"Secrets of Lost Empires: Stonehenge"

PBS Airdate: February 11, 1997
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__: Tonight, on NOVA, time honored monuments. Wonders of the ancient world. These giant structures reveal the spirit of cultures long past. What they don't reveal is the mystery of how they came to be. Now, NOVA and a cast of hundreds use brute strength and sheer determination to rediscover the technical know-how of the ancient builders. Stonehenge. Inca masonry in Peru. An Egyptian obelisk. A roof for Rome's colosseum. NOVA embarks on a four part building spree to unlock the secrets of lost empires. Now, Part 1, Stonehenge. NOVA is funded by Prudential.

__: Prudential insurance, health care, real estate and financial services. For more than a century, bringing strength and stability to America's families.

__: And by Merck. Merck Pharmaceutical Research. Dedicated to preventing disease and improving health. Merck committed to bringing out the best in medicine. The Corporation for Public Broadcasting and viewers like you. Additional funding for this program is provided by the David H. Koch Charitable Foundation.

NARRATOR (KEACH): It's one of the most mysterious places in the world. A strange set of stones, arranged like no other, stands silently above the plains of souther England. Stonehenge. For centuries, no one knew who built it. According to medieval legend, it was the work of Merlin, the wizard of King Arthur's court. Later, credit for the construction went to the Romans, and then to an ancient pagan cult, the Druids. Only in recent years have archaeologists finally begun to discover who really built Stonehenge—and when. Scientists now believe that these stones were erected almost four thousand, five hundred years ago—long before King Arthur or the Romans, at the end of the Stone Age. It was an amazing achievement. Each of the colossal uprights weighs between fifty and eighty thousand pounds. The stones are harder than granite, but most were carefully shaped and joined together—as if they were made of wood. And although the monument stands on sloping ground, the line of the horizontal stones—called lintels—runs almost perfectly level. All this was done in an age without machinery, without writing, and without any metal tools. Even after fifteen years of studying the area around Stonehenge, archeologist Julian Richards is still impressed by this ancient wonder.

JULIAN RICHARDS: This is the biggest stone at Stonehenge. It's absolutely enormous. It towers over twenty feet above me, and there's eight feet of it buried in the ground. I get really fed up when people come to Stonehenge and say it's smaller than they expected. I mean this is a massive stone. It used to have a pair standing there as well. That one, unfortunately only buried four feet in the ground, fell over a couple of centuries ago. And these two stones, these two massive uprights with a great lintel on top, form a trilithon, one of the biggest and most impressive elements of Stonehenge.

NARRATOR (KEACH): The use of massive blocks, weighing up to 40 tons, is all the more remarkable, because there is no natural source for large stones anywhere near Stonehenge. In the Middle Ages, the mystery inspired reports that the rocks were brought from Africa by an army of giants. Today, archaeologists have come up with a less romantic, but still impressive, explanation. Twenty miles north of Stonehenge stands another stone circle, not as elaborate, but much larger. It's nearly a mile in circumference and now encloses part of a town.

JULIAN RICHARDS: This is Avebury, incredibly huge stone circle, built before Stonehenge, but what it's got in common with Stonehenge, is some of the rocks that it was made of. Sarsens, an incredibly hard sandstone, cemented together with silica, one of the hardest rocks that we know of in this part of England.

NARRATOR (KEACH): Around Avebury, the valleys are littered with sarsen boulders. A few on the scale of Stonehenge still lie half buried in the ground.

JULIAN RICHARDS: Obviously, this is where they came to get the stones for Stonehenge. The only place around here where there's a supply of stones of the right sort of size.

NARRATOR (KEACH): Roger Hopkins is a stonemason from Massachusetts who specializes in moving and shaping granite. For years, he's been amazed by the Stonehenge builders' mastery of hard stone.

ROGER HOPKINS: You know, looking at this site, with all these stones in the way, it must have been a real chore to get these on a—a sled and get 'em out of these fields.

JULIAN RICHARDS: I mean, they weren't using it—I mean, it wasn't quarried. You didn't have to dig into solid rock to get this out, it would have just lain around all over the place.

ROGER HOPKINS: What's the contour, the terrain like between here and there?

