"Secrets of Lost Empires: Roman Bath"

PBS Airdate: February 22, 2000
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NARRATOR: Mist rises off these waters as it has for centuries. Hot springs bubble into a lead lined pool. Against this ancient backdrop, an unusual gathering is taking place. Although most of these people have never met, together they will take a journey into history, when the public bath was one of the most important buildings in the Roman empire. 2,000 years ago, the bath was not just a place for the highborn. It was a community center and a daily ritual that defined what it meant to be Roman.

GARRETT FAGAN: It must have been a sight the like of which the modern mind finds difficult to imagine. Not only is there splendor of the environment, but crowds of people. There is firm evidence that men and women did bathe completely naked together. And all the time, noise. Romans loved to converse and argue and discuss. People would be shouting and laughing. People would be drinking. Some people would have drunk too much. People would be singing in the bath.

NARRATOR: Underlying all the luxury were advanced technologies - copious supplies of hot and cold water piped in from miles away, rooms of intoxicating warmth made possible by sophisticated heating systems. But when the Roman empire collapsed, the world fell into darkness - and the art and science of the baths was lost. Until now. After 2,000 years, NOVA will build a Roman bath and strive to uncover the secrets of the most technologically advanced building of the ancient world.

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NARRATOR: The Roman bath was once a technological marvel. Today, it's a technological mystery. A mystery that this group of engineers, archeologists and historians are hoping to solve as they journey into the mind of the ancient builders.

MAX FORDHAM: I don't think the Romans would habitually have built something that didn't work. They might have made mistakes occasionally.

NARRATOR: Fikret Yegül is an architect and expert on ancient baths.

FIKRET YEGÜL: This is not a design that we created. We don't even take -

NARRATOR: After a lifetime of study, he is designing his first Roman bath - with help from Teoman Yalçinkaya, an engineer, who will build it. But the Romans left no blueprints, no technical specifications. All they have to go on are the ruins that remain after 2,000 years. Crumbling evidence of heating systems that reveal little of how they worked - remnants of pipe that suggest complex plumbing. Even the pools where the Romans bathed have fallen into ruin.

FIKRET YEGÜL: This is really an imitation of a type of Roman bath that I have seen and worked again and again and again.

TONY ROOK: That's interesting, because I haven't -

FIKRET YEGÜL: This is a well known -

NARRATOR: Among his colleagues here, Fikret's design is problematic. Most of them think it won't work.

TONY ROOK: I think we're rather a long way away from the Romans here.

NARRATOR: Who were these Roman builders? Emanating from the city of Rome, their empire spanned more than 3,000 miles, from Syria to Scotland, and reigned supreme for 1,000 years. Few civilizations, before or since, have built with such intensity - spectacular feats of engineering and magnificent monuments. Building was ingrained in the Roman character.

FIKRET YEGÜL: Unlike the Greeks, who were probably more interested in the pristine beauty of things, Romans were more functional people. They were proud to bring water to their cities. They were proud to open comfortable and safe highways to travel on, and bridges to cross valleys and riverbeds.

NARRATOR: But the real genius of the Roman engineers was exploiting what they learned from other cultures.

PETER AICHER: As they spread across the Mediterranean, coming into contact and actually conquering one land after another, they would absorb a lot of the ideas and develop some of the technologies that had been started in other lands.

NARRATOR: With ideas, money, and slave labor appropriated from conquered nations, the emperors of Rome built increasingly complex structures - among them, the baths. The Romans built so many of them, the baths became an experimental laboratory to test out new concepts.

FIKRET YEGÜL: The baths occupy a special position in the course of Roman engineering and architecture - it's a building type extremely advanced in its vaulting techniques, water supply, and heating techniques, and some of the earliest experiments in Roman concrete technology.

NARRATOR: In modern day Turkey lies an ancient Roman city called Sardis. It's here, in the shadow of the bath at Sardis, that NOVA will try to uncover the secrets that have been lost for centuries. Building a Roman bath begins the same way it did 2,000 years ago - with a good piece of land. Fikret Yegül has arrived with Teoman Yalçinkaya, an engineer with an interesting sideline.

FIKRET YEGÜL: Teoman, I think this site may be the ideal place for the placement of the bath.

NARRATOR: For 30 years, Teoman has also been a member of the Sardis excavation team.

FIKRET YEGÜL: Now, the sun is rising here, over there.

TEOMAN YALÇINKAYA: From the east, from over there. And going to the west, over there.

FIRKET YEGÜL: Over there.

NARRATOR: The Romans understood solar heating and made best use of the sun's warmth by orienting the windows of the hottest room toward the south.

