MOUNDS OF OBSERVATION.
It has already been several times remarked, that the most commanding positions on the hills bordering the valleys of the West, are often crowned with mounds, generally of intermediate, but sometimes of large size,—suggesting at once the purposes to which some of the cairns or hill-mounds of the Celts were applied, namely, that of signal or alarm posts.
Ranges of these mounds may be observed extending along the valleys for many miles. Between Chillicothe and Columbus, on the eastern border of the Scioto valley, not far from twenty may be selected, so placed in respect to each other, that it is believed, if the country were cleared of forests, signals of fire might be transmitted in a few minutes along the whole line. On a hill opposite Chillicothe, nearly six hundred feet in height, the loftiest in the entire region, one of p182 these mounds is placed. After the fall of the leaves in autumn, it is a conspicuous object from every work laid down on the Map of a section of twelve miles of the Scioto valley, to which such frequent reference has been made, as well as from other works not exhibited in the map. It is indicated by the figure 5 in this map. A fire built upon it would be distinctly visible for fifteen or twenty miles up, and an equal distance down the valley, (including in its range the Circleville works, twenty miles distant,) as also for a long way up the broad valleys of the two Paint creeks,—both of which abound in remains, and seem to have been especial favorites with the mound-builders. In the Map of six miles of the Miami valley, (Plate [III],) a similar feature will be observed. Upon a hill three hundred feet in height, overlooking the Colerain work, and commanding an extensive view of the valley, are placed two mounds, which exhibit—in connection with other circumstances not entirely consistent with the conclusion that they were simple signal-stations—strong marks of fire on and around them. Similar mounds occur, at intervals, along the Wabash and Illinois rivers, as also on the Upper Mississippi, the Ohio, the Miamis, and the Scioto. On the high hills overlooking the Portsmouth and Marietta works, (Plates [XXVI] and [XXVII],) mounds of stone are situated; those at the former place exhibit evident marks of fire. On the heights around the works at Grave creek in Virginia, similar features have been observed.[122] A trip of exploration, made with special reference to this and kindred points, disclosed the fact that, between the mouths of the Scioto and Guyandotte rivers, the hills upon both sides of the Ohio, for the entire distance, were studded with mounds. Many of them, however, occurred in groups, their bases joining, and were placed so far back from the brow of the hills as to be entirely invisible from the valley,—facts wholly opposed to the hypothesis which ascribes a common purpose to all of the hill-mounds. Indeed, for the distance above specified, these mounds, though less in size, seemed quite as numerous as those in the valley; in which, besides mounds and a few small circles, no works of magnitude were discovered,—another fact which may not be without its importance in this connection.
Some of the hill-mounds bordering on the Ohio have been opened by explorers, and found to contain human remains, but whether of an ancient or modern date, it is difficult, from the imperfect nature of the accounts, to determine. The remarkable mound already mentioned, situated on the high hill near Chillicothe, was opened some twelve or fifteen years ago; and, it is said, human remains and a variety of relics were discovered in it. Although the investigation of this class of mounds has, from a variety of causes, been comparatively limited, yet enough has been ascertained concerning them, to justify the belief that a large proportion contain human remains, undoubtedly those of the mound-builders. And, although traces of fire are to be observed around very many, the marks are not sufficiently strong to sustain the inference that all were look-outs, and that fires were kindled upon them as signals. It is not impossible that a portion were devoted to sepulture, another portion to observation, and that some answered a double purpose. p183 This is a point which remains to be settled by the disclosures of the mattock and spade, and by a close and extended observation of the dependences which exist, not only between the hill-mounds themselves, but between them and the other monuments of the same people.
It may perhaps seem, from what has been adduced, that the classification of any portion of the hill-mounds as places of observation, is not sufficiently well authorized. The positions however which many of them occupy, are such as would most naturally be chosen for such purposes, though not necessarily for such only. The apparent dependence which exists between some of them and the larger earthworks would also seem to favor the idea that they were look-outs. But whether signal-stations or otherwise, there can be no doubt that the ancient people selected prominent and elevated positions upon which to build large fires, which were kept burning for long periods, or renewed at frequent intervals. For what purposes they were built, whether to communicate intelligence or to celebrate some religious rite, it is not undertaken to say.[123] The traces of these fires are only observed upon the brows of the hills: they appear to have been built generally upon heaps of stones, which are broken up and sometimes partially vitrified. In all cases they exhibit marks of intense and protracted heat. They are vulgarly supposed to be the remains of “furnaces,” from the amount of scoriaceous material accompanying them, which often covers a large area, and is several feet in thickness. This popular error has led to some very extravagant conjectures as to the former mineral wealth of the vicinity in which they occur; an error which has been perpetuated in various works on American antiquities.
The dependence which exists between certain mounds, and the defensive structures within or near which they are located, is too evident to admit of doubt. It has already been made a subject of remark, (page [43],) and need only be referred to here. In the case of the fortified hill, Plate [VI], we find a large mound commanding the only avenue leading to it, and so placed that no approach could be made unobserved from its summit. Similar dependences, perhaps still more marked, are perceived in other works, where mounds are placed on the approaches, or at such points within or without the walls as are best adapted for observation. (See Plate [XI], Nos. 1 and 2.) p184