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[Administration]

We had a discussion much earlier, with Doc, on the level of metallurgical development in South America. Doc argued that it was on a par with, or even more advanced, than in the Old World and if I remember correctly, we ended up agreeing that it was not.

It seems to me that this thread is covering similar territory, though in North America.

There are amateur historians with entrenched positions, who wish to see evidence to support their position: Amerindians either were more advanced than orthodoxy accepts, or more advanced because of early European influence (i.e. pre-Columbian voyages). There are others, I believe, who dismiss their development.

They scavenge historical and archaeological journals (and so on) looking for crumbs to shore up their walls.

As you say, Bart, if they had bronze, then they must have been able to smelt copper. All one has to do is prove the Bronze Age in Wisconsin during prehistoric times. If it existed, there will be masses of reliable evidence plain for all to see, from the metal working to artefacts. It will not be found in a dispute over one or two artefacts.

Same with copper. Where are the furnaces and related paraphernalia?

I see one big problem: much (if not all) of the evidence for copper smelting is unreliable. One reason for this is understandable: much was dug unscientifically and therefore we do not have either context or reliable data open to later, independent analysis.

However, archaeology has made great strides in the last so many decades and much has been done in this region. If copper was smelted, or there was a Bronze Age, there will be shelves stacked with authoritative books on the subject. A phone call to a local museum or university archaeological department would sort this out.

[Baja Bush Pilot]

The use of copper and gold marked the transition from the Stone Age to a more modern way of life. Ancient civilizations could use copper because it is found in its native state on the surface of the ground, because it has a distinctive color, and because it is easily worked. 

In addition to the important copper deposits of Cyprus, copper is relatively common around the Mediterranean. It was found in nuggets and masses on the surface of the earth, adjacent to streams, in the walls of canyons. Although exposure to weather changes copper's reddish color to blue-green, it is easy to recognize. Ancient people learned that copper could be shaped by pressure, that is, it is "malleable." 

Objects of beaten copper were used by the Chaldeans in the Middle East about 4500 B.C. Copper weapons and ornaments from about the same time have been found in the ruins of Susa, an ancient civilization located in the area of the nation that is now Iran. Native Americans exploited copper in the Upper Peninsula in Michigan perhaps 7000 years ago. 

We have no way to know for certain how copper was discovered long ago. We know that humans already recognized gold. Maybe they were looking for other substances like gold. Maybe somebody dropped a piece of rock on some copper, and dented the copper without breaking it. Then, this clever ancient inventor might have realized that pure copper could be hammered into a useful or pretty shape. This special property of copper is called malleability. 

Later, another observant person, maybe a potter, accidentally dropped a piece of copper in a fire. This early metal worker learned that the copper became less brittle and easier to shape if hammered after heating. This process is known as tempering. 

Discovery of the idea of working copper also occurred in a number of cultures around the Earth. Thanks to the excellent archeological record in the arid southwest of Asia we know that ancient civilizations of Mesopotamia, especially the city-states of Sumeria, were among the earliest to invent the use of copper and gold. This area is now in the nation of Iraq. 

http://www.unr.edu/sb204/geology/history.html

[Baja Bush Pilot]

As we have seen, the invention of metallurgy involved at first the simple beating of malleable copper into the shape desired. It was discovered that heating, called annealing, made copper more malleable, a process called tempering. The copper was hammered after it was heated. The resulting edge on a tool or weapon was harder and more durable. 

Shaping of copper was also accomplished by cutting or grinding with abrasive stones, with such hard minerals as corundum. 

Most copper is not found in its native state, that is, as a pure reddish brown metal. Usually, the copper is combined with other substances to make a mineral. Minerals may include the purplish cuprite, a combination of copper and oxygen, but most often, it is a green or blue mineral where copper is combined with other substances besides oxygen. When copper is in a mineral, it cannot be used as copper. It cannot be hammered or bent into another shape. Smelting copper ore to separate the copper from copper minerals required a hotter fire than normal cooking fires. It also required easily melted copper-bearing ore minerals such as green malachite and blue azurite or purplish red cuprite. The hotter fire was known by some cultures already, due to the development of fired pottery in a kiln. Probably by accident, it was discovered that the blue or green or purplish stones could be reduced to liquid copper metal in a fire. The fire must be hotter than a normal campfire, so there are two likely explanations for the discovery of smelting: 

A potter left some blue-green stones in her kiln, perhaps to prop up a pot; 
Or a campfire in a canyon became unusually hot due to the draft of air fanning it.