FIKRET YEGÜL: If we put the caldarium over there, with an exposure to the south and the west, we have the ideal Roman way of doing things.

NARRATOR: The next step is to mark the footprint of the building in the ground. This bath will be small - like the private baths attached to the homes of very rich Romans. The sheep are about to lose their favorite grazing area to an experiment in history. It will take all day just to mark and prepare the foundation. In the meantime, Garrett Fagan has also arrived in Turkey. An expert in Roman culture, he is here to experience a Turkish hamam, a direct descendant of the Roman bath.

GARRETT FAGAN: This is a hot room. It's over 100 degrees in here. And I have to perspire in here. What I do is, I lie down on this slab and - for about 10 minutes, and relax and sweat. In the Roman bath, the system was quite different. They would come into a medium heated room, where they would be oiled down by a slave. They might have dirt thrown on them at that stage, if they wanted to wrestle outside, because the next process was to go outside into the exercise yard, the palestra.

NARRATOR: The exercise wasn't strenuous, it was just meant to work up a sweat.

GARRETT FAGAN: The Romans would have come in from the exercise ground, covered in their oil and sweat, and there they would have been strigiled in this rather unusual process involving these implements called strigils.

NARRATOR: Romans did not have soap. They just scraped off the dirt and oil.

GARRETT FAGAN: And they would flick it onto the ground and onto the walls of the bath. Imagine the germs and bacteria that have accumulated in this substance that the Greeks called gloios.

NARRATOR: Unaware of germs, Roman doctors collected the gloios from the floor and mixed it into medicinal ointments. After sponging down, the next step was decidedly less pleasant. Body hair was not fashionable in ancient Rome - so the bather could hire a depilator, a hair plucker.

GARRETT FAGAN: They would pluck out the hairs, even their underarm hairs. And in fact, Seneca the Younger describes the howls of the depilators who are looking for customers, which are only exceeded by the howls of the customers who are being plucked.

NARRATOR: After a gentle soaping, Garrett's hamam will be over. But a Roman bath lasted several hours, culminating in the caldarium, where the floor was so hot, wooden sandals were an absolute necessity. The rest of the afternoon was spent socializing and arranging the evening's activity. Garrett also hopes to experience a Roman bath - but he'll have to wait until it's built. As groundbreaking begins, Teoman has a tough job ahead of him. Limited to the tools and techniques known in ancient times, he has agreed to build the bath in seven weeks. For the Romans, it might have taken months. NOVA set up a time-lapse camera to capture every minute of the action. The stones have been delivered and the foundation begins to take shape. There will be three rooms, the bare necessity for a proper Roman bath. The frigidarium, or cold room, will have a round cold pool in the apse. The tepidarium, or warm room, is where the bathers will change their clothes and have a massage. And in the caldarium, or hot room, there is a heated pool toward the back. From cold to warm to hot, it's all a product of the heating system. Below the hot pool, a fireplace, or furnace, will heat the floor, three walls of the caldarium, and one wall of the tepidarium. Whether the heating system will work or not remains to be seen. But first things first. The walls must go up. Two weeks of work is collapsed into 20 seconds. Here, one of Rome's greatest engineering achievements is beginning to take shape. The vaulted or domed roof was a technological leap forward in architecture. Before the Romans, the Greeks also built large buildings. The interiors were filled with columns to support the heavy flat roof above. But the Romans perfected a better idea. They built the roof in sections, forming a curve. At the top, a keystone is dropped in. The downward thrust of the keystone pushes the sections outward, creating a pressure that holds the entire roof together. With the curved roof, the columns are unnecessary. The roof supports itself - freeing an enormous amount of interior space. By the second century AD, the Romans had engineered the ultimate dome - the Pantheon, a temple to all the gods. For 1500 years it stood as the largest open interior space in the world. This remarkable building owes its existence to the thousands of baths built before it. With each one, the Romans perfected the art and science of the dome.

FIKRET YEGÜL: The great dome of the Pantheon had already been experimented by domes reaching half that size, which is still respectable in bath buildings that were built a good 60, 70 years before the Pantheon. They were really forerunners in Roman building technology, and veritable laboratories of working with vaulting.

NARRATOR: Our vaulted roof is made of brick. The wood forms maintain the domed shape and hold the bricks in place until the roof is finished. A thin piece of wood ensures the correct distance and angle between the bricks. It will take several days to complete the roof. Meanwhile, Tony Rook and his colleague Bryan Scott have arrived.

TONY ROOK: Hello. Lovely to see you. Lovely.

FIKRET YEGÜL: First time in Turkey, eh?

