(STEPHEN HAWKING) Let me take you back in time
to a place without the wonders of the modern world.
500 years ago, the Earth was dark - a place of mystery and superstition.
But then science changed everything.
HORNS BEEP
This series will tell the stories
of the British scientists who changed the world.
We have asked some of the great scientists and inventors of today
to tell us about their heroes.
Now, let's start her up.
It opened up a whole new world of the very small.
Heat was Thomson's big idea!
For me, Hunter is a true hero.
Exciting possibilities.
He made science in Britain really matter.
Britain has a tremendous scientific legacy
that most people know little about.
We want to set the record straight
and put science back on the map.
The world is full of wonders, but they become more wonderful
when science looks at them.
Our story began with a handful of young men
who gazed up at the sky and discovered the underlying laws
of the universe.
The generation which followed was just as extraordinary.
Recorded here together in this group portrait,
a crowded roomful of brilliant minds.
We want to tell you about six of them.
Each of us has our favourites, from the son of a boat builder
to the richest man in England.
From a country doctor
to a charismatic adventurer.
At a time when there was no electric light,
disease killed countless thousands
and most people knew little of the world beyond Britain's borders.
These six men would use science to save lives,
generate power and allow man to fly for the first time.
Between them, they would transform the world
and take science from the abstract to the practical.
My man is the great Sir Joseph Banks.
Gentleman, amateur naturalist,
president of the Royal Society for over 40 years
and founder of a tradition of scientific exploration
that was ultimately to lead to Charles Darwin.
Here he is in the engraving as an old man,
right at the heart of the scientific world.
Lauded in his own time, today he's little remembered.
To me, he is an unsung hero -
the founding father ofa tradition of scientific expeditions,
which would have a massive impact on both Britain and the world.
As a boy, Joseph Banks was a keen collector
of insects and bird's eggs,
but the story goes that he found his true vocation
one afternoon when he was 15
and he went for a swim in the Thames near Eton.
And as he got out, he was suddenly overwhelmed by the beauty
of the wildflowers on the bank.
He determined there and then he would become a botanist.
And he was in the fortunate position to have the money
to pursue his dream.
When Banks went up to Oxford, he employed a tutor from Cambridge
specially to teach him botany.
This display of initiative and confidence, no doubt helped
by breeding and wealth, was to characterise Banks' approach
to learning and getting things done.
After his father's death,
the young Joseph Banks inherited several estates and a vast fortune.
And what he did with it was quite extraordinary.
Instead of setting off on the usual grand tour of Europe,
he arranged to join Captain Cook, who was preparing to set off
for the Pacific to find the recently discovered island
of Tahiti on the other side of the world.
Tahiti already had a thrilling reputation as an island paradise,
populated by noble savages and beautiful, friendly women.
But the scientific purpose of the expedition was to observe
the transit of the planet Venus across the disc of the sun -
a rare astronomical event.
The measurement would help calculate the distance
between the Earth and the sun.
And that would help in calculating longitude,
essential for accurate navigation,
and, in turn, for the extension of British sea power.
For Banks, it was a wonderful opportunity to discover
just how varied animals and plants were outside Europe.
By the mid-18th century, Britain's horizons had changed.
She had colonies and trading posts in America, Africa and India.
This fuelled an intense desire to explore, collect and classify
the wonders of the world,
from shells to beetles, and flowers to fossils.
So Banks' imminent voyage
was causing great excitement in the salons.
He was already well connected and well known.
Now he was going where few men had gone before,
and who could tell what he might find there?
He insisted on taking with him eight companions and two greyhounds.
But Captain Cook's ship The Endeavour
was only 100 feet long and it was already overcrowded.
It had a crew of 85,
astronomers together with their equipment,
stores for 18 months at sea,
a goat and the ship's cat.
Navy rules allowed each sailor only 14 inches of hammock space.
Captain Cook's great cabin was only 12 feet square,
but he would have to share it with Banks and two of his entourage,
their scientific equipment,
as well as all the specimens of fish,
mammals, birds and plants
that they would collect along the way.
Uncomfortable, yes, but also extremely dangerous.
As Dr Johnson put it, a ship is like a jail,
with the added risk of being drowned.
But apart from shipwreck,
there was also the danger from scurvy and other diseases,
and fatal encounters with natives in unknown savage lands.
And indeed, of Banks' party of eight,
only three would return alive.
The Endeavour set sail from Plymouth on 25th August 1768,
bound for the South Pacific and immortality.
It would be three years before Banks saw England again.
