USE OF COPPER IMPLEMENTS BY AMERICAN ABORIGINES. 101 



therefore, still imbedded, and when they left it seven feet below the rocky bot- 

 tom of their trench. There are neither marks of a cutting tool nor of fire upon 

 these masses of copper. 



At the Minnesota mine in the vicinity of Ontonagon River, a group of rude 

 ancient trenches shows the position of the copper vein for more than two miles, 

 and the excavations are some of thirty feet in depth. In one of these there was 

 found when first discovered, in 1847, a detached mass of copper weighing nearly 

 eight tons, which lay "upon a cob-work of round logs, or skids, six to eight 

 inches in diameter, the ends of which showed plainly the stroke of a small ax or 

 cutting-tool, about two and a half inches wide." These skids were of oak, and, 

 on drying, shrank and cracked as water-soaked timber which has been long 

 buried, is sure to do, and possessed little strength. "The mass of copper had 

 been raised several feet on the timbers by means of wedges." " Its upper sur- 

 face and edges were beaten and pounded smooth, all the irregularities taken off, 

 and around the outside a rim or lip was formed, bending downwards." Char- 

 coal and ashes were found in all these trenches. One of the stone mauls froni 

 this vicinity weighed thirty-six pounds, and was provided with a double groove, 

 being, doubtless, intended to be used by two men. 



In one of the pits a rude ladder was found, formed of an oak tree trimmed 

 so as to leave the stumps of the branches projecting, on which men could readily 

 descend or ascend to or from their work. Wooden levers were also found among 

 the rubbish, preserved by the water, which covered them continually. On the 

 edge of the excavation in which the mass of copper described was found, there 

 stood an aged hemlock, the roots of which extended across the ditch. I (Colonel 

 Whittlesey) counted the rings of annual growth on its stump, and found them to 

 be 290. Mr. Knapp mentions another tree which had 395. The fallen and 

 decayed trunks of trees of a previous generation were seen lying across the pits. 

 According to Mr. Foster, the number of ancient hammers taken from these 

 excavations alone exceed ten cart-loads. 



" In cleaning out one of these pits the workmen came upon the remains of 

 a wooden bowl, which, it was inferred from the splintery fragments of rock im- 

 bedded in the rim, must have been employed in baling out water." From the 

 uniformity with which marks of fire are found in these trenches, it is plausibly 

 inferred that the rock vein was heated, and water dashed upon it to destroy its 

 cohesion, and make it crumble more easily under the blows of the rude mauls 

 wielded by the ancient miners. "This method was practiced by civilized nations 

 before the invention of gunpc^vder, and is even at this day in the mining districts 

 of the Hartz and Altenberg." At Isle Royale, on Lake Michigan, some of the 

 ancient mining pits are fifty feet in depth, and according to Foster and Whitney, 

 there is scarcely a productive vein in all the copper region that does not give 

 evidence of having been worked in prehistoric times. — Chicago Advance. 