NARRATOR: At their first meeting, Tony was skeptical of Fikret's design, especially of the heating system.

TONY ROOK: I think what we've got - what we're trying to do here is to construct something that the Romans would have built.

NARRATOR: Tony thought it would never heat up properly, and soon enough he will find out if he was right. Before he studied archeology, Tony was a building materials specialist.

TONY ROOK: Our rubble is a lot more rubbly because we use flint.

FIKRET YEGÜL: Yes, that's right. I know what you're talking about.

NARRATOR: And one material in particular, now going on the vaulted roof, is considered by many to be Rome's greatest contribution to engineering. Cheap, durable, versatile concrete. Concrete enabled the Romans to become spectacular builders. Without it, the Colosseum would not exist, nor would the Pantheon.

TONY ROOK: Concrete has the great advantage of being cast. In other words, you can make it any shape you like. It has the great advantage of being strong, so you can make shapes which bridge large spaces, and therefore you can make things like great big public baths.

NARRATOR: The recipe for concrete was written down by the Roman architect Vitruvius in the first century BC. The main ingredient comes from one of the most common materials in the world, limestone.

TONY ROOK: If you take ordinary limestone, which is a pretty heavy sort of stuff, and heat it to red hot, and leave it long enough at red hot, when you finish, you get stuff which is like this, which is very, very light, it's a very, very light material, and that's called quicklime.

NARRATOR: Quicklime is chemically very different from limestone. All the carbon dioxide has been burned off. Then, when water is added, something strange starts to happen.

TONY ROOK: Hear it starting to do something. It starts crackling. All the hissing is just steam coming out of it. Each individual bit is swelling and turning into a new material. Because it is very, very hot now. In fact, you wouldn't be able to put your hand close to it now. And it's slowly turning itself into one of the finest powders you can make, which is called hydrated lime, or just lime.

NARRATOR: As more water is added, the powder turns into a putty adhesive enough to bond the coarse materials that make up concrete.

TONY ROOK: Look, it's actually boiling in front of me here now, blowing up nice bubbles of steam.

NARRATOR: Added to the lime - sand and an aggregate of rock. To make the concrete waterproof, the Romans also mixed in crushed tile. They preferred volcanic ash, but it wasn't available in most places.

TONY ROOK: You finish up with a beautiful pink concrete. Absolutely characteristically Roman, you find it in hypocausts, you find it in baths, places where it's going to be underwater, where you want a waterproof material.

NARRATOR: Almost four weeks - more than half the time has passed and Teoman is anxious to move on. With the exterior work mostly done, it is time to tackle the hardest part - the heating system inside. The roof forms over the frigidarium will stay up a little while longer. But the heating system goes in the tepidarium and caldarium - so there the scaffolding must come down. Tearing down the vault planking is a nerve-wracking process. If the roof wasn't built right, it might not hold together. Everyone is relieved when the roof stays up. The heart of the heating system is the fireplace or furnace, as they call it. Fikret is putting on the final touches.

FIKRET YEGÜL: Oh Max!

MAX FORDHAM: Hello.

FIKRET YEGÜL: Welcome. Good to see you here. Hi. Hello.

NARRATOR: Max Fordham and his colleague Tristan Couch are heating engineers.

MAX FORDHAM: What's it like under here?

NARRATOR: Max has designed some of the most complex climate control systems in the world, including Britain's Tate Gallery and the Savoy Theatre.

MAX FORDHAM: It's long and flat.

FIKRET YEGÜL: Yeah, it's our heating canal, and -

MAX FORDHAM: Yes.

NARRATOR: These ruins from Bath, England show that the heating system was a tour de force of Roman engineering. They even had a name for it: hypocaust, which means "fire underneath." A Roman writer credited the invention of the hypocaust to an entrepreneur named Sergius Orata and his love for oysters. Orata wanted to cultivate and sell oysters, but he needed a constant supply of warm water to breed them. So he mounted oyster pans on pillars and lit a fire underneath. The hot air circulated beneath the oyster beds, heating the water inside. The best temperature for breeding was achieved by adjusting the size of the fire. It's a good story, but most historians don't buy it.

FIKRET YEGÜL: We have a number of examples, archeologically backed examples, that show us that the hypocaust systems or quasi-hypocaust systems, things that looked like hypocausts, were being used even during a generation or two before Orata's time.