JULIAN RICHARDS: It varies quite a lot. There's a fairly flat river valley, and then a very steep hill to get you up onto Salisbury Plain, from whereon it just undulates gently until you get all the way to Stonehenge.

NARRATOR (KEACH) If Avebury was the source for the massive sarsens, how did the ancient builders transport them across twenty miles of rolling hills and erect them in the shape of Stonehenge? After centuries of mystery and debate, Julian and Roger are determined to find out. Their plan is to reconstruct the Great Trilithon of Stonehenge. But to pull it off, they'll need a little help. This small army of volunteers will provide the labor in an historic attempt to move and raise blocks exactly like those in Stonehenge, using Stone Age technology.

MARK WHITBY: We'll have to . . . We'll have to lift the end when we're going to do it

NARRATOR (KEACH): Along with Julian and Roger, the team will be led by engineer Mark Whitby.

MARK WHITBY: The reality of taking two forty ton stones and turn them on their ends without using any machine power whatsoever, it's quite a—quite a daunting task. I don't think people have really stopped to think about the problem at Stonehenge in a realistic way. All the theories are put together by people who haven't actually been faced with the practical task of doing it.

NARRATOR (KEACH): One of the old theories is that the stones were moved on top of large rollers—made of tree trunks. And tests performed with concrete blocks—like this one weighing nine tons—have shown that rollers can work. But the biggest stones at Stonehenge were more than four times as heavy. This is a concrete replica of the largest stone at the ancient site. It's almost thirty feet long and weighs over forty tons. Mark is convinced that such a huge weight would crush and flatten even the hardest wooden rollers.

MARK WHITBY: I've watched people drag a boat up a beach, and they had rollers there, but the rollers didn't rotate. They actually had grooves in them where the keel of the boat went over the top of them. And, lo and behold they were putting grease on that groove to uh, to uh, make it slide. And it's quite obvious things would rather slide, and if you get it greased, it's easier to make it slide than it is to make it roll.

NARRATOR (KEACH): So instead of rollers, Mark has constructed a simple track, made of two parallel lines of timbers set into the ground. The forty ton megalith sits on a wooden sled. The bottom of the sled is equipped with a keel which keeps it centered on the track and prevents it from going off course. To make it easier for the stone to slide, Mark has the rails of the track slathered with grease. In ancient times, the workers could have used animal fat, known as tallow. The team will attempt to pull the stone up a slight incline, typical of the terrain surrounding Stonehenge.

MARK WHITBY: It's going to be very hard work getting up the slope. We've got everybody lined up here to pull, and it's going to be, you know, very interesting to see if they can do it. It's not going to be easy.

NARRATOR (KEACH): In true engineering fashion, Mark has done some elaborate calculations. He's determined that it will take a minimum of two hundred and twenty people to pull the weight uphill. Unfortunately, only a hundred and thirty volunteers showed up. Despite their efforts, the stone hasn't moved an inch. The liberal application of grease appears to have backfired, and the forty ton stone is glued to the track.

MIKE O'RORKE: Take the strain of the rope!

MARK WHITBY: We've got a real, sort of, static friction as they'd call it, it's stuck down with all the grease underneath it. And you've got to break that first for it to move. Once you've broken that, we'll be off—Hopefully.

NARRATOR (KEACH): Mark will try just about anything to get the stone unstuck.

JULIAN RICHARDS: How many people have we got hanging around the back here? Why don't we all just go on the ropes up there?

NARRATOR (KEACH): Roger Hopkins is on hand to provide practical advice. He's the only one on the team with any firsthand experience moving large stones. He recommends breaking the suction by lifting the stone with levers.

MARK WHITBY: I think this'll work. I think this'll lift it up. That'll unstick it and we should be away. But it's gonna be, it's the job of unsticking it which we've got to do now. We need to get it in further.

MIKE O'RORKE: Drop it! Drop this one here! This one here! Drop it!

MARK WHITBY: Get them to move more in a straight line.

NARRATOR (KEACH): In order to get things moving, project manager Mike O'Rorke has to get the pullers and the levers to work together. Suddenly, the levers do the trick.

