Nancy Benco on sun 25 may 97
Hi everyone,
Thanks to those who responded to my inquiry about setting up a
ranking (less to more difficult) system to assess different kinds of
manufacturing techniques used for ancient pottery.
I'm going to sign off the listserve, but before I do I'd like to
contribute to the S-crack debate. Ancient potters also got S-cracks. These
were restricted to wheel-thrown vessels. Some of the archeological
literature related to ancient pottery technology suggests that S-cracks
on the base of vessels are typical drying defects (exaggerated in firing)
and caused by differential water and the resultant uneven drying
shrinkage. Let me quote from Prudence Rice's book, Pottery Analysis: A
Sourcebook, 1987, University of Chicago Press, p. 67-68:
"The method of shaping a clay body may contribute to uneven
shrinkage, and hence warping or cracking, through differential
water--uneven water content in different portions of the body. Areas that
are repeatedly stroked and smoothed during forming generally are wetter
than other parts; on a pot thrown on a wheel, for example, the exterior
will be wetter than the interior and the base wetter than the upper
portion. The portion of the body contained more water will shrink more
(because it has more water to lose) than the drier portion, causing
stresses that lead to warping or cracking, such as S-cracks."
Most of Rice's information comes from studies of contemporary but
traditional potters (through ethnographies) and ceramic science. Good luck
to all!
Nancy Benco
Nancy L. Benco
Dept. of Anthropology
George Washington University
Washington, DC 20052
E-mail: BENCO@GWIS2.CIRC.GWU.EDU
Fax: (202) 994-6097
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