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In graduating a street in Cincinnati, there was found, twenty-five
feet below the surface of the earth, a small horse shoe, in which were
several nails. It is said to present the appearance of such erosion as
would result from the oxidation of some centuries. It was smaller than
would be required for a common mule.[12]

Many are the instances of pieces of timber found, various depths below
the surface of the earth, with the marks of the axe palpably visible
on them.[13] A sword too, said to have been enclosed in the wood of
the roots of a tree not less than five hundred years old, is preserved
in Ohio as a curiosity. Many other instances might, if necessary, be
adduced to prove, that implements of iron were in use in this country,
prior to its occupation by the whites. Now if a people once have the
use of that metal, it is far from probable that it will ever after be
lost to them: the essential purposes to which it may be applied, would
preserve it to them. The Indians however, till taught by the
Europeans, had no knowledge of it.