How It's Made (2001–…): Season 3, Episode 5 - Horse-drawn Carriages/Artificial Eyes/Dog Food and Cat Food/Mirrors - full transcript

Narrator:
TODAY ON "HOW IT'S MADE"...

...HORSE-DRAWN CARRIAGES...

...ARTIFICIAL EYES...

...DOG AND CAT FOOD...

...AND MIRRORS.

NOTHING TAKES YOU
BACK TO THE PAST

QUITE LIKE A RIDE
IN A HORSE-DRAWN CARRIAGE,

A TIMELESS VEHICLE IN BOTH
APPEARANCE AND CONSTRUCTION.

BUILDING ONE TODAY
STILL REQUIRES THE EXPERTISE

OF SEVERAL
TRADITIONAL CRAFTSPEOPLE,

FROM IRONWORKERS
TO WHEELWRIGHTS.



THE CARRIAGE'S TURNING MECHANISM
IS A FIFTH WHEEL

THAT IS POSITIONED HORIZONTALLY
ABOVE THE TWO FRONT WHEELS.

WORKERS WELD THE FIFTH WHEEL
TO THE CARRIAGE'S STEEL FRAME

THEN WELD THE BOARDING STEPS
TO THE FRAME.

UNTIL NOW THE FRAME
HAS BEEN POSITIONED UPSIDE DOWN.

NOW THEY TURN IT RIGHT SIDE UP
TO INSTALL THE DRIVER'S SEAT.

FIRST THEY MEASURE CAREFULLY

TO ENSURE
IT'S PERFECTLY CENTERED.

THEN THEY WELD IT IN PLACE.

ONCE THE FRAME IS COMPLETE,

IT GOES THROUGH AN ACID WASH
TO REMOVE ANY RESIDUE.

THEN THEY BUFF THE WELDED JOINTS
TO SMOOTH OUT THEIR SURFACE.

THE CARRIAGE HAS DRUM BRAKES.

WORKERS INSTALL THEM
ONTO THE AXLE



THEN ASSEMBLE THE STEEL SPRINGS
THAT MAKE UP THE SUSPENSION

AND BOLT THEM ONTO THE AXLE
AS WELL.

NEXT, THEY CONNECT
THE BRAKE LINE.

THEN THEY INSTALL
THE WHOLE ASSEMBLY

UNDER THE CARRIAGE'S FRAME.

LIKE IN THE OLDEN DAYS,

THEY MAKE THE WHEELS
OUT OF WOOD.

METAL ISN'T FLEXIBLE ENOUGH
TO WITHSTAND BUMPS IN THE ROAD.

THEY USE ASH

BECAUSE IT'S A VERY HARD WOOD
THAT DOESN'T ROT EASILY.

WORKERS POSITION 16 SPOKES
AROUND A STEEL HUB.

THEY CLAMP THE SPOKES IN PLACE,

COMPRESSING THEM
AGAINST THE HUB.

THEN THEY SECURE THEM
WITH NUTS AND BOLTS.

NEXT, THEY MARK THE SPOKES
IN TWO PLACES.

THE FIRST LINE SHOWS
HOW LONG TO CUT EACH SPOKE,

THE SECOND LINE
HOW FAR TO DOWEL THE END.

TO FORM THE DOWEL,

THEY FIRST SHAPE THE END
INTO A CONE.

THEN THE CONE INTO A DOWEL.

THOSE DOWELED SPOKES WILL FIT
INTO CORRESPONDING HOLES

THEY NOW DRILL INTO TWO
SEMICIRCULAR STRIPS OF WOOD.

THE STRIPS FORM
WHAT'S CALLED THE FELLOW,

THE ROUND PART OF THE WHEEL.

WORKERS TIGHTEN THE HUB

THEN PRESS A STEEL BAND CALLED
A CHANNEL AGAINST THE FELLOW.

THEY CUT THE CHANNEL TO SIZE.

THEN WELD THE ENDS TOGETHER.

FINALLY,
THEY BUFF THE JOINT SMOOTH.

