Originally, cones forms were made of the glaze the potter was using. These cones were set insde the kiln in front of a peep hole. As the temperature of the kiln rose, the cone would melt in front of the peep hole telling, the potter it had reached the right temperature. Unfortunitly, it was unreliable and inconsistant. Then potters varied the glzae mixture to be just above or just below the right temperature. Setting three cones in a row by a peep hole, the potter could predict just when to stop stoking the fire. Modern potters buy accurately formulated cones compounded to melt at specific tempertures. Firing consistantly is an art that relies on science and experience.
thin, tapered length of molded ceramic materials formulated to melt at a prescribed temperature providing an indication of temperature inside the kiln. Also the temperature of firing for a specific process or clay body, ranging from cone 022 (low) to cone 12 (high).
Small conical object made of compressed graduated glaze materials with a known melting point, used to indicate temperature reached in a kiln at a given point.