open to everyone.
0:21:25 > 0:21:28Here's something that the elite doesn't really understand
0:21:28 > 0:21:31and we might be able to understand it.
0:21:31 > 0:21:34Here's something that the elite can't really control
0:21:34 > 0:21:37but we might be able to control.
0:21:37 > 0:21:42And here's something above all which is the source of superstition.
0:21:42 > 0:21:45And we, rational, egalitarian,
0:21:45 > 0:21:48potentially democratic, intellectuals,
0:21:48 > 0:21:51we will be able to reason it out,
0:21:51 > 0:21:56without appearing to be the slaves of magic or mystery.
0:21:57 > 0:22:01So Franklin decided to use the power of reason
0:22:01 > 0:22:03to rationally explain what many
0:22:03 > 0:22:05considered a magical phenomenon...
0:22:05 > 0:22:07Lightning.
0:22:07 > 0:22:11THUNDER BOOMS
0:22:11 > 0:22:15This is probably one of the most famous scientific images
0:22:15 > 0:22:17of the 18th century.
0:22:17 > 0:22:20It shows Benjamin Franklin, the heroic scientist,
0:22:20 > 0:22:23flying a kite in a storm,
0:22:23 > 0:22:27proving that lightning is electrical.
0:22:27 > 0:22:31But although Franklin proposed this experiment,
0:22:31 > 0:22:33he almost certainly never performed it.
0:22:35 > 0:22:39Much more likely is that his most significant experiment
0:22:39 > 0:22:43was another one which he proposed but didn't even conduct.
0:22:43 > 0:22:47In fact, it didn't even happen in America.
0:22:47 > 0:22:50It took place here in a small village north of Paris
0:22:50 > 0:22:52called Marly La Ville.
0:22:55 > 0:23:00The French adored Franklin, especially his anti-British politics,
0:23:00 > 0:23:03and they took it upon themselves to perform
0:23:03 > 0:23:06his other lightning experiments without him.
0:23:07 > 0:23:12I've come to the very spot where that experiment took place.
0:23:19 > 0:23:23In May 1752, George Louis Leclerc,
0:23:23 > 0:23:27known across France as the Compte de Buffon,
0:23:27 > 0:23:30and his friend Thomas Francois Dalibard,
0:23:30 > 0:23:35erected a 40-ft metal pole, more than twice as high as this one,
0:23:35 > 0:23:38held in place by three wooden staves,
0:23:38 > 0:23:41just outside Dalibard's house here in the Marly La Ville.
0:23:41 > 0:23:47The metal pole rested at the bottom inside an empty wine bottle.
0:23:50 > 0:23:54Franklin's big idea had been that the long pole
0:23:54 > 0:23:58would capture the lightning, pass it down the metal rod
0:23:58 > 0:24:01and store it in the wine bottle at the base
0:24:01 > 0:24:03which worked as a Leiden jar.
0:24:03 > 0:24:08Then, he could confirm what lightning actually was.
0:24:08 > 0:24:12All his French followers had to do was wait for a storm.
0:24:17 > 0:24:21And then on May 23rd, the heavens opened.
0:24:21 > 0:24:23THUNDER
0:24:23 > 0:24:26At 12.20, a loud thunderclap was heard
0:24:26 > 0:24:29as lightning hit the top of the pole.
0:24:31 > 0:24:33An assistant ran to the bottle,
0:24:33 > 0:24:36a spark leapt across
0:24:36 > 0:24:39between the metal and his finger with a loud crack
0:24:39 > 0:24:42and a sulphurous smell, burning his hand.
0:24:42 > 0:24:47The spark revealed lightning for what it really was.
0:24:47 > 0:24:51It was the same as the electricity made by man.
0:24:55 > 0:24:58It is hard to overestimate the significance of this moment.
0:24:58 > 0:25:03Nature had been mastered, not only that but the wrath of God itself
0:25:03 > 0:25:06had been brought under the control of mankind.
0:25:06 > 0:25:09It was a kind of heresy.
0:25:09 > 0:25:14Franklin's experiment was very important because it showed that
0:25:14 > 0:25:18lightning storms produce or are produced by electricity
0:25:18 > 0:25:22and that you can bring this electricity down,
0:25:22 > 0:25:24that electricity is a force of nature
0:25:24 > 0:25:26that's waiting out there to be tapped.
0:25:29 > 0:25:34Next, Franklin turned his rational mind to another question.
0:25:34 > 0:25:40Why the Leiden jar made the biggest sparks when it was held in the hand?