NEXT, THEY DRILL EIGHT HOLES
THROUGH THE CHANNEL

THEN, USING A TAPERING TOOL,

THREAD THE HOLES
TO FIT THE BOLTS

THAT BIND THE CHANNEL
TO THE FELLOW.

FINALLY, THEY TIGHTEN THE BOLTS
WITH A SPECIAL GUN.

THE TIRES ARE MADE OF RUBBER.

THEY CONTAIN TWO STEEL WIRES

TO HOLD THEM IN PLACE
OVER THE WHEEL.

WORKERS GREASE THE CHANNEL
OF THE NOW-PAINTED WHEEL

SO THAT THE TIRE
WILL SLIP ON EASILY.

THEN THEY MOUNT THE WHEEL

ON THE AUTOMATED
TIRE-INSTALLATION MACHINE,

WHICH PULLS ON THE WIRES,

INSTALLING THE TIRE
TIGHTLY OVER THE WHEEL.

THEY SOLDER THE WIRE ENDS
TOGETHER

USING BRONZE SOLDER
FOR A STRONGER JOINT.

THEN -- HERE COMES
THE HIGH-TECH PART --

THEY BANG THE WHEEL ON
THE GROUND FOUR OR FIVE TIMES

UNTIL THE DISTANCE
BETWEEN THE TIRE ENDS CLOSES,

COVERING THE SOLDERED WIRES
INSIDE.

A TAP OF THE HAMMER
FOLLOWED BY A FINAL BANG

ENSURES THE TIRE JOINT
IS SECURE.

NOW THEY CAN MOUNT THE WHEELS
ONTO THE AXLES

AND INSTALL THE AXLES
UNDER THE BODY OF THE CARRIAGE.

AFTER TESTING THE FIFTH WHEEL
AND THE BRAKES...

...IT'S TIME TO APPLY
THE FINISHING ARTISTIC TOUCHES.

ALL THEY NEED NOW
IS A LITTLE HORSEPOWER.

Narrator:
THE ANCIENT ROMANS AND EGYPTIANS

FASHIONED ARTIFICIAL EYES
OUT OF PAINTED CLAY.

BY THE 1500s,

EUROPEANS STARTED MAKING THEM
OUT OF ENAMELED GOLD

AND SOON OUT OF GLASS,

WHICH REMAINED THE NORM
FOR HUNDREDS OF YEARS.

TODAY MOST ARTIFICIAL EYES
ARE MADE OF ACRYLIC.

IF YOU'VE LOST AN EYE
IN AN ACCIDENT OR TO A DISEASE,

A SPECIALIST
KNOWN AS AN OCULARIST

CAN FIT YOU
WITH AN ARTIFICIAL EYE.

YOU CAN GET A READY-MADE MODEL
OR A CUSTOM-MADE PROSTHESIS,

LIKE THE ONE FOR WHICH
THIS PATIENT IS BEING FITTED.

NO TWO PEOPLE'S EYE SOCKETS
ARE THE SAME,

SO THE FIRST STEP
IS TO TAKE AN IMPRESSION.

AFTER INSERTING
AN IMPRESSION TRAY,

THEY INJECT A MATERIAL
CALLED ALGINATE,

FILLING THE ENTIRE
SOCKET CAVITY.

AFTER 90 SECONDS,
THE ALGINATE SETS,

AND THEY CAN REMOVE
THE HARDENED IMPRESSION.

THEY PLACE THE IMPRESSION
IN A MOLD.

AND POUR IN A TYPE OF PLASTER.

WHEN THE PLASTER HAS HARDENED,

THEY REMOVE THE IMPRESSION TRAY
AND THEN THE IMPRESSION ITSELF.

WHAT'S LEFT IN THE MOLD IS
A PLASTER REPLICA OF THE SOCKET.

NOW THEY PUT A WAD OF ACRYLIC
PLASTIC DOUGH INTO THE MOLD...

...LOCK THE MOLD INTO A PRESS,

AND SUBMERGE IT
IN A HIGH-PRESSURE CURING UNIT

FOR 25 MINUTES.

