Meaning of “Mound Builders”—Location of Mound Building tribes—All Mounds not the work of men—Altar Mounds—Objects found on the Altars—Altar Mounds possibly burial Mounds—Burial Mounds—Mounds not the only Cemeteries of these tribes—Terraced Mounds —Cahokia Mound—Historical notice of a group of Mounds—The Etowah group—Signal Mounds—Effigy Mounds—How they represented different animals—Explanation of the Effigy Mounds—Effigy Mounds in other localities—Inclosures of the Scioto Valley—At Newark, Ohio—At Marietta, Ohio—Graded Ways—Fortified Inclosures—Ft. Ancient, Ohio—Inclosures of Northern Ohio—Works of unknown import—Ancient Canals in Missouri—Implements and Weapons of Stone—Their knowledge of Copper—Ancient mining —Ornamental pipes—Their knowledge of pottery—Of Agriculture—Government and Religion—Hard to distinguish them from the Indians. The past of our race is irradiated here and there by the light of science sufficiently to enable us to form quite vivid conceptions of vanished peoples. As the naturalist, from the inspection of a single bone, is enabled to determine the animal from which it was derived, though there be no longer a living representative, so the archæologist, by the aid of fragmentary remains, is able to tell us of manners and times now long since removed. In the words of another: “The scientist to-day passes up and down the valleys, and among the relics and bones of vanished people, and as he touches them with the magic wand of scientific induction, these ancient men stand upon their feet, revivified, rehabilitated, and proclaim with solemn voice the story of their nameless tribe or race, the contemporaneous animals, and physical appearance of the earth during those prehistoric ages.”2 We have already learned that the world is full of mysteries, and though, by the exertion of scholars, we begin to have a clearer idea of some topics, yet our information is after all but vague and shadowy. The amount of positive knowledge in regard to the mysterious tribes of the older Stone Age, or the barbarians of the Neolithic period, or the struggling civilization of the early Metallic Ages, is lamentably deficient. On our Western Continent we have the mysterious remains in the gold-bearing gravels of the Pacific coast, the significance of which is yet in dispute. We have the Paleolithic Age of Europe, represented by the remains found in the gravels of the Delaware at Trenton, New Jersey. When deposited there, and by what people used, is, perhaps, still enshrouded in doubt.