MARK WHITBY: Perfect, absolutely brilliant. I mean if anything, quite fast. I mean, you think how far that would go in a day on that basis.

NARRATOR (KEACH): In the end, Mark's system worked better than even he expected. But is there any evidence that the Stonehenge builders used a wooden trackway like this one?

ROGER HOPKINS: The method seems to be workable, but I just wonder, you know, if they would have bothered to build a trackway all the way from...where? Marlborough Downs?

JULIAN RICHARDS: Twenty- five miles.

ROGER HOPKINS: Twenty- five miles?

JULIAN RICHARDS: Well, I think the effort that you put into doing something like this certainly makes it a lot easier. I mean, the thing that bothers me is, is having demonstrated that this works, you know, would, would we be able to find any trace of it in the ground? I don't think we would.

NARRATOR (KEACH): As a result of weather and soil conditions in this part of England, combined with centuries of farming, very few of the tools and materials used in the construction of Stonehenge have survived. But we do know that parts of the countryside were once heavily wooded, providing plenty of timber for the Stonehenge builders. Jake Keen has spent years investigating Stone Age tools and technology. He believes that the ancient builders were extremely resourceful, and exploited the forest for much more than timber. Using only stone and wooden tools, Jake carefully removes the bark from a common tree of the region—the small leaf lime. He then submerges the strips in the nearby stream, and leaves them there for several weeks.

JAKE KEEN: After being in the mud for about six weeks, this is the smelly end product, which of course is the inner bark. And the layers, bast layers, have separated off, uh, the little microorganisms have nibbled away at the gummy material, and, uh, this is broken down into something like ten or twelve separate ribbon like layers. Which is what we make the string from, and, uh, if we twist these together, they're very, very strong. I don't think there's probably any stronger plant fiber native to this island.

NARRATOR (KEACH): Strong rope was essential for moving heavy stones, and with fibers like this, the ancient builders could easily have made rope capable of pulling the giant blocks of Stonehenge. But why did they bother to drag the stones over twenty miles to this shallow valley? No one knows why it was chosen, but there's evidence that this site was considered sacred centuries before Stonehenge was built. After excavating the area and radiocarbon dating the pieces of bone and charcoal found here, archaeologists have retraced a unique sequence of construction. The first monument was built over five thousand years ago and contained no stones at all. It was a simple earthwork enclosure, consisting of a circular ditch, a bank, and fifty- six wooden posts dug into the ground. Over the next four hundred years, a series of wooden buildings occupied the center of this circle. Tiny fragments of the foundations remain. The first stones arrived around 2600 BC, when the buildings were replaced by a double crescent of small pillars, called "bluestones". Just a hundred years later, the monument took on its final form. Thirty giant sarsens, each weighing about twenty- five tons, were neatly arranged in a ring, about one hundred feet across. Along their tops were placed thirty lintels, forming a true circle, sixteen feet above the ground. Within the circle stood the largest stones. Five massive trilithons formed a horseshoe. The tallest towered twenty- five feet above the ground. The builders had never before attempted to raise stones on such a colossal scale. How did they manage to do it? Archaeologists discovered important clues when they excavated the soil around the largest stone. They found that it stood in a giant hole, with almost a third of it underground. One side of the pit was slanted, indicating that the stone had been lowered into the ground at a steep angle. Remnants of deer antler revealed how the hole was dug out of the hard chalk.

JULIAN RICHARDS: It would certainly have been possible to have dug a hole with an antler pick like this. It would take, perhaps, two people three days, maybe, to dig a hole of this size.

NARRATOR (KEACH): With the forty ton stone poised over the pit, can the team replicate the ancient feat of standing it upright? Mark Whitby has a plan.

MARK WHITBY: What we've got is one of the forty ton uprights. And it's been dragged to a position where it's now ready to be toppled into the hole that we have in the ground. And the hole is pretty precise because it's exactly the same as the hole that they've got at Stonehenge. The basic concept is we've put six tons now on the back of the stone by dragging it up these ramps. We've tied it together as a bundle. We've put it on a little greased chariot here, rather like we had for the big stone. And that's running on a very simple bearing down here. It's not nearly as heavy as the big stone, and we've got it tied back with a, with a rope, which is lassoed right around the back here. And that rope's gonna mean that when it travels a certain distance along this stone, it's gonna stop. However, before it reaches that point, it will have passed this magic point of the center of gravity. We'll be inducing the force which will make the whole stone start to turn. It will happen slowly to begin with, and then it will just go.