THEN THEY COOL THE MOLD
IN COLD WATER.

HERE'S THE ORIGINAL IMPRESSION

COMPARED TO THE ACRYLIC MODEL
THEY'VE JUST CAST.

THIS MODEL IS CALLED
THE FITTING SHAPE

BECAUSE THEY USE IT

TO FIT AND MARK THE POSITIONING
OF THE FAKE IRIS.

THEY ACCENTUATE THE MARKINGS,

THEN ATTACH A PEG
WITH A DROP OF WAX.

THE PEG INDICATES
THE NATURAL ANGLE OF THE IRIS

WHEN THE PATIENT
IS LOOKING FORWARD.

NEXT, THEY ADD WAX
AROUND THE PERIMETER

TO ENLARGE THE FITTING SHAPE.

THIS EXCESS
WILL GIVE THE OCULARIST

SOME ROOM TO WORK WITH
FOR THE FINAL SIZING.

NOW THEY TAKE THIS MARKED
AND ENLARGED FITTING SHAPE

AND MAKE A PLASTER MOLD.

THEY WILL LATER USE THAT MOLD

TO CAST
THE ACTUAL ARTIFICIAL EYE.

BUT FIRST THEY HAVE TO MAKE
THE IRIS.

THEY TAKE A CURVED,
BLACK ACRYLIC DISC

AND PAINT IT
AS REALISTICALLY AS POSSIBLE

WITH HIGH-QUALITY ARTIST OILS.

THE PATIENT HAS TO BE PRESENT
SO THEY CAN MATCH THE REAL EYE.

NEXT, THEY GLUE
AN ACRYLIC CORNEA

WITH AN APPROPRIATE-SIZED PUPIL
ONTO THE PAINTED IRIS.

AT THIS POINT,

THE ARTIFICIAL IRIS
IS HALF AN INCH IN DIAMETER.

IF THE PATIENT'S REAL IRIS
IS SMALLER,

THEY TRIM DOWN THE REPLICA
TO MATCH.

THE IRIS THEN GOES
INTO THE PLASTER MOLD

COVERED WITH
WHITE ACRYLIC DOUGH.

AFTER THE SAME HIGH-PRESSURE
CURING PROCESS AS BEFORE,

OUT COMES THE ARTIFICIAL EYE

COVERED WITH
EXCESS WHITE ACRYLIC.

THEY TRIM OFF THAT EXCESS
AND THE PEG

USING A GRINDING TOOL
AND A CUTTER.

THIS REFINES THE SHAPE

AND EXPOSES THE IRIS
BURIED UNDERNEATH.

THEY SMOOTH THE SURFACE
AGAINST A GRINDING STONE

AND VERIFY THE MEASUREMENTS.

THEN,
USING HARD COLORING PENCILS,

THEY ADD FINISHING TOUCHES
TO THE IRIS

AND DRAW BLOOD VESSELS.

THEY LABEL THE EYE
WITH THE PATIENT'S INITIALS

AND THEN APPLY
AN ACRYLIC COATING

TO SEAL THE PENCIL MARKS.

TO CREATE VEINS
WITH SOME DIMENSION,

THEY USE
THE SAME ACRYLIC COATING

TO STICK ON
SOME DELICATE SILK THREADS.

ONCE THEY'RE SATISFIED

THE ARTIFICIAL EYE
IS A PERFECT MATCH,

THEY SEAL THE ARTWORK
WITH ANOTHER ACRYLIC COATING.

ONCE THAT CURES,

THEY POLISH THE EYE TO A SHINE
WITH A COTTON WHEEL.

THE SHAPES AND COLORS
OF ARTIFICIAL EYES ARE ENDLESS

BECAUSE PATIENTS' EYE SOCKETS
AND IRISES VARY GREATLY,

AS DO THEIR SCLERAS,
THE WHITE OF THE EYE.

THIS ARTIFICIAL EYE,
OR OCULAR PROSTHESIS, IS READY.

