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  #31   Report Post  
Old June 26th 04, 08:21 AM
Inger E Johansson
 
Posts: n/a
Default Copper Casting In America (Trevelyan)


"Eric Stevens" skrev i meddelandet
...
On Fri, 25 Jun 2004 19:24:15 -0500, Tom McDonald
wrote:

Eric Stevens wrote:

On Wed, 23 Jun 2004 23:46:01 -0500, Tom McDonald
wrote:


Eric Stevens wrote:


On Fri, 11 Jun 2004 22:57:04 GMT, (Gary Coffman)
wrote:

snip

Realize that casting is primarily a technique used for cheap mass
produced items.


With respect, that is nonsense. Casting is a technique which is used
to make shapes and structures which cannot be easily made any other
way.

Eric,

In the case of the copper artifacts in the upper Great Lakes
area, all of the shapes and structures have been shown to have
been made via cold and hot-working techniques.


This is not my understanding. Metallurgical examination has shown that
some of the artifacts have been cast.


Eric,

That could be. That's why I wrote the below.

My point here is that at least two researchers have done
experiments using only cold and hot working, without casting,
making all of the major types of artifacts found in the Great
Lakes area. This is not to say that some might not have been
cast. That's the issue. Contrary to what you write above, I
have not yet completed my own look into whether some might have
been cast. I'm not willing to take at face value reports of
research the originals of which I haven't yet found.


Fair enough. You may remember that some years ago I reported that I
had tried to track down Mallery's papers (left to the Smithsonian on
his death) to obtain copies of the originals upon which he relied, but
all the papers seem to have vanished into a black hole. It might be
worth another try.


Eric,
I thought I told you last summer that Mallery's paper is found in a Private
Museum? Didn't you get any of the files I have from the Keller deposit? I am
sure we discussed photos taken of the artifacts.

Inger E



(Note that I am
not saying that all the copper artifacts were so made; only that
casting was not necessary.)


That seems to be a different topic. Are you saying that even if they
were found to be cast, it wasn't necessary for them to be cast?


It's the same topic. I was trying to avoid just this confusion
by stating frankly that the research I mentioned does not rule
out casting. And to your question, yes. I'm saying that it
seems to me at this point that both casting and smithing could
have produced the tools we find.


Only if your assessment is based on simplistic visual examination.
Appropriate metallurgical tests are unambiguous.

The issue is whether both
techniques were used, and if so over what time period and what
places within the region.



As for whether certain types of
tools and ornaments might be more easily made by casting, this
is only true if the technology for casting has been developed.
That is what is at issue.


I think you and I are approaching the question from opposite ends. You
seem to be saying that no artifacts can have been cast, in the absence
of direct evidence for casting techniques. I am saying that cast
artifacts are evidence for the existence of casting techniques, even
if direct evidence for such techniques is not known.


You mistake my meaning. I am saying that casting and smithing
both could have been used. If there are artifacts that were
cast, then that fact should inform future archaeological work.

I'm not sure that you know this, but the main copper-using
cultures of the upper Great Lakes areas are very poorly
represented by habitation sites. In Wisconsin and the UP of
Michigan, there are only a few such sites that have been found
and studied from this period (Late Archaic to the transition to
Early Woodland--ca. 3-4000 to ca. 100 BC).

There are a great many sites with copper artifacts, but they
are mostly either surface finds, or are in mortuary contexts;
not where the ancient smiths/foundryfolk might have been
expected to ply their trades

I am less sanguine than you that old reports for which we have
only second-hand sources, and for which we don't know the
caveats and limitations of the researchers, can be accepted
uncritically in the face of nearly unanimous statement from
those who have studied the copper artifacts intensively that
they haven't found convincing evidence of casting. However, I
take offense at the suggestion that I've ruled out casting when
I am actually looking into the issue with an open mind.


I didn't say, or even imply, that you have unconditionally ruled out
the possibility of cast artifacts.



It allows relatively low skilled workers to produce
large numbers of relatively complex identical items.


You do them a disservice to describe them as "low skilled". The work
is difficult and dnagerous, and it took centuries to develop the
techniques.