NARRATOR (KEACH): Instead of moving the stone, the volunteers will pull a heavy weight that will tip the block.

ROGER HOPKINS: This is a good example of modern man trying to over- engineer ancient techniques. This is a bit over elaborate, but it—I'm hoping it works. It would save us a lot of work in the long run.

MIKE O'RORKE: Alright. This is what we've been waiting for. There's one very, very important thing. When that stone starts to stand, do not rush to the stone. You must all stay back until the engineers have checked to see if it's safe. We can crawl all over it once it's safe, but you mustn't, under any circumstances, come forward of where you are now.

NARRATOR (KEACH): The safety of the workers is foremost in everyone's mind, but there are also fears for the stone itself. The megalith could tumble out of control, or even break apart from he force of impact.

MARK WHITBY: I'm excited in one sense and in another sense I wish I was a long way away. You know. . .it's. . .we'll see. . .you know. . .something's going to happen.

NARRATOR (KEACH): Mark realizes he's got just one chance to get it right. It's now or never.

MARK WHITBY: Ah! Brilliant! Well, let's have a look. It literally just dropped just as we planned it to drop. And the only thing that is slightly different is it's kicked out the back here, but that's, uh, that's just better than we expected. That means it's more upright and we've got less work to do, you know, tomorrow.

ROGER HOPKINS: Well this really worked a lot better than we had hoped for.

MARK WHITBY: I think better than we both hoped for—better than I hoped and I was hoping the most probably.

JULIAN RICHRDS: I think it was probably one of the most spectacular ways that one can think of getting a stone this size into a stone hole. Whether that was possibly a way that they did it, we shall honestly never know. Um. . . I've heard comments that it was a perhaps an over engineered approach. Um, I'm not convinced about that. I mean, the people who built Stonehenge were very sophisticated, were obviously capable of thinking out grand schemes like that and carrying them through. And I don't see why, especially after you'd perhaps had a go with some smaller stones that somebody wouldn't have come up with an idea like this: "Let's use the weight of some smaller stones to help us move a bigger one." So, I don't find it completely implausible—we shall never know is the answer, of course.

MARK WHITBY: I think we can all go home to a nice rest—and a little relief.

NARRATOR (KEACH): Mark chose this method for tipping the stones because it required the least number of people. No one really knows how many workers were used in the construction of Stonehenge, because there's so little evidence. There are no written records from this period. The houses and farms that once supported the workforce have by now completely vanished. All that's left for archaeologists to find and study are pieces of pottery, stone tools and bones. But this meager evidence can give us some idea of what life was like in Stone Age England, forty- five hundred years ago. The people were farmers, moving from place to place in search of fertile soil. They herded sheep and cattle and hunted for wild deer. Gradually, as farming techniques improved, the population grew, providing the labor force for ambitious construction projects. Centuries before Stonehenge, communities started coming together to build large tombs. One of the most impressive is over three hundred and forty feet long and has an entrance constructed of massive sarsens.

JULIAN RICHARDS: We've got one of the earliest examples here of the ability to construct with huge stones. Massive sarsens dragged from he surrounding downs, some placed upright, others—like this one here, placed on top if it as cap stones, almost giving an idea of what Stonehenge was going to be like when it was built with uprights and horizontal lintels. But here, these massive stones forming, effectively boxes, parts of a chambered tomb. It's effectively the house of the dead. Five stone chambers lie on either side of this passage and in these were found the remains of forty- seven individuals buried over a period of perhaps twenty- five generations. What's very interesting is the way that the bodies came into this tomb. Not all of them as completely fleshed bodies, but some of them just as collections of bones with hints that they might been buried elsewhere for a while—they might have been exposed for animals and the elements to remove the flesh from the corpses, brought in here as a bundle of bones when the tomb was opened up. And we get hints as well, that there was a rearrangement of the bones—skulls placed in one corner, long bones in another—the other bit and bob tidied off to one side. And one thing I find fascinating is that there are some bits that aren't all there. There aren't quite enough heads to go around.

