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, crum