secured food for servants and attendants on these works, with all their painful toil in preparing tools under the greatest disadvantages, must have represented another immense outlay of human energy.

Of the nearly twelve thousand works remaining in Ohio, when the general critical examination was made in 1845-7, fifteen hundred were inclosures. These consisted of walls, sometimes miles in total length, surrounding and sometimes surrounded by-mounds of various size and form, which, with modern facilities for moving earth, would represent the labor of thousands of men and animals for a great length of time. The inclosures and mounds have been classified as fortifications, temples, altars, sepulchres, signal stations and symbolic figures. Various circumstances make the aim in their construction, and sometimes their actual use after they were built, very evident to the student of them who makes the study with due intelligence and care. Too many have been explored with haste by persons who did not suspect the great importance of uncovering ancient buried relics with caution and leaving them in undisturbed position until an extensive observation had been made and recorded of their relation to each other and to their surroundings; for by these circumstances much of their significance is usually determined. They often reveal the manner and the purpose of burial.

2

* More than thirty years of the nineteenth century had passed before the investigations of men of science in Europe were directed to the buried traces of pre-historic man on that continent, and the idea of gaining precise information from such studies was not fully accepted by high scientific authorities. until some years after. It is not surprising, therefore, that these mounds, widely scattered in a new country where scientific experts were less numerous than in the Old World, should be little noticed, and never studied with sufficient carefulness to discover the right key to their revelations. They had not been unnoticed, however, and some extravagant theories con

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cerning their origin had been based on superficial observations of their appearance and the curious relics often found in them. These theories had little value, because not founded on sufficiently minute and extended examination.

In 1845 a careful survey of the mounds in Ohio was begun and continued for two years, by thoroughly competent observers, with a scientific care and accuracy that led to important conclusions. A description of these studies, that discarded vague suppositions and loose estimates and furnished detailed and accurate explanations of the leading features of the mounds and their contents, was published. Much interest was awakened in the scientific world, the mounds in all parts of the country were critically examined by suitable persons, and the information already gained was confirmed and extended.

The information here given, and the interesting inferences drawn, are gathered from these scientific records. Their accuracy can not be questioned, for as the number of thoroughly trained observers has increased in recent years, the facts have been repeatedly re-studied and verified.

Some of the mounds were evidently military structures, designed for defence against enemies, most of the points fortified being selected with a judgment that would do honor to a modern engineer corps, and with a lavish display of labor and pains that is extremely significant. Fort Hill, Ohio, was a fortress of great strength, occupying the summit of a hill five hundred feet high on two of its sides, and surrounded with a wall along the edge of the hill, the materials for which were thrown up from a deep ditch dug around the brow. The wall and the ditch are more than a mile and a half in circuit and enclose an area of forty-eight acres. The wall, at the more accessible points, is said to be still from six to fifteen feet in height. When examined, it was covered with a heavy forest of gigantic trees, standing and fallen, and some of the latter could not have been less than a thousand years old. Large artificial reservoirs for water indicate that it was once provided with all the means to stand a formidable siege.

Another defensive work, called Fort Ancient, on the Little Miami River, had walls nearly four miles in length, besides mounds, parallels and curtain walls. These were, when carefully surveyed by a competent party from Cincinnati, eighteen to twenty feet high at exposed points, and the number of cubic yards of excavation made in constructing them was estimated at nearly seven hundred thousand. These are but what remain after the storms of perhaps thousands of years have done their best to diminish and wash them away.

Another, in the Scioto Valley, embraces within its defenses an area of one hundred and twenty acres; a stream was turned out of its course to permit a complete circuit of wall; and it includes mounds which, with the walls, contain three million cubic feet of earth. Fortified and covered ways sometimes lead from fortresses on heights to the streams below. Evidences of military foresight and skill in the art of defence are often very striking, and indicate mature reflection after extensive experience as well as command of unlimited labor for long periods.

One military work included between 600,000 and 700,000 cubic yards of earth thrown up; and the system of defenses at the mouth of the Scioto River is said to be at least twenty miles in total length, though embracing not more than two hundred acres of inclosure. These defensive works are usually on the points of bluffs in bends of rivers, or in the angle formed by the meeting of the streams. They are usually in the vicinity of numerous works of a different character, indicating the presence of a large population and a center of the community. They were evidently designed to form a protection, and probably, as danger grew more threatening, became places of retreat for the inhabitants. Sometimes these inclosures are so extensive, and embrace so many mounds of various form and size, as to suggest that here was a walled town.

A curious implication of foresight and ability in defence is