PALEOLITHIC MAN IN AMERICA. 29 



by Metz was laid down by a turbulent ice-bearing river but a 

 few miles from the glacier's margin. The implement, unlike 

 those recorded by Aughey, McGee, and N. H. Winchell, is of 

 the rude type commonly called paleolithic, and thus indicates 

 primitive customs among its makers; but neither alone nor in 

 conjunction with the similar implement found by the same indi- 

 vidual under like conditions at Lovelands does it tell whether the 

 inhabitant of the ice-front in the Ohio valley was hunter, fisher- 

 man, or husbandman, troglodyte, nomad, or house-builder; and 

 only the geologic evidence suggests conditions of life approaching 

 those of the modern Esquimau. 



When the primitive man of Trenton flourished, the later 

 Quaternary mer de glace covered New York and New England, 

 and extended far into northern New Jersey and Pennsylvania. 

 The ice was from five hundred to one thousand feet in thickness 

 near its margin, and overflowed the highest mountains, though 

 they somewhat impeded its progress ; the land beneath was some- 

 what depressed and was tilted northward toward the ice-front; 

 and flooded rivers, born upon and beneath the edge of the ice- 

 sheet, swept into their lower courses and into the sea, glacial 

 mud, sand, and pebbles, while upon their surfaces floated ice-floes 

 laden sometimes with larger pebbles and anon with great bowl- 

 ders. Among these rivers was the Delaware, which was trans- 

 formed in its middle course from a constricted torrent rushing 

 swiftly over a rocky bottom (as it is to-day and as it was anterior 

 to the second ice-epoch) into a broad slack-water estuary, tidal 

 probably to the mouth of the Lehigh. This estuary found its 

 source at the edge of the ice, where now lies the terminal moraine 

 (just below Belvidere) ; and at what is now the head of tide at 

 Trenton it embouched into a broad, shallow bay. At the ice- 

 front it gathered a harvest of cobble-stones which were washed 

 down-stream and deposited in a series of terraces more than one 

 hundred feet in height and two miles or more in width, extend- 

 ing ten miles down the river ; the cobbles growing finer and finer 

 and finally passing into beds of gravel and sand. There, too, the 

 waters became charged with glacial mud — the rock-flour forming 

 the grist of the glacial mill — which was more slowly deposited 

 in the form of fine loam sometimes enveloping the cobbles and 

 abundantly intermixed with the finer gravel and sand as far south 

 as Philadelphia, but most abundantly above Trenton. There, also, 

 the river gathered sand, fine and coarse pebbles, great bowlders, 

 and heterogeneous debris, which were frozen into ice-floes, floated 

 gently down-stream, and dropped as the floes melted, equally far 

 southward, but most abundantly where the river embouched into 

 the bay and where the floes lingered longest in the slackened cur- 

 rent, These aqueo-glacial deposits extend continuously from the 



