Philosophy
A recent release concerning the city of Cahokia and the analysis of copper smithing brought to mind this huge city near St. Louis, Missouri some 600 years ago.
EVANSTON, Ill. --- Northwestern University researchers ditched many of their high-tech tools and turned to large stones, fire and some old-fashioned elbow grease to recreate techniques used by Native American coppersmiths who lived more than 600 years ago.
This prehistoric approach to metalworking was part of a metallurgical analysis of copper artifacts left behind by the Mississippians of the Cahokia Mounds, who lived in southeastern Illinois from 700 until 1400 A.D. The study was published in the Journal of Archaeological Science in May.
The researchers were able to identify how the coppersmiths of Cahokia likely set up their workshop and the methods and tools used to work copper nuggets into sacred jewelry, headdresses, breastplates and other regalia.
"Metals store clues within their structure that can help explain how they were processed," said David Dunand, the James N. and Margie M. Krebs Professor of materials science and engineering at Northwestern's McCormick School of Engineering and Applied Science and co-author of the paper. "We were lucky enough to analyze small, discarded pieces of copper found on the ground of the excavated 'copper workshop house' in Cahokia and determine how the metal was worked by the Cahokians."
Two materials science and engineering students conducted much of the research. Matt Chastain, a Northwestern undergraduate at the time of the study, worked alongside Alix Deymier-Black, a graduate student in the materials science and engineering department. Chastain, first author of the paper, undertook the metallurgical analysis of the samples, supplied from ongoing excavations at Mound 34 in Cahokia. Chastain followed up his analysis by volunteering at the excavation site.
"We cut through some samples of the copper pieces and polished them to look at the grain structures of the copper with a microscope," said Deymier-Black, second author of the paper. "From the size, shape and features of the grains inside the copper, we determined that the coppersmiths were likely hammering the copper, probably with a heavy rock, then putting the copper in the hot coals of a wood fire for five to 10 minutes to soften it and repeating the cycle until they had created a thin sheet of copper. "
After using basic metallurgical science to better understand the methods the Cahokians used to create copper sheets, Deymier-Black and Chastain recreated the metalworking process in the lab with natural copper nuggets, fire and a heavy stone ---pounding and heating the copper into thin sheets.
The researchers also tested theories that some archeologists had made about the coppersmiths' techniques. One idea was that they made large copper pieces, like ceremonial breastplates, by "laminating" sheets of copper together through a hammering technique. Deymier-Black said that the lamination could not be reproduced, even with much greater weights achievable with a modern press. The other hypothesis, that the Cahokians used copper knobs or copper rivets and other mechanical devices to secure sheets of copper together, seems more likely.
Another puzzle was how the Cahokians cut the hammered sheets of copper into regular shapes. The researchers cut replicated hammered sheets by four different methods: grinding an embossed ridge, shearing with scissors, hammering against a sharp corner, and bending the sheet back and forth. Only the bent edge looked similar to the edge of the historical artifacts, indicating that the Cahokians most likely used that method to cut copper.
Scientific insight into the process used to create the sacred copper artifacts of Cahokian people is helpful to James Brown, professor of anthropology at Northwestern Weinberg College of Arts and Sciences and John E. Kelly, professor of anthropology at Washington University in St. Louis. The two researchers, co-authors on the study, are credited with pinpointing the location of the copper workshop at Cahokia.
"I'm delighted that through the scientific process we were able to confirm some of the techniques and end some disputes about how the copper artifacts were made," said Brown, also an international expert on Native American archaeology. "This study gives some of the real details, so that an observer can imagine how it was done and could possibly hook onto other kinds of observations about the people of Cahokia."
wbur.org release...
The biggest city on American soil that you never heard of vanished a thousand years ago.
Cahokia, near St. Louis today, was bigger in its time than London — and its story reads now like something out of an Indiana Jones movie.
It had pyramids, temples, a “wood henge” for telling time — and organized mass human sacrifices on the Mississippi. It influenced almost every American native tribe — and the Cahokia site today is helping change our understanding of pre-Columbian America.
Cahokia [Wikipedia]
Cahokia Mounds
Cahokia: Ancient America's Great City on the Mississippi
by
Timothy R. Pauketat
ISBN-10: 9780670020904
ISBN-13: 978-0670020904
ASIN: 0670020907
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Philosophy
Cahokia...ancient American city
A recent release concerning the city of Cahokia and the analysis of copper smithing brought to mind this huge city near St. Louis, Missouri some 600 years ago.
"Science explains ancient copper artifacts"
Researchers reveal how prehistoric Native Americans of Cahokia made copper artifacts
by
Erin White
June 13th, 2011
Northwestern University
Researchers reveal how prehistoric Native Americans of Cahokia made copper artifacts
by
Erin White
June 13th, 2011
Northwestern University
EVANSTON, Ill. --- Northwestern University researchers ditched many of their high-tech tools and turned to large stones, fire and some old-fashioned elbow grease to recreate techniques used by Native American coppersmiths who lived more than 600 years ago.