Yes, especially wrt copper (see Gary's discussion of copper
casting problems below). So far as I can see at this point,
there isn't good evidence for such a period of development in
the archaeological record.

OTOH, at least for the Old Copper and Red Ochre complexes in
the Upper Great Lakes region, there don't seem to be many
well-documented sites from that period (ca. 3000-1000 BC); and
stratified sites are even more rare. Most of the copper
artifacts were surface finds, and many came from collectors
whose documentation of their finds generally ranged from fair to
non-existent.



Cold working is
a much more challenging, and artistically unique, way to produce
intricate copper ceremonial items. The smith has to have a higher
level of skill than the foundryman to produce equally complex work.


Which is why the people who know how to melt and cast copper use that
technique rather than straight smith-work.

Again, I don't know that that is true wrt copper, given the
difficulty the technique appears to have in creating strong,
high-quality results. OTOH, cold and hot working were known by
the Native peoples in the Great Lakes ares to produce that very
strong, high-quality result.

snip

But that said, casting pure copper is a bitch.


This from the guy who has just written that the task can be undertaken
by low-skilled workers?

Eric, I read that to mean that casting, in general (as with
iron, silver, bronze, gold, etc.) can be done by folks with
fewer skills than smiths. However, copper appears to present
particular problems with casting that are not so pronounced with
other metals, and which require higher skill levels than would
be required by those who cast other metals.


I don't read 'low skilled' as meaning 'lower skilled'.


Read it again. No mention of 'low skilled'.


Gary Coffman originally wrote of casting "It allows relatively low
skilled workers to produce ... " and it was to this which I originally
repsonded. My point was that casting is not a low skilled technique.

Merely that a
smith needs 'higher level of skill' than a foundryman. A
neurosurgeon may need a 'higher level of skill' than a
dermatologist. Does this make the dermatologist 'low skilled'?q


But is the fundamental proposition correct, that a dermatologist is
necessarily of lower skill than a neurosurgeon? My observation is that
while the disciplines are different, the skill levels are equally high
in each.


This should be taken into consideration along with the fact
that Great Lakes copper, and drift copper, don't need to be
smelted to use. In other areas, where smelting ore _is_
required, the technology for melting metal is a given; here, it
isn't.


There is a difference between 'smelted' as in refinining and 'melted'
as for casting. I am not aware of evidence for the for the former in
NA but there may be evidence for the latter in the form of cast
artifacts.


Of course smelting ore and melting for casting are different.
However, if one needs and has the technology for smelting,
melting for casting is not a technological leap. If one does
not need to smelt ore, then melting it for casting requires that
technological leap. The issue is whether that leap was made in
this case.


The discovery of either smelting or melting would initially be
accidental. I could think of circumstances in which melting could
still occur when working with pure meteoric copper.

If cast artifacts are found, then looking for
evidence of the development of that technology would be a higher
archaeological priority than it is now.


I do not share your certainty. Cast artifacts do seem to have been
found. I am not aware that the reports cited by Mallery have been
followed up in any way. As far as I can tell, nobody has even followed
them up for the purpose of showing that they were wrong or that
Mallery has misinterpreted them. The whole subject seems to have been
treated as a non-issue.




Porosity is the enemy,
even for modern copper founders. They charge a hefty premium for
low porosity castings. Alloying the copper to make bronze improves
matters *enormously*, and production of such alloys was a huge
technological leap forward for the casting industry.

*If* the Native Americans of millenia past made the technological
leap of producing bronze alloy, it would be a significant achievement
(as it was when Old World artisans did it). But I've seen no evidence
produced in this thread that the ancient Native Americans made
such a technological leap forward.

The artifacts described appear to all be relatively pure native

copper.
As such, the *intelligent* way of working the material would have
been smithing rather than casting. So if the motive were to make
ancient Native Americans appear stupid, then claiming that they
used open casting techniques would be the method of choice to do
so. Now ask yourself which side of the argument is making that
claim.


Neither. The claim merely is that some copper items have been cast.

Eric, Yuri was making the claim that to say Indians of the
Great Lakes area didn't cast copper was to express bigotry
towards the First Nations of the area. Gary's argument flows

from Yuri's standard 'mainstreamers are racists' rap, with its

particular application in the cast vs. worked copper issue.

