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.