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Narrator: historically, wheels
Were made of metal or wood.
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With the invention
Of air filled car tires
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00:00:58,689 --> 00:01:00,965
In the early part
Of the 20th century,
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00:01:00,965 --> 00:01:03,517
The ride was revolutionized.
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00:01:03,517 --> 00:01:04,931
The inflated rubber tires
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00:01:04,931 --> 00:01:07,275
Could better absorb
The bumps on the road
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00:01:07,275 --> 00:01:08,689
And the addition of tread
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00:01:08,689 --> 00:01:11,827
Gave the invention
Serious traction.
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00:01:14,551 --> 00:01:18,137
Car tires have come a long way
In the last century.
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00:01:18,137 --> 00:01:20,310
The modern summer tire
Is made of
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10 to 15 different components,
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00:01:22,517 --> 00:01:25,793
Which include
Natural and synthetic rubber,
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00:01:25,793 --> 00:01:29,517
Chemical additives,
And carbon black -- a pigment.
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00:01:29,517 --> 00:01:31,931
Giant blenders
Mix these ingredients
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00:01:31,931 --> 00:01:34,310
Under heat
And tremendous pressure.
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There are various formulations
For different parts of the tire.
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00:01:38,172 --> 00:01:41,517
In each case, the result is
Gummy rubber dough,
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Which machinery
Then rolls into sheets
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00:01:44,482 --> 00:01:47,620
To await further kneading
And processing.
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00:01:47,620 --> 00:01:51,965
Polyester fabric unrolls into
A machine called a calender.
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00:01:51,965 --> 00:01:54,344
The calender
Is equipped with rollers
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That apply warm rubber
To both sides of the fabric.
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00:01:57,482 --> 00:02:00,068
This produces
A rubberized fabric
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00:02:00,068 --> 00:02:03,172
That will be used
To reinforce the tire.
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00:02:03,172 --> 00:02:06,068
This fabric ply is needed
Because rubber alone
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00:02:06,068 --> 00:02:09,482
Isn't sturdy enough
To make a tire.
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00:02:09,482 --> 00:02:14,034
Numerous cotton cords now
Spin off bobbins simultaneously.
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00:02:14,034 --> 00:02:17,655
Machinery pulls them onto
The warm, rubberized fabric.
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00:02:17,655 --> 00:02:20,586
They land on a bit of an angle
And adhere.
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00:02:22,448 --> 00:02:25,862
This cording creates channels
That provide pathways
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00:02:25,862 --> 00:02:30,379
For venting air
During the actual tire building.
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00:02:30,379 --> 00:02:32,344
Making rubber for tread requires
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00:02:32,344 --> 00:02:34,758
Three different
Rubber formulations.
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00:02:34,758 --> 00:02:37,965
Extruders shape
The three streams of rubber
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00:02:37,965 --> 00:02:41,655
And then they enter a die
That forms them into one.
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00:02:41,655 --> 00:02:44,724
Mini paint rollers apply
Different colored stripes.
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00:02:44,724 --> 00:02:46,896
It's a coding system
For identification
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00:02:46,896 --> 00:02:49,862
Of the ingredients
During processing.
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00:02:49,862 --> 00:02:54,344
To avoid tension, the system
Creates slack in the feed.
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00:02:54,344 --> 00:02:56,827
A blade slices the tread rubber
To length.
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00:02:56,827 --> 00:03:01,275
Next, many steel cables uncoil
At once to make the bead --
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00:03:01,275 --> 00:03:03,655
The part of the tire that gives
It the strength it needs
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To stay on the wheel rim.
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00:03:07,034 --> 00:03:10,586
Machinery arranges the cables
In the desired configuration
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00:03:10,586 --> 00:03:13,172
And encases them in rubber.
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00:03:13,172 --> 00:03:16,172
More equipment rolls
The bead material into hoops
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00:03:16,172 --> 00:03:18,000
Sized to fit the wheel rim.
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00:03:22,517 --> 00:03:24,655
They're now
Ready to build the tire.
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00:03:24,655 --> 00:03:27,034
Using a special rotating drum,
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00:03:27,034 --> 00:03:30,482
A worker arranges
The two bead hoops on it.
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00:03:30,482 --> 00:03:33,241
Next up is
An airtight piece of rubber
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00:03:33,241 --> 00:03:37,655
That will act as an inner tube
Followed by the corded ply.