I'm still agnostic, and am reading up on the archaeological
references I can find. If you, or other folks, have suggestions
for reading, I'm all eyes.

BTW, I've just gotten Mallery's book (the 1979 version, revised
and extended by Mary Roberts Harrison). I've only skimmed a bit
of it, so I don't have an informed opinion on it yet. Will advise.


Very much the curate's egg.


I'm not familiar with that. Will you explain for me?

A 19th century 'Punch' cartoon. The very new curate is having
breakfast with his bishop and finds the boiled egg he has been served
is rotten. The curate lacks the courage to complain about the bishop's
breakfast fodder but the expression on his face alerts the bishop to
the fact that all is not well. The bishop then asks ' ... and how is
your egg?' The curate still too nervous to say the egg is rotten
replies "Parts of it are excellent, my lord". That last is the comment
I applied to Mallery's book.



Eric Stevens




  #32   Report Post  
Old June 26th 04, 10:57 AM
Eric Stevens
 
Posts: n/a
Default Copper Casting In America (Trevelyan)

On Sat, 26 Jun 2004 07:21:52 GMT, "Inger E Johansson"
wrote:


"Eric Stevens" skrev i meddelandet
.. .
On Fri, 25 Jun 2004 19:24:15 -0500, Tom McDonald
wrote:

Eric Stevens wrote:

On Wed, 23 Jun 2004 23:46:01 -0500, Tom McDonald
wrote:

--- snip ---

That could be. That's why I wrote the below.

My point here is that at least two researchers have done
experiments using only cold and hot working, without casting,
making all of the major types of artifacts found in the Great
Lakes area. This is not to say that some might not have been
cast. That's the issue. Contrary to what you write above, I
have not yet completed my own look into whether some might have
been cast. I'm not willing to take at face value reports of
research the originals of which I haven't yet found.


Fair enough. You may remember that some years ago I reported that I
had tried to track down Mallery's papers (left to the Smithsonian on
his death) to obtain copies of the originals upon which he relied, but
all the papers seem to have vanished into a black hole. It might be
worth another try.


Eric,
I thought I told you last summer that Mallery's paper is found in a Private
Museum? Didn't you get any of the files I have from the Keller deposit? I am
sure we discussed photos taken of the artifacts.



All that I can find which might possibly relate to that is "Shipley,
Marie A. [Brown]. The Norse Colonization in America by the Light of
the Vatican Finds. Lucerne: H. Keller's Foreign Printing Office,
[1899]."

It doesn't seem to relate to Mallery in any way.

--- snip ----



Eric Stevens
  #33   Report Post  
Old June 26th 04, 11:06 AM
Inger E Johansson
 
Posts: n/a
Default Copper Casting In America (Trevelyan)


"Eric Stevens" skrev i meddelandet
...
On Sat, 26 Jun 2004 07:21:52 GMT, "Inger E Johansson"
wrote:


"Eric Stevens" skrev i meddelandet
.. .
On Fri, 25 Jun 2004 19:24:15 -0500, Tom McDonald
wrote:

Eric Stevens wrote:

On Wed, 23 Jun 2004 23:46:01 -0500, Tom McDonald
wrote:

--- snip ---

That could be. That's why I wrote the below.

My point here is that at least two researchers have done
experiments using only cold and hot working, without casting,
making all of the major types of artifacts found in the Great
Lakes area. This is not to say that some might not have been
cast. That's the issue. Contrary to what you write above, I
have not yet completed my own look into whether some might have
been cast. I'm not willing to take at face value reports of
research the originals of which I haven't yet found.

Fair enough. You may remember that some years ago I reported that I
had tried to track down Mallery's papers (left to the Smithsonian on
his death) to obtain copies of the originals upon which he relied, but
all the papers seem to have vanished into a black hole. It might be
worth another try.


Eric,
I thought I told you last summer that Mallery's paper is found in a

Private
Museum? Didn't you get any of the files I have from the Keller deposit? I

am
sure we discussed photos taken of the artifacts.



All that I can find which might possibly relate to that is "Shipley,
Marie A. [Brown]. The Norse Colonization in America by the Light of
the Vatican Finds. Lucerne: H. Keller's Foreign Printing Office,
[1899]."