NARRATOR (KEACH): Around the time that Stonehenge was built, burial practices were changing. Abandoning the large communal tombs, important individuals were buried alone, under circular mounds of earth, called round barrows. Over three hundred of these tombs still remain within two miles of Stonehenge. Inside each one is a single body, surrounded by a few prized possessions.

JULIAN RICHARDS: It's obvious society's changing at the time that the Stonehenge that we know today was built. I mean, there aren't the communal burials with lots of people put into one burial mound. Instead, every hill top around here is covered with individual burial mounds, round barrows. And each one of those is the burial place of somebody rich and powerful. They had to be, to be buried this close to Stonehenge. And of all these barrows, the most important, the richest person of the lot, appears to be buried in this one. Excavated about one hundred and eighty years ago—I mean, he's still in there. The bones were recorded as being of a tall and robust man, but the excavators at that time weren't interested in the bones themselves. They left the burial where it was. What they were interested in was the objects and that's what gives us a clue as to just how powerful this person was. This person was buried with some absolutely incredible gold objects.

NARRATOR (KEACH): A breastplate. A belt buckle. Pure gold, finely hammered and etched. Other graves revealed more treasures: gold earrings and buttons—bronze daggers and spears. Four thousand years ago, these objects adorned the richest and most powerful people. And these ancient lords and ladies chose one location, above all others, as their final resting place: the hills surrounding Stonehenge. In the midst of this enormous cemetery, the circle of stones was like a great cathedral, standing guard over the graves of its wealthiest patrons. Back at the construction site, the crew is contemplating its next major task. The enormous concrete block is standing in the hole at a steep angle of seventy degrees. The team now has to pull it just twenty more degrees to vertical. But this will turn out to be a much greater challenge than Mark Whitby ever expected.

ROGER HOPKINS: Well, this would have been a distinct problem—getting these things perfectly vertical.

MARK WHITBY: Well, we've not solved that one, have we?

ROGER HOPKINS: No.

NARRATOR (KEACH): To maximize the workers' efforts, Mark has erected two huge timber poles, attached by ropes to the top of the stone. The ninety volunteers will pull on another set of ropes that is tied to the top of the timbers. With this arrangement, Mark hopes the poles will act like giant levers, multiplying the force of the pull, and making it much easier to move the stone upright. Mark put a lot of thought into his plan, but apparently not quite enough. The upright poles are dangerously unstable, and more time and energy is spent struggling to avoid a catastrophic collapse than actually moving the stone.

MARK WHITBY: Mike, you've got to get your team to the front to slack it off and these teams put it back.

MIKE O'RORKE: Ease off! Ease off towards me!

MARK WHITBY: That team's not pulling hard enough ... that team ... that team.

NARRATOR (KEACH): Mark is forced to admit that his plan is flawed and agrees to tie the poles into a giant A- frame, a much more stable arrangement.

MARK WHITBY: I think get it into a bit of an A- frame and we might be able to make something of it, but it proves there's some value in that. We should have an A- frame. Perfect! Right, now lash it together.

INTERVIEWER: Why have you decided to use an A- frame now?

MARK WHITBY: Because we should have always had an A- frame, basically. It's fairly obvious that an A- frame is more stable, and what we've got is a problem of them all falling down sideways, and we're having to use too much energy or effort in terms of these people to hold the thing up on the left and the right flanks. So we could maybe, by making it an A- frame, concentrate our efforts on pulling it forward.

INTERVIEWER: Why didn't you think of that before?

MARK WHITBY: I probably did, but somehow it got lost in the translation somewhere. I know we've had all sorts of ideas, and this is one of those ones that we should have stuck with, but we somehow thought that things might be better than they really would be.

NARRATOR (KEACH): But an entire day has been lost. Mark and the team will have to wait until tomorrow to see if the A- frame works. The original builders of Stonehenge experienced their own share of setbacks. Along with moving and raising the stones, every block had to be carefully shaped. The horizontal lintels were secured to the supporting stones by unusual mortise- and- tenon joints. A large projection on top of each upright had to fit precisely into a hole on the underside of the lintel. With only stone tools, pounding out the holes must have been an excruciatingly slow and tedious job.

