Lily Krakowski on mon 4 nov 02
Hermann Seger of blessed memory invented the cone. which he called bowling
pins.
I think it was in the 1880s at the Royal Porcelain Works in Berlin, I
think.
His cones measured heat. HEAT. Boy, its hot in here, the pots cried.
Orton about whom I know zip, improved the Seger cone and made it into a
recorder of WORK. Boy it's hot in here, the pots cry, but has the work the
potter wanted done on the clay and glazes been accomplished?
The difference is quite big. Not in degrees but in idea. When you cook you
notice that the cookbook says bring to a boil slowly; cook gently, and so
on. That is to tell you that the proper work on your sauce cannot be
accomplished quickly with a blast of heat, but needs to be done slowly over
the extended period asked for.
Pyrometers measure HEAT. And as the Orton cone charts show the rate of heat
increase matters. In the sense that the temperature at which the cone falls
will be different if the rate of heating is different.
So pyrometers are neatissimo if you want to know how hot the kiln is and if
for instance your rate of heat increase is what you desire. "Look, Ma, it
is 200o degrees hotter than forty minutes ago." "Not so good, dear, that is
too fast for this stage of the firing...." Pyrometers are great if you have
different peepholes and want to check quickly about evern uneven heating.
But as to actual firing--trust your cones.
Lili Krakowski
P.O. Box #1
Constableville, N.Y.
(315) 942-5916/ 397-2389
Be of good courage...
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