Whether or not these floods had any part in piling up the clay at the doorway, beyond doubt it was to them that the clay, gravel, and sand resting upon the floor of the main cave owe their origin. To them is likewise due the dark earth overlying the clay at the rear and covering the floor of the recess in the east wall. Clearly, there was at one time in the cave's history a current at intervals, which carried mud and small rocks from the interior of the cave, or from the outside surface through sink holes, and left at least a part of it where the velocity of the stream was checked. Later, much of this water found other drainage channels, and the coarser matter could no longer be carried into the cave; but at times of unusually heavy precipitation enough of the torrent followed the old course to bring in the dark earth. The last is due to top soil containing a large amount of humus from decaying vegetation. Finally, no more water came this way except as seepage, which is the condition at present.
The pool at the rear may be entirely empty in dry seasons; and after heavy rains may contain a depth of 2 feet. This water now has a greasy looking scum and a sour, unpleasant odor.
The cave was inhabited before the water had entirely ceased to flow through it; this is proven by the alternation of refuse and silt in the recess under the east wall. Kitchen waste would be thrown here, and when the water rose sediment would cover it. There was then dry ground near the doorway; and the water in the pool, having an outlet toward the east, through the crevice, was fit for use, except, perhaps, when turbid.
On the rear slope, 18 feet from the water, the excavation was carried to the level of the bottom of the pool. The lower 2 feet was mud, and at the bottom water oozed in. Scattered through this muddy earth was much charcoal in small fragments; and for a short distance it also occurred for a few inches below the surface of the red clay. This charcoal was carried in by the water at the same time as the earth with which it was associated, and must be due to fires on the hill outside. At any rate, it did not come from any fires made within the cavern. No refuse or worked objects of any kind were found in this black earth, except in the recess in the east wall, as described, and in the upper portion immediately under the ashes. Such as existed outside the recess may have become mixed in the same way; that is, by being thrown on the top as it existed at the moment and being later covered by the water; or it may have worked in from the ashes above. Nor was there much refuse in the ashes on the rear slope, although these were quite regularly stratified.
To entirely remove the rocks and clay and expose in a satisfactory manner the bedrock floor would require months of labor, the use of mechanical appliances, and complete drainage to the rear wall through the mouth of the cave.
Without attempting to make a detailed list, there may be given a summary of the objects shipped to the National Museum:
- 12 skulls, most of them more or less broken.
- 10 partial skeletons, including those of children.
- 8 fragments of skulls from different individuals not included in the above.
- 74 objects of shell.
- 711 worked flint objects; knives, scrapers, cores, etc.
- 10 grooved axes, tomahawks, and flint hammers.
- 10 mortars.
- 40 pestles, stone hammers, rubbing stones, etc.
- 413 wrought objects of bone and stag horn.
- 2 clay pipes.
- 1 box of pottery fragments.
- A number of small objects, not classified.
There were left in the cavern several hundred broken flints; more than 60 mortars; probably 200 stones used as pestles, hammers, etc., and several large wagonloads of shell, bone, and broken pottery.
There is no way in which the age of the deposits in either the Miller or the Sells Cave can be determined. The accumulation of ashes in the one and of talus at the front of the other would certainly imply the lapse of several centuries, perhaps a thousand years of continuous occupation. Intermittent habitation would lengthen this period.