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The sutema: a
stabilizing chamber |
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The sutema: a
stabilizing chamber |
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As is commonly the case with terms taken out of their original cultural context, the word anagama is applied to a variety of kiln designs. To me it suggests a single chambered climbing kiln, longer than it is wide, and used for extended wood firings with the aim of exploiting natural ash deposits. If stabilizing chambers become the norm I may have to change my expectations to include a second chamber, as advocated by the late Michio Furutani. He introduced a smaller second chamber to his anagamas, located between the main chamber and the chimney. He called the second chamber a sutema (pronounce that something like stemma). Its primary purpose is to stabilize the firing conditions in the main chamber, although some pots may be fired in the sutema if external access is available. The volume of the sutema as advocated by Furutani ranged from relatively small up to nearly half the volume of the main chamber. He maintained that a sutema made a kiln easier to control and improved the front to back heat distribution. An article by Bede Clarke in the Log Book issue 27 reports that a sutema will reduce the amount of smoke issuing from the chimney during heavy stokings, and an injection of forced air into the the sutema will eliminate the smoke completely. |
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Transverse sutema |
Integral sutema |
When it comes to construction of a sutema there are two obvious options: partition off the rear section of the anagama chamber, or construct a separate chamber at the back of the main chamber, witan arch at right angles to the main chamber arch.
The advantage of the transverse sutema is that it is relatively easy to build a door in one end to allow access to the chamber so that pots can be fired in it. This is not necessarily a good practice as worrying about conditions in the sutema may distract from concentration on firing the main chamber. It is well known that chasing too many rabbits at once may decrease your chances of catching a meal.
An integral chamber can be installed in an existing anagama, and if the wall built to form the sutema is not too well tied into the existing arch there is the possibility of changing the sutema size to fit the number of pots ready to fire. This may well be useful for woodfirers who overestimate their long term personal energy supply and make their kilns too large. This is common amongst young players. Using high precision measuring instruments scientists have shown conclusively that woodfirers' brains get bigger as they get older, and their kilns get smaller.
Thre images below are links to relevant pages
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