0:25:40 > 0:25:44Why didn't all the electricity just drain away?
0:25:44 > 0:25:49In drawing on his experience as a successful businessman,
0:25:49 > 0:25:52he saw something no-one else had.
0:25:52 > 0:25:55That like money in a bank,
0:25:55 > 0:26:00electricity can be in credit, what he called positive,
0:26:00 > 0:26:03or debit, negative.
0:26:05 > 0:26:09For him, the problem of the Leiden jar is one of accountancy.
0:26:09 > 0:26:17Franklin's idea was every body has around an electrical atmosphere.
0:26:17 > 0:26:22And there is a natural amount of electric fluid around each body.
0:26:22 > 0:26:26If there is too much, we will call it positive.
0:26:26 > 0:26:29If there is too little, we will call it negative.
0:26:29 > 0:26:33And nature is organised so the positives and negatives
0:26:33 > 0:26:35always want to balance out,
0:26:35 > 0:26:38like an ideal American economy.
0:26:41 > 0:26:46Franklin's insight was that electricity was actually just positive charge
0:26:46 > 0:26:50flowing to cancel out negative charge.
0:26:50 > 0:26:52And he believed this simple idea
0:26:52 > 0:26:56could solve the mystery of the Leiden jar.
0:26:59 > 0:27:01As the jar is charged up,
0:27:01 > 0:27:08negative electrical charge is poured down the wire and into the water.
0:27:08 > 0:27:13If the jar rests on an insulator, a small amount builds up in the water.
0:27:18 > 0:27:23But, if instead the jar is held by someone as it is being charged,
0:27:23 > 0:27:25positive electric charge
0:27:25 > 0:27:28is sucked up through their body from the ground
0:27:28 > 0:27:30to the outside of the jar,
0:27:30 > 0:27:34trying to cancel out the negative charge inside.
0:27:36 > 0:27:38But the positive and negative charges
0:27:38 > 0:27:41are stopped from cancelling out
0:27:41 > 0:27:45by the glass which acts as an insulator.
0:27:45 > 0:27:50Instead, the charge just grows and grows on both sides of the glass.
0:27:53 > 0:27:56Then, touching the top of the jar with it the other hand,
0:27:56 > 0:28:00completes a circuit allowing the negative charge on the inside
0:28:00 > 0:28:05to pass through the hand to the positive on the outside,
0:28:05 > 0:28:07finally cancelling it out.
0:28:10 > 0:28:16The movement of this charge causes a massive shock and often a spark.
0:28:22 > 0:28:27The modern equivalent of the Leiden jar is this - the capacitor.
0:28:27 > 0:28:30It is one of the most ubiquitous of electronic components.
0:28:30 > 0:28:32It is found everywhere.
0:28:32 > 0:28:37There are a number of smaller ones scattered around on this circuit board from a computer.
0:28:37 > 0:28:40They help smooth out electrical surges,
0:28:40 > 0:28:43protecting sensitive components,
0:28:43 > 0:28:46even in the most modern electric circuit.
0:28:57 > 0:29:00Solving the mystery of the Leiden jar
0:29:00 > 0:29:04and recognising lightning as merely a kind of electricity
0:29:04 > 0:29:06were two great successes for Franklin
0:29:06 > 0:29:09and the new Enlightenment movement.
0:29:11 > 0:29:14But the forces of trade and commerce,
0:29:14 > 0:29:17which helped fuel the Enlightenment,
0:29:17 > 0:29:19were about to throw up a new
0:29:19 > 0:29:23and even more perplexing electrical mystery.
0:29:23 > 0:29:26A completely new kind of electricity.
0:29:31 > 0:29:33This is the English Channel.
0:29:33 > 0:29:36By the 17th and 18th centuries,
0:29:36 > 0:29:40a good fraction of the world's wealth flowed up this stretch of water
0:29:40 > 0:29:43from all corners of the British Empire
0:29:43 > 0:29:45and beyond, on its way to London.
0:29:45 > 0:29:48Spices from India, sugar from the Caribbean,
0:29:48 > 0:29:51wheat from America, tea from China.
0:29:51 > 0:29:54But, of course, it wasn't just commerce.
0:29:58 > 0:30:00New plants and animal specimens
0:30:00 > 0:30:04from all over the world came flooding into London,
0:30:04 > 0:30:08including one that particularly fascinated the electricians.
0:30:11 > 0:30:16Called the torpedo fish, it had been the stuff of fishermen's tales.
0:30:16 > 0:30:22Its sting, it was said, was capable of knocking a grown man down.
