Base ingots were formed as a temporary end-product for a specific purpose. After mining and scouring copper, it had to be compacted and reduced to manageable sizes. Sharp edges, so common on mined copper, had to be folded and pounded down for storage and shipping. Rough edges might well tear their birch bark containers. Shifting loads of sharp copper would have worked their way through the bottom of canoes and months of work lost. We can see the practical purpose of base ingots.
Bar ingots were practical for the same reasons, and even better shaped for transporting and accounting for in number. They were orderly. They were, however, extra work, and as base ingots were sufficient, bars would appear unnecessary and therefore extravagant. One might argue that the added work made them more appealing and as trade objects appeal justified extra work.
On the other hand bars are not so common as base ingots, especially in mining areas. Base ingot catches are common, whereas this researcher knows of no exclusive bar ingot catches. None were noted in the study of more than 2000 modified pieces of copper. None are mentioned in the literature. None have been reported to me by those metal detecting copper.
It is possible that bars were not created as a specific goal, but as a stage in creating artifacts. Franklin 1981 studied the Copper Inuit’s’ methods of crafting copper. He noted that many objects were crafted from copper bars and some of the modified pieces he pictures are similar to Old Copper culture bar ingots.
Joseph Neubauer Sr., age 81, of Pine City Minnesota, is crafting Old Copper culture artifacts (reproductions) from native copper, (Peterson 2003). He works with tools and materials similar to those used by ancient copper craftsmen. He has found that he must first create copper bars (bar ingots) and it is from these bar ingots that he creates implements and ornaments.
If Neubaur has rediscovered the ancient coppersmiths’ method of crafting copper, perhaps preforms and blanks are the other two intermediate steps. The first stage would have been native copper, followed by scoured copper, base ingots, bar ingots, preforms, blanks and finally the completed object. This is not to say that bars, preforms and blanks were not sometimes deliberately set aside for future completion or for trade. They surely were, just as were their cousins in stone.
As attractive as this theory might be to some, it has drawbacks. As mentioned, base ingots are common, but bars are rare. If bare were regularly used as intermediate steps between base ingots and preforms, as reported by Franklin 1981 and Peterson 2003, they would be as common, or nearly as common as base ingots. They are not. Base ingots, preforms and blanks are not only common, but we can clearly see purpose in their creation, and their roles in the class structure followed in creating copper artifacts. For the present, bar ingots remain somewhat of an enigma.
Franklin, U.M., Badone, E., Gotthardt, R. & Yorga, B.
1981 An Examination Of prehistoric Copper Technology And Copper Sources In Western Arctic And Subarctic North America. National Museum Of Man Series. Archaeological Survey Of Canada, paper No. 101:32-41
Peterson, David H.
2003 Red Metal Poundings And The “Neubauer Process”: Copper Culture Metallurgical Technology. Central States Archaeological Journal 50(2):102-105.
1963 A Copper Ingot? The Wisconsin Archaeologist 44(4):15-16
4 November 2001