THE FINAL STEP IS TO ENSURE
THAT THE FIT IS PERFECT.

THE PATIENT'S OCULAR MUSCLES
ATTACH TO THE IMPLANT,

ENABLING HIS ARTIFICIAL EYE

TO MOVE IN UNISON
WITH HIS REAL EYE.

Narrator: SO MUCH FOR FEEDING
FIDO SCRAPS FROM THE TABLE.

TODAY'S PET FOOD

IS THE STUFF OF SOPHISTICATED
NUTRITIONAL SCIENCE.

IT'S ABOUT PROTEIN,
CARBOHYDRATES,

VITAMINS, MINERALS --
A WELL-BALANCED DIET.

WANT TO BET SOME DOGS AND CATS
EAT HEALTHIER THAN THEIR OWNERS?

THE FORMULAS
FOR DOG AND CAT FOOD DIFFER

BECAUSE DOGS AND CATS

HAVE DIFFERENT
NUTRITIONAL REQUIREMENTS.

CATS, FOR INSTANCE,

NEED MORE FAT AND PROTEIN
IN THEIR DIET THAN DOGS DO.

BUT THE BASIC INGREDIENTS
THAT FACTORIES GRIND UP

TO MAKE DOG AND CAT FOOD
ARE SIMILAR.

FIRST, CORN KERNELS.

THEN CEREALS, SUCH AS BARLEY...

WHEAT...

AND RICE.

WORKERS WEIGH THE INGREDIENTS,
GRIND THEM IN A MILL,

THEN COMBINE EVERYTHING
IN A MIXER

UNTIL THEY HAVE AN EVEN
AND WELL-BLENDED POWDER.

A MACHINE CALLED THE EXTRUDER
TRANSFORMS THAT POWDER

INTO BITE-SIZED PIECES
OF PET FOOD.

IT STEAM-COATS THE MIXTURE,

THEN FORCES IT THROUGH DIES
AT HIGH PRESSURE.

THE DIES SHAPE IT,
THE WAY THE TIP OF A PASTRY BAG

SHAPES ICING INTO SWIRLS
OR ROSES.

CHECK OUT THIS DOG-BONE DIE.

AS THE CONTINUOUS STREAM
OF SHAPED MIXTURE EXITS THE DIE,

A SPINNING KNIFE
CUTS IT INTO PIECES.

THE COMPANY HAS DIFFERENT DIES
TO PRODUCE DIFFERENT SHAPES.

THIS IS A BATCH OF ROUND PIECES.

NEXT STOP, A HOT-AIR DRYER
FOR 25 MINUTES.

IT HEATS THE PIECES
TO 300 DEGREES FAHRENHEIT

TO DRAW OUT THE MOISTURE,

THEN COOLS THEM
AT ROOM TEMPERATURE.

ONCE THE PIECES EXIT THE DRYER,
THEY ENTER A REVOLVING DRUM,

WHERE THEY'RE SPRAYED WITH FAT
AND FLAVORING.

THE FAT IS DESIGNED
TO ADD FOOD ENERGY

WHILE THE FLAVORING
GIVES THE BLAND PIECES

AN APPETIZING ODOR AND TASTE --

APPETIZING FOR PETS, THAT IS.

THE ROTATION ENSURES THE PIECES
GET COATED EVENLY.

FROM HERE, THE PIECES GO
INTO STORAGE SILOS.

WHEN THEY LEAVE THE SILOS
FOR BAGGING,

THE MACHINERY SCREENS OUT
ANY CRUMBS.

THE PET-FOOD INDUSTRY HAS MADE
SOME INTERESTING OBSERVATIONS

ABOUT THE LIKES AND DISLIKES
OF ITS FOUR-LEGGED CLIENTELE.

APPARENTLY, CATS AND DOGS
AREN'T CRAZY ABOUT FOOD

THAT'S TOO DRY,
TOO HARD TO CHEW, OR TOO MUSHY.

IF THE PIECES ARE TOO SMALL,
THEY'LL SWALLOW THEM WHOLE

WITHOUT CHEWING
AND NOT DIGEST THEM PROPERLY.