0:30:22 > 0:30:26But as the electricians started to investigate the sting,
0:30:26 > 0:30:30they realised it felt strangely similar to a shock
0:30:30 > 0:30:31from a Leiden jar.
0:30:34 > 0:30:38Could its sting actually be an electric shock?
0:30:43 > 0:30:48At first, many people dismissed the torpedo fish's shock as occult.
0:30:48 > 0:30:51Some said it was probably just the fish biting.
0:30:51 > 0:30:55Others that it could not be a shock because, without a spark,
0:30:55 > 0:30:57it just wasn't electricity.
0:30:57 > 0:30:59But, for most, it was a very strange
0:30:59 > 0:31:01and inexplicable new mystery.
0:31:01 > 0:31:03It would take one of the oddest
0:31:03 > 0:31:06yet most brilliant characters in British science
0:31:06 > 0:31:09to begin to unlock the secrets of the torpedo fish.
0:31:14 > 0:31:18This is the only picture in existence
0:31:18 > 0:31:23of the pathologically shy but exceptional Henry Cavendish.
0:31:23 > 0:31:27This one only exists because an artist sketched his coat
0:31:27 > 0:31:32as it hung on a peg, then filled in the face from memory.
0:31:35 > 0:31:38His family were fantastically rich.
0:31:38 > 0:31:40They were the Devonshires
0:31:40 > 0:31:44who still own Chatsworth House in Derbyshire.
0:31:44 > 0:31:47Henry Cavendish decided to turn his back
0:31:47 > 0:31:49on his family's wealth and status
0:31:49 > 0:31:53to live in London near his beloved Royal Society
0:31:53 > 0:31:58where he could quietly pursue his passion for experimental science.
0:31:58 > 0:32:04When he heard about the electric torpedo fish, he was intrigued.
0:32:04 > 0:32:05A friend wrote to him...
0:32:05 > 0:32:10"On this, my first experience of the effect of the torpedo,
0:32:10 > 0:32:14"I exclaimed that this is certainly electricity.
0:32:14 > 0:32:16"But how?"
0:32:16 > 0:32:21And to work out how a living thing could produce electricity,
0:32:21 > 0:32:27he decided to make his own artificial fish.
0:32:28 > 0:32:30These are his plans.
0:32:30 > 0:32:35Two Leiden jars shaped like the fish which were buried under sand.
0:32:35 > 0:32:41When the sand was touched, they discharged, giving a nasty shock.
0:32:41 > 0:32:46His model helped convince him that the real torpedo fish was electric.
0:32:46 > 0:32:50But it still left him with a nagging problem.
0:32:52 > 0:32:56Although both the real fish and Cavendish's artificial one
0:32:56 > 0:32:58gave powerful electric shocks,
0:32:58 > 0:33:02the real fish never sparked.
0:33:02 > 0:33:04Cavendish was perplexed.
0:33:04 > 0:33:07How could it be the same kind of electricity
0:33:07 > 0:33:10if they didn't both do the same kinds of things?
0:33:12 > 0:33:17Cavendish spent the winter of 1773 in his laboratory
0:33:17 > 0:33:19trying to come up with an answer.
0:33:19 > 0:33:22In the spring, he had a brainwave.
0:33:24 > 0:33:27Cavendish's ingenious answer was to point out a subtle distinction
0:33:27 > 0:33:32between the amount of electricity and its intensity.
0:33:32 > 0:33:36The real fish produced the same kind of electricity.
0:33:36 > 0:33:39It is just that it was less intense.
0:33:39 > 0:33:43For a physicist like me, this marks a crucial turning point.
0:33:43 > 0:33:49But it is the moment when two genuinely innovative scientific ideas first crop up.
0:33:49 > 0:33:53What Cavendish refers to as the amount of electricity,
0:33:53 > 0:33:56we now call "electric charge".
0:33:56 > 0:33:59His intensity is what we call
0:33:59 > 0:34:02the potential difference or "voltage".
0:34:05 > 0:34:09So the Leiden jar's shock was high-voltage but low charge
0:34:09 > 0:34:15whereas the fish was low voltage and high charge.
0:34:15 > 0:34:18It's possible to actually measure that.
0:34:21 > 0:34:25Hiding at the bottom of this tank under the sand
0:34:25 > 0:34:28is the Torpedo marmorata and it's an electric ray.
0:34:28 > 0:34:33You can just see its eyes protruding from the sand.
0:34:33 > 0:34:35This is a fully grown female
0:34:35 > 0:34:37and I am going to try and measure
0:34:37 > 0:34:41the electricity it gives off with this bait.
