Earth-work in Pike County, Ohio.
EARTH-WORKS.
The different enclosures of a group are often connected by parallel embankments. Similar embankments protect the roads leading from fortified works to the river bank or other source of water. Many are not connected with any enclosures, though in their vicinity; and in such cases they are very slight, from seven hundred to eight hundred feet long, and sixty to eighty feet apart. Some of these parallels were very likely raised roads instead of enclosed ones, as on the Little Miami River, where the embankments extend about a quarter of a mile from two mounds, forming a semicircle round a third, being a rod wide and only three feet high. At Madison, Louisiana, there is a raised way three feet high, seventy-five feet wide, and two thousand seven hundred feet long, with broad excavations three feet in depth extending on both sides for about two thirds its length. Two parallel banks at Piketon, Ohio, are shown in the cut. They are ten hundred and eighty feet long, two hundred and three feet apart at one end, and two hundred and fifteen at the other; the height on the outside being from five to eleven feet, but on the inside twenty-two feet at one end. A modern carriage road now runs between the mounds. From the end of one of them a slight embankment extends twenty-five hundred and eighty feet to a group of mounds.
DITCHES AND MOUNDS.
In the north ditches seem never to occur, except with embankments; but in the south, where embankments are rarely if ever found, ditches, or moats, are sometimes employed to enclose other works, especially in Georgia. Such a moat at Carterville communicates with the river, extends to a pond perhaps artificial, and has two reservoirs, each of an acre, connected with it. The mounds and other monuments are located between the river and the moat. I have already spoken of the pits which furnished earth for the various works, sometimes called wells; some wells of another class, found in the bed of streams and supplied with round covers, were found by Mr Squier to be the natural casts of septaria, or imbedded nodules of hard clay.
The mound or heap form is the one most common in American antiquities as in those of nearly the whole world. Mounds are found throughout the Mississippi region as before bounded, and beyond its limits in many directions they merge into the small stone heaps which are known to have been thrown up by the Indians at road-crossings and over graves. They are most numerous in the upper Mississippi and Ohio valleys, in the same region where the embankments also most abound. As I have said, the number in Ohio alone is estimated at more than ten thousand. They are almost always found in connection with embankments and other works of the different classes described, but they are also very numerous in regions where enclosures rarely or never occur, as in Wisconsin and in the gulf states. From the central region about the junction of the Mississippi, Missouri, and Ohio, they gradually diminish in numbers in every direction, and also in size except perhaps towards the south. They are found in valley and plain, on hill-side and hill-top; isolated and in groups; within and without enclosures; and at long distances from other works. By their location alone no satisfactory classification could possibly be made; still, when considered in connection with their contents and other circumstances, their location assumes importance. By their forms the tumuli are classified as temple-mounds, animal-mounds, and conical mounds.
TEMPLE-MOUNDS.
Temple-mounds always have level summit platforms, and are supposed to have once supported wooden structures, although no traces of such temples remain. A graded road straight or winding, of gentler slope than the sides of the mound, often leads to the top; and in many cases the sides have one or more terraces. One in Tennessee, four hundred and fifty feet in diameter and fifty feet high, has ten clearly marked terraces, except on the east. The bases assume a variety of forms, square, rectangular, octagonal, round, oval, etc., but the curves and angles are always extremely regular. In the north they are usually within enclosures, but in the south, where they are most numerous, they have no embankments and are often arranged in groups, the smaller about a larger central mound. In size the temple-mounds vary from a height of five feet and a diameter of forty feet to ninety feet in altitude and a base-area of eight acres. In respect to form, material, structure, contents, and probable use they admit of no subdivision. Like the embankments they are made of earth, or rarely of stones, simply heaped up, with little care in the choice of material and none at all in the order of deposit.
The largest mound of this, or in fact of any, class is that at Cahokia, Illinois. Its base measures seven hundred by five hundred feet. The height is ninety feet. On one end above mid-height is a terrace platform one hundred and sixty by three hundred and fifty feet, and the summit area is two hundred by four hundred and fifty feet, or nearly two acres, the base covering over eight acres. On the top a small conical mound was found, with some human bones, a deposit of doubtful antiquity. A mound is described at Lovedale, Kentucky, as being of octagonal base, five feet high, with sides of a hundred and fifty feet, three graded ascents, and two conical mounds on its summit. Mr Jones states that parapet embankments, round the edge of the summit, sometimes occur on the southern temple-mounds.