Adena Earthwork in Circleville Ohio

 Circleville Ohio Adena Enclosure

    Work is sixteen miles distant from the one last described, and is situated on the left bank of the North fork of Paint creek. A portion of it is included in the town limits of Frankfort, better known as "Oldtown," or "Old Chillicothe.
The combination of the great circle and the square, in this work, is identical with that which exists in the celebrated Circleville work,—which work, it may be observed, is no more remarkable than numbers of others, and owes its celebrity entirely to the fact, that it has been several times described with some minuteness.
      A reduced plan of the Circleville work, is herewith presented, which will sufficiently illustrate this remark. Its dimensions were considerably less than those of the analogous structures already described. The sides of the square measured not far from nine hundred feet in length, and the diameter of the circle was a little more than one thousand feet. The work was peculiar in having a double embankment constituting the circle. It is now almost entirely destroyed, and its features are no longer traceable
        The walls of the rectangular portion of the Frankfort work, where not obliterated by the improvements of the town, are still several feet high. They were, within the recollection of many people, much higher. They are composed of clay (while the embankment of the circle is composed of gravel and loam), which, as in the case of the square work described, appears to have been very much burned.
The isolated mound near the upper boundary of the circle is composed entirely of clay, and is twelve feet high; the others are of gravel, the largest being no less than twenty feet in altitude. Various dug holes or pits, from which the material for the embankments and mounds was evidently taken, are indicated in the plan. Some of them are, at this time, fifteen or twenty feet deep. The subsoil at this locality, as shown by excavation, is clay. If there was no design, therefore, in constructing the walls of the square of that material, it follows that it was built last, and after the loam and gravel had been removed from the pits.
       A portion of the large circle has been encroached upon and destroyed by the creek, which has since receded something over a fifth of a mile, leaving a low rich bottom intervening.
Such are the predominant features of this remarkable series of works. As already remarked, the coincidences observable between them could not have been the result of accident, and it is very manifest that they were erected for common purposes. What those purposes were, the reader must judge. Without entering into an argument upon the subject, we may content ourselves with the simple expression of opinion, that they were in some manner connected with the superstitions of the builders.
There is one deduction to be drawn from the fact, that the figures entering into these works are of uniform dimensions, which is of considerable importance in its bearing upon the state of knowledge among the people who erected, them. It is that the builders possessed a standard of measurement, and had some means of determining angles. The most skilful engineer of the day would find it difficult, without the aid of instruments, to lay down an accurate square of the great dimensions of those above represented, measuring as they do more than four fifths of a mile in circumference. It would not, it is true, be impossible to construct circles of considerable size, without instruments; the difficulty of doing so, when we come to the construction of works five thousand four hundred feet, or over a mile in circumference, is nevertheless apparent. But we not only find accurate squares and perfect circles, but also, as we have seen, octagons of great dimensions. Other evidences tending to sustain the above conclusions will be adduced in the progress of this work.