0:34:41 > 0:34:43I have a fish connected to a metal rod and hooked up
0:34:43 > 0:34:45to an oscilloscope
0:34:45 > 0:34:49to see if I can measure the voltage as it catches its prey.
0:34:49 > 0:34:51Here goes!
0:35:03 > 0:35:04Oh! There's one!
0:35:10 > 0:35:12There's another one.
0:35:12 > 0:35:15The fish gave a shock of about 240 volts,
0:35:15 > 0:35:20the same as mains electricity, but still roughly 10 times less
0:35:20 > 0:35:23than the Leiden jar.
0:35:23 > 0:35:26That would have given me quite a nasty shock
0:35:26 > 0:35:29and I can only try and imagine what it must have been like
0:35:29 > 0:35:32for scientists in the 18th century to witness this.
0:35:32 > 0:35:36An animal, a fish, producing its own electricity.
0:35:39 > 0:35:43Cavendish had shown that the torpedo fish made electricity
0:35:43 > 0:35:46but he didn't know if it was the same kind of electricity
0:35:46 > 0:35:49as that made from an electrical machine.
0:35:51 > 0:35:54Is the electrical shock that a torpedo produces
0:35:54 > 0:35:59the same as produced by an electrical machine?
0:35:59 > 0:36:00Or are there two kinds?
0:36:00 > 0:36:05A kind generated artificially or is there a kind of animal electricity
0:36:05 > 0:36:08that only exists in living bodies?
0:36:08 > 0:36:12This was a huge debate that divided opinion for several decades.
0:36:16 > 0:36:21Out of that bitter debate came a new discovery.
0:36:21 > 0:36:26The discovery that electricity needn't be a brief shock or spark.
0:36:26 > 0:36:29It could actually be continuous.
0:36:29 > 0:36:32And the generation of continuous electricity
0:36:32 > 0:36:35would ultimately propel us into our modern age.
0:36:48 > 0:36:52But the next step in the story of electricity would come about
0:36:52 > 0:36:56because of a fierce personal and professional rivalry
0:36:56 > 0:36:59between two Italian academics.
0:37:03 > 0:37:08BELL RINGS
0:37:14 > 0:37:19This is Bologna University, one of the oldest in Europe.
0:37:19 > 0:37:21In the late 18th century,
0:37:21 > 0:37:23the city of Bologna was ruled from papal Rome
0:37:23 > 0:37:26which meant that the university was powerful
0:37:26 > 0:37:27but conservative in its thinking.
0:37:30 > 0:37:34It was steeped in traditional Christianity,
0:37:34 > 0:37:37one where got ruled earth from heaven
0:37:37 > 0:37:39but that the way he ran the world
0:37:39 > 0:37:42was hidden from us mere mortals
0:37:42 > 0:37:46who were not meant to understand him,
0:37:46 > 0:37:48only to serve him.
0:37:48 > 0:37:51One of the university's brightest stars
0:37:51 > 0:37:54was the anatomist Luigi Aloisio Galvani.
0:37:54 > 0:37:57But, in a neighbouring city,
0:37:57 > 0:38:01a rival electrician was about to take Galvani to task.
0:38:11 > 0:38:14This is Pavia, only 150 miles from Bologna,
0:38:14 > 0:38:17but by the end of the 18th century,
0:38:17 > 0:38:19worlds apart politically.
0:38:19 > 0:38:22It was part of the Austrian empire which put it
0:38:22 > 0:38:25at the very heart of the European Enlightenment.
0:38:25 > 0:38:28Liberal in its thinking, politically radical
0:38:28 > 0:38:32and obsessed with the new science of electricity.
0:38:32 > 0:38:35It was also home to Alessandro Volta.
0:38:39 > 0:38:43Alessandro Volta couldn't have been more unlike Galvani.
0:38:43 > 0:38:48From an old Lombardi family, he was young, arrogant, charismatic,
0:38:48 > 0:38:50a real ladies' man,
0:38:50 > 0:38:52and he courted controversy.
0:38:52 > 0:38:56Unlike Galvani, he liked to show off his experiments
0:38:56 > 0:38:59on an international stage to any audience.
0:38:59 > 0:39:05Volta's ideas were unfettered by Galvani's religious dogma.
0:39:05 > 0:39:09Like Benjamin Franklin and the European Enlightenment,
0:39:09 > 0:39:11he believed in rationality -
0:39:11 > 0:39:13that scientific truth,
0:39:13 > 0:39:17like a Greek god, would cast ignorance to the floor.
