Ancient Impossible (2014–…): Season 1, Episode 2 - Moving Mountains - full transcript

How did the Romans
defy gravity and make millions

of gallons of water flow up and
over mountains?

How did ancient Egyptians carve
massive granite obelisks

thousands of years before the
Washington monument?

And why would the Roman army
move a Mountain?

Monuments more colossal than our
own, warships mightier than

aircraft carriers, technology so
precise, it defies reinvention,

the ancient world was not
primitive.

Their discoveries were so
advanced we still use them

today.
Travel to a world closer than we

imagine, an ancient age where
nothing was impossible.



2,000 years ago it was mission
impossible for the mighty Roman

army.
They had to take this

impregnable Mountain fortress
surrounded by sheer cliffs

standing hundreds of feet above
the judean desert.

What incredible feats would
Roman soldiers have to do to

achieve the impossible?
At the time, Rome was the

largest empire in the world,
stretching all the way from the

British isles on the Atlantic to
the middle east in Asia.

Rome let nothing stand in its
way.

And of the greatest examples
of this is at Masada, in modern-

day Israel.
This isolated plateau tells the

story of one of the Roman army's
most sensational triumphs and

one of the greatest engineering
feats ever.

Today, the only easy way up is
by cable car.



The cable car brings you up
to the top in about a minute or

so, but to go over top and see
the path that people actually

took in ancient times, making
their way up, bringing supplies,

getting up to the top of the
plateau, it's an incredible

- endeavor.
- Masada was built as

a luxury stronghold by king
herod, who understood the

military value of this isolated
plateau.

As super fortresses go,
Masada is about as good as it

- gets.
- 100 years later,

Masada was occupied by nearly a
thousand Jewish rebels.

They believed an attack on
Masada was impossible.

The Jewish rebels take over
this garrison here in Masada,

attack some of the nearby
villages and slaughter a lot of

people.
At that point, they have Rome's

- attention.
- Governor flavius

silva led around 10,000 Roman
troops in the siege at Masada.

But even with all that manpower,
how could the Romans take this

supposedly impregnable fortress?
Scattered around Masada are

clues still visible today.
The Romans started by trying to

starve the rebels to death.
To do this, they would have to

build a 5-mile long wall
encircling Masada.

They built what is known as a
circumvallation, which is

building a wall around, trying
to stop supplies coming in to

- the castle.
- Working in the

desert where the temperatures
can reach 110 degrees seems an

impossible task.
That was constructed with

sheer grit, determination, and
hard work by the thousands that

- were there.
- Building a wall of

this scale is an epic
undertaking even with today's

equipment.
Modern excavation uses powerful

machinery like this drag-line
excavator.

The largest are as big as a
house.

The dragline bucket can dig out
up to 360 tons of earth and

rubble in one scoop.
That's more weight than a jumbo

jet.
It does the work of 5,000 men.

All the Roman soldiers had in
their arsenal was a simple

entrenching tool like this,
called a dolabra, which makes

their achievements seem all the
more unimaginable.

The Roman army, it turns out,
weren't just deadly with their

swords.
They were also deadly thanks to

- their shovels.
- Through sheer

determination and manpower, the
Romans completed the wall

around Masada in just a few
days.

But they didn't realize how
well-stocked the rebels were.

They were ready for a very long
siege.

What amazing engineering secrets
did this fortress in the sky

hold that could enable the
rebels to believe they could

outlast the Roman army?
Cut deep into the rock of the

Mountain itself are huge
cisterns.

And there were storehouses and
granaries for food that were

also carefully built to keep
everything at an even

temperature.
Whoa.

- That is absolutely incredible.
- All over Masada,

cisterns like this stored what
little rainwater fell from a

network of channels.
This has really got the Roman

military preoccupied because
they know that the rebels can

hold out a long time.
They know about the cisterns.

They know that they can resist.
They themselves coming here,

setting up a camp, they don't
have those kind of resources.

They have to bring in the water.
They have to bring in the

materials if the Romans

couldn't starve the rebels out,
they would take Masada by force.