And he would come back with a huge booty of new specimens.
These would capture the attention of the public and the King,
and help Banks take science from the interest of the privileged few
to an activity at the heart of the nation's pride and success.
(HAWKING) But while Banks and Cook were away on their voyage to Tahiti...
..back in Britain, a more humble man was dreaming of something so radical
that it would transform the landscape of Britain
and then the world.
This elegant launch
can go upstream or downstream, irrespective of the wind.
It's powered by a small steam engine.
HOOTING
For the whole of human history, man's only source of power
was muscle, wind and water.
That all changed with steam.
The man who discovered how to power the world
was not a rich Etonian gentleman, like Joseph Banks,
but the son of a Scottish craftsman.
His name was James Watt, and his steam engine
was to drive the Industrial Revolution.
And while Cook and Banks were sailing to the other side of the world,
Watt was struggling with prototypes in his Glasgow workshop.
I spent five years building 5,127 prototypes,
so I know how he felt.
James Watt was the son of a shipbuilder on the Clyde
and he would spend time in his father's workshop, much like this,
taking things apart and putting them back together again.
As an inventor, you always hope
for the eureka moment. But the truth is often far more prosaic,
and so it was with Watt's discovery.
The story goes that he was inspired
by watching the lid lifting on a boiling kettle.
In fact, his interest in the power of steam began
when he was asked to mend a broken model
of an already existing steam engine.
In 1764, a broken Newcomen engine arrived in Watt's workshop.
There were dozens in existence, used for pumping water out of mines.
But they were inefficient and expensive to run.
This waste of energy began to obsess Watt.
He couldn't believe there wasn't a more efficient
and much cheaper way of doing things.
Then it suddenly occurred to him what was wrong.
Steam was injected into the cylinder
and then condensed with cooling water to make a vacuum
to pull down the piston.
To get steam back into the system, the whole thing had to be heated up
all over again.
The answer was to cool and condense
the steam in a separate chamber
outside the main cylinder, instead of inside it.
This would speed the cycle up as well as saving energy.
This was James Watt's great idea.
That was a breakthrough, because it meant
that you wouldn't have to heat and cool and heat and cool
the cylinder and the piston with every stroke.
That would be a wonderful saving of energy
and allow the engine to be three times more efficient
than the Newcomen engine.
Fired with enthusiasm, James Watt rushed back into his workshop.
Within a few days he'd got the system working.
But although it was a moment of genius,
it would be ten years before he had a full-size working steam engine.
The future had arrived.
Watt's monsters throbbed day and night.
And there seemed no limit to the power they gave to man.
And here it is. A James Watt steam engine.
Over here we have the big counterbalance weight of 16 tonnes.
And the pump can lift three-quarters of a tonne of water up to 200 feet.
And here's the piston going down into the huge cylinder.
And underneath my feet, Watt's great invention - a separate condenser,
out of the way, exactly as it should be.
James Watt's invention changed the world.
He gave almost unlimited power for mines,
for factories, for transport,
and even the power to make electricity.
He made the future and our present.
This was the beginning of the Industrial Revolution.
Britain was the first nation to industrialise.
Watt himself made a fortune, setting up factories,
taking out patents, devising new and ever more impressive machinery
to harness the power of steam.
Where Britain went, the world followed
and the modern economy was born.
(HAWKING) But while Watt was toiling away in his Glasgow workshop...
a fellow Scot was scouring the back streets of London,
buying corpses.
Modern surgery may seem miraculous.
But in fact it's the result of centuries of research
into the human body and how it works.
And the roots of modern surgery can be found
in the stinking streets and stews of 18th-century London.
Then, medicine was a horror show.
But in the entrails of the dead, one man was seeking the truth.
His name was John Hunter.
And here he is in a painting by Joshua Reynolds
in the Royal College Of Surgeons.
There's the intense look on his face.
This obsessive workaholic, surrounded by all the wonderful objects
in biology which so fascinated him.
But Hunter's interest in the wonders of nature
was tied to his determination to discover how the body really worked.
And so how to operate on it.
An 18th-century surgeon was more butcher than scientist.
Cut and cauterise were the basic techniques
and speed was essential because there were no anaesthetics.
A good surgeon,
with instruments like this, could take off a leg in 15 seconds flat.
And if the patient didn't die of shock,
there was always the severe risk of infection.
The problem of course was ignorance.
Nobody really knew how the body worked,
so what the surgeon did was to cut and hope for the best.
Like James Watt,
John Hunter came from a relatively humble background in lowland Scotland.