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00:03:37,655 --> 00:03:40,448
Inflated bladders
Roll the rubber around the bead
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00:03:40,448 --> 00:03:43,896
On both sides and then retract.
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00:03:43,896 --> 00:03:48,517
A server
Applies side walls to the beads.
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00:03:48,517 --> 00:03:52,379
Little rollers fold
The side walls over the beads.
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00:03:52,379 --> 00:03:56,620
This completes the inner part,
Or skeleton, of the tire.
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00:03:56,620 --> 00:03:59,379
They assemble
The outer layer separately
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00:03:59,379 --> 00:04:03,344
Beginning with strips of rubber
Embedded with steel cord.
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00:04:03,344 --> 00:04:05,724
The system wraps this rubber
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00:04:05,724 --> 00:04:08,862
Around a second
Tire-building drum.
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00:04:08,862 --> 00:04:11,689
Next up
Are narrow strips of rubber ply.
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00:04:11,689 --> 00:04:14,172
The computerized system
Winds them
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00:04:14,172 --> 00:04:18,206
With just the right amount of
Tension for a graduated effect.
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00:04:18,206 --> 00:04:20,448
They're now ready for
The last layer --
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The tread rubber.
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Machinery applies it to the ply.
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00:04:25,103 --> 00:04:29,758
It's time for the two
Tire fabrications to become one.
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00:04:29,758 --> 00:04:32,655
A transfer ring
Collects the assembly
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00:04:32,655 --> 00:04:35,413
And transfers it
To the inner part.
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00:04:35,413 --> 00:04:38,275
Compressed air inflates the tire
To shape it
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00:04:38,275 --> 00:04:41,827
And all the sticky layers
Adhere together.
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00:04:44,310 --> 00:04:47,620
The machine rolls
The edge of the tread rubber
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00:04:47,620 --> 00:04:49,206
Over the side walls.
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00:04:49,206 --> 00:04:53,103
They now have what's known in
The industry as a green tire --
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An uncured tire
Without tread pattern.
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Next, it's into a mold
To bake and shape the tire.
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The two parts of the mold come
Together like a waffle iron.
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Inside, hot steamy bladders
Expand to shape the tire
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00:05:11,034 --> 00:05:13,758
And transfer the tread pattern
To it.
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00:05:13,758 --> 00:05:18,310
This specific tread pattern
Is designed for summer tires.
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This cutout of a car tire
Demonstrates
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How all the layers
Have been fused together.
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00:05:24,517 --> 00:05:26,862
The time
In the hot, pressurized mold
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Has caused the
Rubber to vulcanize --
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00:05:29,172 --> 00:05:31,482
A chemical reaction
That transforms it
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From a weak and sticky substance
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To one that's
Strong and elastic.
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A worker trims excess rubber.
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00:05:38,689 --> 00:05:40,655
After final inspections confirm
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The tire shape is uniform
And geometrically correct,
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The tire is ready for shipment.
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It's time for the rubber
To hit the road.
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00:06:01,275 --> 00:06:03,689
Narrator:
Silk fabric originated in china
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At least 5,000 years ago
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And became a coveted luxury.
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00:06:07,689 --> 00:06:10,379
Silk thread
Is produced by silkworms
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00:06:10,379 --> 00:06:11,827
When they make their cocoons.
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Sericulture,
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00:06:13,448 --> 00:06:16,275
Or commercially breeding
Silkworms for silk production,
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Is practiced
In several asian countries.
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00:06:23,172 --> 00:06:26,310
From home goods
To accessories and clothing,
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There are few textiles
As elegant and luxurious,
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00:06:29,724 --> 00:06:33,034
Or as prized
Throughout the ages, as silk.
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It's hard to believe
This beautiful fabric
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00:06:34,931 --> 00:06:37,655
Comes from worms.
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00:06:37,655 --> 00:06:41,448
The female silkworm
Lays up to 400 eggs in one shot
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00:06:41,448 --> 00:06:43,344
Then promptly dies.
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00:06:43,344 --> 00:06:47,068
Each egg, about two weeks later,
Hatches into a larva.
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00:06:47,068 --> 00:06:50,103
The larva feeds on fresh
Mulberry leaves continuously,
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Increasing its body weight
10,000 fold
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And growing to a length
Of about three inches.
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00:06:56,586 --> 00:07:00,103
Then, as it enters the
Pupa phase of its life cycle,
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It excretes liquid raw silk
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00:07:02,000 --> 00:07:04,827
From salivary glands
In its mouth.