BUT IF THE PIECES ARE TOO BIG,

THEY'LL GAG AND GET TURNED OFF
TO THE FOOD ALTOGETHER.

IN THE PACKAGING DEPARTMENT,

AUTOMATED SCALES WEIGH
THE EXACT QUANTITY PER PACKAGE.

THIS BATCH IS DESTINED FOR BAGS
WEIGHING ABOUT 6 1/2 POUNDS.

THE PACKAGE SIZES RANGE
FROM JUST UNDER ONE POUND

ALL THE WAY UP TO 44 POUNDS.

SHELF LIFE IS FROM 12
TO 16 MONTHS,

DEPENDING ON THE FORMULA.

PET-FOOD EXPERTS SAY

DOGS AND CATS PREFER FOOD
WITH A FATTIER CONTENT

AND A COMBINED
MEAT-AND-CEREAL FORMULA

OVER JUST CEREAL ALONE,

BUT TOO MUCH MEAT FLAVORING
CAN TURN THEM OFF.

CATS, AS A RULE,
ARE MORE PARTICULAR.

THEY FAVOR MORE ACIDIC FOOD,

WHILE DOGS TEND TO HAVE
A SWEETER TOOTH.

AND YOU THOUGHT KIDS
WERE FUSSY EATERS.

Narrator: NO BATHROOM
IS COMPLETE WITHOUT ONE.

AND ANY PARENT WILL TELL YOU

THAT NO TEENAGER
CAN SURVIVE WITHOUT ONE.

MIRROR, MIRROR ON THE WALL,
HOW DO THEY MAKE YOU, AFTER ALL?

WELL, "HOW IT'S MADE"
IS ABOUT TO SHOW YOU.

BUT FIRST, LET'S REFLECT
ON THE HISTORY OF MIRRORS.

THE EARLIEST MIRRORS WERE CURVED
PIECES OF HIGHLY POLISHED METAL,

SUCH AS BRASS OR BRONZE.

THEY'RE EVEN MENTIONED
IN THE BIBLE.

THEN, IN THE 14th CENTURY,

THE VENETIANS INVENTED
VERY CRUDE GLASS MIRRORS

THAT REFLECTED OFF
A METALLIC BACKING.

THEY LATER PERFECTED
THIS TECHNIQUE

USING AN AMALGAM
OF TIN AND MERCURY.

EVENTUALLY, THE SECRET
OF MIRROR-MAKING SPREAD

TO OTHER CITIES.

BY 1835,
A GERMAN CHEMIST DEVELOPED

THE SILVER-BACKED MIRROR
THAT WE KNOW TODAY.

A MIRROR STARTS OUT
AS CLEAR GLASS.

A ROBOT LAYS EACH PANEL
HORIZONTALLY ON A CONVEYOR BELT,

WHICH TRANSPORTS IT
TO THE WASHING STATION.

THERE, SPRAYERS BLAST THE GLASS
WITH WATER AND CERIUM OXIDE,

A POWDER DERIVED
FROM A TYPE OF SOIL.

ROTATING BRUSHES SCRUB
AND POLISH

BOTH THE TOP
AND BOTTOM SURFACES,

REMOVING OILS
AND OTHER CONTAMINANTS.

THIS WASHING PROCESS TAKES
ABOUT A MINUTE PER PANEL.

NEXT, SPRAYERS RINSE THE GLASS

WITH PIPING-HOT
DEMINERALIZED WATER,

DEMINERALIZED BECAUSE
THE MINERALS IN PLAIN TAP WATER

WOULD DAMAGE THE METALS
THEY APPLY NEXT.

THE FIRST METAL
IS LIQUEFIED TIN,

WHICH GOES ON WHAT WILL BE
THE BACK OF THE MIRROR.

IT ALLOWS THE SECOND METAL,
SILVER, TO ADHERE

BECAUSE SILVER WON'T STICK
DIRECTLY TO GLASS.

