1 00:00:01,840 --> 00:00:08,680 Speaker 1: Welcome to Brainstuff, a production of iHeartRadio, Hey Brainstuff Lauren Vogelbaum. Here, 2 00:00:10,480 --> 00:00:14,440 Speaker 1: when it comes to durable materials, artists, architects, and homebodies 3 00:00:14,440 --> 00:00:17,160 Speaker 1: alike may need to look no further than terra cotta. 4 00:00:18,079 --> 00:00:19,880 Speaker 1: If you need proof, a look at the army of 5 00:00:19,960 --> 00:00:22,759 Speaker 1: terracotta soldiers that was crafted more than two thousand years 6 00:00:22,800 --> 00:00:26,520 Speaker 1: ago in what's now northwest China. Or consider the Venus 7 00:00:26,520 --> 00:00:30,639 Speaker 1: of Dolni Vestanitze, the oldest known terracotta sculpture, which dates 8 00:00:30,640 --> 00:00:33,440 Speaker 1: from between twenty six to twenty eight thousand years ago. 9 00:00:35,000 --> 00:00:37,720 Speaker 1: There are plenty of other ancient examples of terra cotta 10 00:00:37,840 --> 00:00:41,040 Speaker 1: because humans have long understood the benefits of baked clay, 11 00:00:41,479 --> 00:00:44,800 Speaker 1: which is the basic definition of terra cotta. Today, this 12 00:00:44,920 --> 00:00:49,000 Speaker 1: material can be found everywhere from roofs to gardens. However, 13 00:00:49,240 --> 00:00:53,960 Speaker 1: even though it's widely used, it's not always clearly understood. 14 00:00:54,240 --> 00:00:56,960 Speaker 1: The term terra cotta comes from the Latin for baked earth, 15 00:00:57,080 --> 00:01:00,480 Speaker 1: and it itself has been around since the seventeen hundreds, though, 16 00:01:00,520 --> 00:01:03,360 Speaker 1: of course, as the prior examples show, the practice of 17 00:01:03,440 --> 00:01:08,080 Speaker 1: firing clay has been around for much longer. For the article, 18 00:01:08,120 --> 00:01:10,200 Speaker 1: this episode is based on it has to work. Spoke 19 00:01:10,240 --> 00:01:13,160 Speaker 1: via email with Sarah Barak, the head of Conservation and 20 00:01:13,319 --> 00:01:17,360 Speaker 1: Senior Objects Conservator at Cooper Hewitt the Smithsonian Design Museum. 21 00:01:18,160 --> 00:01:22,000 Speaker 1: She explained terra cotta refers to a low fired porous 22 00:01:22,040 --> 00:01:25,360 Speaker 1: ceramic that has been used for millennia. It generally has 23 00:01:25,440 --> 00:01:27,600 Speaker 1: a reddish or pink color due to the iron in 24 00:01:27,600 --> 00:01:33,959 Speaker 1: the clay, which oxidizes during the firing process. In simple terms, 25 00:01:34,120 --> 00:01:37,000 Speaker 1: clay is the substance that comes from the earth. It 26 00:01:37,040 --> 00:01:39,160 Speaker 1: can be mixed with other materials to make it better 27 00:01:39,200 --> 00:01:42,440 Speaker 1: to work with, and these composites are called clay bodies. 28 00:01:43,000 --> 00:01:46,240 Speaker 1: There are three main types of clay bodies earthenware, stoneware, 29 00:01:46,360 --> 00:01:50,600 Speaker 1: and porcelain. Earthenware is a low fire product, which means 30 00:01:50,600 --> 00:01:53,800 Speaker 1: it's fired at relatively low temperatures one thousand, eight hundred 31 00:01:53,840 --> 00:01:56,800 Speaker 1: two two thousand, one hundred degrees fahrenheit that's about nine 32 00:01:56,880 --> 00:02:02,160 Speaker 1: fifty two one one hundred and fifty degrees elsius. Earthenware 33 00:02:02,240 --> 00:02:04,560 Speaker 1: can be red or white, and when it's red we 34 00:02:04,640 --> 00:02:08,680 Speaker 1: call it terra cotta. Stoneware and porcelain are fired hotter 35 00:02:09,040 --> 00:02:12,960 Speaker 1: so that the clay body undergoes vitrification. That's the process 36 00:02:12,960 --> 00:02:17,440 Speaker 1: in which fired clay becomes glassy, hard and non porous, 37 00:02:17,440 --> 00:02:21,639 Speaker 1: so terra cotta, when unglazed, remains porous, unlike say, porcelain. 38 00:02:23,919 --> 00:02:27,080 Speaker 1: Historic examples of terracotta are common around the world and 39 00:02:27,160 --> 00:02:30,320 Speaker 1: have been found from the Mediterranean to sub Saharan Africa, 40 00:02:30,400 --> 00:02:34,120 Speaker 1: to the pre Columbian Americas to what's now Pakistan and beyond. 41 00:02:35,160 --> 00:02:38,000 Speaker 1: Modern examples abound too, though some of those are based 42 00:02:38,000 --> 00:02:41,679 Speaker 1: on designs that have lasted thousands of years. For example, 43 00:02:41,760 --> 00:02:45,000 Speaker 1: ovens called tandors are still commonly made from terra cotta 44 00:02:45,040 --> 00:02:48,040 Speaker 1: and used to bake flatbreads and other foods throughout South 45 00:02:48,040 --> 00:02:52,000 Speaker 1: and Western Asia, and a familiar site from southern Europe 46 00:02:52,040 --> 00:02:56,440 Speaker 1: to southern Florida are terracotta roofs, also called clay tile roofs. 