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00:07:04,827 --> 00:07:07,620
When that liquid silk
Contacts with the air,
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It hardens into a single thread.
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00:07:10,655 --> 00:07:14,172
Pupating larva
Winds that thread around itself
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00:07:14,172 --> 00:07:17,586
Into a thick, cozy cocoon.
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00:07:17,586 --> 00:07:20,931
Normally,
The pupa inside becomes a moth
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00:07:20,931 --> 00:07:23,448
And the cocoon
Breaks as it emerges.
122
00:07:23,448 --> 00:07:26,655
However, this severs
The continuous silk thread.
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00:07:26,655 --> 00:07:28,379
So to keep the thread intact,
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00:07:28,379 --> 00:07:31,103
They boil the cocoon
For about three minutes
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00:07:31,103 --> 00:07:32,931
To kill the pupa inside
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00:07:32,931 --> 00:07:35,655
Before it
Transforms into a moth.
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00:07:37,655 --> 00:07:40,034
Boiling the cocoons also
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00:07:40,034 --> 00:07:42,655
Makes the wound thread
Easier to unravel
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00:07:42,655 --> 00:07:45,172
By melting away
Most of the sericin --
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00:07:45,172 --> 00:07:48,137
The gelatinous protein
That binds it.
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00:07:48,137 --> 00:07:50,620
To harvest the silk,
They take threads
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00:07:50,620 --> 00:07:53,206
From 30 to 50 cocoons at a time.
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They feed them all together
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00:07:54,758 --> 00:07:56,758
Through a hole
In the bamboo stick
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00:07:56,758 --> 00:07:59,103
Onto a hand-operated reel.
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00:07:59,103 --> 00:08:02,379
Then, slowly and carefully,
They turn the reel,
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00:08:02,379 --> 00:08:06,448
Unraveling the cocoons.
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00:08:06,448 --> 00:08:09,172
As the thread passes together
Through the stick,
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00:08:09,172 --> 00:08:11,965
The remaining sericin
Glues them together
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00:08:11,965 --> 00:08:15,034
Forming a single,
Thicker thread.
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00:08:17,310 --> 00:08:20,586
The silk threads coming together
Are so fine --
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00:08:20,586 --> 00:08:24,275
Only about one one-hundredth
Of a millimeter in diameter --
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00:08:24,275 --> 00:08:26,862
That it takes
2,000 to 3,000 cocoons
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00:08:26,862 --> 00:08:29,724
To produce
A pound of silk thread.
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00:08:32,482 --> 00:08:35,724
Unraveling cocoons
Is a time-consuming process,
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00:08:35,724 --> 00:08:38,034
Because a single thread
Can be as long as
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Nine professional soccer fields.
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00:08:41,517 --> 00:08:45,103
To make this feather-like
Silk thread easier to handle,
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00:08:45,103 --> 00:08:48,862
They weigh it down with sand
Before rolling it into a bundle.
150
00:08:53,965 --> 00:08:57,862
Next, they wash away
The sand and remaining sericin,
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00:08:57,862 --> 00:09:01,655
Then bleach the thread
So it will uniformly absorb
152
00:09:01,655 --> 00:09:05,103
The synthetic dye.
153
00:09:05,103 --> 00:09:09,137
It's critical to monitor
The ratio of dye to hot water,
154
00:09:09,137 --> 00:09:12,241
As well as water temperature
And soaking time,
155
00:09:12,241 --> 00:09:16,241
As all these factors combined
Effect the quality of the color.
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00:09:16,241 --> 00:09:20,931
After rinsing away the
Excess dye with lukewarm water,
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00:09:20,931 --> 00:09:23,379
They hang the thread to dry.
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00:09:29,413 --> 00:09:32,344
They mount the bundles
Of dry, dyed silk thread
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00:09:32,344 --> 00:09:33,482
On a big machine,
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00:09:33,482 --> 00:09:36,000
Which transfers them
To smaller rollers.
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00:09:42,344 --> 00:09:46,000
Those rollers then
Go on an automated machine,
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00:09:46,000 --> 00:09:49,482
Which transfers the thread
To small bobbins.
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00:09:49,482 --> 00:09:50,896
To craft silk fabric,
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00:09:50,896 --> 00:09:53,896
Weavers will pass
Bobbins of thread horizontally
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Between vertical threads
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00:09:55,655 --> 00:09:58,586
On a traditional,
Hand-operated loom.
