- hace 6 meses
Categoría
📺
TVTranscripción
00:00The Peruvian Andes of South America are among the most rugged mountain chains on Earth.
00:09Battered by earthquakes, volcanoes, and powerful storms, the Andes are a dynamic land of environmental extremes.
00:22Steamy Amazon jungle quickly gives way to jagged 20,000 foot high peaks.
00:34The spine of the Andes separates arid coastal desert from bleak high altitude plateau.
00:42Too dry or too vertical for normal living, this land seems an unlikely place to find a great civilization.
00:52But 500 years ago, an ambitious Andean people called the Inca were building spectacular cities in the clouds.
01:09Their intrepid engineers linked these mountaintop citadels with a phenomenal system of roads and gossamer-like suspension bridges made only of grass.
01:26500 years ago, before the Spanish came to the New World, the Inca Empire was the greatest in the Americas, stretching almost the entire length of the Andes.
01:39The Incas were certainly the strangest and most bizarre civilization that the Earth has ever seen.
01:45They had none of the things that we think of as the prerequisites for a major civilization.
01:49No arch, no wheel, no codified mathematics.
01:53They couldn't write. They couldn't even scratch down an arithmetic problem.
01:56And yet they could do this amazing engineering.
01:58The Incas' engineering medium was stone.
02:03In their walls and buildings, they showed a mastery over stone that is unrivaled.
02:09Without mortar, the Incas created walls of interlocking blocks that have successfully withstood earthquakes for centuries.
02:19But their interest in stone went beyond the utilitarian.
02:28The Incas worshipped rocks.
02:32They carved intricate designs on natural outcrops and poured chichamese beer or sacrificial blood down the channels
02:42to honor their mummified ancestors housed in rock-cut chambers below.
02:48of the ancient native forest.
02:54In the desert they include the Eccles.
02:59Choosing high vantage points at sacred sites, the Incas created mysterious stone columns
03:06dubbed Hitching Posts of the Sun.
03:10They worshipped the Sun and may have used the shafts for sighting stars.
03:17Blending their stonework into the natural landscape, the Incas carved rocks to mimic
03:25the shape of the mountains behind.
03:31But their most impressive and mysterious stonework is found in the walls of their citadels.
03:38Giant blocks, some weighing a hundred tons, sit next to each other so precisely that not
03:45even a razor blade can fit between them.
03:50Without iron tools, draft animals, or the wheel, how did the Inca builders move and set
03:57such large blocks?
04:01To answer this question, NOVA invited several experts with widely different backgrounds
04:07to come to Peru.
04:09We're pretty good at finding the evidence today if...
04:14Professor of Architecture, Jean-Pierre Protzen, studies the Incas' use of stone.
04:24He's written a book about Inca architecture and has some definite ideas about their construction
04:28methods.
04:29Ed Frankebant is both an anthropologist and a building contractor who lived in a Peruvian
04:44village for several years.
04:46His particular interest is how the Inca builders organized their labor force.
04:53Philippe Petit is the man who walked a tightrope between the towers of the World Trade Center.
05:04He wants to know how the Inca builders used grass to make the strong ropes that support their
05:17high suspension bridges.
05:18And he's come here to help build one.
05:23Vince Lee is an architect and explorer who has traveled extensively in the Andes looking
05:33for lost Inca sites.
05:35He has a theory about how the Inca stonemasons made such precise joints with such giant stones.
05:47A good place to start looking for clues is the citadel overlooking the town of Ollantaytambo.
05:59About 500 years ago, a sun temple was under construction inside the fortress.
06:04So with all these blocks of stones here, this is clearly a construction site that was abandoned
06:10in private.
06:11The question is, where do these stones come from and how did they get here?
06:16Well, they came from the quarries on the other side of the river at the base of this mountain
06:23here.
06:26The team decides to follow the route to the quarry taken by the ancient stone haulers.
06:40The hike will take them down a sloping ramp to the valley floor.
06:45Along the way, they find massive blocks abandoned by the Inca workers.
06:50The villagers call these rocks piedras cansadas, weary stones.
07:03One legend tells of stones that grew tired, wept blood, and refused to move.
