From the size of the walls, their position, and other circumstances, it has been supposed that this was a fortified place. If palisaded, it would certainly be impregnable to any savage attack. If designed as a sacred place, its sloping area would be most fit for the observance of sacrifices or ceremonies.

What may have been the purpose of the mysterious parallels, is more than we, at this period, can venture to say.

PLATE XXVIII. PORTSMOUTH WORKS—GROUP B.

This group also occupies the third terrace, and, though not so imposing in magnitude as the one just described, seems to be the grand centre from which the parallel lines, characterizing this series of works, radiate. Its details are intricate, and can only be understood by the aid of the plan. The two crescent or horse-shoe-shaped walls constitute the first striking feature which presents itself. They are both of about the same size and shape, measuring eighty feet in length by seventy in breadth. The earth around them appears to have been considerably excavated. Enclosing these in part is a circular wall now about five feet high. The elevation to the right appears to be natural, although evidently much modified by art. It is eighteen feet high at the end next the principal division of the work, but gradually p081 subsides into a low ridge towards the enclosed mound a b. A full view of the entire group may be had from its summit. The mound just mentioned is twenty-eight feet high, by one hundred and ten base; it is truncated and surrounded by a low circumvallation. There are several small circles, measuring from one hundred and fifty to two hundred and fifty feet in diameter; also a few mounds, in the positions indicated in the plan.

No one, after examining its details, would be apt to ascribe a military origin to this group. The most reasonable conjecture respecting it is, that it was in some way connected with the superstitions of the builders; in what manner, of course, it is impossible to determine. A thorough examination of the mounds might throw some light on the question. At any rate, it is entirely unique in many of its features, and furnishes an interesting study for the antiquary.

PLATE XXVIII. PORTSMOUTH WORKS—GROUP C.

This group is on the Kentucky shore, and principally occupies the third terrace, or high level at the base of the hills bordering the valley. The ground is here considerably broken. The northern portion of the work is somewhat lower than the remainder, and a small brook cuts through the outer wall on the south. This work is in many respects novel, and for this reason, as well as from the connection in which it is found, is entitled to an attention not otherwise merited; for no person looking merely for what is striking from position, or imposing from magnitude, would be apt to pay it a second visit. It consists of four concentric circles, placed at irregular intervals in respect to each other, and cut at right angles by four broad avenues, which conform in bearing very nearly to the cardinal points. A large mound is placed in the centre; it is truncated and terraced, and has a graded way leading to its summit. A reference to the plan and sections will exhibit in one view the dimensions and general aspect of the work, obviating the necessity of a detailed description.

The mound in the centre, at first glance, would be taken for a natural elevation; and it is possible that it is a detached spur of a hill, modified and perhaps enlarged by art. A hillock in such a position is, however, a circumstance of very rare occurrence. From the level summit of this mound, a complete view of every part of the surrounding work is commanded. Were it not for the obstructing forests, it is believed the eye might obtain, from this position, a view of the river and intermediate plain, as also of the works beyond, and several miles distant. On the supposition that this work was in some way connected with the religious rites and ceremonies of the builders, this mound must have afforded a most conspicuous place for their observance and celebration. And it is easy, while standing on its p082 summit, to people it with the strange priesthood of ancient superstition, and fill its avenues and line its walls with the thronging devotees of a mysterious worship. Whatever may have been the divinity of their belief, order, symmetry, and design were among his attributes; if, as appears most likely, the works that most strongly exhibit these features were dedicated to religious purposes, and were symbolical in their design.

About one mile to the west of this work are a number of mounds, some of considerable size, and also a small circular work, D, of exquisite symmetry and proportion. It consists of an embankment of earth five feet high by thirty feet base, with an interior ditch twenty-five feet across by six feet deep, enclosing an area ninety feet in diameter, in the centre of which rises a mound eight feet high by forty feet base. A narrow gateway through the parapet, and a causeway over the ditch, lead to the enclosed mound.