In the year 1882, after I had traced the glacial boundary westward from the Delaware River, across the States of Pennsylvania, Ohio, and Indiana, I was struck with the similarity between the terrace at Trenton and numerous terraces which I had attributed to the Glacial age in Ohio and the other States. It adds much to the interest of subsequent discoveries to note that in 1884, in my report to the Western Reserve Historical Society upon the glacial boundary of Ohio, I wrote as follows: [Illustration: Fig. 68.--Argillite implement found by Dr. C. C Abbott, March, 1879, at A. K. Rowan's farm, Trenton, New Jersey, in gravel sixteen feet from surface: a, face view; b, side view (No. 11,286) (Putnam).] "The gravel in which they [Dr. Abbott's implements] are found is glacial gravel deposited upon the banks of the Delaware when, during the last stages of the Glacial period, the river was swollen with vast floods of water from the melting ice. Man was on this continent at that period when the climate and ice of Greenland extended to the mouth of New York Harbor. The probability is, that if he was in New Jersey at that time, he was also upon the banks of the Ohio, and the extensive terrace and gravel deposits in the southern part of our State should be closely scanned by archæologists. When observers become familiar with the rude form of these palæolithic implements, they will doubtless find them in abundance. But whether we find them or not in this State [Ohio], if you admit, as I am compelled to do, the genuineness of those found by Dr. Abbott, our investigation into the glacial phenomena of Ohio must have an important archæological significance, for they bear upon the question of the chronology of the Glacial period, and so upon that of man's appearance in New Jersey." [Illustration: Fig. 69.--Chipped pebble of black chert, found by Dr. C. L. Metz. October, 1885, at Madisonville, Ohio, in gravel eight feet from surface under clay: _a_, face view; _b_, side view.] The expectation of finding evidence of preglacial man in Ohio was justified soon after this (in 1885), when Dr. C L. Metz, while co-co-operating with Professor F. W. Putnam, of the Peabody Museum, Cambridge, Mass., in field work, discovered a flint implement of palæolithic type in undisturbed strata of the glacial terrace of the Little Miami River, near his residence at Madisonville, Ohio. In 1887 Dr. Metz found another implement in the terrace of the same river, at Loveland, about twenty-five miles farther up the stream. The implement at Madisonville occurred eight feet below the surface, and about a mile back from the edge of the terrace; while that at Loveland was found in a coarser deposit, about a quarter of a mile back from the present stream, and thirty feet below the surface. Mastodon-bones also were discovered in close proximity to the implement at Loveland. [Illustration: Fig. 70.]