47 00:02:56,600 --> 00:03:02,079 Speaker 1: With their overlapping plates of brownish red orange clay, these 48 00:03:02,160 --> 00:03:05,440 Speaker 1: roofs can last for one hundred years barring natural disasters, 49 00:03:05,960 --> 00:03:08,560 Speaker 1: and from an energy standpoint, they're good at keeping the 50 00:03:08,639 --> 00:03:12,320 Speaker 1: outside temperature where it belongs. Instead of absorbing the heat 51 00:03:12,400 --> 00:03:15,320 Speaker 1: into your home, the clay tile roofs reflect heat back 52 00:03:15,320 --> 00:03:19,360 Speaker 1: into the atmosphere. The color glazes expand the esthetic possibilities 53 00:03:19,440 --> 00:03:24,560 Speaker 1: and provide water resistance. Terra Cotta makes an ideal solution 54 00:03:24,680 --> 00:03:27,560 Speaker 1: for other areas of buildings too, like walls and floors. 55 00:03:28,240 --> 00:03:31,280 Speaker 1: Iconic structures like New York's Flat Iron Building and Chicago's 56 00:03:31,280 --> 00:03:36,920 Speaker 1: Wrigley Building feature it. But as with those early decorative examples, 57 00:03:37,000 --> 00:03:39,760 Speaker 1: the fired clay is still used to make art and 58 00:03:40,160 --> 00:03:44,920 Speaker 1: esthetic functional pieces. Barack said. Given the low firing nature, 59 00:03:45,120 --> 00:03:48,000 Speaker 1: the ceramic is not as brittle as higher fired wares 60 00:03:48,040 --> 00:03:50,560 Speaker 1: such as porcelain. It can be cast in a mold, 61 00:03:50,840 --> 00:03:53,520 Speaker 1: hand built, or thrown on a wheeld. As with other clays. 62 00:03:54,280 --> 00:03:56,920 Speaker 1: Expressive results can be achieved when artists work this clay 63 00:03:56,920 --> 00:04:01,120 Speaker 1: with tools in a sculptural manner. That means that you 64 00:04:01,200 --> 00:04:04,240 Speaker 1: can find fine art ceramics and vessels in terra cotta. 65 00:04:05,040 --> 00:04:07,560 Speaker 1: With the right types of outer glaze applied, these vessels 66 00:04:07,600 --> 00:04:10,240 Speaker 1: can be water tight, meaning they won't soak up your 67 00:04:10,360 --> 00:04:12,600 Speaker 1: coffee the way that a planter would soak up water, 68 00:04:14,520 --> 00:04:17,200 Speaker 1: and for many people today, terracotta does call to mind 69 00:04:17,279 --> 00:04:20,520 Speaker 1: the classic terra cotta plant pots. These can bring a 70 00:04:20,560 --> 00:04:24,000 Speaker 1: gardener benefits that other materials don't. The thick walls of 71 00:04:24,000 --> 00:04:27,160 Speaker 1: a terra cotta clay pot provide insulation from temperature changes, 72 00:04:27,800 --> 00:04:31,520 Speaker 1: and because they're porous and thus breathe, terracotta pots allow 73 00:04:31,600 --> 00:04:34,880 Speaker 1: for excess moisture to evaporate. That means that you prevent 74 00:04:34,920 --> 00:04:37,560 Speaker 1: trapped water in the pot and thus reduce the risk 75 00:04:37,600 --> 00:04:42,960 Speaker 1: of root diseases and avoid overwatering. However, that also means 76 00:04:42,960 --> 00:04:45,360 Speaker 1: that not every plant is a fit for terra cotta. 77 00:04:46,040 --> 00:04:49,200 Speaker 1: For those that crave consistently moist soil, terra cotta may 78 00:04:49,240 --> 00:04:52,840 Speaker 1: pull away moisture too quickly. Unglazed terra cotta can also 79 00:04:52,880 --> 00:04:55,680 Speaker 1: start to fall apart after many years of soaking up moisture, 80 00:04:56,080 --> 00:04:59,359 Speaker 1: or can break if freezing temperatures catch water droplets inside 81 00:04:59,360 --> 00:05:03,400 Speaker 1: the clay. If you do choose a terracotta pot for 82 00:05:03,440 --> 00:05:06,680 Speaker 1: a plant, here's a tip. Soak it overnight before you 83 00:05:06,720 --> 00:05:10,080 Speaker 1: put soil and a plant in. This will hydrate the 84 00:05:10,120 --> 00:05:12,720 Speaker 1: clay and protect the soil from drying out too quickly 85 00:05:12,800 --> 00:05:15,400 Speaker 1: during the delicate process of transferring a plant to a 86 00:05:15,400 --> 00:05:18,200 Speaker 1: new home. The idea is that if the pot is 87 00:05:18,240 --> 00:05:21,120 Speaker 1: already moist it won't pull as much water from the soil. 88 00:05:26,120 --> 00:05:28,599 Speaker 1: Today's episode is based on the article from Plant Pots 89 00:05:28,640 --> 00:05:32,320 Speaker 1: to Ancient Armies. Terracotta is universal on how Stuffworks dot Com, 90 00:05:32,360 --> 00:05:35,479 Speaker 1: written by Kerry Whitney. Brainstuff is production of iHeartRadio in 91 00:05:35,520 --> 00:05:37,760 Speaker 1: partnership with how Stuffworks dot Com and is produced by 92 00:05:37,760 --> 00:05:40,920 Speaker 1: Tyler Klain. Four more podcasts from my heart Radio, visit 93 00:05:40,920 --> 00:05:43,760 Speaker 1: the iHeartRadio app, Apple Podcasts, or wherever you listen to 94 00:05:43,800 --> 00:05:44,680 Speaker 1: your favorite shows.