  Azurite
  Malachite
  Native Copper
  Cuprite

The primitive process of extracting metallic copper from copper-bearing stones by melting it is called smelting. Working with metal to extract it from ore and to form it into useful objects is called Metallurgy. 

Copper was extracted from ore such as the mineral malachite. Ore is a mineral or aggregate of minerals from which a substance, usually a metal, can be extracted at a profit. 

Shaping copper by casting it, that is, by pouring molten liquid copper into a mold, also first happened before anyone wrote it down, or even could write it down. Perhaps a bit of liquid metal ran into a footprint in the dirt by a campfire, where it formed a perfect cast of the footprint. 

Smelting was used as well to make bronze, an alloy. Alloys are mixtures of metals. Bronze is an alloy of copper and tin. 



Smelting was accomplished initially in an open fire. A hole one to two feet in diameter was dug in the ground. The hole was lined with fire-resistant clay or stone. Charcoal was placed in a layer on top of the clay, then was covered by copper ore. Charcoal burns particularly hot, raising temperatures enough to melt the copper. The charcoal also releases gases that react with the copper minerals to reduce them to copper metal. A molten mass of the dense copper formed, topped by lighter waste products, or slag. When the mass was cool, the brittle, glassy slag could be broken off, leaving a cake of refined copper behind. The furnace in this method is called an open hearth. Remnants of open hearths have been found in Sumerian ruins. 

A more complex method used the crucible, a ceramic pot into which the charcoal and copper ore were placed. The crucible was placed into a fireplace, or furnace. Bellows, often made of goat skins, directed a draft of air to raise the temperature. The copper cake produced by this method was cleaner than that in the open hearth. Copper ingots were cast into the shape of bars, rings, and other shapes suitable to be transported to Sumerian cities. 

[Baja Bush Pilot]

Before you can beat or smelt or cast copper, it must be taken from the ground. In the beginning of mining, people simply picked up pieces of copper or gold, two metals that have a distinctive color, are found in large masses, and can be worked with primitive tools such as stone axes and hammers. 

As civilizations began to use and depend on metals, the amount of pure copper or copper minerals found right at the surface was not enough anymore. Other ways of obtaining copper had to be developed. 

These earliest miners quickly realized that some copper minerals exposed on the surface were the tip of a deposit going down into the earth. Using stone, and later copper and bronze implements, the miners dug down to follow the deposit. The implements were crude picks, hammers, chisels and shovels. Since no method of blasting was available, miners were confined to much slower and more tedious methods of opening the rock wall or face. The miners picked at loose stones with their tools. If no cracks or loose stones were available, fire was used to create sudden changes of temperature to crack the rock. Logs were piled against the rock face, then set afire. When the rock was very hot, the fire was quenched with water. Then miners used their tools to pull out the loosened rock. 

Sometimes the miners followed loose nuggets of ore in gravel, called placers. Some metals make placers better than others. Gold makes excellent placer deposits because it tends not to react with air or water. Copper placers are less common. Tin, needed for bronze, makes excellent placers, while silver rarely is found as a placer deposit. Sometimes the miners followed veins into the solid rock, called lode deposits.



In Egypt, a great interest in gold drove exploration for mineral deposits south into Nubia (presently the nation of Sudan). Mining technology also improved. Excavations of large rooms underground, called stopes, were supported by pillars of unmined rock, or even by stone walls. Torches and oil lamps supplied a flickering, smoky light. Ventilation in these underground workings was very poor. 

Slaves, prisoners of war, and criminals were forced to labor in the mines. Skeletons of those killed by falling rocks have been found, left buried where they died. Children would carry the pieces of ore to the surface in baskets strapped to their back. Once the ore reached the surface, other people who were too frail to work underground sorted the ore into richer and poorer pieces. Ore was moved by caravan to trade routes on the rivers, the Tigris, Euphrates, and Nile. 

[Baja Bush Pilot]

Besides areas in Western Asia, the use of copper was discovered in England where copper is found in Cornwall and Devon, western France, Italy, Spain, and central Europe in Saxony and Bohemia. Native American copper implements are known from Michigan, as well. Asian civilizations, too, discovered ways to use copper.

Back in the Middle East, the Sumerian city-states comprised the first great metal-using civilization. The Sumerians navigated the Euphrates River for commerce, including the transportation of copper from Armenia to the north. The Sumerian word for copper, "urudu", is the same word for the Euphrates, literally, their "copper river."