It doesn't seem to relate to Mallery in any way.


It must either have been eaten of your computer when it was sent to service
or been sent via the one of telia's servers which has had problems sending
files to Australia and New Zealand.

I do have a lot of info. I am writing on a thriller for the moment, together
with an old friend of mine. Thus I can't put it in my computer before
midnight Swedish time when I am home after we have gone thru some of the
chapters in the book. You will have the first files tomorrow.

Inger E


  #34   Report Post  
Old June 26th 04, 09:20 PM
George
 
Posts: n/a
Default Copper Casting In America (Trevelyan)

"Inger E Johansson" wrote in message ...
"Eric Stevens" skrev i meddelandet
...

snip


All that I can find which might possibly relate to that is "Shipley,
Marie A. [Brown]. The Norse Colonization in America by the Light of
the Vatican Finds. Lucerne: H. Keller's Foreign Printing Office,
[1899]."

It doesn't seem to relate to Mallery in any way.


It must either have been eaten of your computer when it was sent to service
or been sent via the one of telia's servers which has had problems sending
files to Australia and New Zealand.



hey Eric dont you let that one go by. Start Inger off on an A+ course



I do have a lot of info. I am writing on a thriller for the moment, together
with an old friend of mine. Thus I can't put it in my computer before
midnight Swedish time when I am home after we have gone thru some of the
chapters in the book. You will have the first files tomorrow.


Hey what number excuse are we up to here?
Is the klock still running
  #35   Report Post  
Old June 27th 04, 07:58 AM
Gary Coffman
 
Posts: n/a
Default Copper Casting In America (Trevelyan)

On Fri, 18 Jun 2004 16:34:00 GMT, Seppo Renfors wrote:
Gary Coffman wrote:
If they did open atmospheric casting (and I'd strongly contend they
didn't have the technology to do any other kind, nobody did until the
latter half of the 19th century, and then only as a laboratory curiosity),
the resulting copper wouldn't be suitable for cold work, too much
porosity.


I agree that is most likely to have been the procedure. On the other
hand what we don't really know is if the porosity was a problem for
them.


It would be a problem, a big problem.

If they did attempt to salvage copper scraps, they likely *hammer
welded* them. That's done at temperatures below the melting point
of copper, so porosity doesn't become as serious a problem.


....and it would also eliminate porosity, would it not? So the small
bit could well be melted and cast into a small ingot - to later
"hammer weld" the porosity out of it.


No, it couldn't. Porosity isn't just little bubbles in the metal. Those
bubbles contain air, and at molten temperatures, the oxygen in that
air would oxidize the inside of the bubble. So what you wind up with is
a mass of copper with a lot of oxidized holes in it. You can't weld
copper that is oxidized. If this happens when a modern TIG welder
is welding copper (gas shield failure), the only thing he can do is
grind out all the porosity and start over.

You need to understand that copper behaves *differently* from silver,
gold, or even iron. Those metals respond well to casting techniques.
Nearly pure copper does not.


I'm aware of the difficulty - as well as the evidence it provides of
casting. As such evidence does exist, even if not widely, it indicates
the ability to melt copper.


No trick to melting copper. Doing something intelligent with the molten
metal in an atmospheric environment is a different matter. As I noted
previously, casting pure copper is difficult, even today. For a people
without inert gas shielded continuous casting furnaces, it would be
nothing but frustration.

Gary


  #37   Report Post  
Old June 27th 04, 08:11 AM
Gary Coffman
 
Posts: n/a
Default Copper Casting In America (Trevelyan)

On Sat, 26 Jun 2004 11:13:49 +1200, Eric Stevens wrote:
On Wed, 23 Jun 2004 23:46:01 -0500, Tom McDonald
wrote:
In the case of the copper artifacts in the upper Great Lakes
area, all of the shapes and structures have been shown to have
been made via cold and hot-working techniques.


This is not my understanding. Metallurgical examination has shown that
some of the artifacts have been cast.


The evidence brought out in this thread is that *one* copper artifact
shows radiographic evidence (characteristic porosity) for part of it
being heated above the melting point in atmosphere at some point.
That is in no way conclusive evidence of casting technology. The
piece may have been an attempt at casting, or it may simply have
been overheated while being worked.

