Billets of wood that bear the marks of a tolerably sharp-cutting tool are often found in the old mines where water has been suffered to remain since their abandonment. In the Waterbury Mine wooden shovels were found about three and one half feet long, some of which were much worn upon the blade, and appeared as though they had been used for scraping together and throwing out the refuse rock and dirt from the mine.[A] At the same locality a wooden bowl was found, the side being so worn as to show conclusively that it had been used for baling water from the mine. Similar implements have been found at the mines in the Portage Lake and Ontonagon districts. When first found, these wooden implements appear sound, and being thoroughly saturated with water are heavy and can be handled without breaking; but when dried they often crack and warp so as to retain little of their original form and appearance. It is to be regretted that but few of these wooden relics were saved and properly preserved by those who found them. In a few instances the wooden withe or handle has been found attached to the hammers, but upon being dried they usually fall to pieces.
At the Hilton Mine in the Ontonagon district, in October, 1863, as the men were removing the vegetable mould that had accumulated in one of the old pits, they found at the depth of about nine feet a leather bag, which was eleven inches long and seven inches wide. It was lying upon a mass of native copper which the ancient miners had unsuccessfully attempted to remove from its parent vein. The bag was in a remarkable state of preservation, the leather being quite pliable and as tough as sheepskin. It was made up with the hair inside, was sewed across the bottom and up one side with a leather string, and near the top holes were cut and a leather string inserted to close the mouth by drawing it together. The bag was empty, but from its appearance I judged that it had been used for transporting copper or other mineral,—the leather in places showing marks of much service, and the hair being almost entirely worn off. I was unable to determine what kind of skin it was, but inclined to the belief that it was from the walrus, as the short, stubby hairs more closely resembled those of that animal than of any other with which I am acquainted. At the time I saw the bag,—the day after it was discovered,—it was in the possession of C. M. Sanderson, Esq., the agent of the Knowlton Mine; but I hear it has since been taken to Boston and sold.
In several of the ancient mines considerable masses of pure copper detached from the main lode have been found, which were left there by those who mined it. At the Central Mine, not far from Eagle Harbor, a mass of copper was found in one of these old pits that weighed forty-six tons. Every portion of the surface was smooth, and appeared as though it had been hammered by those who detached it from its original vein. In the Mesnard Mine, in the Portage Lake district, a detached mass of copper was found that weighed eighteen tons, hammered smooth like the mass before named.
But the most interesting specimen was found in an old pit near the Minnesota Mine. In removing the accumulated leaves and vegetable mould, the workmen, at the depth of eighteen feet, discovered a mass of copper ten feet long, three feet wide, and more than a foot thick, weighing six tons. On removing the earth around the mass, it was found to rest upon skids, or timbers, piled up to the height of about five feet. These timbers, having been constantly covered with water, were in a good state of preservation, and at the ends showed plainly the marks of the tool used in cutting them. It was thought by those who saw the billets when they were plump, that they were a species of oak; but the few remaining pieces which I have seen were so cracked and shrivelled that I have been unable to form an opinion as to the kind of wood. This mass of copper, like all others found in those ancient pits, was divested of all its ragged points, and hammered perfectly smooth. There was nothing in its appearance to show that it had ever been cut from another mass; but upon clearing out the rubbish from the bottom of the mine, which was about twenty-six feet below the surface, a vein of pure metal was found from which this had evidently been taken.
A few unfinished jobs have been found in these ancient pits, which throw some light upon the manner in which the work was carried on. In two instances there were projecting masses somewhat resembling urns, or inverted short-necked bottles, and completely smoothed by hammering, especially at the thinner portion or neck. It appears that the ancient miners first removed the rock from around the veins of copper. This was done by building fires upon or about it, and, when heated, crumbling it by throwing on water. By means of stone mauls the fragments were broken up and removed. When the vein was sufficiently exposed on all sides, a point was selected where the copper was thinner or narrower than the average of the vein. Here they commenced cutting off a mass, and by patient and long-continued hammering severed the two portions of the vein. In all the ancient mines which I have visited there is abundant evidence that fire was extensively used in the removal of rock; for not only do the rocks give proof of having been heated, but charcoal and ashes are invariably found at the bottom of all the rock excavations.
In general, the mining was done by surface openings along the line of the outcrop of the vein; but occasionally adits are driven into the rock, similar to the one first discovered at the Minnesota Mine before alluded to.