At Gerza on the Nile River just south of the modern site of Cairo, the Gerzeans developed a civilization based on the metallurgy of copper. In about 3500 B.C. they learned basic copper metallurgy from immigrants from Mesopotamia.



The First Dynasty of Egypt began about 200 years later, under King Menes. The tomb of the queen of Pharoah Snefru of the Second Dynasty contained copper stoneworking tools. It was not until the Third Dynasty, however, that the great stone tombs and monuments were begun. The pyramids and other great buildings of the Egyptian civilization were built of stones that had been quarried and shaped using copper tools.

While the rock used in the buildings was found nearby, the Eygptians mined copper in the Sinai Peninsula. The scale of copper mining in the Sinai reached a size that made it the first real industry of the ancient world. The Egyptians mined deposits of the green copper mineral malachite. Malachite, a copper carbonate, was prized because it was the easiest copper mineral to reduce to copper metal. The closely related blue copper carbonate mineral azurite also was discovered. Near these two copper ore minerals, the early prospectors often found another copper mineral, blue-green turquoise. Turquoise is still prized around the world as a gem stone. Ruins of the old mines, the miners' huts, and inscriptions to the Goddess Hathor, the Lady of the Turquoise, can be found to this day in the Sinai. Copper mining in the Sinai Peninsula continued until the reign of Ramses III, in 1150 B.C., over 2,000 years later.

With the help of copper implements, King Zoser, founder of the Third Dynasty of Egypt, built the first great pyramid, the Pyramid of Saqqara, about 2900 B.C. The Great Pyramid of Gizeh, built by King Khufu, followed 100 years later.

Copper reached the island of Crete from Egypt. A copper axe from about 3000 B.C. was found on the floor of the ruins of a house. Egyptian barges carried copper to the western coast of Asia Minor, where they traded for the famous cedar wood from what is now Lebanon. The ships then went west to Cyprus, further west to Crete, then 320 miles south back to the Nile Delta. Ruins of the great Cretan civilization hold artifacts with Egyptian influence, such as fresco painting, pottery, and stone statuettes. However, the form of the metal objects is more like that from Asia Minor.

Metallurgy from Asia Minor reached Cyprus about 2600 B.C. The peoples of Anatolia (now Turkey) migrated west on favorable sea currents in the eastern Mediterranean. The people of Crete developed an industry based on copper, giving the copper miners of Cyprus an incentive to expand their mines. Egyptians traded fabrics and gold for copper from Cyprus. Myceneans settled near the copper deposit of Skouriotissa on Cyprus. This deposit was rediscovered by Charles Gunther and mined again in modern times.

Early metalsmiths of Sumer, Babylon, and Egypt were highly prized members of their society. Often, they were not free, owing their obedience and livelihood to temple priests and authorities. They were so valuable that invading armies made a special effort to carry them off in captivity. Metalsmiths transmitted their secrets to their children. Their guilds may have been the first trade unions in history.

http://www.unr.edu/sb204/geology/civilztn.html

[Baja Bush Pilot]

Is there any evidence of tin mines in North America?  Or South America, for that matter.  Tin, I believe, is needed for bronze.  Why is there so much evidence over there and so little here?  Or vice versa, depending on where you are.  And it seems to me that being able to cast a copper (or bronze) point, be it arrow or dart, would constitute an incredible trade advantage.  Most other advances seemed to move around this continent very rapidly.  Was this technology somehow kept as a trade secret?  Why isn't it found elsewhere? 

[Administration]

Is there any evidence of tin mines in North America?  Or South America, for that matter.  Tin, I believe, is needed for bronze.  Why is there so much evidence over there and so little here?  Or vice versa, depending on where you are.  And it seems to me that being able to cast a copper (or bronze) point, be it arrow or dart, would constitute an incredible trade advantage.  Most other advances seemed to move around this continent very rapidly.  Was this technology somehow kept as a trade secret?  Why isn't it found elsewhere? 

All good questions, none of which am I qualified to answer.

Google tells me that there is tin in the Americas. Bolivia is the main source, though the USA, Mexico and Canada do mine tin.

There is some tin in Europe. A primary source was Cornwall, England and traders have been sailing there for millennia.

Maybe I'm totally wrong, but it is my impression that heating and beating soft metals gathered on or near the surface is a lot easier than making bronze and iron from metals mined deeply (as in Cornwall).

