Another phase of American archaeology remains to be considered. It is represented in the museum by a unique and most interesting series of specimens illustrating every detail with the greatest particularity and exactness, so that future students need lose no essential feature of the picture that lay before the original explorers and describers. In the northeastern part of Anderson township, near the Little Miami River, a group of earth-works exist which are among the most remarkable of all the thousands scattered throughout the Ohio valley. The owner gave to the museum the exclusive right of exploration, and the locality was mapped and investigated with that scientific care which alone can give the results entire credibility and value. Several of the thirteen mounds within one of the encircling walls contained basins or "altars" of burned clay, on two of which were literally thousands of objects of interest, embracing forms unlike anything known before, and exhibiting an unsuspected degree of cultivation in their makers,--cultivation which, it is fair to suppose, could have been arrived at only after a long period of peaceful and prosperous life in the community. I have space to mention only a few of these articles. One altar contained about two bushels of ornaments made of stone, mica, shells, pearls, and the teeth of bears and other animals. Pearls were so plentiful, indeed, that as many as sixty thousand are in the possession of the museum. They seem to have been derived mainly, if not wholly, from the fresh-water mussels, and are of all shapes and sizes, out of which might be selected hundreds of perfect spheres, from the size of bird-shot to that of a cherry. What splendid necklaces must the latter have made! But, alas for the mercenary collector, all are ruined by fire,--a fact advantageous to science. Like nearly all the other objects, every pearl is perforated for suspension. Articles of copper are none too common anywhere, and the collection of relics hammered from that native metal (which must have been obtained, through barter, from the tribes that mined it on Lake Superior, showing how extensive were the tradings of those days) has not only thrown much light on this branch of ancient art and craftsmanship in America generally, but added some peculiar forms to the museum's stock, chiefly in the line of pendent ornaments. One of the forms procured, represented by many specimens, was a spool-shaped ear-ring: something like it had been seen heretofore, but its purpose had been a mystery. Several of the ornaments of copper were covered with native silver, which had been hammered out into thin sheets and folded over the copper. A few were similarly covered with gold; and this is the first time this metal has been found in the mounds.