NARRATOR: There's nothing in the record about how well Orata's oyster business did, but there's a great deal of evidence that hypocausts eventually heated every Roman bath built. The hypocaust starts in the furnace which connects to the caldarium, the hottest room. There is an opening on the right to the tepidarium, the warm room. Pillars, called pilae, will raise the floor about three feet. On top of the pilae, large floor tiles, called bipedalis, will be installed. A layer of concrete goes on top and then another layer of marble. For the system to work, the hot gases are drawn from the furnace through the rooms, where they rise and spread out, heating the floor as they go. There are four flues, or chimneys, to draw the hot gases toward them, promoting the circulation of the heat and providing a way out for the smoke. Part of Max's role is to assess whether the gases will flow properly. If the system isn't pulling a draft, it will never heat up the bath.

MAX FORDHAM: Don't breathe it. You see the wind drifting about, and then we'll see where it's - it's going quite nicely in, look. There we go.

NARRATOR: This is a good sign that the system might be working properly, taking air from the outside and drawing it in. But will the chimneys draw air as well? Max steps inside the caldarium to check.

MAX FORDHAM: The flame's drawing. You see now, they're not going in yet.

NARRATOR: His method is decidedly low tech, but it may well have been how the Romans tested it too.

MAX FORDHAM: They're going up the chimney.

FIKRET YEGÜL: Oh, there. Yes. You're right.

MAX FORDHAM: Anything.

FIKRET YEGÜL: Good grief.

MAX FORDHAM: And then you see, even being drawn down there.

NARRATOR: Next, Max goes to the furnace to see if the heat of the fire will be drawn into the room as it should.

MAX FORDHAM: It will depend on the redirection. Oh, look at that!

FIKRET YEGÜL: Look at that. It's coming - it's beautiful!

MAX FORDHAM: It's playing like anything in.

FIKRET YEGÜL: Right. And that's what we need.

NARRATOR: This might look like a good sign, but the room is wide open. If the raised floor isn't designed and installed properly, the gas flow could be blocked and the room won't heat.

MAX FORDHAM: The gases have got to come in here, about as fast as that.

NARRATOR: The men start building the pilae.

MAX FORDHAM: Tristan, here I come. Ah. Right.

NARRATOR: After the mortar sets, Max tries to crawl through. The Romans would have built the heating system large enough for a slave to fit under for cleaning or repair.

MAX FORDHAM: It's just as well I haven't got my smart shoes on. What you have to do is imagine that I'm seven years old and rather small.

NARRATOR: The pilae in this bath are several centimeters closer together than the Romans usually built them. Max worries it will impede the flow of hot gases.

TRISTAN COUCH: Do you think you can do a left hand turn there?

MAX FORDHAM: I'm just wondering, that's rather -

NARRATOR: But the spacing of the pilae was limited by the size of the tiles that will go on top.

TRISTAN COUCH: I suppose you have to remember that you've got to get out again.

MAX FORDHAM: Yeah.

NARRATOR: Making those tiles was a frustrating and expensive lesson for Teoman. And now he has to face the criticism of Tony Rook.

TONY ROOK: These don't look very much like the tiles we were talking about, do they? What's happened?

TEOMAN YALÇINKAYA: Yeah. We have problems with the manufacture of tiles, because we didn't have enough time to dry them out.

NARRATOR: The clay tiles kept cracking, some even exploded inside the kiln. The Romans would have let them dry for months, even years. But Teoman only had a few weeks. The final solution was decidedly un-Roman.

TEOMAN YALÇINKAYA: At the end, we come to a solution of having a frame made of steel to support the tiles which are cracked. Instead of putting a one-piece tile like this, we are going to put -

TONY ROOK: Oh, dear.

TEOMAN YALÇINKAYA: - the tiles in the frames. So it's going to support it. We don't have time. We have a schedule. We have to catch up with the schedule. So therefore we found this solution.

TONY ROOK: I like this, anyway, I mean -

TEOMAN YALÇINKAYA: Therefore, we -

TONY ROOK: - we're learning a lot here, you know.

TEOMAN YALÇINKAYA: Yes.

TONY ROOK: I mean, we're learning the Romans knew how to do it, and we don't.

NARRATOR: The floor tiles, each in a steel frame, are carefully placed a few inches away from the wall. The reason will soon be apparent. For centuries, the Romans only used under floor heating. Then, around the first century AD, archeological evidence revealed something new. This is Ephesus, Turkey, a nearby Roman city with several baths. And each one reveals a surprising new addition - hollow clay boxes, called tubuli, lining the walls of the heated rooms. The Romans had introduced radiant wall heating, which made the system much more complex. The tubuli are placed over the hole between the ledge and the floor tile. When stacked on top of each other, a vertical channel is formed for hot gases to rise. The round holes, placed side by side, create a horizontal path so the gases can also circulate across the wall. But what to do when they get to the top is a mystery. This ancient bath at Ephesus has no roof. The grand imperial baths of Caracalla in Rome have no roof. And neither does the bath at Sardis. There are so few archeological remains that our team differed widely about how the hot gases might flow through the tubuli and vent out.