07:09It's always there.
07:14So this is where the quarry is.
07:16The lower quarry at the bottom of this rockfall.
07:19You can see some ramps.
07:22The other quarry is way up there at the foot of the cliff.
07:26Jean-Pierre, JP to his friends, leads the team along the remains of a roadway that leads to the quarry.
07:38Actually, a rockfall created by rocks eroding from the cliffs above.
07:43Here, they find a 70-ton stone that Inca quarry workers had turned into a rectangular block.
07:53JP believes that all the boulders were first squared off in the quarry.
07:58But how did the Incas transport these heavy blocks down the mountain and up to the Sun Temple on the other side of the valley?
08:08Spanish chronicles tell us that the Incas did not possess the wheel or strong draft animals like oxen.
08:17David Canal, a community leader and Inca descendant, believes they hold the blocks by hand.
08:27He's organized a team of pullers to transport a one-ton rock along the same route taken by the Incas between the quarry and the citadel.
08:38For most of its length, the ramp has a gentle slope.
08:41But halfway down the mountain, the incline suddenly turns into an almost vertical 800-foot chute to the valley below.
08:50With a block more than ten times the size of this one, it must have been extremely difficult for the ancient stone haulers to negotiate this chute.
09:05Unlike the Inca blocks observed on the transport route, this boulder has not been squared off, and it tumbles out of control.
09:16Probably not the way the Incas wanted to see it happen.
09:20No, no. Absolutely not.
09:21And you know, once it turned this way, it was kind of cylindrical.
09:24It was kind of easy for it to get rolling where a big square block might not have been there.
09:28That's true.
09:29Having gotten the boulder down in pieces by a distinctly non-Inca method, everyone hopes to do better with the next challenge, getting a block across the Urubamba River.
09:42At this time of year, the water level is at its lowest, and the river looks quite placid.
09:51But after the rainy season, it becomes a torrent impossible to afford.
09:57David believes the Inca hauling teams would have chosen to cross at the shallowest stretch.
10:12But even here, there's a stiff current, and many of his men can't swim.
10:27To appease the spirits of the river, David has arranged for an offering of cane alcohol.
10:37The wet stones are slippery for the men.
10:47But this turns out to be an advantage when it comes time to pull the rock.
10:52Go!
10:53Go, John, go, Lisa.
11:05Go, John!
11:09Bravo! Bravo!
11:14Bravo!
11:16Bravo!
11:18Bravo!
11:20Bravo!
11:26Bravo!
11:27Arriba!
11:29Arriba!
11:31Bravo!
11:33They're perfect.
11:36It's easier than moving it on the ground.
11:38It went pretty quick.
11:40Just exactly like I thought it would.
11:43The task of getting the rock across the urubamba
11:46turned out to be much easier than everyone had imagined.
11:55But crossing the fields on the valley bottom
11:57is much more of a problem
11:59because the stone acts like a plow digging into the soft ground.
12:04There was probably once a road crossing the valley,
12:12but it has been destroyed by centuries of farming.
12:15Permission has been obtained to excavate one of the blocks abandoned in Inca times
12:20to see if there is any evidence of a roadbed underneath.
12:25What turned up underneath was a layer of small stones
12:28on top of what appears to be a prepared gravel road base.
12:32So the resulting surface that the stone appears to have actually been bearing on
12:35is just these stones about the size of a softball, not necessarily round, but you know.
12:41And that's not unlike the surface we find on the ramps today still.
12:46Now that they have found the kind of road used by the Inca stone haulers,
12:50the team wants to see how difficult it would be
12:53to drag a much heavier block on a similar surface.
12:56In the plaza below the citadel, they find a genuine 15-ton Inca block,
13:07and the sloping, cobbled surface is a good approximation of the 8-degree ramp
13:12that leads up to the Sun Temple.
13:15To pull the block, David has assembled a team of 250 men, women and children
13:26from Ollantaytambo and neighboring villages.
13:33There's a festive atmosphere.
13:35Everyone's turned out to see the great block being dragged through town.
13:45Unfortunately, the stone refuses to budge.
13:58But after another offering of cane alcohol and some levering,
14:02the stone finally comes unstuck.
