This is the two chambered catenary arch kiln I built in Sunbury in 1978 and used until 1984. I fired to stoneware in the large chamber and the the heat passed through the small chamber before entering the chimney. I could divert all or some of the heat through the small chamber depending on if I was using it for bisque or glaze. 1300 deg C in the large chamber would produce about 800 in the small one. I could then close off the large chamber with a damper and bring the small kiln up to bisque at about 1000 deg C with it's own burners. I was able to fire in any configuration. Both to stoneware or either one to stoneware while the other was empty or loaded with bisque. This post was supposed to appear after the Welcome one but I can't figure out how to move them.