[Bart]

   I am not sure that any, or even many are claiming there was ever a bronze age per se, or bronze making in N. America at all. Tin is required to produce bronze. Bronze making and copper smelting to me are two separate and distinct processes. I agree that there are many out there who claim copper smelting without good evidence to support their claims, and further extrapolations that ancient Phoenicians or other ancient mariners mined and shipped boat loads of copper are probably even a bigger stretch. But I have seen photos of forms carved into rock, forms which have been claimed to be for smelted copper. And when ancient artifacts which could well have come from these forms are found nearby, that is an easy conclusion to draw, right or wrong.

   Misconception or otherwise, these notions are out there and very prevalent here in the US, at least from the several years of interest in the topic that I have had. Perhaps it is not so much a matter of what evidence there currently exists as much as a dissemination of the evidence. There are ancient furnaces here in the US, claimed or suspected, but about 100 years ago they were pronounced as early European settlers works, without any testing being done, and that mindset has been maintained to this day. One may well ask how can this be? Is it any wonder that this position is doubted? Unless some testing is done, this notion will never go away. While some private testing has been done, it is not 'official' or accepted as proper or 'scientific'. The private testing indicates that the furnaces are at least ancient, and the assumption by many on both sides is that they are not the work of Amerindians. I see assumptions on both sides of the issue, and that ought not be.

   If this is an issue that has been cleared up long ago, then better dissemination of that data would go a long way toward dispelling the misconceptions out there. Mistakes have been made in the past, but we need to move forward, in the proper directions.

   No testing will be done because they can't be ancient European/ Mideastern. When those that ought to have done the testing make pronouncements without testing, it seems to me it is only reasonable to question it. When those pronouncements are made on the basis of the belief that there were  no ancients visiting here from 'over wherever', it seems even more justifiable to question this. Sort of a catch 22, they can't be because there weren't any. Pronouncements based upon belief do not supercede the evidence. The position can be maintained as long as the evidence is never examined.

   Perhaps this thread will help to paint a better picture for those in need of such. I don't necessarily desire to 'prove' that ancients from across the ocean were here, but to simply have the evidence examined without bias, to the best of our abilities, and properly disseminated.

Bart

[Bart]

A basic timeline of key events related to this topic. It seems safe to state that the Americas missed participation in the bronze aspect of the Bronze Age.

� ca. 8000 B.C. American Archaic cultures are those that occur between Paleoindian hunter groups and the peoples who have realized some combination of pottery making, burial mound construction, and garden technology. The combination varies from area to area.

� ca. 5000 B.C. Indian Knoll and other shell-mound sites along the Green River, in Kentucky, begin to be occupied.

� ca. 4000 B.C. Small conical burial mounds are the earliest earthworks along the Mississippi.

� ca. 3500 B.C. People of the Old Copper culture around the Great Lakes use native copper for tools.

� ca. 3000 B.C. Lovelock Cave, an open rock shelter in western Nevada, is inhabited, and remains in use until historic times. Large quantities of perishable materials such as bird decoys, baskets, basketry items, featherwork, and skin blankets have been discovered there.

� ca. 2500 B.C. Pottery is made in the lower Savannah River valley of Georgia and South Carolina.

 

[Administration]

Bart, ignorant though I am of much American history, even so I realise what a minefield this is (pun warning: mine:minefield).

Dating of furnaces and smelting artefacts is very easy. There is C¹⁴ for carbon and even a method for dating when rock was heated to a high temperature.

There can be no excuse if this has not been performed on all likely sites.

My interest is now aroused. I will study more.

[Bart]

For what is is worth, perhaps a starting point for further analysis...

Crucibles For Casting Found At Cahokia?

Neiburger's Evidence: Native Americans

Melted, Cast Copper at 1,000 BC Site

   Scientific evidence of prehistoric Indian copper casting was published in an article in North American Archaeologist, written by an Evanston, IL dentist, Ellis J. Neiburger, a man who became interested in metallurgy while in dental school. The title of Neiburger's paper is "Melted Copper From the Archaic Midwest," 1991, V 12-4, Baywood Publishing Co., Amityville, NY. This paper offers xeroradiographic proof of ancient casting. All of Neiburger's photos and images which appear in this web site are: Copyright, E.J. Neiburger, 2001. Dr. Neiburger has kindly permitted me to publish information from this here in "America's Mysterious Furnaces." His 1991 paper contains important evidence of prehistoric copper melting and casting.

View R666 Copper Lump
   Describing this copper artifact from an archaeological site in Menominee County, Michigan, Neiburger said it is "a large lump of documented copper" from the 1000 BC Riverside side just north of the Wisconsin state line. The lump weighs 5407 gm and is 6.1 cm long, 4.1 cm wide and 0.8 cm thick.

