Friday, 1 June 2012

Elephant No. 243: Carved Brick

I found a fist-sized fragment of old brick on the road a couple of days ago, and thought it might make an interesting elephant. Victorian brick like this is relatively soft and porous, so I think it might carve well. Then again, I could be wrong.

The oldest bricks ever found were discovered at Tell Aswad in Syria. Made of shaped mud, the bricks are thought to have been made sometime before 7500 B.C. Bricks found at Jericho and Çatal Höyük are almost as old, as are bricks discovered in the Indus Valley.

The Jetawana Stupa at Isura Ranatunga, Sri Lanka is the
largest brick structure in the world.

The first ceramic bricks were made in the Indus Valley around 4500 B.C., and the first sun-dried bricks were produced in Ur, Mesopotamia around 4000 B.C. Many other ancient civilizations used sun-dried or fired bricks, including the Romans. Roman legions actually operated mobile kilns, thereby introducing fired bricks to many parts of their extended empire. Interestingly, Roman bricks are often stamped with the mark of the legion supervising their production.

Roman brick stamped with the mark of the Tenth Legion.

During the twelfth century A.D., bricks from northwestern Italy arrived in northern Germany, which developed its own brickmaking tradition. A whole Gothic style of brickwork developed in northern Europe as a result, especially in areas without significant amounts of rock with which to construct large buildings.

By the Renaissance and the Baroque periods in Europe, visible brickwork had become unfashionable. As a result, it was often covered with plaster, and it wasn't until the middle of the eighteenth century that visible brick regained its popularity.

Long-distance transportation of large quantities of brick was rare before the advent of canals and reliable roads. Bricks were thus made close to where they were to be used. During the eighteenth century, transporting a cartload of bricks even 16 kilometres (10 miles) could more than double their price.

Today, brick is rarely used as a structural material, particularly for any building over three storeys. Brickwork is more often a form of cladding over buildings made primarily of wood or, in the case of skyscrapers, concrete and steel.

Brickmakers in many parts of the world used more or less the same process for millennia. First they mixed clay and water, driving oxen over the mixture to blend it into a thick paste. The paste was placed in wooden frames, levelled with wire, then left to dry. The bricks were then removed from the frames and stamped.

Brickmakers also loaded the kilns with wood or coal, stacked the bricks in the kiln, and removed the bricks while they were still hot. Kilnmasters were responsible for ensuring that the temperature inside the kiln stayed at a temperature that caused the clay to "shimmer with the colour of molten gold or silver." They also had to know when the kiln should be quenched with water to produce a hard surface glaze.

Although bricks can be made of materials such as slate, concrete, and even shaped stone, the most common type of brick is still a clay-based ceramic. Today's clay bricks are normally 50–60% sand, 20–30% clay, 2–5% lime, 5–6% iron oxide, and a trace amount of magnesium. They are made in one of three ways: soft mud, dry press, or extrusion. 

Soft mud is the most common method, because it is the least expensive. To make the mud, raw clay is mixed with sand to reduce shrinkage, followed by materials such as lime, ash and organic matter to speed firing. The raw materials are ground and mixed with water to the desired consistency, and pressed into steel moulds with a hydraulic press. The shaped clay is then fired at 900–1000˚C (1650–1830˚F). In most modern soft-mud brickworks, the kiln is either a tunnel or trench, through which the bricks move on a conveyor belt. This helps to ensure uniform firing for all bricks. 

Dry-pressed bricks are produced in a similar way to mud bricks, but start with a much thicker clay mix, allowing more accurate, sharper-edged bricks. Because it requires greater force to press the bricks, and longer firing times, this method is more expensive than soft mud.

Extruded bricks are made from a clay mixture that is forced through a die to create a long cable of material in the desired shape. A wall of wires then cuts the clay cable into bricks of the correct length. Most modern structural bricks are made this way, because it produces hard, dense bricks. The die can also incorporate holes and other perforations. Holes reduce the amount of clay required, thus reducing costs. These bricks are dried using waste heat from the kiln for 20–40 hours before being fired at high temperatures.  