14:15The ease with which the block travels on the cobbled surface
14:27proves that it could have been dragged up the slope to the Sun Temple.
14:32I had no doubt that we could do it.
14:38Our ancestors did it, so I knew we could do it too.
14:41Human labor can accomplish anything.
14:51The determination displayed by David's people
14:54makes the speed and scale of the Inca's empire-building achievements
14:58much more understandable.
15:04According to legend, around 1450 A.D.,
15:07a leader called Pachacuti, whose name means Earthshaker,
15:12began an aggressive military campaign that transformed the Incas
15:16from a small Cusco Valley community
15:19into a juggernaut that swallowed up all its Andean neighbors.
15:27In return for the benefits of a stable state,
15:30conquered peoples paid tax to their Inca masters
15:33in the form of labor.
15:40This huge workforce enabled Pachacuti and his successors
15:43to build the infrastructure that could support
15:46their rapidly expanding territorial gains.
15:49In the Urubamba Valley, wide rambling sections of the river
16:06were placed in canals to create cultivatable land.
16:10Terraces watered by elaborate irrigation schemes
16:17climbed the mountainsides,
16:19further increasing food production.
16:24On the peaks above the Urubamba River,
16:26the Inca lords built a chain of remarkable citadels in the sky.
16:31The most magnificent and mysterious of all, Machu Picchu.
16:42It's difficult for us to grasp the scale of the Inca's imagination
16:46and ambition in producing places like this.
16:50As archaeologists, we like to work with potsherds or tools
16:54or walls or a building, things that are people scale.
16:59But the Inca's vision was much bigger than that.
17:08The real Inca media was the entire immense Andean landscape around him.
17:14He spent extra time to find very special places within the Andean landscape.
17:23Spent time studying them to understand their true nature.
17:28Embellished them with stone.
17:31Ran sparkling and rushing water through prepared watercourses.
17:38And in the end, produced works of singular beauty
17:41that represent a harmony with nature
17:43that few other civilizations have achieved.
17:54So remote was its location,
17:57Machu Picchu's existence remained a secret
18:00from the time of the Incas until the early part of this century.
18:11But 30 miles upriver, the town of Ollantaytambo
18:15has been lived in continuously since the time of the Inca.
18:23Its buildings are well-preserved.
18:27But the very finest Inca stonework
18:30is found in the citadel above the residential quarters.
18:33Replicating joints like this is the challenge J.P. Protzen and Vince Lee have set themselves.
18:44You know, J.P., this part of Ollantaytambo has always been one of my favorites.
18:49I mean, this is Inca stone masonry as good as it gets.
18:52Don't you agree?
18:54It's not just the craftsmanship, it's just the playfulness of the joining.
18:58And the problem that they elected to solve is just so complicated.
19:02It's wonderful.
19:04I mean, you really see that here they perfected their skills.
19:07Yeah. And you know the other thing, it seems to me,
19:09that where other cultures use stone as a material for sculptural decor of one kind or another,
19:16these guys just use the stone itself.
19:18They're just telling you that stone is itself a beautiful material.
19:21You don't have to carve anything into it, really.
19:23No. No, this is sculpture.
19:24Yeah, exactly that.
19:27You know, people often say, oh, you can't get a knife blade in the joints of Inca.
19:31You can't get anything in this.
19:32Not even an eraser blade.
19:33No. No, it's an absolutely perfect joint.
19:36Yeah.
19:38I mean, the craftsmanship is mind-boggling, especially if you try to do it.
19:41If you try to duplicate it yourself.
19:43J.P. has duplicated Inca stonework using Inca tools.
19:47In an ancient quarry, he discovered some rounded stones that probably came from the river.
19:55Using these as hammer stones, he found them as effective as the modern steel chisels used by stonemasons today.
20:02To create a beveled edge, J.P. used a smaller hammer stone.
20:16The resulting tool marks are identical to those found on Inca masonry, rough in the center and smooth at the edges.
20:29But how did the Inca masons go about setting the stones?
20:32A half-finished citadel wall provides an important clue.
20:41To achieve the perfect Inca joint, an imprint is marked on the block below.