View Xeroradiograph
This xeroradiograph of the Riverside copper lump shows numerous large, ovoid radiolucenties grouped in clusters. This indicative of melting in which gas bubbles, trapped in the molten metal, will cause porosity as the artifact hardens. Hammered (unmelted) or natural float copper will show faint elongated voids where laps and folds in the metal occur. In the R666 lump, however, one sees aggregate porosity indicative of casting.

Photomicrographs (200x) of (FC) cast and hammered float copper, (prepared by author), on left side, is compared to that of the R666 Riverside sample, on the right side of the image.

   The abstract of this article says that: "A large lump of documented copper from the 1000 BC Riverside, Michigan site was found to posses internal porosity and a microstructure indicative of casting and hammering as the means of manufacture. Prior to this discovery, Archaic Native American Indians were considered technologically primitive and incapable of possessing the high heat technology necessary to cast metal."

   Neiburger's article thus offers photographic proof of small voids in the 1000 BC copper artifact. These would only form as bubbles of gas in molten copper. Also in his article he points out that the Great Lakes native copper deposits were not the result of the cooling of molten lava, but were rather deposited by geologic precipitation about one billion years ago. Thus the native metal would contain no such gas voids.

   So far the Riverside lump is the only such artifact from a well documented site known to Neiburger which shows clear evidence of prehistoric casting. Other artifacts examined by Neiburger and found to have evidence of casting are surface finds, and therefore not completely conclusive, because of the possibility that they are modern copies of Indian artifacts.

   An example of evidence of casting in a surface find can be seen in Neiburger's xeroradiograph of a copper celt from the Perkins Collection of the Milwaukee Public Museum, Milwaukee, WI. A photo of the celt is on the left and the xeroradiograph is on the right. The casting bubble can clearly been seen near of the middle of the wide end of the xeroradiograph of the celt, far right:

Commenting on the need for further testing, Neiburger said "Further xeroradiographic surveys and analysis of the 25,000 existing copper artifacts from that period (Archaic Midwestern United States) are necessary for the determination of how extensively early Native Americans had used melted metal."

August 31, 2001: Seeking more answers to the question of whether or not prehistoric North American Indians cast copper, recently I wrote to Dr. Ellis Neiburger, who seems to be one of the world's most knowledgeable amateur archaeo-metallurgists in the field of copper casting.

   As it turns out, after a telephone conversation with him, I've learned that much of his knowledge comes from his hobby of metal casting. He is the operator of a so-called "backyard foundry," and has been for many years. He told me he has made over 2,000 castings.

   Neiburger, of Waukegan, Illinois, has enlightened me on some things he has learned which I am using to revise this web page. I'm sure his input will lead to a better understanding of the issues involved in our project to examine and evaluate evidence of prehistoric copper casting in North America.

   He pointed out to me, for instance, that evidence suggesting the use of casting such as surface depression or concavity, large size and symmetrical form are not by themselves fool-proof evidence of prehistoric casting. This calls into question evidence of casting cited by Arlington Mallery and Earle Caley 50 years ago, which is discussed further on in this section of "America's Mysterious Furnaces."

   Also, and equally important, he said any copper artifact considered for xeroradiographic testing should first be subjected to a specific gravity test.  If the artifact is found to weigh less than an equal volume of native copper, the presence of casting voids is indicated. The Riverside lump R666 was first given a specific gravity test. After it tested less (8.2) than native copper (8.9), Neiburger had the xeroradiograph made shown above.

Source

[Bart]

Could Radiographic Tests Of Large Copper Artifacts 'Revolutionize' North American Archaeology?

Author Of This Site Was Unable To Have Larger Artifact Tested

   A program of Radiographic (X-ray) testing of large copper artifacts to seek evidence of casting should be conducted to determine if any prehistoric North American artifacts were made by casting!  An unsuccessful test was made by the author of this web site, but unfortunately, the artifact selected for the test was, in my opinion, too small.   While large prehistoric copper artifacts are valuable, and while those in charge of such artifacts are reluctant to send them away for testing, failure to conduct such tests in my opinion is just unscientific.

   This project came about a result of the author's participation in the Arch-Metals e-mail discussion group. Some Arch-Metals members agreed recently, after a prolonged discussion, that most large, prehistoric copper artifacts had been cast nearly everywhere in the prehistoric world except in North America.