The Romans had to take the
place, which meant that they had

to get up to that wall, knock a
hole through it, and storm into

- the fortress itself.
- But how could the

Romans hope to launch an
assault on this impregnable

fortress in the sky?
Up on top of the plateau in

the former palace of herod, you
have Jewish rebels that are

holding out.
Now eventually, in comes the

military.
Thousands of soldiers are ready

to make the assault, but how are
they gonna get up there?

That's a challenge, because
there was only narrow pathways

leading up.
So however many men you've got,

however many legions you've got,
people have got to come up

single file, and the defenders
can pick them off.

The Roman army
faced an impossible problem.

What could they do?
A closer look at one side of the

plateau reveals how the Romans
would achieve the impossible.

The solution is to build a ramp.

The Roman army
would build a Mountain to reach

the top.
The fact is, siege ramps had

been part of ancient warfare for
thousands of years.

You can find examples throughout
the ancient world.

In the fourth century bc,
Alexander the great built this

causeway 200 feet wide and 3,000
feet long in order to lay siege

on the island fortress of tyre.
But this ramp was a flat road

across a narrow stretch of
water.

At Masada, the Romans needed an
engineering miracle

three quarters of the sides
of the plateau, the height is

about 400 feet.
But on one side, on the Western

side, it's actually only about
240 feet.

That's what they target.
That is where they're gonna

- build their ramp.
- But even building

on the shorter side is a very
tall order.

In the modern world, we use
massive machines to shift tons

of earth and rubble.
This is a powertrain haul truck,

the biggest dumpster in the
world.

One of these can carry a load
up to 100 tons on its own.

Just think of how many people
would have to dig and then carry

that.
So when we compare this, our

modern technology, to what the
Romans had to do all by hand,

it's really just incredible.
For the Romans, everything came

down to muscle power.
To dig out the earth in the

first place, you had to use
spades and picks.

You then put the spoil into
baskets.

You put the baskets either on
your own back, on the back of a

mule or maybe into a cart, but
it came down to human and

animal muscle power to extract
that spoil and then move it up

against the side of a Mountain
before you could even begin your

assault on Masada itself.
I'm on the ramp that the

Romans constructed to take out
the Jewish rebels up on top.

You can feel history.
You get a sense of the... the sun,

the wind, the du, to say
nothing of the rebels that are

throwing stuff on you as you're
trying to construct this massive

- ramp.
- The rebels

underestimated how determined
and ruthless the Romans were.

They were not going to let
nature get in the way.

Moving a Mountain of earth to
get to the fortress was an

engineering marvel, but how
would the soldiers storm the

fortress itself?
Coming up, the Romans do the

impossible... they move one of the
ancient world's deadliest siege

towers up a Mountain.
And later, how the Egyptians

transported some of history's
largest monoliths.

The ancient world
was far more advanced than we

ever imagined.
Now we are uncovering new

evidence of how the ancients
were able to overcome vast

engineering challenges and make
the impossible possible.

At Masada, Roman soldiers
combined their engineering and

fighting skills to create the
greatest siege ramp of the

ancient world.
This ancient mega move would

create a ramp 650 feet long
rising 240 feet at an incline of

1 in 3.
The Romans moved the equivalent

weight of one and a half empire
state buildings by muscle

power alone.
Put yourselves in the shoes

of the Jewish rebels up on top
here at Masada.

So initially, you're starting
off, you're in a fortification.

It's impregnable, and then the
Roman army shows up, and they've

surrounded the entire plateau.
Then the construction of the

ramp begins.
And you see it start, and in a

couple of months, it's building
up and up

within two months,
the ramp to the fortress was

complete.
But how would the Romans storm

the fortress itself?
They wanna bring their siege

engines, their big towers, up to
the walls and then smash those

walls, break through and kill
the rebels.

But what amazing
piece of engineering would break

through the heavily defended
walls?

The Romans needed something like
this.

It was called the helepolis.
This massive armored siege tower

was constructed to besiege the
Greek city of rhodes in the

fourth century bc.
The helepolis was a masterful

feat of ancient engineering
construction.

It was the largest siege tower
ever constructed in antiquity.

We think it was something like
140 feet high, and it required

something like 3,000 people
working in relays to push it

forward and keep it moving.
But when it was in place, it was

a devastating destruction
machine.