20:48The area that will seat the new block is then hammered out.
20:51Repeated fittings fine-tune the joint.
21:13Spots where stone dust is compressed indicate raised areas that need more hammering.
21:19Using ever smaller hammer stones to avoid damaging the edges, J.P. finished the joint within a few hours.
21:36It shows that with the sort of simple tools that I have found in this quarry,
21:41it is absolutely possible to achieve the kind of perfection of stone work that we observe throughout Cusco and the Inca Empire.
21:51J.P.'s method works well with small stones that can be easily maneuvered.
21:55But as the stones get bigger, handling them becomes increasingly difficult.
22:13Here, at the Inca fortress of Saxo-Huaman, the trial and error method of setting giant multi-ton blocks seems a daunting prospect.
22:21But despite their size, the blocks in the retaining wall all have the famous Inca fit, mortarless and snug.
22:31The answer may be a simple builder's tool called a scribe.
22:44A tool that may have enabled the Inca masons to make joints without any painstaking trial and error.
22:49Back in Noyante Tambo, Vince is about to use his scribe as he attempts to make a perfect Inca joint between two stones his masons have worked on for several days.
23:05We're getting the rock into position to scribe this prepared joint into this one that's yet to be prepared.
23:18And so far everything we've done, anyone fitting these two rocks together would have to do.
23:23You would have to rough cut your rocks and basically decide which rock was going where, and you'd have to get them in position.
23:30Now is the point where the method I'm proposing perhaps differs from others because what I'm saying is that by using this scribe,
23:37this end, this blunt end is designed to work against a previously prepared smooth surface.
23:45Now what we have to do is make this edge exactly match it.
23:48And the way we do that is by taking this scribe and running it down this pre-finished surface,
23:54maintaining the string hanging through the center of its hole with this little plumb bob
24:00so that we don't accidentally mess up our joint by allowing the scribe to move in this plane.
24:06As long as we keep the string in the center of the hole and as long as this is rubbing against that pre-finished surface,
24:14all we have to do is chop this rock out so that this end of the scribe exactly fits no matter where we put the scribe.
24:22Then we can achieve the fit we want by moving this rock one more time, simply closing the joint.
24:28End of story.
24:32Time constraints have forced Vince's men to use steel chisels to work the hard andesite rock.
24:58Well, this is it, the moment of truth for Vince's project.
25:01He's been scribing and chomping and chipping and polishing,
25:04and right now these two stones are supposed to go together like incommationary, be right close together.
25:10What do you think, gonna work? Can it happen?
25:12It's absolutely right. It's time to stop talking and start moving rocks, so let's do it.
25:16Let's do it.
25:37The joint that we've gotten is certainly not as good as the ones we've seen up in the ruins.
25:40But it isn't bad. What we did here today is we fitted two large rocks together, moving them together only one time.
25:48That's the essence of my idea, basically.
25:50Absolutely.
25:51We didn't have to try this back and forth at all.
25:55We fit it once and we got a pretty good joint.
25:57If you set us down here for three more weeks, we'd do twice as good a job, I believe,
26:01because we know now all the mistakes that we made and we know not to make them next time.
26:05But I think it's not too bad.
26:07The second stage of Vince's experiment is much more complicated.
26:11He has to create a cornered joint that fits perfectly with neighboring stones, both horizontally and vertically.
26:18In order to fit this corner right here of this stone into this seat that Hector is shaping,
26:26we have to bring this stone around and prop it up above the seat that it's intended to fill,
26:33and then put poles under it, and you'll see perhaps these Wacos or these notches in the rock,
26:40and that's what they're for.
26:42We'll put poles under the stone.
26:43We'll probably leave some stones at this end under the very tail end of the rock,
26:48and we'll be able to remove all these stones so that it's hollow underneath the stone,
26:52and that gives us a place to use the scribe.
26:56And the scribe in this case is just like the other one,
26:59but it will be used in a 45-degree orientation.
27:02It'll come down the rising face and across the base,
27:05and you see in order to get all the way across,
27:07we have to move all these stones out of the way underneath the rock.
27:11This is undoubtedly the most tricky part of this technique.
