Posts Tagged ‘salt firing’

Adam Smith Wasn’t Always Right

February 23, 2014

In economics, success and growth walk hand in hand.  Except when they don’t.  George Henderson’s Dorchester Pottery Works in Dorchester, MA started as a large industrial stoneware factory but ended up flourishing as a small family run pottery.

George started the business in 1885.  His factory employed 28 workers who turned out “industrial” salt fired stoneware crocks, acid jars, etc.  George built a gigantic newfangled gas fired downdraft kiln in 1914.  It cost a whopping $250,000 and was one of only two of it’s kind in the nation at the time.

This situation presented George with a choice: continue with salt firing (and what salt would do to his phenomenally expensive kiln) or switch to glazed work.  Glazing meant either an Albany slip or a feldspathic Bristol glaze.  George opted for the Bristol glaze.

The British invented the Bristol glaze as an alternative to both lead and salt.  The off-white Bristol glaze used zinc oxide, calcium, feldspar, and china clay to create the world’s first eutectic “trick.”  That is, by mixing zinc and calcium (both requiring very high temperatures to melt), their combined melting point becomes dramatically lower.  Thus, Bristol glazes matured at low temperatures, speeding up firing time and lowering fuel usage.

America imported Bristol glazes since their creation in the early 19th century.  But potters at the New Orleans Exposition of 1884 were especially impressed.  Before 1920 Bristol was generally used in combination with the black Albany slip glaze.  After 1920, it was pretty much Bristol all the way.

When George Henderson died in 1928, his son Charles struggled with the albatross his dad left him. Demand for industrial wares plummeted during the Great Depression.  In 1940, Charles’ wife Ethel took charge.  Ethel scaled everything way back and switched to just tableware.  In the process, Dorchester became the first American pottery to fully develop the Bristol glaze’s potential for precise detail and extreme control of painted decoration.

For the next 40 years Dorchester turned out decorative tableware.  Many of their most popular designs came from customer suggestions.  Ethel and George were even able to retain a few of the Italian potters George’s dad had imported to work in the factory, including their principle thrower Nando Ricci.

Fire destroyed the building and the business in 1979.  But the Dorchester Pottery Works left behind a reassuring legacy; It’s ok to be small.

Readings:

American Stonewares.  Georgeanna Greer.  Schiffer Publishing Ltd./Exton, PA.  1981.

Raised in Clay, The Southern Pottery Tradition.  Nancy Sweezy.  Smithsonian Institution Press/Washington DC.  1984.

 

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The Secret to Success

January 17, 2010

Rarely did anyone bother to write about pottery making during America’s early days.  One who did was Nathan Clark, working from 1839 to 1851 in Rochester, NY.  He wrote “Rules for Making & Burning Stone Ware.

1st.  Let the wheelman be careful to have every piece run exactly true on the wheel.  Make them of a kind precisely of the same height & width.  Have the ware turned light, of a handsome shape, smooth inside & outside, the bottom a suitable thickness, and a good top.

2nd.  Let it be handsomely & smoothly polished in proper season.

3rd.  Let the ware when dry be carefully set in the loft washed and blued.

4th.  Let the plats be well made, Kiln cleaned out and mended in complete order for setting.

5th.  Care must be taken to set the courses plum and one piece exactly over the other.

6th.  Have your wood in good order, raise your fire progressively, neither too fast nor too slow.  Examine well & understand the management of your Kiln so as to heat all parts alike.  Be careful not to throw your wood in the arches too soon or do any other act that may have a tendency to retard the heat.  When fit to glaze have your salt dry.  Scatter it well in every part of your Kiln (during this act you must keep a full and clear blaze so as to accelerate the glazing and give the ware a bright gloss).  Stop it perfectly tight and in six days you may draw a good kiln of ware.

Reading:
The Art of the Potter. Diana and J. Garrison Stradling.  Main Street-Universe Books/New York.  1977.