Copper Casting In Ancient America - Part 2

Thanks to Eric Stevens, who posted this interesting info
in article .
Now I'm reposting this for the benefit of the folks in
rec.crafts.metalworking.
[begin quote from Eric's post]
In the previously quoted Appendix A to "The Rediscovery of Lost
America", Mallery at first describes how James A. Ford, of the
American
Museum of Natural History, "selected three tools of a type which might
have been hammered from crude copper to be examined by the well known
New York Testing Laboratories."
He went on to quote from the subsequent report:
Begin Quote:
+++++++++++++++++++++++++++++++==
A transverse section taken from each of the submitted specimens was
prepared and examined at 100 magnifications to determine the type of
material and the nature of fabrication. The specimens were found to be
forged from cast material. The microstructure of the
axe and chisel consists of coarse-grained copper and in addition
several annealing twins were detected in the structure. The above
condition indicates that the tools were hot forged and the annealing
twins were formed on reheating. The microstructure of the spearhead
consists of pure copper crystals or grains. This tool has been
subjected to a greater degree of working at a lower temperature than
the previous tools, as indication of severe grain distortion is
clearly detected in the structure.
SPEARHEAD:-- 100 Magnifications--Etched.
STRUCTURE:--Shows pure copper crystals or grains. The above structure
is largely distorted due to subsequent working below the
recrystallization temperature.
AXE:--100 Magnifications--Etched.
STRUCTURE:--Shows pure copper crystals.
The dark parallel bands are annealing twins formed after reheating
from the forging or working operations.
CHISEL:--l00 Magnifications--Etched.
STRUCTURE:--Shows coarse-grained copper crystals. Several annealing
twins are also detected in the microstructure.
X-RAY EXAMINATION:--The tools were radiographed using standard
techniques. A review of the radiographs led to the following
observations:
# I--The three tools were originally cast.
#2--The copper chisel No. 20/6772 shows indications of piping in the
interior. There were no indications of any washing of the mold
material within the tool. Therefore, the mold was probably a stone
mold.
#3--The axe No. 20/6804 and the spearhead No. I 922T both show
indications of entrapped mold wash material. This would indicate that
a clay mold was used.
SUMMARY:--The three copper specimens all show relatively low amounts
of
impurities with the exception of the phosphorous content of the chisel
which is present in an appreciable amount. Metallographical
examination indicates low oxygen content in all cases. The specimens
are originally cast but apparently have been reheated and worked to
some extent.
++++++++++++++++++++++++++++++++++++++++++++++++=
Mallery went on to say:
"Following this report, six leading American museums furnished
tools from the United States, Canada, Mexico, Guatemala, and
Peru for testing. Various metallurgists who have examined the
micrographs of these tools concur in the findings of the New
York Testing Laboratories, Inc. that many of the specimens
examined have been cast. Dr. George P. Ellinger, metallurgist
for the National Bureau of Standards, said, after examining the
submitted specimens, "The presence of cuprous oxide in the
interior of the tools tested and the concavity caused by
shrinking justify the conclusion that the vast majority of the
ancient tools were cast."
[end quote from Eric's post]
I guess all this info speaks for itself. The American archaeological
establishment doesn't seem to show any interest in these advanced
metal-working techniques as used by the ancient Native Americans.
The reason for this may not be all that clear, but it certainly seems
to have something to do with prior political presuppositions.
So this is what happens when scientific research is driven by
political expectations.
Regards,
Yuri.
Yuri Kuchinsky -=O=-
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A great many people think they are thinking when they are merely
rearranging their prejudices -=O=- William James
Reply to
Yuri Kuchinsky
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Yuri, I am not sure specifically where these specimens were located. For example, the unique native copper nodules found in Michigan may have given those locals an advantage, diminishing the credit for innovation to a degree. I also might agree somewhat if these finds and reports were in the mid 1800s, as the prejudices in anthropology were in certainly in place at that time due to the conflicts with indigenous peoples, much as the class divisions in Europe (east and west) were at that time. We have moved past that stage here in America, and were surprised at the bickering that went on in Europe when the "Ice Man" was discovered. Alan Black
Reply to
Alan Black

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