JULIAN RICHARDS: I think it's likely that the uprights would have been in place with the tenons worked on the top of them before the fine work took place on the lintel. That would have involved pounding out these massive mortise holes. I mean, this would have taken weeks to do, I would imagine. The biggest of them holds about eighteen gallons of water. But clearly they didn't always get it right because on this side, there is the start of a couple of other mortise holes. So, clearly, they started here, turned it over and worked them on this side. And I would have hated to be the person who told the workers that they got it wrong and they've got to turn it over and start all over again. I don't think he'd have been very popular.

MIKE O'RORKE: One, two, three, pull! One, two, three, pull!

MARK WHITBY: Hold it—let's just leave it.

MIKE O'RORKE: We let it go?

MARK WHITBY: Yeah. Let it go.

MIKE O'RORKE: It seems a shame to let it go now that it's up there.

MARK WHITBY: I know. I know. It's all right. . .

NARRATOR (KEACH): After yesterday's disappointments, Mark's own popularity is suffering a bit.

MARK WHITBY: I'd like to try putting stones up, not timbers up.

MIKE O'RORKE: Yeah. Stones are a lot easier.

NARRATOR (KEACH): Today, he's hoping to redeem himself with a new and improved A- frame.

MARK WHITBY: I reckon that we should really just get another means of getting these poles up, otherwise people get . . .

NARRATOR (KEACH): He uses a model to calculate how many people will be needed to finally get the stone vertical.

MARK WHITBY: I've got the stone to seventy degrees as far as I'm concerned is the most difficult bit. All we've got to do now is just get it through the next twenty degrees to vertical. And what I'm going to do is gonna use this A- frame. We made the A- frame so it's strong in this direction. It's not going to fall over this way. But we've made it so it's an A- frame which is a lever, a great big lever and it's pivoting in a point of the ground here—we're pulling with all we've got on the top of the frame here. Attach the ropes that are pulling from the stone to the A- frame to the point about a quarter of the way up—the height, the over- all height of the lever. The effect of that is that when the people pull here, I can multiply the pulling force that they achieve by a factor of four. Now, let's just look at how many people may be required to do the job. I've got weights on the end of here. This is a fifty gram weight—that's approximately equivalent to 50 people pulling. And now I am going to add another twenty to this team—that's seventy. And then another five to that—that seventy- five in total. And I've got my stone to vertical.

NARRATOR (KEACH): But what if there were no A- frame?

MARK WHITBY: Okay. Let's imagine we were to do the brute force approach. Let's imagine we're to pull this thing to vertical without the A- frame. I've got seventy- five on here. Let's just add a few people to this. Let's just add two hundred more people to this team—I haven't got two hundred people, let's just add them, though, let's imagine we've got them, and see if we can do the job with two hundred and seventy- five—no, we can't. Let's add another fifty. This is three hundred and twenty- five people pulling now. They're still not managing. Let's add another ten to that, that's three hundred and thirty- five people—and away it goes. That's the amount we would have needed to pull and we just haven't got them.

NARRATOR (KEACH): The full- size A- frame is up and ready to go. But as usual, Roger Hopkins isn't satisfied with the construction.

ROGER HOPKINS: A proper A- frame should be built with a cross member at one third of the way up lashed in securely to keep it from racking. Uh, I don't think you're out of the woods yet. And I think the A- frame, you know, probably should be in a lot closer so that we have a little bit more leverage with it. And then we would just run the rope right over the top and the pull the sucker over. I think this is a great example of engineering learning some field experience.

MARK WHITBY: I think you're absolutely right. There's no doubt we did a lot of things wrong yesterday. We should have planned the A- frame to begin with - - it's absolutely absurd that we haven't. We still haven't—I agree with you—it's not the best A- frame in the world, but we've got something of an A- frame and I believe that's going to work.

ROGER HOPKINS: Well, I wish you luck. I just don't think that A- frame's going to hold together the way she's rigged.

MIKE O'RORKE: One, two, three, pull! One, two, three, pull!

