WHAT IS THE KILN?

A chamber built for the firing (baking) of pottery, used from prehistoric times. These, usually dome-shaped, structures are designed to produce the high temperatures needed for the industry. In a pottery kiln, the pots were often stacked upside-down on a shelf. An opening for draft was left at the top, and a flue provided at the side. Fuel was piled within and around the kiln, and when the heat was at its greatest the openings were shut to preserve the temperatures and fire the pots inside, with temperatures of 800–1000°C achieved. Other versions were used in glassmaking or the parching of corn. The kiln, like the potter’s wheel, implies craft specialization, and appears only at advanced stages of economic development. Important types of kilns include: bottle (updraft kiln with a narrow chimney shaped like a bottle), clamp (open-topped updraft kiln of semipermanent construction), climbing (kiln set along a slope to aid the draft), continuous (in which ware is fed continuously into the kiln on a track, moving through it during firing), downdraft (an enclosed periodic kiln in which the heat is passed to the top of the kiln, then the draft carries it down through the ware), intermittent or periodic (kiln that is loaded, fired, cooled, and then unloaded before firing a new batch), muffle (kiln constructed so that the ware is not directly subjected to the radiant heat from the flame or heating elements), pit (clamp that is dug partly into the ground), scove (updraft kiln usually having no permanent parts), tunnel (type of continuous kiln), and updraft (kiln in which the heat or flame passes upward through the ware and then is vented outside).