He came to London to join his older brother,
already a well-established surgeon.
John's most important job was finding bodies
for dissection and demonstration.
He mingled with the lowlife around Covent Garden,
paying good money for fresh corpses.
Some came straight from the gallows, others from the graves of paupers,
courtesy of freelance body snatchers,
known as "resurrectionists".
But out of this gruesome world, he discovered
he had an exceptional talent for dissection.
Hunter's determination to drag surgery out of the Middle Ages
and put it on a scientific basis
meant making accurate maps of the body and how the parts interact and function.
And that meant anatomising
both animals and humans, normal and abnormal.
Hunter did hundreds of dissections, and little by little,
he built up a detailed knowledge of human anatomy.
This was the basis for his surgical technique.
He soon built a reputation as the surgeon least likely to kill you.
He knew what he was doing,
and that's why he was willing to take on the cases
nobody else would touch.
So, in October 1775, when a ship's rigger called John Burley
with a facial tumour twice the size of his head
arrived at St George's Hospital, he'd come to the right place.
He had heard that John Hunter was different from other surgeons.
Without that meticulous technique - and no anaesthetic, remember -
the operation would have been unthinkable.
But John Hunter did it in 25 minutes flat,
and he says in his diary, "The man did not cry out once."
So this is John Burley's monstrous tumour.
Look at this.
This is a parotid tumour on the side of the face,
and the facial nerve could be anywhere.
And the thing that every surgeon dreads
is cutting the facial nerve, which would leave his face paralysed.
And here we see the result of the surgery with the scar afterwards.
What Hunter has done is to make his incision sufficiently beyond
the back of the tumour to avoid the facial nerve.
That meant an excellent knowledge of anatomy.
So he leaves this scar with no trace of facial paralysis,
an eyelid that doesn't droop and a straight mouth. A remarkable result.
John Hunter wrote three great treatises,
which became the standard works on human teeth,
gunshot wounds and venereal disease.
He was appointed Surgeon Extraordinary to the King
and became the highest paid surgeon in the land.
But behind all his great achievements was a driving interest
in the workings of the human body.
He collected specimens of everything.
And the interested and the well-connected
all came to see his wonderful museum of anatomical curiosities.
Much of his collection was destroyed.
And this is the Hunterian Museum, where the rest of the collection
is preserved, at the Royal College of Surgeons.
The museum is a testament to Hunter's passion
for scientific experimentation and to his obsessive desire for collection.
While his friend Banks had set sail for Tahiti
to find the most extraordinary specimens he could,
Hunter was scarcely less extreme.
There's one last story about Hunter that I can't resist telling.
It's about his interest in abnormalities and mutations
and, intriguingly, it's hinted at in the Reynolds painting here.
These feet once belonged to a man
called Charles Byrne, who eked out a living
at fairgrounds and freak shows, calling himself the "Irish Giant".
John Hunter badly wanted him for his museum.
The story goes that Byrne was so frightened of being dissected
after his death that he asked his friends to bury him at sea in a lead coffin,
but his friends betrayed him for money.
Whether this is true or not, we don't know.
But certainly we know that Hunter paid 130 for the body,
a lot of money in today's terms - about 15,000,
and he took the corpse, dismembered it, boiled it up
in his great cauldron and then reassembled the bones for display.
And here he is - Charles Byrne, the Irish Giant.
Died at the age of 22.
He had acromegaly - a tumour of the pituitary gland.
So much growth hormone that he grew so large so young
and died in consequence.
But, for me,
John Hunter is a true hero because he informed so much of what we do.
Even my own research has been influenced directly by him.
His real legacy is not his marvellous museum, but the scientific rigour
he passed down through generations of surgeons.
Meticulous technique based on detailed anatomical understanding.
He helped take surgery from butchery to science.
A skilled profession based on real knowledge.
Hunter was the founding father of modern surgery.
Hunter more than earned his place in our story.
But he has another claim to our attention
as the teacher of the great Edward Jenner.
In 1796, Jenner would carry out
one of the most important scientific experiments of all time,
the results of which would ultimately save millions of lives.
Edward Jenner was a country doctor who lived
in the Gloucestershire town of Berkeley.
I think he was probably rather a good doctor,
but more important, he was a very good scientist -
a good observer, a good experimenter
and the idea he came up with could be said to have saved more lives
than any other in medical history.
Jenner was interested in everything -
natural history, animal behaviour, physics.
But his interests in these areas are footnotes
to his most important experiment.