RIGGERS: Keep going! Keep going!

MIKE O'RORKE: Okay. Stop!

MARK WHITBY: Go on! Keep it up!

MIKE O'RORKE: Yeah. It's all right to say "go on"—they're pulling!

ROGER HOPKINS: The proper way to have done this right from the beginning was that when we had the motion to just keep on pulling. Whenever we tipped up large stones, we always try to keep the momentum going because it's a lot of work any other way. I have a feeling these neolithical people were probably a lot handier with these tools than we are.

MARK WHITBY: I am sure of that. Certainly, A- frames.

ROGER HOPKINS: Yeah. (they laugh) Remind me to get you the boy scout manual—you might want to read it.

NARRATOR (KEACH): Despite Roger's concerns, Mark forges ahead with the operation. And Roger has nothing to do, but retreat to the sidelines.

MIKE O'RORKE: One, two, three, pull!

VOICES: It's going!

NARRATOR (KEACH): The A- frame—although a bit precarious—makes a difference, and the monolith inches its way to vertical. Four thousand years ago, the Stonehenge builders had to raise and precisely position forty of these huge blocks. The whole monument was symmetrically arranged around a central axis that runs through the entrance and down the middle of a processional avenue. It points directly to the spot on the horizon where the sun first appears on June twenty- first, the summer solstice. Every year on this day, the sun rises above the Heel Stone, a sarsen boulder that stands near the entrance. Six months later, on December 21st, the shortest day of the year, the sun sets on the opposite side of the circle, between two uprights of the now- fallen central trilithon. Some people believe that Stonehenge is also aligned with the moon and the stars, and can help predict eclipses, but none of these theories are proven. It is possible that the circle of stones served as a kind of crude calendar, alerting farmers to important events in the annual growing season. But most likely, Stonehenge was built as a temple, a special place for the community to gather, to perform sacred rituals, and to honor their gods. In the 20th century, a modern cult of Druids adopted the temple as their own, and used it as a stage for elaborate solstice ceremonies. But in the 1970's and 80's, their pagan services were gradually overwhelmed by hippies, drugs, and the international press. To protect the monument, British authorities now close Stonehenge on the summer solstice. Barbed wire and armed guards keep everyone away from the ancient stones, including archaeologists.

JULIAN RICHARDS: It's June 21st, the summer solstice, which should, I suppose, be a beautiful day with the sun rising up over the heel stone, but it's raining. It's actually quite cold and miserable now. It's, it's a place that I wanted to be at the midsummer. I feel somebody really ought to be here, but it's not a very spiritual experience. I think it could be and it obviously was to the people who built it. I mean, forget all the engineering and forget the calculations and the big stones. I mean, this is the culmination of all that effort. This is why people dragged those stones those great distances and put them up. They were building a temple and they were building a temple that is important, certainly at this time of the year, possibly at another time of the year in the winter. Clearly, there was a tremendous amount of feeling on most peoples' part. . .

NARRATOR (KEACH): The ancient builders needed this motivation when they faced their final challenge: raising the nine ton lintel twenty- three feet to the top of the uprights. The traditional idea is that the smaller stone was raised slowly with large wooden levers and a timber crib. Roger is eager to show how well this can work. With each lift, thick pieces of timber are slid underneath the stone.

ROGER HOPKINS: Comin through. Ease off.

NARRATOR (KEACH): Little by little, the pile of timber grows, and, accordingly to the theory, will gradually lift the stone to the top of the uprights.

MARK WHITBY: I think it's clear it would be a perfectly feasible way of getting the lintel up which is the nice thing about it. I mean, when it really—this is the text book way and bigger timbers would be useful, and maybe they wouldn't have been quite so regular in size, which might have been a bit of a problem.

NARRATOR (KEACH): Mark thinks the operation is too slow and, at a height of twenty feet, would become too precarious. He wanted to raise the lintel up a large ramp made out of earth, but unfortunately, British safety officers insisted that he use steel scaffolding instead. Underneath all the scaffolding, stands the forty ton stone. The second identical upright has been raised beside it, and together, the two stones will form the base of the trilithon.