FIKRET YEGÜL: We know how concrete works. We know how cross vaults and barrel vaults work. There's no problem there. The problem is those sort of small details of heating, and how the tubuli work, how the tubuli actually pull the hot air, how the chimneys work. And to this day, we do not know just how hot was a Roman bath. We have no idea.

NARRATOR: The system they settled on works like this. Along the open edges of the floor, the hot gases rise up the vertical channels and flow horizontally through the holes. When they get to the top, they meet up with a horizontal channel connected to the chimney flue. The draft from the chimney draws the hot gases and keeps the circulation going so that a continuous stream of heated air cycles through. Ibrahim Akyar is building the horizontal channel. First, he cuts the hole in the chimney. Then he carefully matches the openings. The tubuli are bonded to the wall by mortar. It's similar to concrete, but without the coarse ingredients. Tons of mortar have been used in this small bath. And giving it all time to dry will become a serious problem. The Romans would have allowed weeks, even months, for the building to dry. But Teoman has only 10 days to complete construction and three days to heat up the building. Such a tight schedule could be a recipe for disaster.

TONY ROOK: If you've got a lot of moisture in a structure and you dry it fast, it shrinks. Now, if it dries slowly, the shrinkage is sort of spread out over the whole thing and it sort of relaxes. But if you dry it fast, then the shrinkage is liable to be concentrated in places, so it will crack for that reason. And the other thing is, if you heat it, it expands. So you've got these two effects going on. You could have - somewhere in the structure, you know, one bit of it getting very hot, and one bit of it drying, and it's going to pull itself apart.

NARRATOR: Teoman is well aware of the problem, but there's still so much to do. The hypocaust floors need a layer of concrete. Four to five inches thick, it will take several days to dry. Only Teoman will wait it out. Everyone else has jobs and things to do back home. They'll return in 10 days to light the furnace. As plastering begins on the ceiling, their problems are about to multiply. Rain not only slows down Teoman's schedule, it also soaks an already wet building. Even the stray puppy that adopted the bath as her new home gets drenched. Of all the engineering achievements of the Roman empire, one stands above all others. Without it, there would have been no baths. Without it, there would have been no Rome. The Roman aqueduct, the single greatest system for the transport of water known to the world until this century. Even today, the water of Rome's Trevi fountain comes from an ancient aqueduct.

PETER AICHER: Romans would not take no for an answer. Just like they conquered other people, they would conquer nature with their engineering. In the end, for this city of a million people, they had 11 aqueducts, 11 channels of over 300 miles, delivering perhaps 150 to 200 gallons per person per day, an amazing amount for the ancient world.

NARRATOR: The source of Rome's water lay 50 miles outside the city, in the foothills of the Apennines, where the Anio River flows. But the best drinking water in all of Rome came from nearby mountain springs. This is where the Aqua Claudia aqueduct was built starting in 38 AD. But there's nothing to see because it's all underground. The Aqua Claudia began with a large, deep basin that collected cold spring water. An underground aqueduct directed it toward Rome, following the contours of the land, sometimes boring deep under the mountains. There were no pumps to move the water along. The system worked solely on gravity - a small, gentle slope for about 50 miles. Much of the Aqua Claudia is still there, buried beneath the surface. Peter Aicher is about to show Garrett Fagan something few people have ever seen.

PETER AICHER: You can feel that cool air coming out.

GARRETT FAGAN: Oh wow.

NARRATOR: The front face of this mountain cliff has broken off, revealing the Aqua Claudia tunnel hidden inside.

PETER AICHER: You game for going up the - there's a good channel to follow.

GARRETT FAGAN: Sure. Let's go.

PETER AICHER: All right. Watch the cobwebs, the bats. You can - right here, I think you can sense the incline.

GARRETT FAGAN: Oh yeah.

NARRATOR: They're walking in the opposite direction the water flowed. As they move deeper into the channel, they find along the wall, remnants of Roman waterproof concrete.

PETER AICHER: And you can also see that the water would probably, since they've only cemented up here maybe about four feet high and this is about six feet high, this channel was not meant to run full.

GARRETT FAGAN: Yeah.

PETER AICHER: Be exposed to the air, which was better for the water and better for the aqueduct.

NARRATOR: They also find a buildup of hard water mineral deposits, centuries old.