Edward Jenner took on the number-one killer in the 18th century -
smallpox. It killed millions.
And if it didn't kill you, it could still hideously disfigure you.
It was something truly horrible.
In 1800, the historian Macaulay said,
"Smallpox was always present.
"Filling the churchyard with corpses, tormenting with constant fear
"all whom it had not yet stricken,
"leaving on those whose lives it spared the hideous traces of its power,
"turning the babe into a changeling
"at which the mother shuddered, and making the eyes and cheeks
"of the betrothed maiden objects of horror for the lover."
Before Jenner came along, it was widely known
that people who'd had smallpox would never get smallpox again.
From quite ancient times, the practice of variolation -
as it later became called - was done.
That meant infecting people deliberately with smallpox
in a way that was hoped - and with some justification -
would not give them full-blown smallpox,
but would give them an attenuated form.
But this was a very risky practice.
Jenner thought a safer alternative
might be found in the fields and farms around his surgery.
It was widely believed that milkmaids had beautiful skin
and the reason people believed that was that they didn't get smallpox.
Could it be that milkmaids were protected from smallpox
by catching cowpox?
This was the theory that Jenner wanted to investigate.
Jenner remembered the maxim of his mentor John Hunter.
"Don't think. Try the experiment."
And, in April 1796, that's exactly what Jenner did.
A girl called Sarah Nelmes caught cowpox from a cow called Blossom
that she was looking after.
Jenner immediately swung into action.
He took puss from Sarah's pustules
and deliberately infected a boy called James Phipps,
an eight-year-old boy who was the son of his gardener,
with cowpox that he got from Sarah.
Then - this was the daring part of the experiment
which would never get past an ethics committee nowadays -
he deliberately infected James with smallpox.
James didn't get smallpox.
This was the key result -
Jenner had demonstrated the possibility of vaccination.
The story of Jenner and the milkmaid and the gardener's son
has become a kind of iconic story in medical history.
It's one of these stories we like to hear, we like to tell.
It kind of conveys the idea in a single, vivid moment in history.
Jenner is rightly regarded as the father of immunology,
one of the most important medical breakthroughs ever.
Many deadly diseases are now avoidable because of immunisation.
And as for smallpox itself,
this is one of the great triumphs of medical science.
In 1980, the World Health Organisation officially declared it extinct.
It's sad that today some people are fearful of vaccinations
and stop their children from having them.
In Jenner's day, vaccination was a silver bullet which stopped
the horrors of a deadly disease and probably saved more children's lives
than any other medical advance.
He was, I think rightly, hailed as a hero.
Watt, Hunter and Jenner all used their scientific imaginations practically,
transforming the lives of millions.
But, for me,
one of the greatest scientists of the 18th century was a man
who had no more thought for the purpose of what he did than a butterfly.
Henry Cavendish was the richest man in England
and one of the most brilliant minds since Newton.
The 18th century was a time of tremendous enthusiasm for science.
Inspiration was being found
not in the cloisters of universities, but out on the high seas...
...in a Glasgow workshop,
on the sordid back streets of London,
and in the grandest houses in the land.
JIM AL-KHALILI: This is Chatsworth House, ancestral home to Henry Cavendish,
one of the most brilliant, if strange, men of the 18th century.
Henry Cavendish was a silent and solitary man, hugely eccentric
and pathologically shy.
I guess these days we'd say he was a perfect example
of Asperger's syndrome.
He even communicated with his servants by writing notes.
In his long career as a natural philosopher,
Cavendish probed the secrets of nature
with brilliant insights and meticulous experiments.
But he wasn't interested in fame or acknowledgement
and often neglected to tell anyone about his discoveries,
many of which remained unpublished until after his death.
But there was something he did tell people about, his discovery in 1766
of one of the most important elements in the universe.
Oh, you've already got your gas in there.
You're going to pour the acid in? Let's have a look.
Cavendish found that if he dissolved zinc in sulphuric acid...
Oh, there you go.
...he could generate a colourless gas and collect itover water.
PUPIL: It should make a loud and squeaky pop.
I like pops in chemistry.
He called the new gas "inflammable air".
(POPPING)
Cavendish had discovered hydrogen, the simplest of all the elements
and the fuel that powers the sun and the stars.
In fact, three-quarters of all the atoms in the universe
are hydrogen atoms.
(POPPING)
Cavendish filled a pig's bladder with his new gas and weighed it.
He found that it was about 11 times lighter than ordinary air.
Now, this suggested exciting possibilities.