Just imagine that kind of
monstrosity of machine moving

towards your city walls bringing
with it the inevitable sense of

destruction.

In the middle of
the desert, the Romans faced an

impossible challenge.
There were no resources or

supplies, none of the material
they needed.

How could they build a siege
tower out of nothing?

They needed wood.
They needed iron plate.

All of this had to be brought
in.

The Roman army was not simply a
bunch of highly trained killers.

It was also a well-oiled,
organized engineering team.

With a huge effort,
the Romans brought the materials

for the tower into the desert.
But a wooden siege tower would

be worthless if the rebels could
set it on fire.

To make sure this couldn't
happen, the Romans put heavy

iron plates on the outside of
the tower...

Iron plates that meant fire
couldn't catch and that most of

the missiles that the enemy
flung at the tower would simply

- be deflected.
- As the rebels

watched, the armored tower,
equipped with a giant battering

ram, was constructed below them.
This is the only ancient

battering ram ever found.
And you would mount that in

the tower so that you could
start to knock the wall down.

The siege engine would have
been an imposing structure, and

it doesn't just serve the
purpose of protecting the people

that are gonna be Manning a
battering ram, but also gives

opportunity to have soldiers
with ballistae, with catapults,

and they could launch them at
the rebels as they go forward

- and smash the walls.
- The Romans were

ready to attack.

It seems an impossible task to
force this vast tower up the

steep ramp.
Hundreds of soldiers pushed it

into position.
You'd feel nothing but panic

because you realize the Romans
mean business.

They're not just showing up at
one part of the plateau.

They've surrounded the entire
area.

There is no escape.
You can't go out the back door.

You can't go down the snake
path.

You are trapped.
You've got your water supply.

You've got your food, but
there's the Roman army, and

they're not going to stop until
they arrive at the top.

They're not going to stop until
every single rebel is dead.

It must have been absolutely
terrifying to think that you

have no way out.
This is the end.

Once the battering
ram smashed the outer wall, the

Romans set fire to the wooden
inner wall and prepared to

attack at dawn.
The Romans smash through the

gates.
They come over the walls.

They come in en masse.
And when they arrive on the

scene on the top of the plateau,
they don't encounter resistance.

- Where are the Jewish rebels?
- When the Romans

finally broke into Masada, they
were confronted with a scene of

carnage and destruction
the account, according to the

great military historian
josephus, is that when the

Romans break through the
defenses, they see that all the

- rebels have committed suicide.
- With only two women

and five children still alive,
the Romans had won.

But the defenders denied them a
full triumph.

They don't give the Romans
the satisfaction.

It's one of history's great
tragic tales.

The Roman army let

nothing stand in its way.
At Masada, they proved they

could harness their engineering
skills not only to move a

Mountain but conquer a seemingly
impregnable fortress in the sky.

But it wasn't just the Romans
who were the great mega movers.

4,000 years ago, the ancient
Egyptians were also creating and

moving monuments on a massive
scale.

Up next, could this site from
ancient Egypt reveal a secret

that could rewrite the history
of how the ancients moved

massive objects?
And later, 2,000-year-old mega

movers still working today.

This is "ancient
impossible," making you believe

the unbelievable by revealing
how advanced the ancient world

actually was.
Roman soldiers could move

mountains at will.
But thousands of years before

the Romans, it was the ancient
Egyptians who first discovered

how to move huge objects.
Obelisks are massive monolithic

pillars that the Egyptians
placed in pairs at the entrance

to temples.
Over centuries, they placed

hundreds of these throughout
their kingdom.

The obelisk was a symbol of ra,
the sun God, and incredibly,

many of these ancient pillars
still stand today.

The obelisks seem impossible to
move, but the Egyptians found a

way.
In aswan in Southern Egypt lies

an important clue.
I am standing on an

unfinished obelisk.
It's 137 feet long, 14 feet wide

at the base, and it's made of
solid granite, which weighs over

- 1,000 tons.
- Unlike the

Washington monument, which has a
steel frame and more than 30,000

stone blocks, Egyptian obelisks
are one solid mass of granite.

Now you might think this
obelisk remains unfinished

because it's simply too big, it
was too huge to move.