PETER AICHER: This eventually would encrust the whole channel. Some were worse than this. And that would be one of the regular maintenance tasks, is to come through and chop this away, and then perhaps to recoat it again with the cement. Now the good -

NARRATOR: There was a surprising benefit to these mineral deposits.

PETER AICHER: - hard water, is that they used a lot of lead pipes -

NARRATOR: They would coat the lead pipes used throughout the city, preventing lead poisons from leaching into the water supply.

GARRETT FAGAN: I see.

PETER AICHER: So they had a useful function as well.

NARRATOR: The Aqua Claudia tunnels underground for more than 40 miles. But eventually, mountains come to an end. That's when aqueducts emerge, in a spectacular display of Roman engineering. Graceful arcades of arches, 60 feet high, carrying water in channels along the top. This bridge carried two aqueducts, the Aqua Claudia on the bottom and the mostly missing channel of the Anio Novis aqueduct on top. At Porte Maggiore, one of the highest spots in the city, the Aqua Claudia, along with seven other aqueducts, finally reaches Rome. At this point, the system switched to closed, pressurized pipes which delivered the water all over town.

PETER AICHER: It can go to all quarters of the city, and back up into fountains for the homes, the baths, the industries, and cleaning the drains, and in general providing water for this whole city of a million, that once the system fell into ruin was not equaled again into the 1800s.

GARRETT FAGAN: Wow!

NARRATOR: Aqueducts were built throughout the Roman empire. Almost 2,000 years ago, an aqueduct sloped down the Tmolos Mountains to supply the bath at Sardis. It used thousands of gallons of water every day. But it never went to waste. After the water was drained from the baths, it was channeled through this multi-seat latrine as a flushing system. With seats lining all the walls, this latrine accommodated two dozen people. It offers a revealing look at Roman culture, where personal habits were surprisingly public.

GARRETT FAGAN: If you look at me, I'm sitting really very close to my neighbors. If this is a busy time, then I'm sort of sitting here. And would I have women beside me, perhaps? And I think the answer is yes. And some consideration of Roman clothing, perhaps, helps to preserve the modesty of the individual toilet users, because they would just simply sort of pull up their togas and tunics, then they could sit here, and everything wasn't hanging out. But that doesn't account for noises, odors, which you would undoubtedly hear, which would be remarkable to the modern western toilet user, to think of that possibility.

NARRATOR: With the rain, the marbling inside the bath house is going very slowly. As they put mortar on one side of the frigidarium wall, the marble on the other side buckles. The mortar is so wet, it settled to the bottom and pushed the marble out. Sections of this wall will have to be redone. For Teoman, this is the last straw. Even though the sky is beginning to clear, he's worried the building won't dry or heat up properly. He needs some advice. But without Max or Tony at hand, Teoman drives down to the village for help. There's no heating engineer here. But there is a baker - who fires his oven every day. He agrees to come up to the site. In the meantime, the wood fuel that Teoman ordered has arrived, at least a week's worth of it.

TEOMAN YALÇINKAYA: I was a little worried about the firing of the furnace. And I showed him our program, and said that we want to fire it in three days, but he objected. He said, we will have cracks, you know, if we fire it in three days. But if we let it lay over eight days instead of three days, then there will be a slower - I mean, less heat, slow heat, but a permanent heat.

NARRATOR: The whole team was looking forward to lighting the fire. But Teoman has made a risky decision - to light it early in the hopes of drying the building. It's a tense time. Will the furnace draw properly? Will the chimneys vent? Will the rooms heat up? And most important, will the building crack? After a half hour, things aren't looking so good. Most of the heat is heading the wrong direction - out of the furnace. The baker will push the fire deep under the caldarium, closer to the chimneys. And a couple of hours later, it's a sight to behold. Not only is smoke pouring out of the chimney, but inside it's even seeping out of the unfinished parts of the doorway between the seams of the tubuli.

TEOMAN YALÇINKAYA: You see, the smoke is coming between the seams of the tubuli. I mean - that means, that shows that it's functioning. You see, it's warm, it's warm and it's going to give its - even the plaster is warming up, slowly. It will be all right. It will be hot.

NARRATOR: Four more nights and the others will arrive to see it.

BRYAN SCOTT: Congratulations, Teoman. It's smoking!

TEOMAN YALÇINKAYA: It is smoking, you see? It's smoking. So you can see from over here.

BRYAN SCOTT: It's real smoke, not a -

TEOMAN YALÇINKAYA: No, it's real smoke. It's real smoke.

MAX FORDHAM: We've got a smoke bomb.

FIKRET YEGÜL: Which ones are pulling?

TEOMAN YALÇINKAYA: All of them.