0:39:17 > 0:39:22Superstition was the enemy. Reason was the future.
0:39:25 > 0:39:28Both men were fascinated by electricity.
0:39:28 > 0:39:33Both brought their different ways of seeing the world to bear on it.
0:39:45 > 0:39:49Galvani had been attracted to the use of electricity
0:39:49 > 0:39:50in medical treatments.
0:39:50 > 0:39:53For instance, in 1759, here in Bologna,
0:39:53 > 0:39:58electricity was used on the muscles of a paralysed man.
0:39:58 > 0:40:01One report said,
0:40:01 > 0:40:07"It was a fine sight to see the mastoid rotate the head,
0:40:07 > 0:40:09"the biceps bend the elbow.
0:40:09 > 0:40:14"In short, to see the force and vitality of all the motions
0:40:14 > 0:40:18"occurring in every paralysed muscle subjected to the stimulus."
0:40:27 > 0:40:30Galvani believed these kinds of examples
0:40:30 > 0:40:35revealed that the body worked using animal electricity,
0:40:35 > 0:40:37a fluid that flows from the brain,
0:40:37 > 0:40:40through the nerves, into the muscles,
0:40:40 > 0:40:42where it's turned into motion.
0:40:43 > 0:40:48He devised a series of grisly experiments to prove it.
0:41:03 > 0:41:05Now, he first prepared a frog.
0:41:05 > 0:41:09He writes, "The frog is skinned and disembowelled.
0:41:09 > 0:41:12"Only their lower limbs are left joined together,
0:41:12 > 0:41:15"containing just the crural nerves."
0:41:15 > 0:41:17I've left my frog mostly intact,
0:41:17 > 0:41:21but I've exposed the nerves that connect to the frog's legs.
0:41:21 > 0:41:25Then he used Hauksbee's electrical machine
0:41:25 > 0:41:28to generate electrostatic charge,
0:41:28 > 0:41:32that would accumulate and travel along this arm
0:41:32 > 0:41:35and out through this copper wire.
0:41:35 > 0:41:39Then he connected the charge-carrying wire to the frog
0:41:39 > 0:41:42and another to the nerve just above the leg.
0:41:43 > 0:41:46Let's see what happens.
0:41:48 > 0:41:52Ooh! And the frogs leg twitches, just as it makes contact.
0:41:52 > 0:41:53There we go!
0:41:55 > 0:42:01For Galvani, what was going on there was that there's a strange,
0:42:01 > 0:42:05special kind of entity in the animal muscle,
0:42:05 > 0:42:07which he calls animal electricity.
0:42:07 > 0:42:12It's not like any other electricity. It's intrinsic to living beings.
0:42:15 > 0:42:21But for Volta, animal electricity smacked of superstition and magic.
0:42:21 > 0:42:26It had no place in rational and enlightened science.
0:42:28 > 0:42:33Volta saw the experiment completely differently to Galvani.
0:42:33 > 0:42:36He believed it revealed something totally new.
0:42:36 > 0:42:39For him, the legs weren't jumping as a result
0:42:39 > 0:42:42of the release of animal electricity from within them,
0:42:42 > 0:42:46but because of the artificial electricity from outside.
0:42:46 > 0:42:49The legs were merely the indicator.
0:42:49 > 0:42:54They were only twitching because of the electricity from the Hauksbee machine.
0:42:57 > 0:43:02Back in Bologna, Galvani reacted furiously to Volta's ideas.
0:43:02 > 0:43:06He believed Volta had crossed a fundamental line -
0:43:06 > 0:43:10from electrical experiments into God's realm,
0:43:10 > 0:43:13and that was tantamount to heresy.
0:43:13 > 0:43:17To have a kind of spirit like electricity,
0:43:17 > 0:43:19to have that produced artificially
0:43:19 > 0:43:22and to say that spirit, that living force,
0:43:22 > 0:43:26that agency was the same as something produced by God,
0:43:26 > 0:43:30that God had put into a living human body or a frog's body,
0:43:30 > 0:43:32that seemed sacrilegious to them,
0:43:32 > 0:43:35because it was eliminating this boundary
0:43:35 > 0:43:37between God's realm of the divine
0:43:37 > 0:43:40and the mundane realm of the material.
0:43:43 > 0:43:47Spurred on by his religious indignation,
0:43:47 > 0:43:50Galvani announced a new series of experimental results,
0:43:50 > 0:43:53which would prove Volta was wrong.