   At this point in the discussion, I posted the fact that North American copper artifacts had been tested by X-ray imaging and the results, which were published 50 years ago by Arlington Mallery, showed evidence of casting. But somehow the opinion that North American Indians never cast copper had become a "fact" among professional archaeologists. One member of Arch-Metals, who responded to my posting of Mallery's test results, asked why they had never been republished and said that if North American prehistoric copper artifacts are found to have been cast, it could "revolutionize" North American archaeology.

   I established the "Early Caley Research Fund" to pay for the cost of a program of prehistoric North American copper artifact testing for evidence of casting. Dr. Martha Otto, curator of archaeology of the Ohio Historical Society Museum of Columbus, and the author of this web site, conducted the test. I also consulted with Dr. David Scott of the Getty Conservation Institute, Getty Museum, Los Angeles, CA.  At the time, I had serious reservations about the small size of the artifact chosen for testing.  And, unfortunately, the test conducted by the Getty for Dr. Otto indicated the small copper celt had been formed merely by cold working. 

The 28-pound Seip Mound Celt Of The Ohio Historical Society Museum

Evidence Of Prehistoric Copper Casting
Endorsed By Caley Nearly 50 Years Ago

   Although archaeologists today seem united in their view that large prehistoric North American Indian copper artifacts were not cast from molten copper, amateurs have been finding evidence to the contrary for many years and their findings have been supported by metallurgists.

   For instance, amateur Arlington Mallery's studies of prehistoric copper use by native Americans of the Great Lakes region convinced him that they melted copper and cast it into axes, chisels, spearheads and sheets. This conclusion received favorable comments from some American professional archaeologists of the 1950's.

   The widely accepted theory that the native North Americans used copper only as malleable stone is wrong, Mallery declared, because many of the heavier pieces, such as axes and chisels, had never been touched by a hammer except at the cutting edge. Therefore, he concluded these pieces could not have been hammered out of material from the naturally occurring native copper deposits, but would have had to have been cast from molten copper.

50-Year-Old Evidence of Prehistoric North American Copper Casting

   As Mallery pointed out in "Great Lakes Copper Culture," an appendix in The Rediscovery of Lost America, micrographs made of samples of these prehistoric objects indicated that the copper had been melted in an open crucible. Tests showed that surfaces of these copper artifacts were impregnated with cuprous oxide, and Mallery said this proved that alloying with oxide during melting had occurred, to produce copper artifacts which are harder and more brittle than pure Great Lakes copper.

   He reasoned that objects made with this pure, native metal would not have cuprous oxide on their surfaces if shaped simply by hammering. Formation of the cuprous oxide would occur only while the copper was molten, reacting with the air to produce the alloy.

   According to Mallery, an indication of the degree to which the native Americans were involved in the production of artifacts of copper can been seen in the fact that over 100,000 copper objects, such and tools and ornaments, have been found in North America. As he said in Lost America, if only a small percentage of the many thousands of copper objects made by the Indians were accepted by archaeologists as being made from cast copper, the whole theory of a stone age pre-Columbian North America must be rejected.

   Dr. Earle E. Caley, then a professor of chemistry at The Ohio State University, reviewed the metallurgical content of Lost America as part of an evaluation of the book by five OSU professors in the Ohio State Archaeological and Historical Quarterly, July 1953. All but Caley had nothing much positive to say about Mallery's conclusions. Caley, while not in agreement with Mallery that the pit furnaces were iron smelters, was in agreement with him about the copper casting. Caley said, "the technical evidence he presents for the existence of the practice of melting and casting copper at an early date in North America is important and appears to be both sound and adequate..."

   This is a very strong endorsement, running against the grain of what the other OSU professors said about Mallery, but it seems to have had little effect. Caley in 1953 was already a published archaeo-metallurgist, and later became noted for his studies of the pre-Inca Moche Indians of Peru, who smelted copper from the ore beginning in 200 AD.

   In the 1950's, evidence of such copper ore smelting in South America was just beginning to be scientifically studied, and Caley's conclusions in "The Smelting of Sulfide Ores of Copper in Preconquest Peru" were controversial. But during the1980s, much more evidence came to light, especially with the publication of "Batan Grande: A Prehistoric Metallurgical Center in Peru" by Izumi Shimada, Stephen Epstein and Alan K. Craig in Science. Shimada, Epstein and Craig reinforced Caley's earlier work, showing that the pre-Columbian Indians of Peru did indeed smelt sulfide and oxide ores of copper.

   To my knowledge, Caley never reversed his positive evaluation of Mallery's evidence of copper melting and casting by North America's pre-Columbian Indians. It is really strange that no American archaeo-metallurgists have seen fit to follow up on this.