THE SILVER
IS ALSO IN LIQUID FORM

MIXED WITH A CHEMICAL ACTIVATOR.

WITHIN SECONDS OF INTERACTING
WITH THE TIN, IT HARDENS.

AND AS IT DOES,
YOU BEGIN TO SEE A REFLECTION.

IT'S THIS SILVER BACKING

THAT TRANSFORMS CLEAR GLASS
INTO A MIRROR.

SPRAYERS RINSE OFF
THE EXCESS SILVER,

WHICH GETS RECYCLED
BACK INTO THE SYSTEM.

THE FACTORY WILL SEAL THE SILVER
BACKING WITH TWO COATS OF PAINT.

PAINT BY ITSELF, HOWEVER,

ISN'T ENOUGH TO PROTECT
THE SILVER IN THE LONG TERM.

SO THEY FIRST SPRAY ON
A LAYER OF COPPER.

SPRAYERS RINSE OFF
THE EXCESS COPPER.

THEN THE PANEL PASSES THROUGH
A DRYER

AT ALMOST 160 DEGREES
FAHRENHEIT.

THIS EVAPORATES THE MOISTURE
ON THE SURFACE

IN JUST 75 SECONDS.

NOW THE PANEL PASSES,
COPPER SIDE UP,

THROUGH WHAT IS CALLED
THE CURTAIN COATER,

A MACHINE THAT RUNS
A CONTINUOUS CURTAIN OF PAINT

ACROSS THE CONVEYOR BELT.

WITH ITS FRESH COAT OF PAINT,

THE MIRROR THEN PASSES THROUGH
AN OVEN

HEATED TO 210 DEGREES
FAHRENHEIT.

AFTER A MINUTE AND 45 SECONDS,
THE PAINT IS CURED.

NOW THE SECOND COAT OF PAINT.

THERE'S NO REASON
FOR THE DIFFERENT COLOR

OTHER THAN TO DIFFERENTIATE
THE COATS.

THIS TIME, THE CURING PERIOD
IS TWICE AS LONG

AND AT A HIGHER TEMPERATURE,
CLOSE TO 245 DEGREES FAHRENHEIT.

AFTER AN ACID WASH TO REMOVE
ANY METAL RESIDUES,

THEY STAND THE PANEL UPRIGHT
TO INSPECT IT.

IF THEY FIND A FAULT,
SUCH AS A BUBBLE IN THE GLASS,

THEY CUT THAT PORTION OUT.

THE FACTORY NOW CUTS
THESE LARGE PANELS

INTO WHATEVER SIZE AND SHAPE
THE CUSTOMER HAS ORDERED

USING A SPECIAL
MIRROR-CUTTING MACHINE

THAT'S PRECISION-GUIDED
BY COMPUTER SOFTWARE.

IT SCORES THE MIRROR
USING A CARBIDE WHEEL.

CARBIDE IS A STRONG METAL.

TO MAKE ROUND MIRRORS,

THE MACHINE FIRST SCORES
THE PANEL INTO SQUARES.

THEN, IN EACH SQUARE,
IT SCORES A CIRCLE.

USING SPECIAL TOOLS,

WORKERS SEPARATE THE SQUARES,
THEN THE CIRCLES.

TO MAKE BEVELED MIRRORS,

THEY USE WHAT'S CALLED
THE SHAPE-BEVEL MACHINE.

FIRST, IT CARVES OUT THE EDGE.

THEN POLISHES IT TO A SHINE
USING CONCENTRATED CERIUM OXIDE,

A STRONGER VERSION
OF WHAT THEY USED EARLIER

TO CLEAN THE GLASS SURFACE
BEFORE PLATING IT WITH METALS.

MIRROR FACTORIES
ALSO SHIP WHOLE PANELS

TO SHOPS THAT DO THE CUTTING
THEMSELVES,

A FRAGILE FEAT THAT'S CERTAINLY
NOT FOR THE SUPERSTITIOUS.

CAPTIONS PAID FOR BY
DISCOVERY COMMUNICATIONS, INC.

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