167
00:09:58,586 --> 00:10:02,586
Another machine, meanwhile,
Winds thread around spools.
168
00:10:02,586 --> 00:10:05,551
A worker then installs
A set number of spool threads
169
00:10:05,551 --> 00:10:06,689
On a mechanism,
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00:10:06,689 --> 00:10:08,827
Which aligns them vertically
On the loom
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00:10:08,827 --> 00:10:11,034
Parallel to each other.
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00:10:11,034 --> 00:10:13,793
Fabric that's
About three feet wide
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00:10:13,793 --> 00:10:16,931
Typically requires
4,000 vertical threads.
174
00:10:16,931 --> 00:10:19,310
By stepping on
The loom's foot pedal,
175
00:10:19,310 --> 00:10:22,724
The weaver repeatedly raises
Every second vertical thread,
176
00:10:22,724 --> 00:10:25,620
And with a tug of a cord,
Passes a shuttle
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00:10:25,620 --> 00:10:29,689
Containing a bobbin of thread
Horizontally in between.
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00:10:29,689 --> 00:10:32,896
This intertwining of
Horizontal and vertical threads
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00:10:32,896 --> 00:10:35,137
Weaves the silk fabric.
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00:10:35,137 --> 00:10:38,448
To create a pattern, the weaver
Uses multiple shuttles
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00:10:38,448 --> 00:10:41,551
Containing threads of different
Colors, thicknesses,
182
00:10:41,551 --> 00:10:43,758
And textures.
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00:10:43,758 --> 00:10:47,103
Some patters, such as an
Intricate weave called brocade,
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00:10:47,103 --> 00:10:50,620
Are so intricate that even
The most experienced weavers
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00:10:50,620 --> 00:10:55,275
Produce just two to six inches
Of fabric per day.
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00:10:55,275 --> 00:10:58,241
Now, that's wearable art.
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Narrator:
A centuries-old painting
Is actually
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00:11:11,206 --> 00:11:14,241
Easier to restore
Than a decades-old painting.
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00:11:14,241 --> 00:11:17,965
For hundreds of years,
Artists used pure oil paints,
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00:11:17,965 --> 00:11:19,551
But by the 20th century,
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00:11:19,551 --> 00:11:22,448
Artists began using
Different types of paint,
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00:11:22,448 --> 00:11:25,793
Making restoration
More challenging.
193
00:11:30,068 --> 00:11:33,379
A traditional painting
Is typically oil on canvas,
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00:11:33,379 --> 00:11:36,482
Protected with a layer
Of natural resin varnish.
195
00:11:36,482 --> 00:11:40,137
Over time, a linen canvas
Can become brittle,
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00:11:40,137 --> 00:11:42,413
Distort, and sometimes tear.
197
00:11:42,413 --> 00:11:46,275
Varnish yellows
And dirt and dust accumulate,
198
00:11:46,275 --> 00:11:49,620
Rendering the once-vibrant
Painting dark and dull
199
00:11:49,620 --> 00:11:52,448
And in dire need of
Professional conservation.
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00:11:52,448 --> 00:11:56,241
The conservation process
Is multi-faceted.
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00:11:56,241 --> 00:11:59,724
They have to strip away
Any previous restoration,
202
00:11:59,724 --> 00:12:01,965
Then perform a new restoration,
203
00:12:01,965 --> 00:12:07,000
Yet make it entirely reversible
To allow for future restoration.
204
00:12:07,000 --> 00:12:09,344
The conservators
Begin with spot tests
205
00:12:09,344 --> 00:12:12,103
To observe how
Different colors in the painting
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00:12:12,103 --> 00:12:14,241
React to cleaning.
207
00:12:14,241 --> 00:12:16,241
They dip a cotton swap
In mild detergent
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00:12:16,241 --> 00:12:17,724
And rub gently,
209
00:12:17,724 --> 00:12:19,689
Testing for discolored varnish
210
00:12:19,689 --> 00:12:22,275
And any previous restoration.
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00:12:22,275 --> 00:12:25,482
When all that's done,
They swab on some solvent
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00:12:25,482 --> 00:12:28,068
To neutralize
The detergent residue.
213
00:12:28,068 --> 00:12:31,586
Next, they spray the back
Of the canvas with water
214
00:12:31,586 --> 00:12:34,275
And lie the painting
On a vacuum hot table.