Before long, the first hydrogen-filled balloon
rose into the sky.
For the very first time, people could see the world from above.
Soon they could cross the English Channel, then the ocean.
His discovery continued to have an impact long after his death.
One day, scientists would find out how hydrogen powers the universe
and learn how to make a bomb.
A result Cavendish can scarcely have dreamt of.
But I can't tell you the story of Cavendish without that of his friend
Joseph Priestley.
Priestley was his direct opposite.
Radical, outgoing, eclectic in his interests and his passions.
And it would take Priestley and Cavendish working together
to crack the secret of one of the world's most common substances.
Priestley was a nonconformist preacher who believed
that a scientific understanding of the world would bring man closer to God.
He made huge contributions to electricity and optics,
but also to theology and philosophy.
His ideas influenced utilitarianism and later socialism.
But it was his politics that would get him into trouble.
When his friends held a dinner party in 1791
to support the French Revolution, patriotic rioters destroyed his house
and Priestley had to flee England for America, never to return.
Priestley's revolutionary politics showed he wasn't afraid to question
what others accepted as a given.
This was the key to his scientific genius.
20 years before he was forced to flee the country,
Priestley was spending all his spare time in a local brewery,
investigating the nature of air.
Priestley observed that the air
that gathers at the top of the vat had different properties to normal air.
For instance, if he lit a match and held it over the beer...
...it went out.
It's almost spooky because there's no breeze.
Of course, what Priestley was observing was carbon dioxide
which forms when the yeast in the beer turns sugar into alcohol.
He then studied whether this air was poisonous, and apparently
he held various creatures in it.
Butterflies and insects were fine,
but a mouse had convulsions and a frog lost consciousness.
He later discovered that this air dissolves in water
and made it taste good.
He'd discovered soda water.
Soon drinking soda water became a craze that spread across Europe
and the recipe
eventually fell into the hands of a German called Johann Schweppe.
Cheers!
Priestley himself never sought to make money
from any of his discoveries, but his brilliance was noticed.
Despite his revolutionary politics,
without the patronage of the aristocracy,
he might never had made his greatest discovery.
The Earl of Shelburne heard about Priestley
and hired him as a companion and tutor for his children.
His wife had just died.
Lord Shelburne was fascinated by science and he gave Priestley
a small room in his country home to use as a laboratory.
So it was here, in Bowood House in Wiltshire,
over the next seven years, that Priestley did his best work
and made the discovery for which he is most famous.
Priestley's own experiments had shown that a mouse in a sealed bell jar
would soon use up whatever it was in the air that sustained life.
But he discovered that if you put a mint plant into the jar,
the mouse would revive.
Somehow, the plant was processing the stale air
and replacing it with fresh air.
And it didn't have to be mint.
Spinach worked even better.
On Monday, August 1st, 1774,
in his lab at Bowood House, Priestley discovered
what it was that the mouse needed, and what the plants provided.
It was in this very room that Priestley carried out his famous experiments.
He heated some orange mercuric oxide powder in a glass tube.
A colourless gas was given off.
He was amazed to find it would re-ignite a glowing ember.
A mouse, Priestley found, could live twice as long
breathing this new kind of air as it could breathing ordinary air.
He'd discovered oxygen, the secret of life.
Priestley collected a large amount of it,
so that he could try breathing it for himself.
And he liked it as much as the mice did.
He wrote, "My breast felt peculiarly light
"and easy for some time afterwards.
"Who can tell but that in time,
"this pure air may become a fashionable item?
"Hitherto, only two mice and myself
"have had the privilege of breathing it."
Joseph Priestley is credited with identifying ten different gases,
including nitric oxide and ammonia.
But oxygen was, of course, the big one.
And it was this that drew him and the reclusive Cavendish together.
Cavendish and Priestley did something else
with hydrogen and oxygen, something very important.
They found that a mixture of the two gases,
ignited by an electrical spark, created water.
So water wasn't a fundamental element after all,
something that had been believed since the time of the ancient Greeks.
They'd shown that it's a compound.
Two parts hydrogen to one part oxygen.
H2O.
Together, Cavendish and Priestley laid the foundations of chemistry.
Theirs was a pure science,
the impact less obvious than the work of Watt or Jenner,
and far less exciting to the public than the return of Captain Cook
and Joseph Banks from their long voyage to the southern seas,
bearing exotic specimens from an unknown world.
ATTENBOROUGH: In July 1771, Captain Cook and Joseph Banks
arrived back in London
after spending three years at sea and travelling over 25,000 miles
round the world.
