This work, although possessing several features peculiar to itself, has others closely resembling those that characterize the works bordering the Gulf. It is described as situated in a beautiful rolling country, conveniently interspersed with timber, and watered by Rock river and its tributaries. It is said to consist of a “brick wall” five feet high by twenty-five feet base, enclosing an area of twenty acres, and having the general outline of an oblong square. Upon three sides the wall is interrupted, at intervals of from two to five rods, by «bastions» of the same height as the main wall, and extending seventeen feet beyond it. The inner wall, extending along the bank of the river, is much lighter than those upon the remaining sides, and is destitute of the singular feature last mentioned. Within this enclosure are a number of truncated pyramids, forty or fifty feet square upon the top, and between fifteen and twenty in height. Two of these are connected with each other by an elevated way, after the manner of some of the Mississippi and Louisiana structures. (See Plate XXXIX.) Two parallel ways or embankments are carried longitudinally, nearly the whole length of the enclosure. Several [p132] conical mounds are mentioned in the description as occurring within the enclosure, but do not appear in the plan. Quite a number occur just exterior to the walls, some of which are represented to be of large size. Covering the south-west angle is a crescent-form work of considerable extent, which also has bastions at intervals throughout its length. A cellar and stairway within one of the square mounds, and a subterranean passage «arched with stone», are mentioned as existing here; but they lack confirmation and deserve little credit.
The walls, which are described as being built of «brick», are composed of clay, probably burned on the spot. Whether they are burned throughout, has not yet been ascertained, and can only be determined by removing a section of the wall. It will doubtless be found that the burning is superficial, resulting from the combustion of some wooden superstructure, or from design. We shall be warranted in ascribing the use of burned bricks to the race which built these works, only upon the most conclusive evidence, and such we do not at present possess.[87] The walls of many of the enclosures in the Scioto valley appear to have been slightly burned. (See page 28.)