It is a well known fact, that since the whites became settled in the country, the Indians were in the habit of collecting the bones of their dead and of depositing them in one general cemetery; but the earth and stone used by them, were taken from the adjacent land. This was not invariably the case, with those ancient heaps of earth found in the west. In regard to many of them, this singular circumstance is said to be a fact, that the earth, of which they are composed, is of an altogether different nature, from that around them; and must, in some instances, have been carried a considerable distance. The tellurine structures at Circleville are of this sort; and the material of which they were constructed, is said to be distinctly different, from the earth any where near to them. The immensity of the size of these and many others, would induce the supposition that they could not have been raised by a race of people as indolent as the Indians have been, ever since a knowledge was had of them. Works, the construction of which would now require the concentrated exertions of at least one thousand men, aided by the mechanical inventions of later days, for several months, could hardly have been erected by persons, so subject to lassitude under labor as they are: unless indeed their population was infinitely greater than we now conceive it to have been. Admitting however, this density of population to have existed, other circumstances would corroborate the belief, that the country once had other inhabitants, than the progenitors of those who have been called, the aborigines of America: one of these circumstances is the uncommon size of many of the skeletons found in the smaller mounds upon the hills. If the fact be, as it is represented, that the larger skeletons are invariably found on elevated situations, remote from the larger water courses, it would tend to show that there was a diversity of habit, and admitting their cotemporaneous existence, perhaps no alliance or intercourse between those, whose remains they are, and the persons by whom those large mounds and fortifications were erected, [37] these being found only on plains in the contiguity of large streams or inland lakes; and containing only the bones of individuals of ordinary stature. Another and stronger evidence that America was occupied by others than the ancestors of the present Indians, is to be found in those antiquities, which demonstrate that iron was once known here, and converted to some of the uses ordinarily made of it. 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]