27:20Well, yeah, I was one of those people who was healthily skeptical of this whole system,
27:23but, you know, it looks dangerous, it looks hard,
27:25and with a bigger stone, I think it'd be more dangerous and more hard.
27:28I still have my doubts, but there is an outline of a method.
27:31That stone is standing there, actually, in the air above the space it's supposed to go in,
27:36propped up on those pieces of wood.
27:38Yeah.
27:42Vince believes that notches cut into the giant blocks at Saxo-Waman support his theory.
27:50But if it's a precarious operation propping up a half-ton rock,
27:54what would it be like with a 25-ton boulder?
27:57Looks very much like the surface we already have is very close to what we want.
28:07As we move it up, it comes out to three-eighths.
28:10So just offhand, it looks like maybe we have to take a little more material off here.
28:16We're now going to drop the stone into its seat and see how well we did.
28:30With Vince rapidly losing his voice, his team is about to start the most hazardous part of the operation,
28:37lowering the block into place.
28:41By tipping the stone a little bit at a time, pull out a stick here, a stick there,
28:44until the whole thing creeps into place.
28:46This seems to me inherently less stable, and I think with a huge...
28:50With a huge stone, it would be even more unstable.
28:55It's clear that Vince and company need to refine the procedure
29:12for getting the block off the stilts and into position,
29:15particularly if this method is to work with stones weighing many tons.
29:20This isn't bad.
29:39Well, we've seen that this can be done, but the question is, is this how it was done?
29:42Did the Incas actually use the scribing method to construct their stone walls to find their fine joints?
29:47I don't know. Do you think so?
29:49Well, as I said at the outset, I'm not sure we'll ever know how the Incas did it.
29:53The point of this was to try to find a way that works, and that would work with big stones.
29:57Now, in the case of the little joint we just fit here, we spent 12 days doing the rough work
30:01that any technique would involve, and one day doing the scribing.
30:05That tells me that the scribing is an efficient way to make the joint.
30:08Had we moved the rock five times and so forth, we might have spent 12 days doing the rough work
30:13and three days making the joint, a less efficient way to do it.
30:17But which way the Incas would have used, I don't know that we'll ever know.
30:21The annual Ollantitambo bullfight is in full swing, and yet another demonstration of how the Incas might have created their amazing stonework is being set up for a rather skeptical audience.
30:47How curved it is affects where its focal length is.
30:53Professor Ivan Watkins teaches geoscience at St. Cloud University in Minnesota.
30:59And now, I need my goggles, I've looked at it too much.
31:05Ivan and his wife Berta are here to test his theory that the Incas used gold parabolic mirrors to concentrate sunlight into a high temperature beam that could melt stone, or as Ivan would say, thermally disaggregated.
31:21You see that little image of the sun there?
31:25OK, now, the idea of this whole thing is to have an image of the sun from the big mirror projected across to a plane mirror, and then use another parabolic mirror to direct the light to whatever is going to be thermally disaggregated.
31:45In this case, what we would thermally disaggregate would be a rock.
31:51OK, now, you can see the bright spot that is there.
31:55If Ivan's parabolic mirrors work, they'll concentrate the sun's energy 10,000 times and melt this small piece of rock.
32:04Well, there, I knock that little piece of rock off for it.
32:07Several years ago, Ivan was touring Inca sites, and this half-finished stone at Machu Picchu attracted his attention.
32:17Certain marks on the rock struck him as a clear indication of the use of parabolic mirrors.
32:25Archaeologist Helene Silverman is not convinced.
32:29Think that's possible?
32:30I think it's ridiculous.
32:32There's absolutely no evidence that the Incas were using mirrors.
32:36And what's more, it's very clear what the technology of this is.
32:39They were chipping away at this.
32:41I agree 100% with you that this is a classic surface that's made by pecking the stone.
32:47Every one of these rocks has peck marks all over it.
32:50But could stone hammers peck out the inside right-angled joints that are so common in Inca walls?
32:58Ivan was convinced they couldn't.
33:03With no evidence of metal tools, Ivan reasoned the only alternative was a ray of amplified sunlight.
33:11Unfortunately, Ivan's prototype mirrors are not truly parabolic and failed to concentrate the sunlight effectively.
