LAKE SUPERIOR,ANCIENT MINING WORKS.
tached mass of copper weighing nearly six tons. It lay upon a cob-work of round logs or skids six or eight inches in diameter, the ends of which showed plainly the marks of a small axe or cutting tool about two and a half inches wide. They soon shriveled and decayed when exposed to the air. The mass of copper had been raised several feet, along the foot of the lode, on timbers, by means of wedges.” At this place was found a stone maul weighing thirty-six pounds, and also a copper maul or sledge weighing twenty-five pounds. Old trees showing 395 rings of annual growth stood in the débris, and “the fallen and decayed trunks of trees of a former generation were seen lying across the pits.” (opposite) presents a section of this mining shaft of the Mound-Builders: a shows the mass of copper; b the bottom of the shaft; c the earth and débris which had been thrown out. The dark spots are masses of copper.