III. The uses for which their principal earth-works were designed, with a conjectural restoration of one of their pueblos; and,
IV. The probable numbers of the people.
The Mound-Builders have disappeared, or, at least, have fallen out of human knowledge, leaving these works and their fabrics as the only evidence of their existence. Consequently the proposed questions, excepting the first, are incapable of specific answers; but they are not beyond the reach of approximate solutions. The mystery in which these tribes are enshrouded, and the unique character of their earth-works, will lead to deceptive inferences, unless facts and principles are carefully considered and rigorously applied, and such deductions only are made as they will fairly warrant. It is easy to magnify the significance of these remains and to form extravagant conclusions concerning them; but neither will advance the truth. They represent a status of human advancement forming a connecting link in the progressive development of man. If, then, the nature of their arts, and more especially the character of their institutions, can be determined with reasonable certainty, the true position of the Mound-Builders can be assigned to them in the scale of human progress, and what was possible and what impossible on their part can be known.
THE HOUSE-LIFE OF THE AMERICAN ABORIGINES, IN THE USAGES OF WHICH THE MOUND-BUILDERS WERE NECESSARILY INVOLVED.
It will be assumed that the tribes who constructed the earth-works of the Ohio Valley were American Indians. No other supposition is tenable. The implements and utensils found in the mounds indicate very plainly that they had attained to the Middle Status of barbarism. They do not fully answer the tests of this condition, since they neither cultivated by irrigation, so far as is known, nor constructed houses of adobe bricks or of stone; but, in addition to the earth-works to be considered, they mined native copper and wrought it into implements and utensils—acts performed by none of the tribes in the Lower Status of barbarism; and they depended
