46 ABORIGINAL MONUMENTS
of course, expect to find but slight traces of instruments or utensils of wood, and but few, and doubtful ones at best, of the materials which went to compose articles of dress. The first inquiry suggested by an inspection of the mounds and other earth-works of the West, relates to the means at the command of the builders in their construction. However dense we may suppose the ancient population to have been, we must regard these works as entirely beyond their capabilities, unless they possessed some artificial aids. As an agricultural people, they must have had some means of clearing the land of forests and of tilling the soil. We can hardly conceive, at this day, how these operations could be performed without the aid of iron; yet we know that the Mexicans and Peruvians, whose monuments emulate the proudest of the old world, were wholly unac- quainted with the uses of that metal, and constructed their edifices and carried on their agricultural operations with implements of wood, stone, and copper. They possessed the secret of hardening the metal last named, so as to make itsubserve most of the uses to which iron is applied. Of it they made axes, chisels, and knives. The mound-builders also, worked it into similar implements, although it is not yet certain that they contrived to give it any extraordinary hardness. A number of axes have been extracted from their deposi- tories, the general form of which is well exhibited in the i \ accompanying engraving. This specimen was found in 4a mound near Chillicothe- It consists of a solid, well-