33:19I'm not getting the temperature high enough there to pop him off.
33:25The crux of Ivan's argument is that solar power concentrated through parabolic mirrors is the only way the Inca stone cutting that we've seen here on Ayante Tambo could have been done.
33:36But how about the stones that we've seen that have clear hammer marks on it?
33:40I mean, are you saying those were not...
33:41Well, no, no. I'm not at all sure when you say they have clear hammer marks.
33:45What is the difference between taking...
33:48I think I went out of this. This is ridiculous. This is really ridiculous.
33:56I need some goggles, though, because I just got blasted.
34:01I want to see this guy cut a stone like I can do, and then I talk, but otherwise that makes no damn sense.
34:09If you can find a radius of curvature again...
34:12Well, this is ridiculous.
34:14...then it is necessary that, indeed, that was not produced by hammering with a stone.
34:19All corners, inside corners in Inca masonry are rounded. There are no sharp inside corners.
34:28And JP appears to be right. There are no sharp right angle joints to be found.
34:38And even the tightest could have been created by polishing with a small hammer stone.
34:47Let's try burning this popsicle stick and watch my finger. I've only got ten.
34:52Okay, I'll try to...I'll try to not de-digitate you.
35:00It doesn't seem to be Ivan's day.
35:02Just singeing a popsicle stick is a problem for his mirrors.
35:07Oh, I can't...
35:18Here we go. There's flame. It's a flame.
35:21Definitely.
35:28Down at the arena, things are not going much better for part-time matador Philippe Petit.
35:33But even the bulls refuse to get fired up.
35:36At its height, the Inca's rugged domain extended for almost the entire 3,500-mile length of the Andes.
35:51To control their diverse empire from the capital Cusco, the Incas built a 14,000-mile network of all-weather roads.
36:06The vertigo-inducing terrain forced Inca engineers to build on steep mountainsides, sometimes carving trails right out of the living rock.
36:21Downhill, then uphill.
36:22Well, this is really the nicest part of the trail.
36:23I know these steps in the living rock are just fantastic.
36:24I'm happy.
36:25Helene Silverman has joined Ed Francomont to explore one of the most dramatic sections of the trail.
36:26Not possessing the wheel.
36:27Helene Silverman has joined Ed Francomont to explore one of the most dramatic sections of the trail.
36:33Not possessing the wheel, the Inca engineers designed the trails for foot traffic and cargo-bearing llamas.
36:40Inca relay runners stationed every day.
36:45Right out of the living rock.
36:46Downhill, then uphill.
36:47Well, this is really the nicest part of the trail.
36:48I know these steps in the living rock are just fantastic.
36:49Helene Silverman has joined Ed Francomont to explore one of the most dramatic sections of the trail.
36:54Not possessing the wheel, the Inca engineers designed the trails for foot traffic and cargo-bearing llamas.
37:01Inca relay runners stationed every few miles carried messages at a speed of 150 miles a day.
37:16The system, the road system, was so good that in 10 days a message could be transmitted from Quito in Ecuador to Cusco, the Inca capital.
37:27That's about as fast as modern-day postal service can send a letter between these two capital cities today.
37:34A number of great rivers posed the most serious obstacle to the Inca road builders.
37:46Particularly after the rainy season, when these waterways became raging torrents, impossible to ford on foot or cross by ferry.
37:55The ingenious solution to the problem?
37:59Suspension bridges that could span up to 150 feet.
38:05One of these bridges crossed the gorge above the Aparimac River, near the remote village of Huinchiri.
38:15The people here still build grass suspension bridges as their ancestors did 500 years ago.
38:22It's said these bridges can be built in just three days.
38:26Ed and Helene want to see how the community organizes itself into such an effective labor force.
38:34But one day before construction is due to start, the only sign of life near the bridge site is the harvesting of grass by Clotilda Vilkas and her family.
38:52It's sobering to realize that these dry-looking stalks will bear the weight of people crossing 60 feet above the Aparimac River.
39:06Clotilda's contribution to the community effort is to twist the grass into 50 yards of two-ply rope and deliver it tomorrow morning.
