The Mound Builders used very little stone and showed no knowledge of masonry. But they built so massively out of the earth, that their works have lasted to this day in many places, just as they left them, except for the heavy growth of trees, which the first settlers found covering them, and which were sometimes seven or eight hundred years old. At Marietta, these works when the white people came were quite perfect and inclosed fifty acres on the bank of the Muskingum, overlooking the Ohio. They were in great variety of design. The largest mound was included in the grounds of the present cemetery, and so has been saved, but the plow of the New England emigrant soon passed over the foundations of the Mound Builders’ temples. At Circleville the shape of their fortifications gave its name to the town, which has long since hid them from sight. One of them was almost perfectly round, and the other nearly square. The round fort was about seventy feet in diameter, and was formed of two walls twenty feet high, with a deep ditch between; the other fort was fifty-five rods square, and it had no ditch; seven gateways opened into it at the side and corners, and it was joined to the round fort by an eighth. It is forever to be regretted that these precious ancient works should have been destroyed to make place for the present town; but within a few years one of the most marvelous of the Mound Builders’ works, the great Serpent Mound near Loudon, in Adams County, has been preserved to after time by the friends of science, and put in the keeping of the Peabody Museum at Harvard University. [Illustration: Serpent Mound 019L] The state of Ohio has passed a law protecting the land around it as a park, and there is now reason to hope that the mound will last as long as the rocky bluff on which the serpent lies coiled. This huge idol is more than twelve hundred feet long, and is the most wonderful symbol in the world of the serpent worship, which was everywhere the earliest religion of our race. The largest military ruin is the famous Fort Ancient in Warren County, where, on a terrace above the Little Miami River, five miles of wall, which can still be easily traced, shut in a hundred acres. In Highland County, about seventeen miles southeast of Hillsborough, another great fortress embraces thirty-five acres oh the crest of a hill overlooking Brush Creek. Itswalls are some twenty-five feet wide at the base, and rise from &ix to ten feet above the ground. Within their circuit are two ponds which could supply water in time of siege, and in the valley, which the hill commands, are the ruins of the Mound Builders’ village, whose people could take refuge in the fort on the hilltop and hold it against any approaching force.