0:43:55 > 0:44:00During one of his experiments, he hung his frogs on an iron wire
0:44:00 > 0:44:04and saw something totally unexpected.
0:44:04 > 0:44:09If he connected copper wire to the wire the frog was hanging from,
0:44:09 > 0:44:13and then touched the other end of the copper to the nerve...
0:44:14 > 0:44:19..it seemed to him he could make the frog's legs twitch
0:44:19 > 0:44:21without any electricity at all.
0:44:28 > 0:44:34Galvani came to the conclusion that it must have been
0:44:34 > 0:44:39something inside the frogs, even if dead,
0:44:39 > 0:44:42that continued for a while after death
0:44:42 > 0:44:44to produce some kind of electricity.
0:44:44 > 0:44:50And the metal wires were somehow releasing that electricity.
0:44:51 > 0:44:53Over the next months,
0:44:53 > 0:44:58Galvani's experiments focused on isolating this animal electricity
0:44:58 > 0:45:01using combinations of frog and metal,
0:45:01 > 0:45:03Leiden jars and electrical machines.
0:45:05 > 0:45:09For Galvani, these experiments were proof the electricity
0:45:09 > 0:45:12was originating within the frog itself.
0:45:12 > 0:45:17The frog's muscles were Leiden jars, storing up the electrical fluid
0:45:17 > 0:45:20and then releasing it in a burst.
0:45:20 > 0:45:25On 30th October, 1786, he published his findings in a book,
0:45:25 > 0:45:31Animali Electricitate - Of Animal Electricity.
0:45:32 > 0:45:35Galvani was so confident of his ideas,
0:45:35 > 0:45:38he even sent a copy of his book to Volta.
0:45:41 > 0:45:46But Volta just couldn't stomach Galvani's idea of animal electricity.
0:45:46 > 0:45:50He thought the electricity just had to come from somewhere else.
0:45:52 > 0:45:53But where?
0:46:04 > 0:46:07In the 1790s, here at the University of Pavia,
0:46:07 > 0:46:12almost certainly in this lecture theatre, which still bears his name,
0:46:12 > 0:46:16Volta began his search for the new source of electricity.
0:46:18 > 0:46:21His suspicions focused on the metals
0:46:21 > 0:46:24that Galvani had used to make his frog's legs twitch.
0:46:24 > 0:46:30His curiosity had been piqued by an odd phenomenon he come across -
0:46:30 > 0:46:33how combinations of metals tasted.
0:46:36 > 0:46:40He found that if he took two different metal coins
0:46:40 > 0:46:42and placed them on the tip of his tongue,
0:46:42 > 0:46:46and then placed a silver spoon on top of both...
0:46:47 > 0:46:50..he got a kind of tingling sensation,
0:46:50 > 0:46:54rather like the tingling you'd get from the discharge of a Leiden jar.
0:46:54 > 0:46:57Volta concluded he could taste the electricity
0:46:57 > 0:47:04and it must be coming from the contact between the different metals in the coins and spoon.
0:47:04 > 0:47:07His theory flew in the face of Galvani's.
0:47:07 > 0:47:11The frog's leg twitched, not because of its own animal electricity,
0:47:11 > 0:47:16but because it was reacting to the electricity from the metals.
0:47:16 > 0:47:21But the electricity his coins generated was incredibly weak.
0:47:21 > 0:47:24How could he make it stronger?
0:47:28 > 0:47:32Then an idea came to him as he revisited the scientific papers
0:47:32 > 0:47:37from the great British scientist, Henry Cavendish,
0:47:37 > 0:47:41and in particular, his famous work on the electric torpedo fish.
0:47:44 > 0:47:49He went back and took a closer look at the torpedo fish
0:47:49 > 0:47:53and in particular, the repeating pattern of chambers in its back.
0:47:53 > 0:47:56He wondered whether it was this repeating pattern
0:47:56 > 0:47:59that held the key to its powerful electric shock.
0:48:02 > 0:48:06Perhaps each chamber was like his coins and spoon,
0:48:06 > 0:48:10each generating a tiny amount of electricity.
0:48:10 > 0:48:13And, perhaps, the fish's powerful shock
0:48:13 > 0:48:19results from the pattern of chambers repeating over and over again.
0:48:20 > 0:48:26With growing confidence in his new ideas, Volta decided to fight back
0:48:26 > 0:48:31by building his own artificial version of the torpedo fish.
0:48:31 > 0:48:36So, he copied the torpedo fish by repeating its pattern,
0:48:36 > 0:48:38but using metal.