215
00:12:34,275 --> 00:12:36,896
The heat
Turns the moisture to steam,
216
00:12:36,896 --> 00:12:39,172
Which relaxes
The paint and linen
217
00:12:39,172 --> 00:12:43,000
As the vacuum pulls
The bumps and puckers flat.
218
00:12:43,000 --> 00:12:45,724
If the canvas
Isn't structurally sound,
219
00:12:45,724 --> 00:12:48,000
They apply adhesive,
A synthetic backing,
220
00:12:48,000 --> 00:12:50,655
Then a new linen canvas.
221
00:12:50,655 --> 00:12:53,068
With thermometers
Monitoring the temperature,
222
00:12:53,068 --> 00:12:55,137
The heat activates the adhesive
223
00:12:55,137 --> 00:12:58,896
And the vacuum draws everything
Taut against the hot table,
224
00:12:58,896 --> 00:13:01,482
Bonding old linen to new.
225
00:13:01,482 --> 00:13:06,068
And the conservators can turn
Their attention to the artwork.
226
00:13:06,068 --> 00:13:08,965
They begin by
Mixing a cleaning solution --
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00:13:08,965 --> 00:13:11,689
1% chemical-grade ammonia,
228
00:13:11,689 --> 00:13:14,896
20% strong detergent,
229
00:13:14,896 --> 00:13:17,241
And 79% water.
230
00:13:27,241 --> 00:13:31,448
They dip a swab
In the cleaning solution
231
00:13:31,448 --> 00:13:35,793
And another in the solvent.
232
00:13:35,793 --> 00:13:38,586
Working a small area at a time,
233
00:13:38,586 --> 00:13:41,000
They gently glide
The cleaning-solution swab
234
00:13:41,000 --> 00:13:42,655
Over the surface.
235
00:13:42,655 --> 00:13:44,689
It's critical not to rub,
236
00:13:44,689 --> 00:13:48,103
As any abrasion
Could harm the painting.
237
00:13:48,103 --> 00:13:52,000
Next, they gently roll the
Solvent swab over the same area
238
00:13:52,000 --> 00:13:56,103
To neutralize
The cleaning-solution residue.
239
00:13:56,103 --> 00:13:59,620
They repeat the solution-solvent
Procedure area by area
240
00:13:59,620 --> 00:14:03,206
Until they've removed surface
Dirt from the entire painting.
241
00:14:03,206 --> 00:14:06,413
Then they start all over again,
242
00:14:06,413 --> 00:14:09,724
This time removing
Old, yellowed varnish,
243
00:14:09,724 --> 00:14:13,344
Embedded dirt,
And previous restoration.
244
00:14:13,344 --> 00:14:15,448
The cleaning completed,
245
00:14:15,448 --> 00:14:19,000
They can now address
The tears and damages.
246
00:14:19,000 --> 00:14:20,862
Using a small pallet knife,
247
00:14:20,862 --> 00:14:23,689
They fill the cavities
Of the tear with gesso,
248
00:14:23,689 --> 00:14:26,965
Material that's used
As a background for paintings.
249
00:14:26,965 --> 00:14:28,655
This gesso is reversible,
250
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Meaning it can
Easily be removed, if required,
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00:14:31,724 --> 00:14:35,034
During a future restoration.
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00:14:35,034 --> 00:14:36,793
Once the gesso dries,
253
00:14:36,793 --> 00:14:39,517
They wipe away the excess
With a damp cloth,
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00:14:39,517 --> 00:14:43,034
Leaving a repair that's flush
With the surrounding surface.
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00:14:44,689 --> 00:14:47,137
Then they
Seal the gesso with varnish.
256
00:14:47,137 --> 00:14:50,310
This creates a barrier
Between the existing paint layer
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00:14:50,310 --> 00:14:52,379
And the one
They're about to add,
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00:14:52,379 --> 00:14:56,827
Making it removable
For future restoration.
259
00:14:56,827 --> 00:14:59,344
They retouch the repaired area,
260
00:14:59,344 --> 00:15:02,620
Expertly
Matching colors to the original
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00:15:02,620 --> 00:15:07,275
And blending them seamlessly
With the surrounding area.
262
00:15:07,275 --> 00:15:09,586
This process, called inpainting,
263
00:15:09,586 --> 00:15:11,965
Is where the conservators'
Fine-art training
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00:15:11,965 --> 00:15:13,965
Is put to the test.