But the truth is quite
different, and it's because of

this crack that you can see down
here.

While this obelisk was being
constructed, this crack became

apparent, and there was no way
they could ever make use of this

obelisk with this huge defect.
So they left it here in the

quarry, where it was being
built.

They definitely could have moved
it.

The ancient Egyptians clearly
had the technology to move

1,000-ton stones.
We've seen them do it with

many other gigantic monuments
to solve the

mystery of how this massive
obelisk could be moved, we first

have to look at how it was
built.

Can you imagine what it
would've been like to be a

worker here?
Digging down through 14 feet of

solid granite, some of the
hardest rock on the planet.

And the only tool you had to do
this is a dolerite rammer, which

is essentially just another
volcanic rock which is slightly

harder.
If you can get a crack in the

right place and use the rammer
on the crack, you can actually

make much more headway than just
pounding away at the solid rock

itself.
So it's really quite clever.

Maybe 130 men all sitting
cross-legged in very cramped

conditions all pounding away.
There would have been dust

clouds flying up.
They would have all been

breathing this dust in.
It would have been very, very

- unpleasant for them.
- Life expectancy for

the average Egyptian man was
about 33 years.

But working on the obelisks was
a privileged position.

We don't think though that
they were slaves, and was

something that you might take
pride in.

This would be something you
might... you might want to do.

Once the Egyptian
workers finished the three sides

of the obelisk, they still faced
the epic task of removing it

from the bedrock
they created a massive fire

along the bottom here.
That created cracks in the

granite that they could then
exploit with their dolerite

pounders.
I mean, that... that is amazing

- technology.
- Once the obelisk

was free, how could it possibly
be moved an inch, let alone

hundreds of miles to its final
location?

After completing this
1,000-ton obelisk, the real

challenge is moving it to its
final location.

The nile is a mile away.
But what's recently been

discovered is a canal, which has
been built, an ancient canal

which would run right through
here.

Could the Egyptians
have made a barge large enough

for this obelisk?
Queen hatshepsut's tomb at dier

El-bahari may hold the answer.
Painted on the wall are

impossibly huge 200-foot barges
built thousands of years before

the great ships of Greece and
Rome.

But how to get a 1,000-ton
obelisk onto the barge.

Let's have a look at how we
solve a problem like this today.

This is the dockwise vanguard...
One of just a handful of ships

capable of transporting a
deepwater drilling rig.

But how do you get a 100,000-ton
oil platform onto its cargo

deck?
Like this.

This semi-submersible heavy lift
ship sinks in the water so tugs

can maneuver the oil platform
into position.

Its known as a flo/flo... float
on and float off.

With a load of up to 117,000
tons in position, this mighty

mega mover rises from the ocean
and it's on its way.

It does what seems impossible,
even today.

But of course it's impossible
that such technology was

available to the ancient
Egyptians 4,000 years ago.

Or is it?
Ancient Egypt had a secret

weapon... the river nile.
Every year the nile flooded,

filling the canal dug next to
the obelisk.

So could the unfinished obelisk
have been moved using the nile

floods?
The barge was weighed down to

sink it, and when the obelisk
was loaded, the ballast was

removed, and the barge could
move anywhere along the nile.

To me, as a modern engineer,
looking at what they were able

to accomplish with such simple
techniques and technologies.

That truly is amazing.
These were incredible ancient

mega-movers.
- The ancient

Egyptians employed innovations
thousands of years before their

time to mega move 1,000-ton
stones.

But the greatest mystery in the
ancient world is how the Romans

moved these massive stones
weighing up to 1,000 tons each,

and they were nowhere near a
river.

Up next, modern historians still
question how it was done.

But can an ancient Roman book
provide a clue?

It's "ancient
impossible," exploring

technologies that are cutting-
edge even by today's standards.

Ancient Rome was a big
civilization that thought big.

But at one site in the Roman
empire, construction was super-

sized.
How these huge blocks were moved

there has been a mystery for
2,000 years.

Look at the size of this stone.
Look at the people beside it.

It's almost impossible to
believe that the Egyptians mega

moved blocks like this using
boats.