FIKRET YEGÜL: All of them?

TEOMAN YALÇINKAYA: Yes, all of them.

MAX FORDHAM: Guaranteed.

TEOMAN YALÇINKAYA: Guaranteed, yes. Well, I can give a warranty paper for that.

FIKRET YEGÜL: Actually, it's not surprising at all, is it? It's just good design.

NARRATOR: Fikret couldn't resist a little jab at those who had doubted his design. Inside, they start feeling the walls to see if the tubuli are heating up evenly.

TEOMAN YALÇINKAYA: And here, we have the flue somewhere around here, you see?

TRISTAN COUCH: You can really feel it here.

TEOMAN YALÇINKAYA: Yes.

TRISTAN COUCH: Feel it more here.

NARRATOR: But Max has brought some equipment that can see right through the walls - an infrared camera that shows heat ranges by color. White is off the charts, red is about 250 degrees Fahrenheit, then the temperature descends from yellow, to green, to blue, and so on. The black areas are where the tubuli stop. It's telling everyone where the gases are flowing inside.

MAX FORDHAM: Well, I think it's absolutely wonderful, this chimney, look, going up there.

FIKRET YEGÜL: The chimney really looks extremely clear, doesn't it?

MAX FORDHAM: Doesn't it?

FIKRET YEGÜL: In a way, it's like a sharp peak.

MAX FORDHAM: That is consistently the hottest chimney with the most gas flow in it.

NARRATOR: With the construction almost done and the building heating up, it's time for the final act - heating up the bath water. No one knows what the temperature of the water actually was, but there are hints. Ancient stories of water so hot that heavy drinkers would have to be carried out, unconscious. The system they used to heat the water was surprisingly similar to ours today - a hot water boiler. Modeled after a boiler found in the ruins of a Roman bath in Algeria, this one will be installed in the morning. A simple task that will stir up some simmering tensions.

TONY ROOK: We think the hot water should come out of that one.

TEOMAN YALÇINKAYA: Is that the hot water?

NARRATOR: As the day begins, Tony and Bryan suggest a change in the plumbing connections to the boiler.

TONY ROOK: If you only displace the hot water with the cold to that one, all that hot water stays in it. You can't get that out. If you take it out of that one, you'll get the extra bit.

TEOMAN YALÇINKAYA: Yes, yes. But that will be sufficient for our purpose, I guess.

TONY ROOK: We don't think it will.

TEOMAN YALÇINKAYA: Well, if - why don't you think it will not be?

BRYAN SCOTT: Well, because we've calculated the volume of -

NARRATOR: The tank is designed to have the hot water come out of one of these side connections. But Tony and Bryan believe that if it came out the top, the boiler would be more efficient. They might be right, but it is, perhaps, one criticism too many. The atmosphere becomes charged.

TEOMAN YALÇINKAYA: Why should we take the risk, you know?

TONY ROOK: Don't you see the advantage, that if we're right, then it will work, and we're not losing anything.

FIKRET YEGÜL: This part might have been quite sufficient, too.

TONY ROOK: I don't think it will.

FIKRET YEGÜL: How can you be so sure?

TONY ROOK: The trouble is, we also calculate that it's going to take a whole day to heat this up.

FIKRET YEGÜL: No, we're just - well, we've gone through this thing before, and you know about the heating system, you said you had the same reservations and the dire predictions, and it's working like a charm.

____: Yes, that's true.

TONY ROOK: It isn't working yet, because we haven't yet got it working. We haven't got the boiler on it yet.

FIKRET YEGÜL: What do you mean, it's not working? Shut up.

MAX FORDHAM: We haven't got it to 50 centigrade yet.

TONY ROOK: We haven't got the boiler on it yet.

FIKRET YEGÜL: Who says we have to get to 50 centigrade? Do you know Roman baths heated to 50 centigrade? Where do you take that number, out of your hat?

MAX FORDHAM: No, I take that number out of the American Society of Heating and Refrigeration and Air Conditioning Engineers.

FIKRET YEGÜL: And how does that relate?

MAX FORDHAM: Oh, because - that is quite well researched.

NARRATOR: Max, the engineer, wants to test the heating system to its engineering limit. Fikret, the historian, wants only to heat it to the limit of a Turkish bath. It becomes a clash of professional disciplines.

MAX FORDHAM: But it doesn't matter what the temperature is.

FIKRET YEGÜL: Turkish baths are all around, and functioning, today.

MAX FORDHAM: Yes.

FIKRET YEGÜL: You've been in one.

MAX FORDHAM: At a slightly lower temperature, I know.

FIKRET YEGÜL: I have done research about Turkish baths.

