These structures are simply circles, or figures approaching to circles, with occasional irregularities. There is a difference of fifty feet in the diameters of the larger one, and the outline bends each way from the curve of a true circle, a few feet, making short straight portions, not capable of representation on our scale. The ditches are at present very slight, and not uniform in depth or breadth. From the top of the bank to the bottom of the ditch, the difference in no place exceeds two and a half feet. On all sides, for miles, is a low clayey plane, inclined to be wet, with very slight undulations. This is the only remarkable fact connected with this work. Its ditch being external, and its openings narrow, indicate a work of defense; and if it were known that the ancient inhabitants of the Scioto used palisades, we might safely conclude this to be a place of defense, relying solely on artificial strength. There is no running water in the vicinity.