Gary
  #38   Report Post  
Old June 27th 04, 07:18 PM
Tom McDonald
 
Posts: n/a
Default Copper Casting In America (Trevelyan)

Gary Coffman wrote:
On Sat, 26 Jun 2004 11:13:49 +1200, Eric Stevens wrote:

On Wed, 23 Jun 2004 23:46:01 -0500, Tom McDonald
wrote:

In the case of the copper artifacts in the upper Great Lakes
area, all of the shapes and structures have been shown to have
been made via cold and hot-working techniques.


This is not my understanding. Metallurgical examination has shown that
some of the artifacts have been cast.



The evidence brought out in this thread is that *one* copper artifact
shows radiographic evidence (characteristic porosity) for part of it
being heated above the melting point in atmosphere at some point.
That is in no way conclusive evidence of casting technology. The
piece may have been an attempt at casting, or it may simply have
been overheated while being worked.

Gary


Gary,

Are you referring to the sort of amorphous, three-cornered blob
listed in Conner's web site as 'R666', and in the Milwaukee
Public Museum (where it's curated) as '55786':

http://www.iwaynet.net/~wdc/copper.htm

If so, I have found additional information about that piece.

Tom McDonald
  #39   Report Post  
Old June 27th 04, 08:33 PM
Gary Coffman
 
Posts: n/a
Default Copper Casting In America (Trevelyan)

On Sun, 27 Jun 2004 13:18:58 -0500, Tom McDonald wrote:
Gary Coffman wrote:
The evidence brought out in this thread is that *one* copper artifact
shows radiographic evidence (characteristic porosity) for part of it
being heated above the melting point in atmosphere at some point.
That is in no way conclusive evidence of casting technology. The
piece may have been an attempt at casting, or it may simply have
been overheated while being worked.

Gary


Gary,

Are you referring to the sort of amorphous, three-cornered blob
listed in Conner's web site as 'R666', and in the Milwaukee
Public Museum (where it's curated) as '55786':

http://www.iwaynet.net/~wdc/copper.htm

If so, I have found additional information about that piece.

Tom McDonald


Yes, that's the one. What have you learned?

Gary

  #40   Report Post  
Old June 27th 04, 08:59 PM
Tom McDonald
 
Posts: n/a
Default Copper Casting In America (Trevelyan)

Gary Coffman wrote:
On Sun, 27 Jun 2004 13:18:58 -0500, Tom McDonald wrote:

Gary Coffman wrote:

The evidence brought out in this thread is that *one* copper artifact
shows radiographic evidence (characteristic porosity) for part of it
being heated above the melting point in atmosphere at some point.
That is in no way conclusive evidence of casting technology. The
piece may have been an attempt at casting, or it may simply have
been overheated while being worked.

Gary


Gary,

Are you referring to the sort of amorphous, three-cornered blob
listed in Conner's web site as 'R666', and in the Milwaukee
Public Museum (where it's curated) as '55786':

http://www.iwaynet.net/~wdc/copper.htm

If so, I have found additional information about that piece.

Tom McDonald



Yes, that's the one. What have you learned?

Gary


Gary,

I corresponded with Dr. Alex Barker of the Milwaukee Public
Museum about this artifact, since they are curating it there.
His response about the description of the artifact was as follows:

"As to why one might wonder if it had been cast, it's relatively
dense for its size, and one surface is fairly smooth and
rounded--not like the upper surface of cast metal, however, but
one might perhaps imagine it as the bottom of an irregular
puddle of metal."

It sounded to me as though he had just looked at it; he was
more than generous with me, running around and looking for the
artifact and associated documentation for me. Unfortunately, he
says he couldn't find a record of any radiograph, but that that
didn't mean it wasn't there. They are changing their records
over to computer files, and the integration of those files won't
start for several months yet. I for one don't doubt the
radiographs shown on Connor's web site, though.

The description he gave seems to fit the photo on Connor's
site. It doesn't look like any purpose-made artifact; but it
does look as one might expect a bit of accidentally melted
copper to look, if it just fell into the ashes of the fire and
cooled there. To my untutored eye, at least.

Tom McDonald





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