265
00:15:19,931 --> 00:15:22,034
Rather than use oil paints,
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00:15:22,034 --> 00:15:25,103
They mix pigments
With acrylic resin.
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00:15:25,103 --> 00:15:28,137
This produces paint
That looks just like oils
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00:15:28,137 --> 00:15:30,344
But is removable
With mild solvents
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00:15:30,344 --> 00:15:32,620
In the event of
A future restoration.
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00:15:37,517 --> 00:15:40,793
They brush varnish
Over the inpainting
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00:15:40,793 --> 00:15:43,793
So that the sheen matches
That of the surrounding area.
272
00:15:46,206 --> 00:15:48,551
And now, the final step.
273
00:15:48,551 --> 00:15:50,344
They spray the entire painting
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00:15:50,344 --> 00:15:53,586
With a light coat of
Removable synthetic varnish that
275
00:15:53,586 --> 00:15:55,758
Doesn't yellow over time.
276
00:15:55,758 --> 00:15:59,103
This evens out
And protects the surface.
277
00:15:59,103 --> 00:16:01,068
Once the varnish cures,
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00:16:01,068 --> 00:16:03,862
The painting
Goes back into its frame,
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00:16:03,862 --> 00:16:06,931
Just the way
The artist intended.
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00:16:16,827 --> 00:16:20,137
Narrator: underwater exploration
Was a shallow experience
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00:16:20,137 --> 00:16:21,965
Until scuba tanks were developed
282
00:16:21,965 --> 00:16:24,103
In the middle of
The 20th century.
283
00:16:24,103 --> 00:16:25,758
Filled with compressed air
284
00:16:25,758 --> 00:16:28,241
And attached to
A breathing regulator,
285
00:16:28,241 --> 00:16:31,413
Scuba tanks enable divers
To stay underwater longer.
286
00:16:31,413 --> 00:16:35,068
This invention took diving
To a whole new level.
287
00:16:38,827 --> 00:16:42,000
Scuba tanks are a way to
Bottle the air we breathe
288
00:16:42,000 --> 00:16:44,551
And take it with us underwater.
289
00:16:44,551 --> 00:16:46,724
To make aluminum scuba tanks,
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00:16:46,724 --> 00:16:51,551
They start with solid,
Cylindrical chunks called slugs.
291
00:16:51,551 --> 00:16:53,275
The aluminum-alloy slugs
292
00:16:53,275 --> 00:16:56,517
Tumble around
In a perforated, rotating drum,
293
00:16:56,517 --> 00:17:00,103
Which takes them through
A series of chemical baths.
294
00:17:00,103 --> 00:17:03,068
The baths clean and treat
The surface of the aluminum
295
00:17:03,068 --> 00:17:07,000
To prepare the slugs
For forming.
296
00:17:07,000 --> 00:17:10,931
The operator loads
The slugs into a feeder system
297
00:17:10,931 --> 00:17:13,275
That serves them up
One at a time
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00:17:13,275 --> 00:17:15,931
To a hydraulic extrusion press.
299
00:17:17,931 --> 00:17:20,275
An extrusion piston
Forces the slug
300
00:17:20,275 --> 00:17:23,344
Into a die inside the press.
301
00:17:23,344 --> 00:17:26,103
It hollows
And stretches the slug
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00:17:26,103 --> 00:17:29,517
Into the shape of a scuba tank.
303
00:17:29,517 --> 00:17:32,206
It takes
About 1,300 tons of force
304
00:17:32,206 --> 00:17:35,620
To transform
A solid, short chunk of aluminum
305
00:17:35,620 --> 00:17:38,620
Into a longer, hollow cylinder.
306
00:17:40,724 --> 00:17:44,000
The shaping process itself
Generates heat,
307
00:17:44,000 --> 00:17:47,620
Making the aluminum
Softer and more malleable.
308
00:17:47,620 --> 00:17:50,931
The press establishes
The outer diameter of the tank,
309
00:17:50,931 --> 00:17:53,689
The inner one, and the base.
310
00:17:53,689 --> 00:17:57,448
The process
Takes just 20 seconds.
311
00:17:57,448 --> 00:18:00,068
The freshly formed cylinder
Now spins
312
00:18:00,068 --> 00:18:03,275
As a roller applies a lubricant
To the open end.
313
00:18:05,103 --> 00:18:09,172
The machine ejects the cylinder.