This prehistoric approach to metalworking was part of a metallurgical analysis of copper artifacts left behind by the Mississippians of the Cahokia Mounds, who lived in southeastern Illinois from 700 until 1400 A.D. The study was published in the Journal of Archaeological Science in May.
The researchers were able to identify how the coppersmiths of Cahokia likely set up their workshop and the methods and tools used to work copper nuggets into sacred jewelry, headdresses, breastplates and other regalia.
"Metals store clues within their structure that can help explain how they were processed," said David Dunand, the James N. and Margie M. Krebs Professor of materials science and engineering at Northwestern's McCormick School of Engineering and Applied Science and co-author of the paper. "We were lucky enough to analyze small, discarded pieces of copper found on the ground of the excavated 'copper workshop house' in Cahokia and determine how the metal was worked by the Cahokians."
Two materials science and engineering students conducted much of the research. Matt Chastain, a Northwestern undergraduate at the time of the study, worked alongside Alix Deymier-Black, a graduate student in the materials science and engineering department. Chastain, first author of the paper, undertook the metallurgical analysis of the samples, supplied from ongoing excavations at Mound 34 in Cahokia. Chastain followed up his analysis by volunteering at the excavation site.
"We cut through some samples of the copper pieces and polished them to look at the grain structures of the copper with a microscope," said Deymier-Black, second author of the paper. "From the size, shape and features of the grains inside the copper, we determined that the coppersmiths were likely hammering the copper, probably with a heavy rock, then putting the copper in the hot coals of a wood fire for five to 10 minutes to soften it and repeating the cycle until they had created a thin sheet of copper. "
After using basic metallurgical science to better understand the methods the Cahokians used to create copper sheets, Deymier-Black and Chastain recreated the metalworking process in the lab with natural copper nuggets, fire and a heavy stone ---pounding and heating the copper into thin sheets.
The researchers also tested theories that some archeologists had made about the coppersmiths' techniques. One idea was that they made large copper pieces, like ceremonial breastplates, by "laminating" sheets of copper together through a hammering technique. Deymier-Black said that the lamination could not be reproduced, even with much greater weights achievable with a modern press. The other hypothesis, that the Cahokians used copper knobs or copper rivets and other mechanical devices to secure sheets of copper together, seems more likely.
Another puzzle was how the Cahokians cut the hammered sheets of copper into regular shapes. The researchers cut replicated hammered sheets by four different methods: grinding an embossed ridge, shearing with scissors, hammering against a sharp corner, and bending the sheet back and forth. Only the bent edge looked similar to the edge of the historical artifacts, indicating that the Cahokians most likely used that method to cut copper.
Scientific insight into the process used to create the sacred copper artifacts of Cahokian people is helpful to James Brown, professor of anthropology at Northwestern Weinberg College of Arts and Sciences and John E. Kelly, professor of anthropology at Washington University in St. Louis. The two researchers, co-authors on the study, are credited with pinpointing the location of the copper workshop at Cahokia.
"I'm delighted that through the scientific process we were able to confirm some of the techniques and end some disputes about how the copper artifacts were made," said Brown, also an international expert on Native American archaeology. "This study gives some of the real details, so that an observer can imagine how it was done and could possibly hook onto other kinds of observations about the people of Cahokia."
wbur.org release...
The biggest city on American soil that you never heard of vanished a thousand years ago.
Cahokia, near St. Louis today, was bigger in its time than London — and its story reads now like something out of an Indiana Jones movie.
It had pyramids, temples, a “wood henge” for telling time — and organized mass human sacrifices on the Mississippi. It influenced almost every American native tribe — and the Cahokia site today is helping change our understanding of pre-Columbian America.
Cahokia [Wikipedia]
Cahokia Mounds
Cahokia: Ancient America's Great City on the Mississippiby
Timothy R. Pauketat
ISBN-10: 9780670020904
ISBN-13: 978-0670020904
ASIN: 0670020907
- Huguette Clark Leaves Big Bucks To Nurse Hadassah Peri
"Huguette Clark, Manhattan billionaire recluse, leaves £21m for nurse" Hadassah Peri looked after copper-mining heiress from 1991 until her death and became a friend and loyal companion by David Batty June 23rd, 2011 guardian.co.uk A billionaire recluse...
- "penny" Poll
Should the penny be dropped from circulation? No...2 Yes...4 Okay, they are a nuisance and have little intrinsic value...not copper anymore. "A penny is the lowest form of American currency, worth only one cent, and is popularly believed to be made solely...
- King Solomon's Mines...a Myth Challenged
A legendary tale well represented by literature and the cinema and exemplifies what a myth may be...an exaggeration of an actual event or situation. We have been told of the enormous wealth of King Solomon's mines: Diamonds, gold, ivory, silver....
- Ancient Metallurgy--art
It is the common case when we go to a museum and observe artifacts made of metal that we often don't even consider the science of metallurgy. We love the golden objects but never give a thought about the art of making the objects. This topic is concentrated...
- Simple Science And Priestly Control
"The Ark of the Covenant"..."Baghdad Battery"--similar in physics and intent? Well, maybe. Probably more for religious significance and crowd control. Great mystery and controversy surround both of these items. The "The Ark of the Covenant" ca. 2,000...