Sakazume Katsuyuki's own kiln for "firing and hardening" now has an overall length of 15 meters.

He has finished constructing the kiln, similar to "Shiki-gama," which was a kiln for "Sueki" or Sue Pottery objects, found having been located at the Mino district of long ago in the Kamakura period (1192-1333), though he has not taken in a flame-dividing column in it. Why has he constructed this way?

"I was also attracted to the ceramic art works of the Azuchi-Momoyama era (1568-1603) at first.

But I thought that the Azuchi-Momoyama earthenware could not have appeared all of sudden. There must have been the previous stage to the climax of its fame. So I decided to pursue the ceramic art preceding this era .

I began to make researches on kilns for "Sueki" or Sue Pottery objects, and on "anagama" or the underground kilns of the Kamakura and Muromachi (1334-1567) periods. How were they operated?

I also read excavation materials that were described from archaeological point of view, until finally I finished constructing the kiln now I am using.

I know that I have to take in a flame-dividing column as an ingenious contrivance, but I am now leaving it out in order to achieve a series of large-scale sculpture projects.

So I made a certain product in place of the flame divider and then set it in front of the firewood-burning chamber."

It usually takes two weeks, and sometimes nearly 20 days, dependent on the weather, to finish the kiln-firing.

It takes long to finally reach 1400 degrees Celsius, an extraordinarily high temperature.

"The temperature inside of the kiln does not go up higher when the ground is not baked enough.

You would come to realize this fact if putting this matter into practice repeatedly.

I have to get this half-underground kiln being deprived of its heat into the underground, thus on one hand worsening its efficiency, but on the other hand ripening its products gradually due to the ashes to have been accumulated there."

It was in 1955 to 1964 when modern ceramic artists, except ARAKAWA Toyozo and KATO Toukuro, began to use "anagama" or underground kilns.

Since then, people have believed that it is the ceramic pieces so arranged as to be put on nearest to the firewood-burning chamber that should be fired best of all, and that the farther away from the combustion chamber ceramic pieces are so arranged as to be put on, the less likely they are to be fired enough. This is a common sense to everyone, they said.

The temperature does not go up over 1000 degrees Celsius around the chimney path, the point farthest away from the combustion chamber, thus changing such ceramic pieces as put on there into mere biscuit ware or something like that, they said.
Sakazume's kiln is, however, in the condition contrary to the above-mentioned, he says.

"The chimney path has a higher temperature.

In fact, the temperature reaches so high that the ceramic pieces so arranged as to be put on around there, are so fused in the midst of flame flow that they cannot be presented as commercially viable products.

How to control the temperature around the chimney path is the most important problem by which I am now confronted.

I am noticing that the temperature just short of stopping feeding the fire with firewood has reached approximately 1370 degrees Celsius in the firewood-burning chamber and up to 1400 degrees Celsius around the chimney path respectively.

It has been said that the firing stream does not bring a higher temperature on its lower reaches, but this is a saying inconceivable to me.

Watch a candle flame. The pointed end over the outside has a highest temperature. The fire flame around the wick has a rather lower temperature.

The shape of a kiln of long ago seems to be the image of the figure of a candle flame that is lying down.

The oven of long ago rounded out in the middle and narrowed down near the end.

It is here at this point that the temperature reaches highest. It seems to be quite natural for people of long ago to have borne a resemblance of the kiln to the candle flame in terms of their mechanism."

Sakazume's ceramic art works are characterized as the one fire-hardened with moisture added, in marked contrast to the one fired too completely.

"It is important to know how to select the clay as well as how to fire.

I have been using the clay from the Iga district. I began to use it about 16 years ago, when nobody did not venture to use this clay.

People believed that nobody could burn the clay because it was a fire-resisting material of a high degree of refractoriness. With such type of the kiln as I have constructed, you could manage to burn it even in those days as well as you can do now, I think."