METALS.
The tribes of the locality of which we are speaking were acquainted at the epoch of the Discovery with a number of metals, but not with the proper technical reduction of any of them. Specimens of gold, silver, iron, and copper have been found in both the older Mound series and the later deposits.
Copper has by far the pre-eminence. The Eskimos and other natives of British America possessed small pieces of it. These were principall; derived from the vicinity of the Coppermine River on the North-west coast, whence they were disseminated both south and north. The copper there occurs in its native state, and may be hammered cold into various shapes. The tribes at the south, along the Pacific, prepare it in large thin sheets one or two feet square, which are a highly-valued medium of exchange among them.
Copper Implements have been unearthed in considerable numbers from the mounds of the Ohio Valley. These have the forms of celts, chisels, hatchet-blades, knives, arrow- and spear-heads, and ornaments. (See Vol. I. p. 97.) It would appear that the useful applications of this metal for tools and weapons obtained in the interior, while toward the eastern and southern coasts it was employed chiefly for decoration. This is easily explained, as the principal source of supply was the native copper deposits around Lake Superior. These were worked with great energy at a period long prehistoric, and when the whites began exploiting the region thou sands of ancient diggings came to light, with the stone mauls and hearths of the ancient workmen, as we shall presently describe.
Nowhere within the area of the United States, however, was the art of smelting copper known to the aborigines. It was all hammered cold into plates, and these were laboriously cut with stone chisels into the shape desired. Moreover, even in the mound relics it is evident that this metal had not by any means risen to an equality with stone for producing a cutting edge. While the copper lance-heads will penetrate flesh and even soft wood, their points are at once turned by substances of the con sistence of serpentine or gypsum.
Silver.—Native silver in small quantities is intermixed with the Lake Superior copper, and sometimes this was carefully hammered out and served to overlay ornaments. Specimens of meteoric iron employed in the same manner have been found in the Ohio mounds.
Gold was obtained from the auriferous sands of North Carolina and Georgia. Its quality was impure, but it early attracted the attention of the Spanish explorers. The natives hammered it into beads and similar small ornaments.
Ancient Jfines.—In several parts of the United States the long-deserted works of the aboriginal miners—locally known as " Indian diggings"— testify to the expenditure of labor by the ancient inhabitants in the pur suit of metals such as they valued.
Thus in California it is evident that they penetrated the earth to a considerable distance in search of cinnabar, which they prized as a paint; in the mountains of North Carolina aboriginal diggings for mica are not only of considerable extent, but also show, from their locality, sagacity and knowledge of the best qualities of the mineral on the part of those who worked the veins. Copper, however, was the metal which elicited their most laborious exertions. This was mined in Northern New Jersey, and, on a much more extended scale, in the islands and on the shores of Lake Superior.
The method employed at this latter locality was almost always surface mining. A large basin-shaped cavity was excavated, following up the sur face indications. These cavities were frequently from one hundred to one hundred and fifty feet in diameter, with a maximum depth of twenty-five feet. The refuse was either thrown out on the sides or back into the portion of the excavation already worked. There are no marks of cutting tools, but occasionally fire was called in aid to split the rocky matrix— never, however, to smelt the metallic product.
Quantities of the mining tools still remain under the refuse-heaps. They are principally stone mauls or sledges for breaking the matrix. Some of these are heavy, and present two grooves around the centre, as if they had been handled by the united strength of two men. One of them weighed thirty-six pounds. Most are fractured at the ends from use. The refuse was removed by shovels of cedar wood, and the water which accumulated in the excavations was baled out with bowls of the same material.
Such old diggings are seen at many localities of the Lake Superior mining region. That their antiquity is considerable is obvious from the fact that the later Indian inhabitants were quite ignorant of this industry, and had no notion as to the origin of the excavations. Moreover, the refuse-heaps are covered with a growth of trees in size and species wholly like the primeval forest around them. It is believed that the most recent date which can be assigned to the close of the native exploitation of these copper deposits is, therefore, as remote as six hundred or seven hundred years ago.