An analysis of voids in ceramics
Citation
Hill, David. (1984). An analysis of voids in ceramics. -- Lambda Alpha Journal of Man, v.16, no.1, p.7-34.
Abstract
Compression voids caused by the presence of air trapped
during the kneading process and given their preferred orientation
by paddling are found in cerawics throughout the ceramic
sequence with few exceptions. These exceptions in Peisker,
Hopewell, and Baeher/Pike sherds may be due to greater pressure
exerted on the clay during vessel thinning. The rarity of compression
voids in Mississippian ceramics requires another
explanation. Paddle and anvil thinning is suggested in Mississippian
ceramics by the strong orientation of the temper particles.
Mushroom shaped pottery anvils have been recovered from Mississippian
sites in the lower Illinois River Valley. In Mississippian
vessels there are air pockets whic~1 are only slightly oriented
parallel to the vessel walls. This may indicate the use of
larger-diameter coils in the construction of Mississippian vessels.
The use of larger coils would make a thicker pot, if the coils
were not compressed very much, and therefore would not deform
the air pockets to any great extent. Drying cracks ~re found in ceramics of all periods
but are less common in -Hopewell and Mississippian ceramics,
indicating better control over the amount of temper used
versus the amount of shrinkage expect'ed in the clay. It
is interesting to note that the ceramic type with the most
drying cracks, White Hall ware, also was the most abundantly
tempered. This may indicate a change in clay resource
utilization from the source used at an earlier period
. and learning to cope wita a- .moister cl!"iY.
Leaching voids are present only in limestone-tempered
ceramics and often have some limestone occupying a much
larger void. These voids are found in most limestone-tempered
sherds.
Ceramics from the lower Illinois River Valley have,
throughout their history, been formed by coiling and the
coil built to walls thinned by the use of paddle and anvil.
Other methods of vessel-shaping were products of a combination
of individual potters' desires and the culture which
produced the potters.