   Quite likely, they've never been made aware of it. So today, our archaeology textbooks still read that the North American Indians did not know how to melt and cast copper. But if the metallurgical tests cited in Lost America are accurate (as conducted by a disinterested commercial laboratory) there is no question that the tested artifacts were copper castings.

   While much of what archaeologists study consists of only of rather enigmatic artifacts and habitation sites, which may shed little direct light on the cultures of its origination, the technological evaluation of metals involves physical science and thus is quite straightforward. Such evidence needs little of the creative interpretation which they of necessity must apply to other prehistoric evidence. So it is difficult for those who wish not to accept such evidence to argue against it, but it has been quite easy for them to just ignore it.

   Indeed, I know of no published technical refutation of Mallery's claims about the Indian copper casting as published in his books. Mallery tells us that at the suggestion of Matthew Stirling, then director of the Bureau of American Ethnology of the Smithsonian Institution, he examined copper artifacts of the Perkins collection in the National Museum of Natural History. Mallery says right away he noticed that there were "a number of castings in the collection." Further, he states that "there are similar castings in nearly every museum in America." And, he says "expert foundrymen who examined the Perkins collection of the Wisconsin Historical Society declared that many of these specimens were cast in a mold."

   And, after examining the results of Mallery's test of prehistoric copper artifacts, Dr. George Ellinger of the National Bureau of Standards said, "The centers of some of these chisels were decidedly depressed or concave. This is caused by the decrease in volume (or shrinkage) of the molten metal upon solidification. It is a common phenomenon well known by all foundrymen and those connected with the melting and casting of metals. This concavity is more or less pronounced in many of the ancient specimens and particularly so in the pentagonal chisels."

   Chisels, spearheads and axes were among the prehistoric North American artifacts Mallery had tested for evidence of casting 50 years ago. The above comments by Ellinger also appeared in "Appendix A, Great Lakes Copper Culture," of both Lost America and The Rediscovery of Lost America.

   Mallery's expertise with metallurgy came from his occupation as a pioneer steel bridge builder. As a registered professional engineer, he designed and built many highway bridges in the 1920's and 1930's. But his expertise in metallurgy wasn't matched by his knowledge or use of archaeological methodology, and this made it easy for his critics to dismiss all of his work, both the good and the bad. Mallery was, very simply, not very good as an archaeologist.

   But since metallurgy is rather straightforward, Mallery, Stirling and Ellinger must have been surprised that the American archaeological community of the day was unresponsive to the news about casting, despite what seemed to be an "overkill" of pro-casting technical evidence.

Archaeologist Was Confused About 'Smelting'

   The opposition of American archaeologists to ancient American copper casting is reflected in an otherwise excellent booklet Miskwabik: Red Metal, The Roles Played by Michigan's Copper In Prehistoric North America published in 1983 and written by John R. Halsey, state archaeologist of Michigan. Halsey says in his book "Of one thing we are certain: no native copper was deliberately smelted. Metallographic analysis of numerous copper specimens from eastern North America has not found telltale changes in their internal crystalline structure that would have occurred if metals were heated to their liquid state to remove their impurities."

   With this statement Halsey deserves a failing grade in Metallurgy 101 since he thinks native copper needs to be smelted and that impurities need to be removed from pure copper! Also, I'm sure a collection of thin copper artifacts could be assembled to "prove" no Indian copper artifacts were ever cast.

   Mistaken, unscientific opposition to evidence of ancient American copper casting is not harmless! A privately owned site such as Spruce Hill in Ross County, Ohio is always in danger of destruction. Indeed considerable destruction has already occurred there. But much evidence remains, which could be highly useful to our understanding of the evidence of ancient metallurgical processes at this important site.

   Still abundant there is evidence of the use of charcoal fueled furnaces to achieve temperatures and conditions which permit the creation of multicolored iron oxide glazes on rocks. Carbon-14 and thermoluminescence tests of such materials, could reveal when these furnaces were in operation. Then perhaps Spruce Hill, which has already been considered, could be included in the Hopewell Culture National Park of the US Park Service and the site could be recognized as a center of ancient metallurgical industry.

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[Bart]

A Mold For A Hopewell Copper Celt?

The Cahoon Mold

   The lump of heat-hardened clay above was found at Spruce Hill near Bourneville, Ohio by John Cahoon on April 25, 1993. Spruce Hill is a 140-acre plateau enclosed by a prehistoric wall of laid-up stone attributed by archaeologists to the Hopewell Culture (200 B.C. to 400 AD). Cahoon, owner of an orchard which adjoins the site, was with members of the Archaeo-Pyrogenics Society (APGS) on a field trip when he found the lump.