0:48:38 > 0:48:42Here's what he did - he took a copper metal plate
0:48:42 > 0:48:47and then placed above it a piece of card soaked in dilute acid.
0:48:47 > 0:48:51Then above that, he took another metal and placed it on top.
0:48:51 > 0:48:56What he had here was exactly the same thing as Galvani's two wires.
0:48:56 > 0:49:00But now Volta repeated the process.
0:49:00 > 0:49:04What he was doing here was building a pile of metal.
0:49:04 > 0:49:09In fact, his invention became known as the pile.
0:49:14 > 0:49:17But it's what it could do that was the really incredible revelation.
0:49:17 > 0:49:22Volta tried his pile out on himself by getting two wires
0:49:22 > 0:49:24and attaching them to each end of the pile
0:49:24 > 0:49:27and bringing the other ends to touch his tongue.
0:49:30 > 0:49:33He could actually taste the electricity.
0:49:33 > 0:49:37This time, it was more powerful than normal and it was constant.
0:49:41 > 0:49:45He'd created the first battery.
0:49:45 > 0:49:51The machine was no longer an electrical and mechanical machine,
0:49:51 > 0:49:54it was just purely an electrical machine.
0:49:54 > 0:49:58So he proved that a machine imitating the fish could work,
0:49:58 > 0:50:03that what he called the metal or contact electricity
0:50:03 > 0:50:05of different metals could work,
0:50:05 > 0:50:09and that he regarded as his final,
0:50:09 > 0:50:14winning move in the controversy with Galvani.
0:50:14 > 0:50:19What Volta's pile showed was that you could develop all the phenomena
0:50:19 > 0:50:24of animal electricity without any animals being present.
0:50:24 > 0:50:30So, from the Voltaic point of view, it seemed as if Galvani was wrong,
0:50:30 > 0:50:34there's nothing special about the electricity in animals.
0:50:34 > 0:50:38It's electricity and it can be completely mimicked
0:50:38 > 0:50:40by this artificial pile.
0:50:43 > 0:50:49But the biggest surprise for Volta was that the electricity it generated was continuous.
0:50:49 > 0:50:53In fact, it poured out like water in a stream.
0:50:53 > 0:50:57And just as in a stream, where the measure of the amount of water
0:50:57 > 0:51:00flowing is called a current, so the electricity flowing
0:51:00 > 0:51:06out of the pile became known as an electrical current.
0:51:10 > 0:51:13200 years after Volta,
0:51:13 > 0:51:17we finally understand what electricity actually is.
0:51:19 > 0:51:23The atoms in metals, like all atoms, have electrically charged
0:51:23 > 0:51:27electrons surrounding a nucleus.
0:51:27 > 0:51:30But in metals, the atoms share their outer electrons
0:51:30 > 0:51:32with each other in a unique way,
0:51:32 > 0:51:36which means they can move from one atom to the next.
0:51:39 > 0:51:43If those electrons move in the same direction at the same time,
0:51:43 > 0:51:48the cumulative effect is a movement of electric charge.
0:51:50 > 0:51:55This flow of electrons is what we call an electric current.
0:52:00 > 0:52:03Within weeks of Volta publishing details of his pile,
0:52:03 > 0:52:08scientists were discovering something incredible about what it could do.
0:52:16 > 0:52:20Its effect on ordinary water was completely unexpected.
0:52:20 > 0:52:23The constant stream of electric charge into the water
0:52:23 > 0:52:27was ripping it up into its constituent parts -
0:52:27 > 0:52:30the gases, oxygen and hydrogen.
0:52:30 > 0:52:34Electricity was heralding the dawn of a new age.
0:52:34 > 0:52:40A new age where electricity ceased being a mere curiosity
0:52:40 > 0:52:44and started being genuinely useful.
0:52:44 > 0:52:47With constant flowing current electricity,
0:52:47 > 0:52:51new chemical elements could be isolated with ease.
0:52:51 > 0:52:56And this laid the foundations for chemistry, physics and modern industry.
0:52:59 > 0:53:02Volta's pile changed everything.
0:53:08 > 0:53:11The pile made Volta an international celebrity,
0:53:11 > 0:53:15feted by the powerful and the rich.
0:53:15 > 0:53:17In recognition,
0:53:17 > 0:53:21a fundamental measure of electricity was named in his honour.
0:53:21 > 0:53:22The volt.
0:53:26 > 0:53:32But his scientific adversary didn't fare quite so well.
0:53:32 > 0:53:38Luigi Aloisio Galvani died on 4th December 1798,
0:53:38 > 0:53:41depressed and in poverty.