And it's even harder to grasp
that the Romans could move them

on land.
This is baalbek in the bekaa

valley in Lebanon.
It contains the largest temple

in all the Roman empire.
It is something on the scale

of the Roman forum.
The sanctuary is amazing.

After conquering
the region, the Roman emperor

Augustus commemorated his
victory by ordering this huge

edifice.
Baalbek covers the same area as

nearly nine football fields.
The sheer size of baalbek is a

reminder to subjected peoples
of the power of Rome.

The scale of the stones is
absolutely amazing.

Just standing right next to them
you realize how large the

enterprise was to bring those
stones into the sanctuary.

It's hardly
believable, but these blocks at

the base of the sanctuary weigh
800 tons each.

Is there a clue at baalbek that
could show us how the Romans

moved them?
The quarry site is 43 feet

higher than the level of the
sanctuary, so certainly this had

a part in the transportation of
the stone blocks.

But how did they do it?
That's the real mystery

to try to show the
most advanced Roman mega moving

technology, we're going to use
some of the most advanced

technology available today.
Let's take a look at the size

of one of these stones.
Here's a person for comparison.

We can see that the stone is
about 12 foot by 14 foot by 65

- feet long.
- How would we move a

block like this today?
This is the liebherr 11200, the

most advanced mobile crane in
the world.

It's got a turning circle
smaller than most cars.

Yet it has the power to lift the
weight of over 500 cars.

This crane has got just
enough power to lift this stone.

We can see that the scale of
this stone is almost as big as

the crane itself.
So the idea of trying to move

this without modern-day
machinery seems unthinkable.

If we look at the stone, we can
see no marks that give us a clue

as to how the Romans moved it.
We know that they moved it from

the quarry to the site, but we
have no idea how they did it.

To make a move like that today
using modern equipment would be

an incredible achievement.
But to have done so 2,000 years

- ago just seems impossible.
- Here's the problem.

The most sophisticated crane in
the Roman world, the

polyspastos, could lift only a
fraction of what today's cranes

can handle, nowhere near enough
to lift these stones.

The Romans did have some other
very ingenious machines.

Meet the capstan, a vertical
drum that wound a cable to move

heavy loads.
But these loads were impossibly

heavy even for capstans.
So how did they mega move this

mega stone into place?
Cedar trees grow all around

the temple site, and they would
be great candidates to make

rollers to try and move this
block.

However, with all this mass,
this could easily turn it into

a battering ram.
So the Romans could have used

capstans to control the rate of
descent down the hill.

However with this rough ground,
I'm not convinced that it would

have been easy to make this
roller system work.

So as far as we can tell, this
impossible engineering feat

- remains impossible.
- To find out how

stones like this were moved,
you'd need to speak to an

ancient Roman engineer.
And incredibly, we found one.

Here in the bodleian library in
Oxford is a book written around

the time the emperor Augustus
had started work on baalbek.

It's by a Roman engineer called
vitruvius.

Would you believe this textbook
on architecture is still used

today?
It describes an engineering

technique that could crack the
code of baalbek's mega mystery.

Let's see.
"Enclose the ends of the

trilithon in wheels.
In the ends, fix pivots and

rings.
The wheel turns on the pivots

enclosed in the rings, and the
stone is enclosed like an axle

in the wheel."
We've transformed the stone

into a giant moving axle.
Now our scale here is much

bigger, but with multiple
capstans it would be possible to

control the movement of this
down the hill.

And with enough of them, we
could roll the stone into

- exactly the right place.
- This impossible

challenge was solved by an
impossibly ingenious solution.

Roman mega movers turned a
static 800-ton block into a

mobile 800-ton axle.
This is an incredible system

for moving the stone from "a" to
"b."

This ingenious
method enabled the Roman

engineers to move impossibly
heavy loads.

But why not simply use smaller
blocks of stone?

There's a lot of speculation
as to why they're quarrying out

and using blocks of that scale.
Is it the part of the bravura on

the part of the engineers?
"We can do this.

We can move these blocks"?
Is there some religious

attribution?
These questions we still don't

- have answers to.
- With impossibly

large blocks of stone tossed
around like toys, baalbek is a

mighty Roman mega move.
But there's evidence of an even

greater mega moving achievement
by Roman engineers.