314
00:18:09,172 --> 00:18:14,103
Then it's over to
The hydraulic neck press.
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00:18:14,103 --> 00:18:16,517
This press
Forces the opening of the tank
316
00:18:16,517 --> 00:18:19,931
Into a die
To narrow it substantially.
317
00:18:21,827 --> 00:18:26,103
This establishes the basic shape
Of the scuba-tank neck.
318
00:18:26,103 --> 00:18:28,103
It still needs more work,
319
00:18:28,103 --> 00:18:31,586
But first, the tank shape
Must be firmed up.
320
00:18:33,793 --> 00:18:38,241
They heat treat and then quench
The scuba tanks in cool water.
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00:18:38,241 --> 00:18:42,344
The shock of the rapid cooling
Hardens the aluminum.
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00:18:44,896 --> 00:18:46,793
Back to the neck now.
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00:18:46,793 --> 00:18:52,413
A spinning, computerized cutter
Shortens it.
324
00:18:52,413 --> 00:18:55,896
Then, another cutter moves in.
325
00:18:55,896 --> 00:18:58,482
Filings fly
As it carves excess metal
326
00:18:58,482 --> 00:19:01,551
From the outside
Of the scuba-tank neck.
327
00:19:08,931 --> 00:19:11,758
A computerized drill
Widens the neck hole
328
00:19:11,758 --> 00:19:14,931
And cuts a pocket
For an o ring seal.
329
00:19:20,068 --> 00:19:21,793
The next tool carves a thread
330
00:19:21,793 --> 00:19:24,620
Into the inside wall
Of the neck.
331
00:19:26,413 --> 00:19:29,310
The threaded profile
Will allow for connections
332
00:19:29,310 --> 00:19:33,620
To an air-fill-up valve
And to a breathing regulator.
333
00:19:38,827 --> 00:19:41,551
Every scuba tank
Undergoes a test
334
00:19:41,551 --> 00:19:44,793
To measure tank expansion
Under pressure.
335
00:19:44,793 --> 00:19:47,068
They fill each scuba tank
With water
336
00:19:47,068 --> 00:19:51,448
And place it in a test jacket
That's also filled with water.
337
00:19:51,448 --> 00:19:54,724
Testing equipment increases
The pressure in the scuba tank,
338
00:19:54,724 --> 00:19:59,034
And the tank expands, placing
Water from the test jacket.
339
00:19:59,034 --> 00:20:02,137
By measuring
The displaced water,
340
00:20:02,137 --> 00:20:05,241
They determine
The rate of tank expansion,
341
00:20:05,241 --> 00:20:08,379
And if it's acceptable,
The tank moves on.
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00:20:11,655 --> 00:20:15,275
A scuba tank now
Spins against a sanding belt.
343
00:20:15,275 --> 00:20:18,620
This sanding gives the exterior
A brushed finish,
344
00:20:18,620 --> 00:20:21,137
Which some divers prefer.
345
00:20:24,862 --> 00:20:27,172
They etch the serial number
And other information
346
00:20:27,172 --> 00:20:29,689
Onto the upper part of the tank.
347
00:20:32,724 --> 00:20:35,689
For a more colorful look,
The factory applies
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00:20:35,689 --> 00:20:40,862
A vibrant, translucent powder
Coat to the brushed finish.
349
00:20:40,862 --> 00:20:43,310
The finish is purely aesthetic.
350
00:20:43,310 --> 00:20:44,724
Aluminum doesn't rust,
351
00:20:44,724 --> 00:20:48,034
So a natural finish would
Weather underwater conditions
352
00:20:48,034 --> 00:20:50,448
As well as the powder coat.
353
00:20:53,689 --> 00:20:57,655
They bake on the powder coat,
Giving the tanks a glossy look.
354
00:21:01,827 --> 00:21:06,620
These aluminum scuba tanks are
Now ready to take the pressure.
355
00:21:06,620 --> 00:21:08,379
Life is sure to be
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00:21:08,379 --> 00:21:11,724
One underwater adventure
After another.
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00:21:11,724 --> 00:21:14,724
--captions by vitac--
Www.Vitac.Com
358
00:21:14,724 --> 00:21:17,689
Captions paid for by
Discovery communications
359
00:21:22,482 --> 00:21:24,793
If you have any comments
About the show,
360
00:21:24,793 --> 00:21:27,655
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361
00:21:27,655 --> 00:21:29,724
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