0:53:41 > 0:53:45For me, it's not the invention of the battery
0:53:45 > 0:53:49that marked the crucial turning point in the story of electricity,
0:53:49 > 0:53:52it's what happened next.
0:54:01 > 0:54:05It took place in London's Royal Institution.
0:54:05 > 0:54:09It was the moment that marked the end of one era
0:54:09 > 0:54:11and the beginning of another.
0:54:15 > 0:54:17It was overseen by Humphry Davy,
0:54:17 > 0:54:21the first of a new generation of electricians.
0:54:21 > 0:54:27Young, confident and fascinated by the possibilities of continuous electrical current.
0:54:27 > 0:54:34So, in 1808, he built the world's largest battery.
0:54:34 > 0:54:37It filled an entire room underneath the Royal Institution.
0:54:37 > 0:54:43It had over 800 individual voltaic piles attached together.
0:54:43 > 0:54:48It must have hissed and breathed sulphurous fumes.
0:54:51 > 0:54:58In a darkened room, lit by centuries-old technology, candles and oil lamps,
0:54:58 > 0:55:02Davy connected his battery to two carbon filaments
0:55:02 > 0:55:05and brought the tips together.
0:55:05 > 0:55:08The continuous flow of electricity from the battery
0:55:08 > 0:55:11through the filaments leapt across the gap,
0:55:11 > 0:55:16giving rise to a constant and blindingly bright spark.
0:55:22 > 0:55:27Out of the darkness came the light.
0:55:38 > 0:55:43Davy's arc light truly symbolises the end of one era
0:55:43 > 0:55:46and the beginning of our era.
0:55:46 > 0:55:48The era of electricity.
0:55:57 > 0:56:04But there's a truly grisly coda to this story.
0:56:04 > 0:56:08In 1803, Galvani's nephew, one Giovanni Aldini,
0:56:08 > 0:56:12came to London with a terrifying new experiment.
0:56:12 > 0:56:15A convicted murderer called George Forster
0:56:15 > 0:56:18had just been hanged in Newgate.
0:56:18 > 0:56:21When the body was cut down from the gallows,
0:56:21 > 0:56:23it was brought directly to the lecture theatre,
0:56:23 > 0:56:27where Aldini started his macabre work.
0:56:30 > 0:56:32Using a voltaic pile,
0:56:32 > 0:56:37he began to apply an electric current to the dead man's body.
0:56:37 > 0:56:43Then Aldini put one electrical conductor in the dead man's anus
0:56:43 > 0:56:45and the other at the top of his spine.
0:56:45 > 0:56:50Forster's limp, dead body sat bolt upright
0:56:50 > 0:56:52and his spine arched and twisted.
0:56:52 > 0:56:55For a moment, it seemed as though the dead body
0:56:55 > 0:56:58had been brought back to life.
0:57:00 > 0:57:06It appeared as though electricity might have the power of resurrection.
0:57:06 > 0:57:11And this made a profound impact on a young writer called Mary Shelley.
0:57:17 > 0:57:22Mary Shelley wrote one of the most powerful and enduring stories ever.
0:57:22 > 0:57:24Based partly here on Lake Como,
0:57:24 > 0:57:27Frankenstein tells the story of a scientist,
0:57:27 > 0:57:30a Galvanist probably based on Aldini,
0:57:30 > 0:57:34who brings a monster to life using electricity.
0:57:34 > 0:57:40And then, disgusted by his own arrogance, he abandons his creation.
0:57:40 > 0:57:45Just like Davy's arc lamp, this book symbolises changing times.
0:57:45 > 0:57:49The end of the era of miracles and romance
0:57:49 > 0:57:54and the beginning of the era of rationality, industry and science.
0:58:06 > 0:58:10And it's that new age we explore in the next programme,
0:58:10 > 0:58:12because at the start of the 19th century,
0:58:12 > 0:58:17scientists realised electricity was intimately connected
0:58:17 > 0:58:21with another of nature's mysterious forces...
0:58:21 > 0:58:22magnetism.
0:58:23 > 0:58:27And that realisation would completely transform our world.
0:58:29 > 0:58:32To find out more about the story of electricity
0:58:32 > 0:58:35and to put your power knowledge to the test,
0:58:35 > 0:58:39try the Open University's interactive energy game.
0:58:39 > 0:58:41Go to...
0:58:44 > 0:58:47..and follow links to the Open University.
0:59:09 > 0:59:12Subtitles by Red Bee Media Ltd
0:59:12 > 0:59:15E-mail subtitling@bbc.co.uk