Several times, their ship had been given up as lost,
and almost half the crew
had died of malaria and dysentery on the way home.
Cook and Banks were national heroes.
For surviving, yes,
but also for the wonders and the stories
that they brought back with them.
They had mapped New Zealand
and they had claimed eastern Australia for the Crown.
They called it New South Wales.
Banks was painted by Joshua Reynolds as a romantic hero.
Young, handsome, charming
and full of traveller's tales, he was the man of the moment.
Stories of erotic adventures in Tahiti
only increased the admiration and wonder he inspired in London society.
Banks and his friends had brought back with them a vast haul
of mammals, birds, reptiles, insects,
sea creatures, ethnological specimens
the like of which had never been seen in Britain or Europe before.
Many of those actual specimens have now disappeared,
but there are lots of drawings and paintings to show us
some of the wonders
that Banks and his friends encountered.
Along with all the plants and flowers, birds and fish,
Banks brought back the skin
of a strange creature they had shot and eaten one morning in Australia.
He commissioned George Stubbs, the artist,
to stuff the skin and paint it.
Stubbs had to make up a few details, but the result was splendid.
The kangaroo caught the public imagination,
and soon Banks would thrill London with another exotic creature.
Banks had wanted to bring back
a Tahitian with him, thinking, in his own words,
"to keep him as a curiosity,
"as my neighbours do lions and tigers".
And when Cook came back from his second voyage,
he did indeed bring a Tahitian.
A young man called Omai.
Banks fitted out Omai and took him to meet the King.
Omai greeted George III with the words "How do, King Tosh?"
And the King was delighted.
George III was fascinated by Banks and his discoveries,
and the two men became close friends, or at any rate,
as close as you can be to a king.
In consequence, the King put Banks in charge
of one of his favourite projects, the botanical gardens at Kew.
The boy who had been inspired to become a naturalist
by the wild flowers
on the banks of the Thames, at only 30 years old
was put in charge of a vast garden by the river,
to be filled with flowers and plants from all over the world.
Banks was to be the unofficial director of Kew
for the rest of his long life, nearly 50 years.
Under his influence, Kew became a clearing house
for plants like tea and rubber.
New species were introduced around the empire, tea and hemp to India,
breadfruit to the West Indies.
These botanical invasions changed landscapes and lives,
fuelling the expanding empire and making Britain rich.
More than this, Banks was also President of the Royal Society.
Under him, the society grew from a small association
of natural philosophers to an increasingly influential group
of practising scientists.
But, for all his grandeur,
Banks himself never lost his fascination
with the exotic and the wonderful, regardless of any apparent utility.
Here is a superb example.
It's the oldest pot plant in the world,
Encephalartos altensteinii.
It's only once borne a cone, in 1819,
and Joseph Banks came here to Kew specially to see it.
It proved to be his last visit.
He was crippled with gout and he died a few months later.
Joseph Banks put botany and zoology firmly on the scientific map.
He revealed how rich and biologically diverse our planet is.
He excited the imagination of the King and of the public.
He made science in Britain really matter.
HAWKING: By Banks's death in 1820, science in Britain had come of age.
The generation before them, Newton, Hooke and Halley,
had turned their attention to the great puzzles of the universe.
Banks and his contemporaries had taken science out into the world.
James Watt's engines were transforming the landscape.
The first great battle of the long war against disease had been won.
And Banks's work at Kew was helping make Britain and her empire rich.
This engraving was commissioned for sale to the public in 1861,
and it shows how much scientists themselves had changed.
This was not just a few independent thinkers,
but a whole roomful of men publicly celebrated
for fuelling the powerhouse that was Victorian Britain.
Like the generation before them, it was curiosity which drove them.
Between them, they had shown
that science could explore the world and transform the way we understand
the very air we breathe and the water we drink.
ATTENBOROUGH: The world is full of wonders,
but they become more wonderful,
not less wonderful, when science looks at them.
You may pick up a rock and find what is clearly a seashell in it,
and you may say that is wonderful, indeed it is.
But it becomes more wonderful
when you know that it is 150 million years old
and was laid down at the bottom of the sea.
And science is full of those revelations.
How wonderful it is that water can rise from the ground here
and come out at the top of these trees behind me.
Science explains that.
It's more wonderful, not less.
AL-KHALILI: Next time, big ideas about energy,
engineering and evolution.
The Victorians revolutionise communication,
turn on the lights and start building the world we live in today.
Subtitles by Red Bee Media Ltd