Paper Umbrellas Coal Aircraft Seats Cremation Urns
Paper umbrellas originated in china and eventually spread throughout asia. Initially, their purpose was solely practical-- to protect against rain and to provide shade from the scorching sun. But before long, they took on symbolic significance and were incorporated into many ceremonies and rituals. They're called oil paper umbrellas because the paper is coated with oil or, like these, with oil paint, making the umbrella waterproof. At this workshop in northern thailand, they cut a bamboo log to the length of the umbrella's radius, then shave off the bark. They split the log into strips of equal thickness, then group these ribs, as they're called, into bundles of 28. Each bundle will become the frame of one umbrella. Next, they thin out the bottom half of each rib and cut a slit in the top half. Then, using a traditional drill, they bore tiny holes at specific points. Taking one bundle at a time, they string the ribs together through the uppermost hole and insert them into slots of a hand-carved wooden hub. Then they tighten and tie off the string to retain the ribs in position and provide a pivot on which the ribs can move up and down. Next, they attach the scaffold, a smaller hub with shorter ribs strung on it. They insert a scaffold rib into the slit of each frame rib, then attach them by threading a string through the aligned holes. The result? Raising and lowering the scaffold moves its ribs along the slit-- pushing the frame ribs up to open the umbrella, or pulling them down to close it. With the umbrella open now, they thread more string through holes in the frame ribs and loop it into a spider-web-type pattern. This produces a sturdy base to support the umbrella's paper skin. After mounting the frame on a wood and bamboo umbrella handle, they wrap two lines of string along the frame perimeter. This will support the paper skin at the edge of the umbrella. They make the paper from the bark of the native saa tree. The first step is to soften the bark by soaking it in water for about 12 hours, then boiling it for another three or four. Next, they mash it with wooden mallets for about an hour, turning it into pulp. They bleach the pulp and wash it again to remove the bleach. Only then is the pulp ready to become paper. They dump the pulp in a large basin of water and stir so that it floats in suspension while they move a plastic screen through the water, catching enough floating pulp to coat the screen in a thin layer. They lay the screen out in the sun for three to four hours until the layer of pulp dries into a thin, fragile sheet of paper. They cut the sheets to the shapes required, then saturate each piece with glue made from cassava, a tropical root vegetable. After applying a circular piece around the hub, they glue pie-shaped pieces onto the rest of the frame. Once they cover the entire frame, they repeat the process to add a second layer. They fold all the pie-shaped pieces over the end to thicken and, thereby, reinforce the edge of the umbrella. After about four hours out in the sun, the glue dries, bonding the now stiff and strengthened paper securely to the frame. They apply three coats of oil paint, allowing four hours of drying time between coats. This is a key step because aside from providing the background color, the oil paint waterproofs the paper. Next, they varnish the handle to make it moisture-resistant. And now for the grand finale-- an artist paints a design in vibrant waterproof oils. The themes are traditional-- flowers, animals, landscapes, people. No stencils to trace or patterns to follow-- the artist works entirely freehand, the result being that no two umbrellas are ever exactly alike. Each oil paper umbrella is a portable work of art. Pretty yet practical, rain or shine. The most-used fuel for producing electricity in the world today is coal. Power plants burn it in their furnaces to heat water into steam that spins giant turbines which generate electricity. At least 40% of the world's electricity is produced by coal-fired power plants. Coal developed from prehistoric vegetation that wound up buried underground due to geological changes. Over millions of years, these decayed plants transformed into combustible rock. This is why we refer to coal as a fossil fuel. Coal runs in seams through other rock layers. Miners drill holes through the seam at several locations, then mix together ammonium nitrate and diesel and pour a precise quantity of this liquid explosive into each bored hole. The plug the holes with dirt to contain the upcoming explosion. This directs the force of the blast sideways so that it'll fracture rock as much horizontally as vertically. They place a blasting cap in each plugged hole, then connect all the blasting cap wires to detonation lines through which they'll send an electrical charge to ignite the explosives. They install detonation