Abbott.] 
128 
[January 19, 
ing slowly under tlie influence of frost and gravity towards its 
base, it was difficult to believe that these specimens, found about 
twelve feet below the top of the bank, had travelled down from 
the superficial soil.” 
Continuing my own researches, in 1877, I made a second report 
on the occurrence of these implements, and re-affirmed my convic- 
tion that in the specimens of artificially chipped pebbles, from 
these gravel deposits, we have evidence of man’s presence at an 
earlier date than the supposed advent of the Red Indian ; and 
referred them geologically to the Glacial epoch, in accordance 
with the writings of Professor Cook, our State Geologist, who had 
pronounced these gravels as of glacial origin. 
This, briefly, is the history of my own labors in this field. 
As the result, in material gathered, there are now in the 
Peabody Museum about four hundred specimens, of which about 
sixty have been taken from recorded depths ; about two hundred 
and fifty from the talus, at the bluff facing the river, and the 
remainder from the surface or derived from collectors who did 
not record the positions or circumstances under which they were 
found. While these figures are approximative only they do not 
materially vary from the notes that I have taken, which, generally 
being packed away with the specimens, I have not the time to 
carefully go over and repeat to you verbatim. 
Somewhat similar conditions occur also in other river valleys, 
as the Schuylkill and Susquehanna, in Pennsylvania, and in the 
valley of the Potomac, near Washington. The geological struc- 
tures of these valleys, with rock formations coming near to or 
constituting the surface, not improbably explains much of this 
difference as compared with the Delaware valley, wherein, south 
of Trenton, H. J., there is no living rock in place except at great 
depths. 
In the valleys of the Schuylkill and Potomac, Mr. Berlin, of 
Reading, Pa., and Dr. Hoffman, of W ashington, D. C., have found 
implements of palaeolithic character under circumstances point- 
ing to a remote antiquity, although none have occurred at as great 
depths as at Trenton, 1ST. J. 
Prof. Haldeman also found rude implements in the Susque- 
hanna valley, which, as his own statement regarding them clearly 
