Glossary One: Terms used in the description of Pipe Kilns

Ash Pit
A pit or channel beneath the fire box and separated from it by fire bars, into which ash from the fire could fall and from which air could pass upwards to the fire.
Chequer
An openwork arrangement of bricks forming the floor of the firing chamber. Constructed to give support for saggars etc. whilst at the same time allowing clear and even passage for gas flow.
Chimney
Flue constructed above or at some distance from the firing chamber to draw the hot gasses through the kiln and carry smoke and noxious fumes away from the workshop area.
Crossdraft
A term applied to kilns in which the direction of travel for hot gasses, from the fire, is horizontal, across the ware chamber to the chimney.
Damper plate
A sheet of material used over an opening in a flue or chimney to control the passage of air or flue gasses.
Dish Setter
A curved piece of pottery kiln furniture with a step in its radial section. Used to separate dishes in stacks within the kiln (Brears 1971-, 131I).
Dottle
The small accumulation of clay formed on the end of the wire as it passed through the stem blank forming the bore. The dottle is often to be seen remaining attached inside the pipe bowl. Detached examples have been recovered by careful washing and sorting of detritus.
Downdraft
A term applied to kilns in which the direction of travel for hot gasses, from the fire, after circulation through the ware chamber, is downward through a flue or flues in its base, to a chimney of sufficient height to draw the whole through the kiln.
Fire Bars
Bars, usually of brick or iron, set at intervals across the floor of the fire box forming a bed for the fire. Constructed in such a manner as to allow clear passage for air to pass upwards to the fire and ash to fall down into the ash pit.
Fire Box
That part of the kiln between the ash pit and the firing chamber in which the fire was set and maintained throughout the firing process.
Firing Chamber
The chamber between the fire box and the chimney to hold the ware, contained either in a muffle or saggars, for firing. Also termed the ware chamber.
Flash Glaze
The phenomena caused by fly ash alighting upon clay surfaces within the kiln and combining with silica therein to form a glaze. This can effect structure, furniture or product and is most commonly seen in the fire box and its immediate proximity.
Fly Ash
Ash drawn from the burning fuel and carried by the gas flow through the kiln chamber or flues.
Furniture
Prefabricated re-usable objects made from clay for use within the muffle or firing chamber to support or separate the pipes or other product of the kiln.
Furniture Supplement
Any piece of material used in conjunction with true furniture to assist in its function. Commonly these are distinguished by the fact that they were introduced into the kiln as plastic clay and once fired are not suitable for re-use.
Muffle Supports
Pillars or corbelled projections usually of brick or sandstone, set in the fire box to support the muffle above.
Muffle
Large refractory pot set inside the firing chamber forming an inner chamber to contain the pipes firing free from direct contact with the flame.
Muffle Buttress
Any projection from the outer surface of the muffle wall spanning the flue space between the muffle and the inner surface of the firing chamber. Commonly these take the form of props or bars. A prop having a vertical section either sub rounded or sub rectangular with more or less equal intersecting diameters or sides. A bar being extended in the vertical dimension.
Open Flame
A term applied to a kiln with a simple ware chamber through which the fire gasses have total access. Such a kiln commonly employs saggars to contain and protect the ware.
Peripheral Shelf
A circular shelf formed either by a step in the wall thickness or as a projection inwards from the inner surface of the muffle wall
Slag
In this work the term slag is used to describe any metamorphic vitrified mass derived from fuel ash under the influence of extreme heat. Support for the use of the term in this context can be found in its definition in the Oxford English Dictionary and in Searle's Encyclopaedia of the Ceramic Industries.
Spew
Trimmings, breakages, unfinished work etc consisting of raw clay which could be wetted for re-use.
Stamp
Object with raised or incuse lettering, wording or design, in reverse, used to impress or print the said device.
Stoke Pit
The area in front of the fire box usually below ground level from which the fire could by fuelled and managed.
Tipping Muffle
Small refractory vessel in which stems were heated to melt glaze applied to their tips. Distinguished by external fire damage, slagging etc. and glaze runs on inside surfaces.
Trimming Ring
Surplus clay extruded from a pipe mould through the knife slot at the top of the bowl.
Updraft
A term applied to a kiln in which the direction of travel of hot gasses from the fire is continuously upward through the ware chamber to the chimney and eventual freedom.
Ware Chamber
The chamber between the fire box and the chimney to hold the ware, contained either in a muffle or saggars, for firing. Also termed the firing chamber.

Explanation of Codes Used in Listing Muffle Characteristics

The incidence and alignment of stem reinforcing in the muffle wall

The incidence of organic filler

Details of buttressing

Details of shelves

Explanation of Codes Used in Listing Kiln Furniture

Fabric Types

Prop types - Explanation of Prop Codes.
Bun types - Explanation of Bun Codes.
Dish types - Explanation of Dish Codes.
Saggar types - Explanation of Saggar Codes.
Bat types - Explanation of Bat Codes.

Codes used in listing furniture supplements

Roll types - Explanation of Roll Codes.

Strap types - Explanation of Strap Codes.

Wad types - Explanation of Wad Codes.

Applied Strip types - Explanation of Applied Strip Codes.

Thin Sheet types - Explanation of Thin Sheet Codes.

Rack types - Explanation of Rack Codes.