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.
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.
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.
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.
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.
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.
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.
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.