delays to time the blast one after another because successive explosions have greater impact than simultaneous ones. The blast dislodge and break up the layers of rock between the surface and the coal seam deep below. Workers clear away the rocks and dirt with a mammoth machine called a dragline. Removing the blasted rock and dirt exposes the coal, which is still a solid, hard seam. The side of the mine pit shows how much rock is on top of this particular coal seam. Once miners blast and clear away that rock, they drill and load the holes to set off more explosives to fracture the coal seam itself. Then front-end loaders load the coal into specialized trucks called coal haulers. In one trip, a coal hauler can transport about 220 tons of coal out of the pit to the coal stockpile. From there, railcars transport the coal to the nearby power plant. When this company prepares to mine an area, it removes the topsoil on which vegetation grows. As part of a land reclamation program, the company stockpiles the topsoil until it finishes mining out the coal. Then it refills the pit with rock and dirt it blasted away, returns the topsoil, and plants native vegetation. The power plant is situated by a man-made lake, the water source for the steam with which it generates electricity. When the coal arrives, crushers grind it up into baseball-sized pieces. After a strategic blending of different grades of coal, to optimize heat output, the coal travels by a conveyor belt to indoor silos. Each silo feeds crushers, which pulverize the coal into powder. Now the coal is ready to fuel the furnace. Meanwhile, huge intake pumps draw lake water. The furnace heats the water to 1,000° fahrenheit, well beyond the boiling point, transforming it into high-pressure steam. The steam then enters and rotates turbines, generating electricity. By the time the steam exits the turbines, it's thermally depleted down to just 120° fahrenheit and depressurized to a vacuum state. It then passes through a condenser containing cold lake water. The water absorbs the remaining heat, converting the steam back to water, which is then recycled into new steam. The combustion process itself creates sulfur dioxide. The plant runs this gas waste through vessels containing a lime solution to neutralize the sulfur. This chemical reaction creates water vapor, which exits the plant's stack. Wires coming off the turbine generators carry the electricity to outdoor transformers. The outdoor transformers convert it to higher voltage in order to have less energy loss, as the power from coal travels through transmission lines to some 350,000 households. When you're traveling by air, you want to be sitting in a comfortable seat. Private aircraft take comfort to a level far above that of commercial airlines with seats that are as cozy and luxurious as fine furniture. They must also be lightweight and fire-resistant. On private and corporate aircraft, it's all about luxury seating. Armchairs often swivel and, at the push of a button, recline with an extending footrest. The cushions are constructed from layers of fireproof foam containing carbon fiber for optimum support and durability. Workers cut the cushion pieces using a band saw with a round blade that slices through foam without tearing or shredding it. They spray adjoining surfaces with water-based contact cement and assemble them. The assembly combines different thicknesses and three different densities to make the cushion soft in certain areas and rigid in others. The densities are color-coded. After letting the glue dry for 12 hours, workers begin the final shaping. This is the seat-cushion assembly. They first saw through it laterally to make the right thickness. Then they temporarily adhere a plastic template of the final cushion shape, trace it, then saw along the trace line. Next, using the technical drawing as a guide, they mark, then grind the cushion's rounded profile. Holding the next layer of foam over the edge, they verify the shape with another template. Then with yet another template, they mark lines for the cushion's creases and, with a foam saw, cut them two inches deep, just enough to insert velcro strips, the backsides of which they glue to the foam with water-based contact cement. Workers construct the backrest cushion just like the seat cushion-- assembling foam pieces of different thicknesses and densities, shaping the perimeter, grinding the edge profile, cutting and velcroing creases. Then they apply a final layer of soft foam, 1/2 inch thick, folding the edges onto the velcro inside the creases. They do the same with the seat cushion, armrests, and footrest. All the foam cushions are now ready to be covered in genuine leather. In accordance with safety regulations, the supplier rendered the leather fireproof by treating it with a calcium-based solution. Seamstresses trace patterns for the cover pieces, then cut