39:35As the first day of construction begins, the usually barren hills are suddenly crowded as local people start arriving at the bridge site.
40:01Villagers responsible for producing rope deliver their 50-yard quota.
40:08In total, the bridge will require over 7,000 yards of half-inch-thick Koya grass rope.
40:19Before construction begins, spiritual matters must be attended to.
40:28Chief bridge builder Victoriano Arisapanam is making an offering to Pachamama, Mother Earth, to ensure her blessing on the enterprise.
40:38This ritual requires the consumption of large amounts of alcohol by the village leaders.
40:50Well, these people are every bit a part of the engineering as the bridge folks are.
40:54What they're doing is making the bridge strong and safe and last.
40:58And their job is to sit here and construct the payments that we make to the earth and make sure that these cables go across and are completely strong.
41:07High-wire walker Philippe Petit cannot resist entertaining the crowd.
41:17With his lifelong passion for knots, rigging and cables, he's thrilled to be part of the effort.
41:22Attendance at the bridge site is carefully noted. By midday, almost 500 people have turned up.
41:43The rope is divided up into sections, each containing 24 strands, 150 feet long.
42:06The ropes are twisted together tightly and evenly.
42:12The flimsy-looking strands that were delivered in the morning are suddenly transformed into something substantial enough to entrust one's life to.
42:32They are stranding the three main ropes into the final rope, into one of the final rope.
42:37So they have to keep the regularity of the braiding, and they have also to be very careful about the torsion.
42:42Sometimes they yell, noodle, the nut, because something is twisted not too much, so it creates a...
42:47It creates, you see? When you take a rope like this, and you go like that.
42:52You see? It creates nuts, you see? So you have to take it out.
43:01Oh, it's beautiful, because its family did one little piece.
43:04Its community brought their own rope. Those ropes, which are like your little finger, are threaded into a bigger one,
43:10and then into those big ones, and then into those big ones, and now three of those big ones.
43:13It's really communion.
43:17By the end of the first day, these load-carrying cables are delivered to the bridge site.
43:29Each cable weighs about 200 pounds.
43:34It's hard, heavy labor, but enthusiasm never wanes.
43:39Bridge-building is as much a party as it is work, and probably always has been.
43:44The bridge builders are farmers living in homesteads, scattered all over the high Puna grassland.
44:01They are well adapted to working at altitudes of 14,000 feet and more,
44:06having long ago developed large-capacity lungs and short, strong legs for climbing steep mountainsides.
44:14Like her ancestors in Inca times, Clotilda is very self-sufficient.
44:26She makes clothes for the family, and barters for the food that she doesn't grow herself.
44:36Today, Ed has asked her to prepare a special Inca dish, guinea pig.
44:42I think I have problems because we keep them as pets in the United States.
44:50Well, it's not a dog.
44:51I know.
44:53No, and I know the whole history of guinea pigs.
44:55There you go.
44:56They're very important.
44:57That's right.
44:58These are what you've been digging up for.
44:59I know.
45:00I've got caches of them.
45:03They're succulent.
45:04Mm-hmm.
45:06Don't you like the guacatay?
45:10Potatoes also came from the land of the Incas, but they've caught on better in the rest of the world than guinea pigs.
45:17They eat well, because the hard work on the bridge is about to begin.
45:30The next morning starts with tossing a rope across the river.
45:33This will be used to pull the main cables over the gorge.
45:43Nova has asked that the bridge cables be strong enough to carry at least five people and two llamas,
45:50the kind of load it might have supported in Inca times.
45:52On either side of the chasm, there are stone abutments that were constructed by the Incas.
46:03They were built into the side of the mountain in order to support the weight of the bridge.
46:12The cables are wound around stone beams anchored into the floor of the abutments,
46:17and they will eventually be securely tied off.
46:28But first, the cables must be tightened inch by inch to get rid of any slack.
46:37Pulling the six cables taut takes the rest of day two.
46:41If all goes well, the bridge will be ready to cross in 24 hours.
46:48The morning of the third and final day finds the riggers swinging in the wind 60 feet above the Apurimak River.
47:14It is not a vision that inspires confidence, but Helene puts on a brave face.
