So the long awaited answer to my question on July 21. What collapsed the pottery industry in the late 1700's?

Well, let me try and give you a visual reference. Pretend it's 1725. You're in the local public house drinking posset with your business associates. Posset was a mixed drink made of milk, egg, wine (usually sack), and spices. You are drinking out of small clay cups and the posset is being served out of a punch bowl.

Pretend it's 1825. You're in the same public house drinking with your business associates, but there is more agriculture now in the USA, so there is more beer, ale, and whiskey. What are you drinking out of? Glass mugs, and you are being served out of glass pitchers.

Glass was cheaper to produce and did not require as much skilled labor. Glass bottles and jars ended the neighborhood potter. Potter then turned more and more to decorative ware. It was more about style than function.

Pottery has continued alternating between style and function. In the pottery world, potters often will define themselves as either functional potters or art potters. Functional potters specialize in mugs, plates, bowls, and tableware. Art potters make scultpture and are more interested in surface decoration. Art potters, in the last twenty years or so, are much more interested china painting than functional potters. One of the great books out there right now that blends the pottery world and the china painting world is China Paint and Overglaze by Paul Lewing. I highly recommend it.

So I have a question for you, my readers. I will answer in a day or two but if you have the answer, then post it.

Here is the question. What industry wiped out pottery as a cottage industry? In the mid-1700's there were small local potteries in every town and city on the Eastern seaboard. Why did most of them disappear?

I am looking forward to class tomorrow night. I am hoping we won't have wild weather again. Last Wednesday, the rain came down in buckets. It was a wild night. My students are truly an intrepid lot and very faithful.

I am back from my trip to Virginia, where I visited the DC area and Williamsburg. In colonial Williamsburg, there is a great museum dedicated to decorative arts. Of course, pottery and ceramics is a large part of the museum. They had a great collection of earthenware pots and jugs. Also, great educational displays on the differences between earthenware, stoneware, and porcelain.

Earthenware is porous, fired at low temps, needs a glaze to be impervious to liquids and is opaque. Earthenware can be yellow, red, brown or black.

Stoneware is fired in the mid-range temperatures, does not need a glaze to be impervious to liquids, is good at withstanding thermal shock, and can be slightly translucent if thinly potted. Stoneware can range from white to gray, tan, borwn, and red.

Porcelain is fired at high temperatures, it does not need a glaze to be impervious to liquids, is great at withstanding thermal schock (they use porcelain for those space shuttle tiles), and is translucent if thinly potted. Porcelain is always white.

Porcelain or china is made of kaolin or china clay, which is a refractory white clay or pure alumina silicate. It is usually glazed with powdered petuntse or feldspathic rock (volcanic rock). The great stumbling block to creating china in Europe was not the ingredients but creating a kiln that could fire hot enough. They figured it out in Meissen, Germany around 1710. The first porcelain, or China, was developed in China around 610-907 AD.

Personally, a display explaining transfer ware, porcelain decorated with designs created originally on copper engraving plates, was a highlight. This has always been a minor mystery to me. How did they do that? Copper plates are flat and cups and bowls are not. Remember they came up with this process in the mid-1700s. No plastic or rubber was available to them. So how did they transfer those designs?

The answer was linen. They printed the design onto linen fabric and then wrapped the linen around the object. They left the linen on the porcelain and then it fired off in the kiln leaving the design. Cool, huh?

The summer classes at Irving are going great. We were joined last week by Skylar and her grandmother, Carol, for this session. Skylar will be an eigth grader next year; she has been working on a scene featuring a wagon train. Last night, four students started on a Santa Claus plate. Also, one of my students is doing a portrait of her mom in a black monochrome.

Still up for trivia? I promised you information on celery dishes. They are about eight to ten inches long with sides that curved up from a flat bottom about three inches across. Celery dishes were popular in the late 1800's and the early part of the 20th Century. Celery was a novelty then, a fresh crunchy texture in the fall or winter. Hello, Califoria. Refrigerated cars made celery a possibility for upper middle class hostesses; so you had to have a special dish. Those celery sticks at Thanksgiving have a history going back at least a hundred years. Who new? Your mom was being upscale.

The class is still busy working on painting in their decals on their tea cups. It will take us two or three more weeks to finish this project. One of the two kilns at Irving is filled with cups and saucers so it has proved to be a successful project. We are lucky at Irving, we have two large kilns. One has an electronic touchpad and the other has an old-fashioned cone-sitter.

Cone-sitters have two prongs or stilts that a pyrotechnic (heat sensitive) cone rests on and then a bar that rests on top of the cone. The bar is levered or caught by a lead weight. The cone will start to slump or bend at set temperature, which lowers the bar and causes the lead weight to fall, which trips a stitch to turn off the kiln. It's really an elegant little device.

The temperature range for china painting is from around 1350F to around 1550F: or cone 018 to around cone 013. For ceramics, these are low temperatures. Typically, our kilns take three to three and half hours to reach the temperature range for china painting and about six to seven hours to cool enough to remove the china.

More about firing later...