JULIAN RICHARDS: Is this how you think that they did it then at the time they built Stonehenge?

MARK WHITBY: Well, Julian, it's quite simple. If you look over there, you will see my big pile of earth—you know, do you see it? Chalk everywhere? It's a pile of earth. I've just put some timbers on it and we're walking up the pile of earth, we're dragging the stone up the pile of earth. So, you know, that's what it is Julian, it's . . . you know . . . it's ancient technology—can't you see:

JULIAN RICHARDS: Perhaps it's the scaffolding that confuses me a bit.

MARK WHITBY: Well, you've got to put your blinkers on at this point, Julian.

JULIAN RICHARDS: I must admit, I find this a twentieth century engineer's approach to how to get the lintel up. I mean, personally, I am happier with a timber crib. It seems less intrusive into, into the monument at the time. And it seems a lot less elaborate than this somehow. You know, perhaps four thousand years ago—yes, I still there's a lot of preparation went into things—but there would have been a willingness to accept that, perhaps, that stone would have inched it's way up over a period of a week.

MARK WHITBY: We tried one method, we can see that. Let's try another method and see how it goes. Ready . . . rope!

NARRATOR (KEACH): Since the A-frame worked so well in raising the stone to vertical, Mark will use it again to drag the lintel up the ramp.

MIKE O'RORKE: One, two, three, pull! One, two, three, pull! One, two, three, pull!

NARRATOR (KEACH): To allow the volunteers to rest between pulls, the top of the ramp is equipped with a log that's supposed to act as a brake, preventing the lintel from sliding backwards. But after a couple of big pulls, it's clear that the brake is not working.

MARK WHITBY: Okay, hold it! Hold it there. Right. We've got to release these back down. This isn't working, at all. Look, just let these ropes right off, okay?

NARRATOR (KEACH): As soon as the volunteers stop pulling, the lintel descends to the bottom of the ramp. It turns out that the riggers have wound the rope the wrong way around the log. Thankfully, the problem is easily fixed. And when the volunteers renew their efforts, the lintel starts to make its way up the ramp. Like the ancient stones, the bottom of the lintel is equipped with two large mortise holes, which must fit exactly over the projections—or tenons—on top of the uprights. To ensure that the stones are properly aligned, the final phase of the operation must be performed slowly and precisely.

WORKER: Nice and easy. Nice and easy.

ROGER HOPKINS: That was quite frightening.

WORKER: My heart is still pumping!

NARRATOR (KEACH): The volunteers are thrilled, but Mark is in no mood to celebrate. As he feared, the mortises and tenons are not lined up. The lintel must somehow be repositioned. Luckily, Roger brought along his levers.

ROGER HOPKINS: Keep that up, and we'll, you know, slowly but surely we'll make it.

NARRATOR (KEACH): It takes some time, but finally, the lintel slides down into position. The trilithon is complete.

MARK WHITBY: I think these Stone Age men were pretty ingenious. We learned an awful lot of respect for them as a result of being handed two forty ton stones and one nine ton stone and asked to sort of stand them on their ends and put the nine ton on top. And I think I probably got nearer to thinking like he might have thought at the time than anybody has for a long time and that's very nice. It's a very nice feeling that gives you to enter into the, sort of, soul of somebody as the result of seeing what they've built.

ROGER HOPKINS: They were pushing the envelope of their technology. They were taking things that they had seen work and applying them to a massive job that was advancing their technology and, by doing so, probably advancing their status in their community.

JULIAN RICHARDS: We haven't got the final answer. You know, we can't say "this is how it was done". What we've demonstrated is how it could be done. And we've tried to be as real to the time that Stonehenge was built as possible. Archaeology can answer some questions about Stonehenge, when it was built, something about the society that built it. And this has answered some of the questions about the task—the engineering, how you motivate people, how you organize people, but there is always going to be a mystique about Stonehenge.

__: NOVA's "Secrets of Lost Empires" will continue in a moment. In our next hour, they straddle the high peaks of the Andes, ancient cities of stone linked by roads and bridges. Join us as we explore the mysterious world of the Inca. How did they move monstrous stones, cut precise joints, weave bridges made of grass? Stay tuned for Inca.

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