This time, it involves thousands
of miles of waterways, the

biggest engineering project
seen for nearly 2,000 years.

Up next, the mega move that
turned Rome into a superpower.

If you think the
ancients were primitive, think

again.
This is "ancient impossible,"

where we prove that the ancient
world achieved feats so awesome,

they still seem impossible to us
today.

As the population of ancient
Rome swelled to more than a

million, early engineers were
faced with the epic task of

moving water from the
countryside to the city.

Fresh water was crucial for
health and hygiene as well as

enterprises such as mining and
farming.

Without it, Rome could never
have attained such unprecedented

power.
Maybe one of the greatest

engineering feats of the Romans
is they're able to move water

from a river, from an original
source into a city, and that

- makes that city great.
- What was the

game-changer that enabled the
Romans to move so much water?

The aqueduct.
They might not have been the

first to move water this way,
but the Romans raised the power

of aqueducts to a whole new
level.

An aqueduct is literally a
bridge for water.

You're finding a natural
source... a spring or a river... and

you're diverting it into a
channel and bringing that water,

through principally gravity
flow, into a city.

A remarkable
example of this Roman ingenuity

is here in caesarea maritima,
in Israel.

When you're sandwiched between
the sea and the desert, what is

there to drink?
Without this aqueduct and the

fresh water it brought, the city
would never have existed.

It's absolutely brilliant
technology, this is one of the

quintessential elements of Roman
civilization.

It's why they are the great
builders and had such a massive

- empire.
- The aqueduct at

caesarea maritima served 50,000
people and ran for 6 miles.

But as impressive as it is, this
aqueduct is one of the smallest

the Romans built.
In all, the Romans built 6,000

miles of aqueducts to quench
their thirsty empire.

At pont du gard in Southern
France, ancient engineers faced

an impossible challenge.
To supply the city with water,

they needed to construct an
aqueduct more than 30 miles in

length, and they would have to
span this deep river gorge.

Why would you build something
so massive over this seemingly

tranquil little river?
At this point, they must

maintain the gravity flow at a
pretty high elevation.

So they have to build a bridge.
The bridge they built stands

16 stories tall
pont du gard is the tallest

bridge, the tallest aqueduct
that the Romans ever built.

It's about the height of the
coliseum, the largest

amphitheatre ever built by the
Romans.

So it's really pushing the
envelope, and it's still

- standing.
- The Romans were

expert at building on a
monumental scale.

Even today, there are still
monumental engineering

endeavors.
In New York City, the current

water tunnel excavation has been
called the greatest non-defense

project of the Western world, a
mega build happening hundreds of

feet beneath the city streets.
Its construction has claimed the

lives of nearly two dozen
workers.

I think it's hard to imagine
the amount of physical effort

that would have gone into
building some of these

aqueducts.
It was a massive civil-

engineering enterprise.
It would have taken huge

expense.
It would have taken huge

manpower, and the actual capital
outlay must have been

absolutely massive.
I'm right at the very top of

the pont du gard.
I'm in the spacus or channel

where the water flowed through,
and this channel had to be

maintained over time.
Otherwise the water wouldn't

reach the city of nimes.
So here we see some of that

calcium over time, it was not
cleaned.

The water flow was constricted.
But it's an incredible

achievement, to be standing on
top of something as tall as the

coliseum.
Walking through the water

channel, I really feel in
contact with the people that

constructed it and the people
that maintained it over time.

It is simply an amazing
experience.

At pont du gard,
Roman engineers had to build

their aqueduct across mountains
and river valleys.

How could they keep the water
flowing over this jagged

landscape?
We all know that gravity makes

water flow downhill.
But Romans engineers achieved

the impossible by maintaining
the most gradual of downward

slopes.
Along 31 long miles, the height

of the aqueduct only drops 56
feet.

That means there is no margin
of error.

You have to be perfect, and this
is an example of the perfection

- of Roman engineering.
- Without lasers,

theodolites or any modern
surveying equipment, Roman

engineers kept the water moving.
Through hills and valleys,

maintaining a steady gradient of
less than 1%.

