Glossary Two: Terms and definitions used in the description of Muffles

Muffle wall
Any part of a muffle which in use had a vertical alignment - commonly curved along one axis and displaying a clean or luted inner (concave) surface with flash glazed or slagged outer (convex) surface.
Muffle base
Any part of a muffle which in use had a horizontal alignment - commonly flat and usually thicker than the walls. The inclusion of pipe bowls around the base periphery is a useful diagnostic feature.
Muffle prop, bar and ridge
These are external features of the muffle and therefore display signs of fire contact on all unbroken or unmasked surfaces. They were originally formed as radial extensions from the outer surface of the muffle wall to act as supports bearing against the inner surface of the firing chamber. In the space bridged by these supports the fire was able to circulate around the muffle. Props are generally columnar in form displaying the irregularities generic in a roughly hand made object. They commonly take the form of a truncated cone, the broad end springing from the muffle Figure 4a. Some examples splay also towards the extremity. Bars occupy the same position and serve the same function differing only in shape. They are of sub-rectangular prism form. In use the greater dimension had a vertical alignment, the bars being arranged in the manner of vertical ribs around the outside of the muffle Figure 4b. The teardrop variation of the bar is described above. Ridges are in the form of triangular prisms lying on one face similar to a pitched roof Figure 4f. Props, bars and ridges are commonly made from the same materials as the muffle and constructed as integral parts of it.
Peripheral shelf
This is an internal projection from the inner surface of the muffle wall, constructed from the same material as the muffle as an integral part of it. Two types of peripheral shelf have been recorded. The first is of similar form to that of an architectural cornice with a flat horizontal upper surface 35 to 50mm wide. The cross section is an irregular trapezium with the projecting profile rounded and the junctions with the muffle wall filled and blended into smooth concave profiles Figure 4d. Additional support is generally provided by pegging into the muffle wall with prefired stems set at regular intervals. The second type is in the form of a step determined by a dramatic reduction in thickness of the muffle wall at this point Figure 4e.
Core fragments
When a fragment displays broken surfaces from every aspect then it is described as a core fragment. Muffle core fragments can only be identified by comparison of the fabric with muffle material from the same context.
Stems/bowls/mouthpieces and wig curlers from the muffle matrix
Any fragment of these items which has been used to reinforce the fabric of a muffle and which has become separated from it. These are characterised by their rough surface texture which is caused by adhering clay.
Layered/flaked lute
In this context, lute is an application of clay slip to surfaces within the kiln. Repeated applications over a period of time resulted in the accumulation of several layers. Lute applications are found on the inner surfaces of muffles and saggars, also on the external surfaces of other kiln furnishings. On destruction of the kiln, flakes of this material, either singly or as layers became separated from their hosts. Identification relies on distinguishing these flakes from the thin sheets. In the case of layered material the layering itself is diagnostic. Where layering is absent a judgement must be made on the characteristics of form and surface texture, which differ markedly from those of thin sheets. Lute applied to dry absorbent surfaces reflects these in the texture of its own contact surface. The exposed face shows the marks left by the smearing action of its application. Differential shrinkage results in ragged cracks, while surface drying causes curling away from the host. Some fragments adopt similar forms to those observed in a sun dried film of mud, irregular broken edges curling away from the underlying adhering surface.
Lining patch
A lining patch is identified as a piece of material with a generally convex contact surface bearing the impression of its host, whilst the generally concave opposing surface bears witness to the method of application. A patch generally becomes thinner towards its extremities. A clean or luted exposed surface indicates a patch from within a muffle.