The Trustees of the Smithsonian Contributions to Knowledge have broken ground with the publication of a careful, elaborate, and critical description of the ancient monuments of the Mississippi Valley, the result of original surveys and explorations, by Mr. Squier and Dr. Davis; and it is only the contemporary publication of the Ethnology and Philology of the United States Exploring Expedition, that makes this the second of the great contributions to ethnological science, which have been supplied by the same country within the same year.
And first, as to the area over which these remains are spread.—West of the Rocky Mountains,[136] the most that has hitherto been found is a few mounds, tumuli, or barrows. They will be called mounds. North, too, of the Great Lakes, the remains are but few, and imperfectly described. On Lake Pepin, on Lake Travers (in 46° N.L.), we find notices of them; so we do for the Missouri, as much as 1000 miles above its junction with the Mississippi. Eastward, they decrease as we approach the Atlantic; i.e. on the Atlantic aspects of Pennsylvania, New York, and Virginia, they become scarcer. They become scarce, too, on the other side of the River Sabine; not that they are wanting in Texas, but that they either fall off in number or change in character as we approach Mexico.
The great centre of their development is the vast valley of the Mississippi, and amongst the valleys of its feeders—that of the Ohio preeminently. Here the accumulation is at its maximum. In Ross country alone, 100 enclosures and 500 mounds have been noticed; whilst the whole amount for the state of Ohio has been reckoned at 10,000 of the former, and 1,000 or 1,500 of the latter.
This indicates their locality and distribution. It has also indicated their nature and character. Oftener earthworks than buildings of stone, they are generally (but not exclusively) either raised mounds or embankments forming enclosures,—mounds in some cases 70 feet in height, and 1000 in circumference at the base, and embankments (with ditches corresponding) enclosing spaces of 300 acres. Such are some of the greatest measurements.
In form both the mound and embankment are very varied. The enclosure may be a square, a circle, a parallelogram, an ellipse, a polygon, or a wholly irregular outline, following the inequalities of the soil or the configuration of the country in which it occurs. The ditch may be either exterior or interior to it; the entrance simple or complex. Sometimes the square and circle are combined; so that a round inclosure leads into a quadrangle, or vice versâ. Sometimes a quadrangle is enclosed with a square.
The mounds are sometimes simple cones; sometimes (an important difference) truncated pyramids; often simple slopes; often terraced. More remarkable, however, than any others, is "a succession of remains, entirely singular in their forms, and presenting but slight analogy to any others of which we have an account, in any portion of the globe. The larger proportion of these are structures of earth, bearing the forms of beasts, birds, reptiles, and even of men; they are frequently of gigantic dimensions, constituting huge basso-relievos upon the face of the country. They are very numerous, and in most cases occur in long and apparently dependent ranges. In connection with them are found many conical mounds and occasional short lines of embankment, in rare instances forming enclosures."[137]