I copied this paragraph from the Tennessee Center for Transportation
Research; Laboratory Procedures and Artifact analysis (found on the
internet).
I was wondering how you all feel about using these dates for a ceramic that
can't be positively identified as whiteware or pearlware and including it in
a mean calculation.



Transitional wares are a category of convenience rather than a true ceramic
type. In this analysis, all refined earthenwares which show characteristic
traits of both pearlware and whiteware are classified as transitional wares
and are given a date range corresponding with the period during which
whiteware gradually superseded pearlware as the common table ceramic,
1820-1835. Historical archaeologists have long attempted to find an easy way
to distinguish late pearlware from early whiteware (Noel-Hume 1970; Price
1979). The most common method is to look for blue puddling of the glaze
combined with a refined thinness of the ceramic body and the use of certain
colors for underglaze enameling (Price 1979:14-15). Unfortunately, this
method can produce erroneous results. The slow whitening of pearlware and
the vestigial bluing of whiteware, combined with the various manufacturers
use of the term "pearl" to refer to their wares long after the disappearance
of what archaeologists call pearlware, make a critical determination of ware
type in some cases almost impossible for the years between 1820 and 1835. To
make matters worse for those who use glaze tint as a criterion, there was a
resurgence in the popularity of blue tinted glazes on whiteware produced for
the provincial English and American markets in the 1840s (Miller
1980:17-18). Fortunately, these later blue tinted whitewares are easily
distinguished from the transitional period wares by their thickness and
decoration. The use of a transitional ware category in the calculation of
Mean Ceramic Dates (South 1977) will tend to even out the discrepancies that
would appear with the use of arbitrary classification of these wares as
either pearlware or whiteware. The root of the debate over the determination
of ware type can be reduced to one concern - chronology. The transitional
wares category addresses this concern by providing a tighter date range for
certain artifacts.


Roberta Charpentier
Archaeology Lab Supervisor
Mashantucket Pequot Museum and Research Center
110 Pequot Trail
Mashantucket, CT  06339
Email:  [log in to unmask] <mailto:[log in to unmask]>
Phone:  860-396-6936
Fax:  860-396-6914