562 ' INTEB-GLACIAL AMERICAN MAN. 



very simple matter that the arcliseologist should dig into a Celtic or 

 Saxon barrow, and find there the implements and pottery of its builder. 

 But English geologists, having determined the character of the tool- 

 bearing gravel of the French drift, have sought for flint implements 

 in corresponding English strata, as they would seek for the fossil 

 shells of the same period, and with like success. Palseolithic imple- 

 ments have now been recovered in this manner in Suffolk, Bedford, 

 Hartford, Kent, Middlesex, Surrey, and other districts in the south of 

 England. So entirely indeed has the man of the drift passed beyond 

 the province of the archseologist, that in 1861 Professor Prestwich 

 followed up his Notes on Further Discoveries of Flint Implements 

 in Beds of Post-Pleiocene Gravel and Clay, with a list of forty-one 

 localities where gravel and clay pits or gravel beds occur, as some of 

 the places in. the south of England where he thought flint imple- 

 ments might also by diligent search possibly be found ; and subsequent 

 discoveries have confirmed his anticipations. 



Dr. Charles C. Abbott has applied the same principle on this 

 continent, and selecting the glacial drift of the valley of the Dela- 

 ware River, New Jersey, for his investigations, has as he believes, 

 been rewarded with a like success. The character of these tool- 

 bearing gr-avel-beds of New Jersey are thus described by Professor 

 N. S. Shaler: " The general structure of the mass is neither that of 

 ordinary boulder clay, nor of stratified gravels, such as are formed 

 by the complete re-arrangement by water of the elements of simple 

 drift deposits. It is made iip of boulders, pebbles and sand, varying 

 in size from masses containing one hundred cubic feet or more, to 

 the finest sand of the ordinary sea beaches. There is little trace of 

 true clay in the deposit. There is rarely enough to give the least 

 trace of cementation to the masses. The various elements are rather 

 confusedly arranged ; the large boulders not being grouped on any 

 particular level, and tlieir major axes not always distinctly coinciding 

 with the horizon. All the pebbles and boulders, so far as observed, 

 are smooth and water-worn ; a careful search having failed to show 

 evidence of a distinct glacial scratching or polishing on their sur- 

 faces. The type of pebble is the sub-ovate or discoidal, and though 

 many depart from this form, yet nearly all observed by me had been 

 worn so as to show that their shajDe had been defcez^mined by running 

 water. The materials comprising the deposit are very varied, but' 

 all I observed could appai-ently with reason be supposed to have. 