An astounding feat.
The Romans were building

these things on the most
enormous scale, and all this was

done without any mathematical
formula or any true scientific

knowledge.
It was just practical

engineering.
I think about the people that

constructed this, the amount of
engineering, the sheer labor

force to go through and cut
these stones and sink them into

place and to construct such a
massive enterprise.

How amazing it was 2,000 years
ago, how amazing it is today.

The Romans used
gravity to move water on a scale

impressive even by today's
standards.

They proved they could transport
water downhill with great

precision, but could they
achieve the impossible?

Coming up, could the Romans
actually make water move uphill?

We'll prove that it was
possible, up next on "ancient

impossible."

The ancient world
had vision and imagination that

equal and sometimes even surpass ours.

The Roman army conquered with
discipline, brute force and

impossible engineering.
But it wasn't just war that the

Romans approached with ruthless
determination.

Rome was the most advanced
civilization of the ancient

world, and crucial to its
ability to expand and flourish

was one simple ingredient...
fresh water.

Keeping the water flowing led to
one of the greatest innovations

of the Roman world.
Maybe one of the greatest

engineering feats of the Romans
is they're able to move water

from a river, from an original
source, into a city, and that

- makes that city great.
- By mastering the

laws of gravity, Roman engineers
brought millions of gallons of

fresh water into Rome each day,
providing access that even

today's modern systems can't
match.

But these ancient engineers did
more than master the laws of

gravity.
Sometimes they defied them.

The Romans are coming up with
solutions to carry water across

valleys, sometimes with a bridge
and sometimes literally pushing

the water up a hill.
So they basically made water

- flow uphill.
- Making water flow

uphill?
Impossible.

But the Romans had an
engineering ace in the hole...

a u-shaped tube like this called
an inverted siphon.

As water fills the tube, it will
always find its level.

If one end of the tube is lower,
water will flow through it, even

uphill.
Essentially what you do is

have two tanks on either side of
the valley, and you're gonna

basically push the water through
from one tank into another.

Roman inverted
siphons only survive in ruins.

But when they were running,
they'd have looked like this.

Across the Roman empire, they
made 10 million gallons of water

flow uphill every hour.
Experimental model maker Richard

windley will attempt to prove
how this impossible feat was

possible
what we've got here today is

a model, which I'm hoping will
explain the principle of the

- inverted siphon.
- Even building an

inverted siphon as small as this
is a daunting prospect.

Richard hopes he can pull it
off.

The calculations are actually
quite tricky on this.

Hopefully we'll have sufficient
head of water here to force the

- water through.
- Richard has built

an inverted siphon to cross not
just one valley, but two, a feat

accomplished many times by the
Romans.

What we're going to do is to
charge the header tank, which is

this one, and the idea is that
once the flow of water from this

tank is released, it will flow
down the verticapipe, along

the horizontal one and then up
the second vertical pipe and

into the second receiving tank,
which is the middle tank.

As that fills up, hopefully the
water from that will transfer to

the outlet and then into the
second siphon and into the final

receiver at the far end of the
model.

The water will have
to climb two hills.

- This is the moment of truth.
- Can Richard really

make water flow uphill like the
Romans?

The water under gravity is
coming out of this primary

tank...
Filling up the intermediate

tank...
And finally into the receiving

tank at the far end.
That's 45 feet away.

It's travelling at a relatively
good velocity and quite a good

- flow.
- The Romans knew

that if each tank is slightly
lower than the previous one, the

water will rise to find its
level and fill the tank.

In the impossibly vast scale of
the real thing, Roman tanks or

cisterns held millions of
gallons of water.

I can't believe how well it's
actually operating.

I had qualms at the beginning
about whether it would work.

It's working beautifully.
As an archaeologist, when I

think about 2,000 years ago,
these engineers are using

physics creating an inverted
siphon for an aqueduct channel.

It's mind-blowing.
It's a staggering feat of

engineering which seems
virtually impossible.

When gravity was
against them, the ancient Romans

boldly defied it.
The Egyptians moved monumental

obelisks along the nile.
The Romans moved mountains and

built massive aqueducts that
carried water thousands of

miles, proving that the ancients
were able to achieve the

impossible.