Speaker 1: Welcome to Brainstuff, a production of iHeartRadio, Hey Brainstuff Lauren Vogelbaum. Here,
Speaker 1: when it comes to durable materials, artists, architects, and homebodies
Speaker 1: alike may need to look no further than terra cotta.
Speaker 1: If you need proof, a look at the army of
Speaker 1: terracotta soldiers that was crafted more than two thousand years
Speaker 1: ago in what's now northwest China. Or consider the Venus
Speaker 1: of Dolni Vestanitze, the oldest known terracotta sculpture, which dates
Speaker 1: from between twenty six to twenty eight thousand years ago.
Speaker 1: There are plenty of other ancient examples of terra cotta
Speaker 1: because humans have long understood the benefits of baked clay,
Speaker 1: which is the basic definition of terra cotta. Today, this
Speaker 1: material can be found everywhere from roofs to gardens. However,
Speaker 1: even though it's widely used, it's not always clearly understood.
Speaker 1: The term terra cotta comes from the Latin for baked earth,
Speaker 1: and it itself has been around since the seventeen hundreds, though,
Speaker 1: of course, as the prior examples show, the practice of
Speaker 1: firing clay has been around for much longer. For the article,
Speaker 1: this episode is based on it has to work. Spoke
Speaker 1: via email with Sarah Barak, the head of Conservation and
Speaker 1: Senior Objects Conservator at Cooper Hewitt the Smithsonian Design Museum.
Speaker 1: She explained terra cotta refers to a low fired porous
Speaker 1: ceramic that has been used for millennia. It generally has
Speaker 1: a reddish or pink color due to the iron in
Speaker 1: the clay, which oxidizes during the firing process. In simple terms,
Speaker 1: clay is the substance that comes from the earth. It
Speaker 1: can be mixed with other materials to make it better
Speaker 1: to work with, and these composites are called clay bodies.
Speaker 1: There are three main types of clay bodies earthenware, stoneware,
Speaker 1: and porcelain. Earthenware is a low fire product, which means
Speaker 1: it's fired at relatively low temperatures one thousand, eight hundred
Speaker 1: two two thousand, one hundred degrees fahrenheit that's about nine
Speaker 1: fifty two one one hundred and fifty degrees elsius. Earthenware
Speaker 1: can be red or white, and when it's red we
Speaker 1: call it terra cotta. Stoneware and porcelain are fired hotter
Speaker 1: so that the clay body undergoes vitrification. That's the process
Speaker 1: in which fired clay becomes glassy, hard and non porous,
Speaker 1: so terra cotta, when unglazed, remains porous, unlike say, porcelain.
Speaker 1: Historic examples of terracotta are common around the world and
Speaker 1: have been found from the Mediterranean to sub Saharan Africa,
Speaker 1: to the pre Columbian Americas to what's now Pakistan and beyond.
Speaker 1: Modern examples abound too, though some of those are based
Speaker 1: on designs that have lasted thousands of years. For example,
Speaker 1: ovens called tandors are still commonly made from terra cotta
Speaker 1: and used to bake flatbreads and other foods throughout South
Speaker 1: and Western Asia, and a familiar site from southern Europe
Speaker 1: to southern Florida are terracotta roofs, also called clay tile roofs.
Speaker 1: With their overlapping plates of brownish red orange clay, these
Speaker 1: roofs can last for one hundred years barring natural disasters,
Speaker 1: and from an energy standpoint, they're good at keeping the
Speaker 1: outside temperature where it belongs. Instead of absorbing the heat
Speaker 1: into your home, the clay tile roofs reflect heat back
Speaker 1: into the atmosphere. The color glazes expand the esthetic possibilities
Speaker 1: and provide water resistance. Terra Cotta makes an ideal solution
Speaker 1: for other areas of buildings too, like walls and floors.
Speaker 1: Iconic structures like New York's Flat Iron Building and Chicago's
Speaker 1: Wrigley Building feature it. But as with those early decorative examples,
Speaker 1: the fired clay is still used to make art and
Speaker 1: esthetic functional pieces. Barack said. Given the low firing nature,
Speaker 1: the ceramic is not as brittle as higher fired wares
Speaker 1: such as porcelain. It can be cast in a mold,
Speaker 1: hand built, or thrown on a wheeld. As with other clays.
Speaker 1: Expressive results can be achieved when artists work this clay
Speaker 1: with tools in a sculptural manner. That means that you
Speaker 1: can find fine art ceramics and vessels in terra cotta.
Speaker 1: With the right types of outer glaze applied, these vessels
Speaker 1: can be water tight, meaning they won't soak up your
Speaker 1: coffee the way that a planter would soak up water,
Speaker 1: and for many people today, terracotta does call to mind
Speaker 1: the classic terra cotta plant pots. These can bring a
Speaker 1: gardener benefits that other materials don't. The thick walls of
Speaker 1: a terra cotta clay pot provide insulation from temperature changes,
Speaker 1: and because they're porous and thus breathe, terracotta pots allow
Speaker 1: for excess moisture to evaporate. That means that you prevent
Speaker 1: trapped water in the pot and thus reduce the risk
Speaker 1: of root diseases and avoid overwatering. However, that also means
Speaker 1: that not every plant is a fit for terra cotta.
Speaker 1: For those that crave consistently moist soil, terra cotta may
Speaker 1: pull away moisture too quickly. Unglazed terra cotta can also
Speaker 1: start to fall apart after many years of soaking up moisture,
Speaker 1: or can break if freezing temperatures catch water droplets inside
Speaker 1: the clay. If you do choose a terracotta pot for
Speaker 1: a plant, here's a tip. Soak it overnight before you
Speaker 1: put soil and a plant in. This will hydrate the
Speaker 1: clay and protect the soil from drying out too quickly
Speaker 1: during the delicate process of transferring a plant to a
Speaker 1: new home. The idea is that if the pot is
Speaker 1: already moist it won't pull as much water from the soil.
Speaker 1: Today's episode is based on the article from Plant Pots
Speaker 1: to Ancient Armies. Terracotta is universal on how Stuffworks dot Com,
Speaker 1: written by Kerry Whitney. Brainstuff is production of iHeartRadio in
Speaker 1: partnership with how Stuffworks dot Com and is produced by
Speaker 1: Tyler Klain. Four more podcasts from my heart Radio, visit
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