Bill
There was a full range of vessel completeness from a single sherd to a fully restored vessel, although the former (one or very few sherds was somewhat more common). I only did glazed yellow ware bodies, no Rockingham, because I was looking at "pure" yellow only. Of nearly 300 vessels in the study, 169 were utilized for color matching. This is a Cincinnati-area study, and although we suspect that most of the vessels were made in Cincinnati (Cincinnati was a major yellow ware manufacturing center in the 19th century), there are certainly East Liverpool specimens, and perhaps some from eastern potters as well. More than half of color-matched vessels were matched to the 2.5Y8/6 chip, with an additional 15% to 2.5Y8.5/6. As many as 91% could be matched to six adjacent chips -- 2.5Y8/6, 2.5Y8.5/6, 2.5Y7/6, 2.5Y8/8, 2.5Y7/8, and 2.5Y8.5/8. 75% could be matched to light yellow to yellow chips -- 2.5Y8/6, 2.5Y8.5/6, and 2.5Y8/8. There were more than a dozen outliers, most on the 2.5Y page, but a number on the 10YR page. The assemblage does include some waster materials from a Covington, Kentucky yellow ware pottery (1859-1864). I also looked at an assemblage of yellow ware sherds from the Mansion Pottery in East Liverpool. Surprisingly (or perhaps not surprisingly), there was more diversity in the assemblage from a single potter than there was from the Cincinnati vessels which represents many potteries. There is considerable overlap in the color matches. The take home message is that it is inadvisable to attempt to sort yellow ware ceramics based upon color. The overlap between samples, and the increased diversity within one were quite compelling. And, you and others are correct. There are many reasons for finished glaze color, including production and post-production issues. My attempt was to establish at least a baseline in reproducible color matches. The issue I discussed was that you could put a pile of sherds/vessels together from one chip match and still clearly see differences in color. That is why a colorimeter would be a better way to go.
Bob Genheimer, RPA
George Rieveschl Curator of Archaeology
Cincinnati Museum Center
1301 Western Avenue
Cincinnati, Ohio 45203
513-455-7161 office
513-846-4898 mobile
513-455-7169 fax
-----Original Message-----
From: HISTORICAL ARCHAEOLOGY [mailto:[log in to unmask]] On Behalf Of Bill
Sent: Monday, February 20, 2012 8:15 AM
To: [log in to unmask]
Subject: Re: Colorimeter for ceramics
Bob,
Was your yellow ware examination restricted to complete vessels, or did it involve sherds or materials from waster sites. A couple of years ago we had the leading collectors of yellow ware come to our offices and have them sort a pile of yellow ware into region (mainly Ohio or Trenton, NJ) and by potter, as they thought they could do this based on color of the Rockingham glaze. What we did not tell them until afterwards was they were from a single potter from Trenton (Coxon's waster dump). They had separated them into several piles and were convinced they were correct ...until we came clean with where they came from. It was not intended to embarrassing them, but more to educate them that the surface appearance of ceramics is influenced by many factors such as George Miller pointed out with clays.
Anyone who has potted knows that the appearance of glazes are dependent upon humidity, temperature, types of fuel, glaze mixtures as well as other factors. Many potter keep logs recording these factors so they can attempt to duplicate products when they turn out well...similar to a fisherman who catches a big bass on a certain overcast day in March when the temperature was 52 degrees.
Bill Liebeknecht, MA RPA
Hunter Research, Inc.
-----Original Message-----
From: HISTORICAL ARCHAEOLOGY [mailto:[log in to unmask]] On Behalf Of Bob Genheimer
Sent: Monday, February 20, 2012 6:56 AM
To: [log in to unmask]
Subject: Re: Colorimeter for ceramics
Chris
I just completed a large scale examination of Cincinnati-area yellow ware, and utilized a full-color Munsell book(s) for color comparison. The Munsell is not fully adequate, because there is still a small range of color within each chip match. I recognized that a colorimeter was the way to go, but taking hundreds of vessels to the colorimeter was just not an option. I would be very interested in comparisons of colorimeter data with Munsell matches.
Bob Genheimer, RPA
George Rieveschl Curator of Archaeology
Cincinnati Museum Center
1301 Western Avenue
Cincinnati, Ohio 45203
513-455-7161 office
513-846-4898 mobile
513-455-7169 fax
-----Original Message-----
From: HISTORICAL ARCHAEOLOGY [mailto:[log in to unmask]] On Behalf Of Christopher Nicholas Marini
Sent: Sunday, February 19, 2012 3:47 PM
To: [log in to unmask]
Subject: Colorimeter for ceramics
Dear List,
I am a graduate student at Indiana University of Pennsylvania and I am currently looking to begin work on my master's thesis. The project I am considering involves using a device called a colorimeter, which measures color, to develop a scale for identifying ceramics, most notably creamware, pearlware, and whiteware, as I have had personal experience with the difficulty in identifying these artifact types.
I have done some research into this topic, but am unsure whether or not anyone else has already attempted it. I have looked through several major journals and have not found any reference to such a project. If anyone knows of work of this type that has been done, please let me know of it so that I may incorporate it into my project or switch thesis topics.
Thank you for your time,
Chris
There is still time to journey through the Age of Steam with our current OMNIMAX feature, Rocky Mountain Express! See incredible vistas and learn about one of the most amazing feats of engineering that is the Canadian Pacific Railroad. The film is open now through March 1.
There is still time to journey through the Age of Steam with our current OMNIMAX feature, Rocky Mountain Express! See incredible vistas and learn about one of the most amazing feats of engineering that is the Canadian Pacific Railroad. The film is open now through March 1.
|
