they moved lies on the drift-clay. This is shown by the subjoined diagrammatic sketch taken on the spot (Fig. 7). It is also shown by the fact that some of the pits are but a few feet above the present lake-level (about thirty feet); since during the period of the drift, and particularly toward its close, the interior lakes and rivers of the North American Continent were much higher than they are now.
It has been agreed for some years, by American archaeologists, that
Fig. 7. Explanation.
a, chips and moved earth in which the stone hammers are found; b, the modified drift-clay; c, the cupriferous rock; d d, depressions in the surface indicating the location of the ancient pits, sometimes refilled by the old miners.
the ancient miners of Lake Superior were identical with the mysterious race known as the mound-builders. The evidence of this, first partially elucidated by Messrs. Squier and Davis, has multiplied by subsequent observations, so that there is now a concurrent series of facts pointing to that conclusion. It consists largely in the discovery of many copper implements in the mounds that have been opened. These implements sometimes contain small nuggets of metallic silver closely welded to the copper. At no other place in the United States are copper and silver found thus naturally combined. They must have been pounded into shape, since the melting of the copper for casting would certainly have produced an alloy in which the appearance of the silver would be entirely lost. This, taken in connection with the well-established mining methods of the Isle Royale miners, undeniably identifies them with the mound-builders.
If we inquire further what relation the mound-builder bore to the aborigines found here by Columbus, we shall be compelled to admit from the evidence that the aborigines themselves were the mound-builders and the ancient miners. As this conclusion is at variance with the generally accepted opinion, it will be necessary to consider some of the characteristics of the mound-builders, as stated by the highest authorities, and to compare them with the known peculiar habits and customs of the Indians:
1. Squier and Davis state that "there probably existed among the mound-builders a state of society something like that which prevailed among the Indians; each tribe had its separate seat, maintaining, with