There is no ditch. Nothing could more clearly mark the difference between this fortification and one that would have been made by a white race. An outer ditch is usually considered as not only of essential importance in works of defence, but its excavation supplies the earth required for the ramparts. It seems evident that either these Indians in their method of defensive warfare did not always consider a ditch to be useful, or it is possible that, in consequence of not having shovels or pickaxes, they preferred obtaining earth in some other manner which they found more convenient.
Upon inquiring among the farmers who were occupying the adjacent land, I found that there was a prevalent opinion amongst them that the earth composing these embankments had been brought from a distance and that it had been carried by hand. It was also believed by them that the fort could not have been made by Indians and that it was built at a very remote period by some other race.
When walking upon the top of the broad ramparts I observed that there were no evidences of the excavations that supplied the earth for the formation of the enormous banks. In some parts of the interior there were some shallow depressions, and also several holes which had been made for some unknown purpose, but they could not have provided the quantities required. It is possible, and, I think probable, that the earth was taken from the surface of the land within the inclosure. A shallow excavation made to a depth not exceeding six inches over the whole area of one hundred and forty acres would have given a sufficient supply. The methods of digging the ground, and of conveying the earth must necessarily have been very primitive, and it is surprising that, with all the difficulties that had to be overcome, works of such magnitude should have been raised.
At a gap in an angle over-looking the river the remains of a road, which led down to the water, can still be traced. At the part where this road entered the fort it is evident that it had been paved with flat water-worn stones. The ramparts here reach their greatest dimensions, being fully twenty feet high. The appearance of Fort Ancient from this position was very remarkable, and the effect was heightened by the beautiful foliage of the forest trees that crowned the summits of these lofty earthworks.
The inner part of the camp was strongly fortified. High banks were raised across the narrow part of the enclosure at the centre, and two mounds guarded the approach. The road to the outer camp from the plain was also protected by two mounds, and from these there ran low parallels for a distance of nearly fourteen hundred yards. They then terminated by closing round another mound which was probably used for the purpose of a look-out. Some labourers at a farm near this position told me that there once existed other parallel banks connected with the fort, which could be traced for several miles, but that these had been destroyed.
There are certain features in the construction of this fortification which have attracted attention, but their purpose has not been, and probably cannot be, explained. There are not less than seventy gaps or openings leading out of the embankments. It has been supposed that these were intended to allow the escape of water from the interior. There is another theory which has been suggested, according to which it is thought possible that they were openings made with the object of enabling the Indians to rush out at several points to repel their enemies, and that they were fenced by stockades.
It, however, happens that these gaps are sometimes in positions where the slopes of the hill are so steep as to be practically inaccessible, and at other places they are on the level ground from which no surplus waters could drain away. They seem to have formed part of the system of fortification, for they occur in the same inexplicable manner at another hill work of defence, built under similar conditions, on the summit of a promontory with precipitous slopes, about forty miles to the south-east of this position, which was evidently built by the same race.
This large earthwork is called Fort Hill, and it is singular in the respect of having afforded to its surveyor the means of forming a judgment upon the question of its antiquity. Consequently it has become possible to establish well-founded conclusions with respect to the dates of the construction of earthworks of a similar character.
Professor Locke, in his report on the geology of that part of Ohio, stated that on the top of the wall of Fort Hill stood a chestnut tree six feet in diameter. “Counting and measuring,” he observes, “the annual layers of wood where an axeman had cut into the trunk, I found them at nearly 200 to the foot, which would give to this tree the age of 600 years. A poplar tree, seven feet in diameter, standing in the ditch, allowing the thickness to the layers which I have found in like poplars, 170 to the foot, would give nearly the same result, 607 years.”[25]
Accepting the deductions of Professor Locke as being correct, it follows that the period when this hill fort was constructed was not later than the thirteenth century. Admitting that the thirteenth century, is therefore the latest age that can be ascribed to works of this type, they may be much older, for the forest trees within the inclosures may have succeeded earlier growths.