   Cahoon found the mold in a rain-filled bulldozer trench in "the isthmus" area of Spruce Hill where ancient furnaces were located. On the day of the field trip, about an inch of rain fell which may have dissolved softer soil from the mold. The object weighs 13.5 pounds. The cavity of the Cahoon mold is about one-half inch deep, two inches wide and six inches long. It widens somewhat at the end facing the ruler, suggesting it perhaps was used to form an elongated celt. Vitrified clay on both sides of the cavity bear witness to the intense heat of the material in the mold. The clay of the mold looks like bog iron ore, and in fact, Cahoon described it as "an ore body."

   The author of this web site has researched copper metallurgy and Native American artifacts made of copper for many years. I've suspected that the Cahoon Mold was used by ancient Indian metal workers to cast a copper celt. But was the Cahoon mold used by Hopewellian Indians to cast copper as I have proposed?

   Maybe not. Replying to my posting about this on Arch-Metals, the archaeo-metallurgy Internet mail list, Chris Salter, of the Materials Science-Based Archaeology Group, Oxford, U.K. replied:

   I am sorry but I have to agree with the others that have said that the material illustrated is not a fragment of a mould. Having examined several hundred mould fragments from all periods, none look like the material illustrated.

   It is difficult to determine what the material is from a single image, but the most likely origins are as a hearth lining, or the result of an uncontrolled fire in a timber and clay building (I have seen similar vitrification in the walls of timber-laced ramparts of British hill forts, and on a stone built charcoal store).

   The essential features required to produce such vitrification appear to be a sufficient supply of fuel, and flue ventilation (good air supply at base, and venting at top, with some mechanism to create a forced draught (be that height of flue, or wind).

Another viewer of the Cahoon Mold, Wes Clark replied:

   Your speculations and information connected to a possible prehistoric copper celt mold are very interesting.  I have a suggestion, however.  Could you provide a better photo of the "mold"?  A lab photo with oblique lighting would show better detail.  The present photo shows to some extent the morphology you contend is a mold for a celt, but is still a little too amorphous for my taste.

   Dr. Neiburger, however, a man who has made some 2,000 castings, believes the "Cahoon Mold" could have been used to cast a copper artifact and has suggested it be tested for traces of copper.

   If the Cahoon mold is not the remains of a copper casting mold, but is a prehistoric Hopewellian artifact, it is still remarkable because of its rectangular shape. Were these Indians sophisticated carpenters who made use of square boards or posts? Is the Cahoon mold an accidental impression left by a burned away prehistoric board or post? Was this impression made by a post used to support a wooden palisade at the top of the fort's walls?

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[Administration]

What is needed to make the case:

- Archaeological excavation of a site where the casting took place.
This could provide a reliable context for the finds.

- Both the structure (e.g. furnace) and tools used in the process.
They must be excavated in the above context and dated reliably.

- Cast artefacts.
Also excavated in context, then analysed and dated.

We seem to have bits and pieces of the puzzle, but not all are reliable.

As I mentioned earlier, if this process took place, then reliable evidence should be available from a number of sites. It really is time that scientists nailed this.

[Bart]

Fire Pits or Furnaces, They Remain A Spruce Hill Mystery

Spruce Hill, the "Ancient Stone Work" as mapped in Ancient Monuments of the Mississippi Valley by Squier and Davis, has attracted generations of archaeologists to its plateau enclosed by walls of loose stone. The purpose of the many mysterious fire pits or furnaces found in the walls has long been a mystery, as has the existence of "the fort" itself.

Although the Cahoon mold may not be the "smoking gun" evidence of copper casting, conclusive evidence needed to solve mystery of the Spruce Hill furnaces may still exist somewhere at the site. And, because of other supporting evidence, I'm still convinced some sort of prehistoric metallurgical operations were conducted there.

The furnace remains were first reported in 1811 by James Foster, editor of the Chillicothe, Ohio newspaper. He was asked to view the site by local residents who were astonished by its existence.

Foster reported seeing "about 30 furnaces" in the Spruce Hill walls upon which huge trees were growing. This implies that the furnaces were at least hundreds of years older than 1811. Foster's Spruce Hill observations were reported in a letter found tucked inside an 1814 book, the American Medical and Philosophical Journal.

For more information on Spruce Hill and its furnaces, go to Ohio's Prehistoric Furnaces.

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