MAX FORDHAM: OK.

FIKRET YEGÜL: It has been published.

MAX FORDHAM: But what we're trying to do here -

FIKRET YEGÜL: 50 is out of the question, period.

TONY ROOK: I think it's high.

MAX FORDHAM: But there were not predictions made. All buildings like this -

FIKRET YEGÜL: 50 is out of the question. You are talking out of your hat, you have no ground to stand on, and this bath heating system -

MAX FORDHAM: I do have ground to stand on, because -

FIKRET YEGÜL: You have no ground to stand on.

NARRATOR: The argument goes on until they reach a compromise. The bath will only be heated to 40 degrees centigrade, but the changes will be made to the boiler. The hot water connections are quickly reconfigured. The boiler is moved into place and attached.

Max returns to his testing and measuring. This time he's checking the depth of the reservoir where water for the bath is stored. Of course there's no aqueduct to fill it, so they'll pump water in from a tank. To put everyone in the right frame of mind, Tony Rook and Bryan don their tunics and take over the operation of the furnace.

TONY ROOK: Now what we've got to do is get the fire under the boiler.

NARRATOR: With the building heated, they can pull the fire back from the middle of the caldarium to where it belongs - under the boiler.

TONY ROOK: Because what we want now is to get the fire under the boiler so the boiler will, quite literally, boil. We've got to have enough boiling water in there -

NARRATOR: It will take all day for the water to heat up. In the meantime, a few finishing touches are left inside. A marble mosaic for the floor, and a fresco for the wall, copied from a Roman house in Ephesus, Turkey. At the end of the day, Tony and Bryan turn on the water. It takes several hours to fill the pool. Tomorrow is bath time. The team has waited seven weeks and a lifetime for this experience. But while everyone sleeps, something goes terribly wrong.

FIKRET YEGÜL: We've got problems.

BRYAN SCOTT: Well, what have we got here, Teoman?

TEOMAN YALÇINKAYA: We have leakage here, from the pool.

NARRATOR: Teoman believes the problem stems from heating the bath early, before the marble walls were completely dry. The mortar at the joints didn't have the proper setting time, and it cracked.

____: It's a lot of water.

TEOMAN YALÇINKAYA: Yes, so, I mean, it's leaking continuously. Whatever you put inside, it's leaking.

BRYAN SCOTT: We've lost the contents of the whole bath.

TEOMAN YALÇINKAYA: Yes.

____: For one pool.

____: Well, one pool, rather.

____: Yes.

NARRATOR: There is a quick solution - silicon sealant. It's not Roman, but time has run out and everyone is anxious to take their bath.

TONY ROOK: Wasn't today the day of the great hot bath?

TEOMAN YALÇINKAYA: Yeah, well -

TONY ROOK: And I sound as though I need it, don't I?

TEOMAN YALÇINKAYA: You will probably have a bath, but if you don't have it, I'll take you to a Turkish bath.

TONY ROOK: Ah, that'll do.

NARRATOR: With some lingering doubts, everyone gathers for a final lunch, a very lengthy lunch, while the pool slowly fills. Few people have waited so long to take a bath.

By late afternoon, they have a date with history. Real Romans would be bathing naked. But real Romans wouldn't be bathing on national television. For these men, a well-placed towel can protect their modesty. The water is about 100 degrees Fahrenheit. The room is even hotter.

GARRETT FAGAN: To step into a bath house was to step into the arms of pleasure, to experience the relaxing effects of the warm water and the warm air, to socialize with your friends and neighbors - altogether, a joyful experience. This is a good Roman experience.

MAX FORDHAM: Push him down there and keep him there for a bit.

GARRETT FAGAN: I'll get you for that, mate.

NARRATOR: As they file out of the hot bath, Garrett is reminded where the heat is coming from.

GARRETT FAGAN: Oo-ee! Watch the floor. That's hot.

NARRATOR: Like good Romans, they head for the cold room. The frigidarium pool has leaked as well. It makes the act of submerging a bit undignified, but it's a required part of the full experiment.

FIKRET YEGÜL: This the only scientific experience that I know in the world which has recreated a model Roman bath, truthfully, using ancient materials and ancient methods as much as we could. And I would dearly love this monument to be preserved and to be known in the scientific and humanistic world.

NARRATOR: Today the little bath still stands in an olive grove in Sart, Turkey. Teoman still lives and works nearby. It will be safe in his hands.

TEOMAN YALÇINKAYA: We'll come and check what's going on with it. It might turn out to be a place for academic people and the tourists to visit. So, that would be something nice coming out of it at the end, it looks like.

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