47:23I feel a lot better about crossing this bridge now than I did before I saw it being built.
47:29And I think that it's structurally sound.
47:32I can even see that as the people are building the bridge,
47:36they're already walking out over it before it's even finished.
47:38Philippe, who has never felt more in his element, has been helping the riggers all morning.
47:56Okay, well this bridge, I should say this piece of art, is now near completion.
48:05They are tying the foot ropes together, and they are doing the connection between the hand rail and the foot.
48:12And it's done very fast.
48:13It's done very fast.
48:14So maestros, artistas.
48:16A me me gusta mucho trabajar con las cuerdas.
48:20Si.
48:21Yes.
48:22Yeah.
48:28Okay.
48:29Pablo, Javier.
48:59With the bridge complete, a roll call is taken to confirm who gets paid.
49:14The Incas were great record keepers, too.
49:18It's been said that if even a pair of sandals were missing from their inventory, they would
49:23know.
49:24But how did they handle such information without writing or arithmetic?
49:28Well, the Incas never had a written system, but it wasn't anywhere near as much of a disadvantage
49:33as you might think.
49:35Because they were able to store really abstract and complicated information using textiles
49:40as a medium.
49:41Right here, what I'm making is a small Inca textile, a kipu, a series of knots which keeps
49:46records on events that happened.
49:48In this case, I'm talking about how many people it took to build the bridge, how much it costs,
49:52the records we might keep.
49:54This is a read-only document.
49:56After it's all done, what I'm going to be able to do is put on the finished records of what's
50:01going on here.
50:02It's not a counting device like an abacus that counts as you go.
50:06Here I've recorded how many people there were from the community of Winchiri who showed up
50:11to work for those six days.
50:13And here is how much we paid all their workers, and over here is how much we paid the authorities
50:18and the bridge master who did the bridge for us.
50:21We want to get back records years from now on how this bridge was made, how long it took,
50:26how many people it took, and what it cost.
50:28We'll be able to code them and keep them forever in a knot of string like this.
50:32Now the workers are taking a rest, and I am alone on that bridge, and I feel like a kid
50:37who is being given a giant gift.
50:40And I start enjoying myself as a wire walker, as I can feel the balance a bit, you see, here.
50:47So I don't know if I can even walk like this, but...
50:56With an Inca bridge, all the load is carried by the four cables which make up the footpath.
51:02The hand ropes are only for balance.
51:08Helene is warned that leaning on them too heavily could cause the bridge to flip over.
51:13I want to look down, but I'm afraid to look down, so I'm looking at everybody across.
51:19I know I can do this.
51:22I think I'm going to be sick.
51:24No, I'm not.
51:28The llamas are even more reluctant to cross the bridge than Helene.
51:34Well, this bridge is certainly tremendous.
51:40It's an amazing example of how the Incas were able to accomplish tremendous amounts of work
51:45in a short period of time, billowing all over the Andes.
51:52In terms of labor organization, I feel as though I've been transported back 500 years to the
51:57Inca times.
51:58I can just imagine the native leaders doing the census saying, okay, guys, ladies, you
52:03make the rope.
52:04Men, you lay out the strands.
52:05We are going to build the bridge.
52:07This is your labor tax.
52:13The Incas were the largest empire of the pre-industrial world and certainly the richest.
52:19They had a control over this land, this wonderful and severe land of the Andes that nobody could
52:25ever imagine.
52:26How they accomplished all these things, we're just beginning to ask the right questions.
52:48Now, log on to another lost empire, ancient Egypt.
52:52At NOVA's website, navigate the tunnels, tombs, and temples of the pharaohs and follow a real-time
52:58excavation at Giza.
53:01Experience Pyramids, the inside story, a NOVA PBS online adventure.
53:18To order NOVA's Secrets of Lost Empires mini-series on videocassette, call 1-800-255-9424.
53:36This five-hour set is $69.95 plus shipping and handling.
53:41Individual programs are also available for $19.95 each.
53:48Next time on NOVA, journey to Egypt for the classic struggle of Mason vs. Stone, obelisk
53:54on Secrets of Lost Empires.
54:09NOVA is a production of WGBH Boston.
Comentarios