GLACIAL MAN IN THE TRENTON GRAVELS. I 7 



most cases the evidence rests upon or consists of field observa- 

 tions, and these cannot be recalled or repeated, and there is 

 absolutely no means of testing directly the value of what is 

 recorded. One may seek either to verify or to discredit the 

 promulgated theories, but years of search may fail to produce a 

 single new item of evidence bearing decisively upon the subject. 

 It is possible that at one period numerous finds of implements 

 should be reported from certain portions of the gravels, and that 

 afterwards the whole remaining body of these formations should 

 be worked over and searched without securing a trace of art ; }■ et 

 this latter evidence, being negative, need not necessaril)' be con- 

 sidered sufficient to overturn the original positive evidence if 

 that happens to be of a high class. There is not the least doubt, 

 however, that positive evidence may be so impaired by various 

 defects anci inconsistencies, that, unsupported by renewed and 

 well verified observations, it will finally 3neld to the negative 

 forces ; and if the theories of a gravel man in the eastern United 

 States, howsoever fortified by accumulated observations, are not 

 really properly supported in every way, they are bound in time 

 to fall to the ground. All I can reasonably hope to do now is to 

 have the evidence relating to glacial man placed on trial, and so 

 fully examined and cross-examined that those who accept gravel 

 man need not longer do so blindly without knowing that there 

 are two sides to the question, and those who do not accept him 

 may know something of the reasons for the belief that is in 

 them. 



The evidence employed to prove the presence of a race of 

 men in the Delaware Valley in glacial times is confined almost 

 wholly to the alleged discovery of rude implements in the glacial 

 gravels. Practically all the evidence has been collected by Dr. 

 C. C. Abbott, and upon his skill as an observer, his faithfulness 

 as a recorder, his correctness of judgment and his integrity of 

 character, the whole matter stands. Many visitors, men of high 

 repute in archeology and geology, have visited the site, but the 

 observations made on such occasions appear not to have been of 

 a nature to be of great value in evidence, the finds being doubt- 