Typical modern extruded brick with holes.

The colour of clay bricks is influenced by the chemical and mineral content of the raw materials, as well as the firing temperature and the atmosphere in the kiln. Red-toned bricks have high iron content, whereas white or yellow bricks have a higher lime content. Red bricks will change colour as the temperature increases, going from dark red to purple to brown or even grey. Bricks often have names as well—such as "Yellow London Stocks" and "Cambridgeshire Whites"—depending on where they were made and/or their colour.

For today's elephant, I guess this fragment of brick is an "Orange Victorian". No idea where it was made, but there are a lot of brick buildings in my neighbourhood, so it probably fell off something that was being renovated.

There were all kinds of crushed bits lying around it on the street, so I figured it would be relatively easy to carve. I've never carved brick before, so I tried a stone file on it first. It was so soft that it was almost like carving plaster.

For tools, I used a rotary tool with pointed bit, and a set of files.

I started by lightly carving the areas where I thought I saw an elephant outline. I used the rotary tool for most of this—for most of the entire elephant, in fact—although I used a file on some of the edges to smooth things out. At this point, it looked a lot like a dolphin.

I continued in much the same way for a bit, carving away more material under the trunk and between the ear and head. I also began adding a few wrinkles and veins in the ear, and made the eye more obvious. I was going to enlarge the eye even more, but elephants actually have very small eyes.

This was a somewhat quiet activity, and raised a lot less dust than the asphyxiating resin garden fairy of a couple of weeks ago. The rise of the head made the elephant look a bit like Larry from The Three Stooges, so I concentrated for awhile on shaving that down. For that part, I used a wide burr bit, which I forgot to photograph.

I kept at it for about an hour in all, then realized it wasn't going to get much better. The piece of brick was a bit too short to make the length of trunk I would have liked, and the ear area was strangely shaped, but I did my best with what I had. I supposed I could have made the whole thing much smaller, but that would have taken a lot more time than I had today.

I liked working with this piece of brick. It had a nice feel to it, and wasn't as hard or as sharp as other brick I've handled. I also like the roughness of the surface, as well as its many imperfections, and wish I'd had more time to make something really nice.

It's very fast to carve with a rotary tool, but also carves nicely with hand files. I almost preferred the rotary tool, however, because it leaves some of the existing texture intact, whereas the files smooth things out a bit more than I liked.

Now that I know how easy it is to carve this kind of brick, I may start haunting some of the local renovation sites. After all, you never know when a stray fragment of Orange Victorian might happen across your path.

Elephant Lore of the Day
Although elephants are often viewed as gentle giants, it should never be forgotten that they are wild animals. As such, they can be extremely unpredictable, and are often very dangerous.

In November 2011, a 52-year-old man called Kasinathan was working as a security guard at a remote brick kiln in southern India. While he was doing his rounds, an elephant burst out of the nearby forest. The elephant's appearance was so sudden that Kasinathan was unable to escape in time.

According to forestry officials, the elephant grabbed the fleeing Kasinathan in its trunk. After flinging the poor man into the air, the elephant trampled on his head. Kasinathan's body was mangled, and his face crushed beyond recognition. No one is quite sure what set the elephant off. It may have been the fact that Kasinathan ran, or the elephant may have been a rogue, or in musth.

To combat such incursions of elephants into populated areas, the region's forestry department began digging trenches on the periphery of all forest areas. Unfortunately, trenches are often not very effective against elephants. Elephants in both Asia and Africa have learned how to break down the berms on either side of a trench until they have made a filled-in depression that is shallow enough to cross.

In 2011, eight people were killed by elephants in the small district in which the brick kiln was located. An average 400 are killed by elephants across India each year.

Asian elephant.


To Support Elephant Welfare
Elephant sanctuaries (this Wikipedia list allows you to click through to information
on a number of sanctuaries around the world)
Wildlife Trust of India

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