Fig. 59.—Terraced Mound.
These mounds are distinguished by their great regularity of form and general large dimensions. They occur most usually within, but sometimes without, the walls of enclosures. They consist chiefly of pyramidal structures, truncated, and generally having graded avenues to their tops. In some instances they are terraced, or have successive stages. But whatever their form, whether round, oval, octangular, square, or oblong, they have invariably flat or level tops, of greater or less area. Examples are known in which, although but a few feet in elevation, they cover several acres of ground; in which cases they are commonly called “platforms.”
Mounds of this class are not numerous in Ohio, and it is believed are only found at Marietta, Newark, Portsmouth, and in the vicinity of Chillicothe. These are all described, and their predominant features illustrated, in the accounts of the works at the several points where they occur, to which attention is directed. (See Plates [XVIII], [XXV], [XXVI].) Those at Marietta are situated within an enclosure; those at Newark and near Chillicothe, in close connection with small circles upon which they seem to have some degree of dependence. So far as ascertained, they cover no remains, and seem obviously designed as the sites of temples or of other structures which have passed away, or as “high places” for the performance of certain ceremonies. The likeness which they bear to the Teocallis of Mexico is striking, and suggestive of their probable purposes.
In addition to the pyramidal structures here noticed, there are others somewhat p174 different in their forms, but which were undoubtedly appropriated to the same purpose. The mound embraced in the circular work connected with the Portsmouth group, is an example. (See Plate [XXVIII].) Though much defaced, its original plan can easily be made out. It is circular, placed on a terrace, is truncated, and has a spiral pathway leading to its summit. The purpose already assigned to it, viz. that of a site for a temple, or a “high place” for the performance of ceremonies probably connected with the superstitions of the ancient people, is indicated not less by the peculiarities of its construction, than by the character of the enclosure in which it is situated.
The feature of truncation is not, however, peculiar to this class of mounds. It is frequently observed in those which, upon investigation, are found to be sepulchral in their character; in which cases it is to be attributed to the falling in of the sepulchral chambers. This circumstance gave the summit of the Grave creek Mound a hollow or dish-shaped form, which was a source of much conjecture, until the excavation of the mound explained the cause.
Along the Mississippi river, and especially as we approach the Gulf, these regular structures increase both in number and magnitude. In Kentucky they are more frequent than in the States north of the Ohio river; and in Tennessee and Mississippi they are still more abundant. Some of the largest, however,
Fig. 60. occur in pretty high latitudes. The great mound at Cahokia, Illinois, is one of the most remarkable. It has often been described, and all accounts concur in respect to its great size. The following approximate plan will serve to give an idea of its general outline. It is of course much rounded, and its regularity to a great degree destroyed, by the storms and changes of centuries; its original plan is, however, represented to be still sufficiently obvious. The form of the mound is that of a parallelogram, seven hundred feet long by five hundred wide at the base. It is ninety feet in height. Upon one side is a broad apron or terrace, which is reached by a graded ascent. At the time this mound was occupied by the monks of La Trappe, the terrace was used as a garden. It is one hundred and sixty feet wide and three hundred and fifty long; the summit or highest part of the mound (A) measures two hundred feet in width by four hundred and fifty in length. Here formerly stood a broad, low mound, which was disturbed in preparing the foundations of a dwelling house. Within it were found human bones, and various implements of stone and pottery, probably belonging to a recent deposit. This mound covers not far from eight acres of ground, and the area of its level summit is about five acres. Its solid contents may be roughly estimated at twenty millions of cubic feet.[114]
Fig. 61. A number of similar mounds, though of less size, occur in this p175 vicinity, and others still exist near the city of St. Louis.[115] Mounds of this class are sometimes surrounded by low embankments of earth. A fine example is furnished by the large conical mound at Marietta, of which a view is elsewhere given. Another occurs on the Virginia shore of the Ohio, nearly opposite the head of Blennerhassett’s Island (Fig. 61). It is lozenge-shaped, and is surrounded by a wall and ditch.[116]