Re: Copper Casting In America (Trevelyan)

From: Eric Stevens (eric.stevens_at_sum.co.nz)
Date: 06/25/04 

Date: Sat, 26 Jun 2004 11:13:49 +1200

On Wed, 23 Jun 2004 23:46:01 -0500, Tom McDonald
<tmcdonald2672@charter.net> wrote:

>Eric Stevens wrote:
>
>> On Fri, 11 Jun 2004 22:57:04 GMT, ke4zv@bellsouth.net (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.

>(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?

> 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.
>
>>
>>
>>>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'.

>
> 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.

>
>>
>>
>>>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.

Eric Stevens

Relevant Pages

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  • Re: Copper Casting In America (Trevelyan)
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