The surface mines are usually nearly filled with leaves and vegetable mould that have accumulated during the centuries that have elapsed since their abandonment, and till within a few years a heavy growth of timber covered the land; hence the numerous slight depressions that occurred along the line of the vein excited no suspicion that they were artificial excavations. By the closest observers they were regarded as natural depressions, caused either by the disintegration of the underlying rock or the peculiar manner in which the overlying drift was deposited. In many of these depressions, which have proved to be abandoned mines, trees of enormous size are found growing, some of which are ascertained, by counting their concentric rings, to be four hundred years old. At the Hilton Mine, directly over the leather bag before alluded to, there was a hemlock-tree about three feet in diameter. I noticed the stump of a tree nearly four feet in diameter in a gap near the Rockland Mine, where a hill had been actually cut asunder by these ancient miners, and a deep valley formed by the removal of the rock. Until very recently this valley was not recognized as an ancient mine; for, being ten rods in width, and cutting nearly at right angles across the strata of the rock that formed the hill, it was considered too extensive to have been made by human hands, and was supposed to be the result of natural causes. But about two years since, during a very dry time, a destructive fire swept through the woods, and so completely burned up all the vegetable matter accumulated there as to expose the underlying rock, and reveal its true character. After the fire had done its work, it was found that copper veins, which had been worked, ran through the rock in the gap, and that the great bank upon the south side of the hill, which was supposed to be a terraced gravel bank, proved to be a vast accumulation of "attle," or refuse stone, that had been taken from the artificial gap and deposited there. The stones forming this immense pile are generally small, and appear to have been broken up by heating to facilitate their removal from the mine, and possibly may have been again broken, with the hope of finding copper in them. In the midst of the pile I noticed several stone hammers, or mauls, some of them measuring twenty inches in girth around their grooves, and one I brought away weighing thirty pounds.
When examining this locality, I was struck with a significant fact, tending to show the long time that must have elapsed since the abandonment of these mines. I noticed in many instances that the artificial groove around the hammers was nearly obliterated upon the upper side, while upon the lower side, less exposed to the abrading agency of the atmosphere and rains, the groove presented a comparatively fresh appearance, and even the slight markings made by the tool that cut them were quite distinct. When I removed the overlying rock, and found a grooved maul in a protected spot, the groove was generally as fresh as though it had been made but a few months before. The compact nature of the stone of which these hammers are made, and their ability to resist the action of weather and moisture, prove conclusively that much time has been required to disintegrate their surface so as to obliterate the artificial work which has been expended upon them.
I feel unwilling to leave this subject without instituting an inquiry relative to the time when these mines were wrought, and the people who worked them. Many who have been taught to regard the present roving tribes of Indians as instinctively wise in matters of medicine and mining are ready to award to that race the credit of having worked these mines; but, inasmuch as even a traditional knowledge of their existence was unknown to the Indians at the time the Jesuit missionaries visited that region in the sixteenth century, we incline to the opinion that an other and distinct race worked them. I am unable to see why the descendants of a people residing in the same country, and subject to the same wants, should abandon the half-worked mines which their ancestors had opened, and even fail to hand down to their posterity a tradition of their existence. If copper was in such demand that the ancestors of the present race of Chippeways were induced to work so perseveringly to obtain it, why did not the children continue to work, at least enough to finish the jobs already commenced by their progenitors? We cannot consistently attribute the Herculean labor expended on these mines to the ancestors of the indolent race of North American Indians. We incline, rather, to the opinion that the miners were the mound-builders, who resided south of the mines, and ultimately found a home in Mexico. The condition in which the mines were left favors this theory; for in many instances unfinished jobs are found,—as in the case of the mass of copper upon skids at the Minnesota Mine, and the half-severed veins in other mines. May we not reasonably suppose that the miners came from the South and worked during the summer months, returning to their homes in winter? The circumstance that no traces of their habitations or burial-places have ever been discovered in the immediate vicinity of the mines leads to the inference that they came from a distance; and the fact that copper rings, chisels, and knives, and occasionally stone hammers, are found in the ancient mounds that extend in an unbroken line from Ohio to Mexico, induces the belief that the ancient miners and the ancient mound-builders were the same people.
It is said that artificial mounds are found in British America; and I was informed of one upon the banks of the Ontonagon River, about six miles from its mouth, but was unable to visit the spot. It is well known that they are quite abundant in Wisconsin, and extend the entire length of the Mississippi Valley.