Dr. Abbott commenced by gathering a very extensive collection, carefully searching his section of country and gathering all specimens of artificially shaped stones. These must have existed there in considerable quantities, as, in three years’ time, he collected over nine thousand specimens,49 carefully examining them as they came from the soil.50 As a result of this extensive and careful research he is able to present us some general conclusions. The surface specimens, including in this classification also those specimens turned up by the plow,51 are characteristically Indian. The material is jasper and quartz, and they are generally carefully made. They used other varieties of stone as well. Like the Neolithic people of Europe, they sought the best varieties of stone for their purpose. But his collection also included rude Paleolithic forms, and he found by taking the history of each specimen separately, that just in proportion as the relics were rude in manufacture and primitive in type the deeper were they buried in the soil.52 Writing in 1875, he says: “We have never met a jasper (flint) arrow-head in or below an undisturbed stratum of sand or gravel, and we have seldom met with a rude implement of the general character of European drift implements on the surface of the ground.”53
These are not theoretical opinions, but are deductions drawn from a very extensive experience. From figured specimens of these rudest formed implements, we see they are veritable Paleolithic forms, resembling in a remarkable manner the rude implements of the old world, whether collected in France or in India. We learned that the Paleolithic people of Europe utilized the easiest attainable stone for their implements. They contented themselves with such pieces of flint as they could gather in their immediate vicinity. The easiest attainable rock in the valley of the Delaware is not flint, but argillite, and such is the material of which the Paleolithic implements are formed. Thus it is shown that the first appearance of a stone-using folk in the valley of the Delaware was in the Paleolithic stage of their culture. Judging from the depths of their buried implements, this long preceded the Neolithic stage.