them out. They line the perimeter of each piece with double-faced tape... Fold over the edges to create a neat hem... And trim the corners flat. Then they sew on velcro strips where required. Finally, they assemble the pieces into covers, sewing an identification label on each one. They hammer every seam flat to prevent bulges. Then they sew what's called a french stitch, a line of straight stitches on either side of each seam. Meanwhile, workers glue fireproof polyester batting to the foam. This layer between foam and leather will even out the surface. They tear the perimeter of the batting to thin it out. Finally, it's time to dress the cushions in their covers. Workers use a metal rod to help push the leather deep into the creases without bunching up. Velcro strips on the cover adhere to the velcro strips inside the creases. The covers also have velcro closures, and certain cushions have velcro strips on the bottom which attach to the seat structure. Once all the covers are on, workers can complete the seat assembly. They attach the armrest to the structure with screws, then install the footrest, which attaches with velcro. It contains a cavity for storing the life vest. The seat cushion also attaches with velcro. The passenger seats and pilot seat are constructed the same way, except for the pilot seat often has a sheepskin insert on the sitting surface to absorb sweat and keep the pilot cool and comfortable. It was the ancient romans who first began using cremation urns. Today the custom continues. The remains are stored in urns permanently or sometimes temporarily before burial. And with cremation, one's final resting place doesn't have to be six feet under. The cremation urn has an important place in some households. It's a constant reminder of the dearly departed, helping to keep the memories alive. The urn starts with a concept. The potter draws a large-scale design, which he'll use as a reference as he shapes a prototype urn from clay. He slaps a lump of clay onto the potter's wheel. The wheel spins, and the potter begins to transform the shapeless lump into the desired form. The process is called throwing, a potter's term for shaping. He leaves the bottom open so the walls can be more easily formed into the desired shape. He'll add a base to the urn later. As he pulls up the clay to produce the walls, he works it to a uniformed thickness. He gathers top to narrow the opening, a technique known as collaring. Then with the potter's wheel at a stop, he takes the shape from round to rectangular and tapers it at the neck. Then it's into a casting box, which exposes only half of the urn prototype. He brushes a release agent onto that half. Using a mixer, he whips up a mix of plaster and water. He blends it until it thickens to the consistency of pancake batter. The liquefied plaster will harden in minutes, so he quickly pours it into the box with the urn prototype and fills it right to the top. As the plaster hardens, the exposed urn prototype makes an impression of half the urn. He'll make another one exactly like it for the other half of the urn. He'll attach them with a key system. For this, he drills notches in one mold half. The notches match up with raised areas on the other mold half to align them. He ties the molds together with suspender-like straps, cinching them tightly together. He adds a base to the urn and straps it to the other two pieces. He sets the assembled mold upright, exposing the opening of the urn. He's now ready to make a copy of the original urn. In fact, he'll make 20 at once using 20 identical plaster molds. He pumps liquid clay into each one, filling it to the brim. Over three to four hours, the plaster absorbs water in the clay it comes into contact with, causing it to solidify. The clay in the center remains liquid. He pours that into a barrel to be strained and reused. And now the big reveal-- he opens the mold and removes the urn. It's exactly like the prototype sculpted by the potter. He lifts a lid from another plaster mold and checks the fit to the urn. After drying and an initial firing to harden the clay, a worker coats the urn and lid with a glaze, working from the inside out. The glaze is a mixture of finely milled minerals and water. It adds color and a glass-like nonporous surface when fired a second time. Cremation urns come in a range of styles and colors. Customers often make a selection that reflects the taste of the deceased. Another worker now brushes a mixture of wax and alumina onto the neck of the urn and lid. This will keep them from fusing together during the final firing. They fire the cremation urns at a very intense 2,200° fahrenheit for about 15 hours. This transforms the clay into a durable ceramic. They cool the urns slowly for 13 hours to prevent cracking. Four days in the making, these urns are now ready to contain a loved one's remains and, in so doing, honor a life.