570 INTEE-GLACIAL AMERICAN MAIN. 



rude implements, which, unlike the so-called ' turtle-back ' celts, is 

 distinctly chipped upon both sides, and has but a slight amount of 

 secondary chipping. The cutting edges, however, are comparatively 

 straight. This and other examples of the supposed stone implements 

 have been submitted to Professor M. E. Wadsworth of Cambridge to 

 determine their mineralogical character, as this has an important 

 bearing on the question of the fracturing being of natural or artificial 

 origin. Prof. "Wadsworth remarks of this specimen : 'It is an argillite. 

 It is highly indurated, with a conchoidal fracture, without cleavage, 

 and fuses to a yellowish green or white glass which is feebly mag- 

 netic. The weathering which it shows could hardly have taken place 

 except before it was covered with soil ; it might possibly, but I 

 think not probably, in a loose open gravel. It is not at all likely 

 to be of natural formation." It measures 3| inches in length, and 

 was found in the undisturbed gravel of the bluff facing tlie Eiver 

 Delaware, at a depth of six feet from the surface. 



Analogous implements worked in flint occur in English river 

 drift, as shown in fig. 452 of Mr. Evans' Ancient Stone Implements, 

 — an oval implement found in gravel dug at Hackney Down, to the 

 north-east of London ; and in fig. 476, one of several specimens, 

 some of them more coarsely chipped, recovered from the Bournmouth 

 gravel, Hampshire. 



So far then it is noticeable that while the flint spear-head — one or 

 more, — found at a depth of six feet, lying apparentely in situ, in 

 undisturbed gravel, is rather calculated to throw doubt on the palaeo- 

 lithic character of the implements of the Delaware river drift; 

 the more abundant .argillite celts accord with the diift gravel in 

 Avhich they occur, and cannot fail to awaken the keenest interest. 

 In the Valley of the Somme, and in some of the English areas 

 equally prolific in palaeolithic flint implements, the archaeologist is 

 led back through successive stages of Frank, Saxon, Roman and 

 Gaulish or British celt, to the neolithic arts of the lake dwellers of 

 Switzerland, or of the Scottish and Irish crannoges ; and so onward 

 to the era of the cave men of an undefined post-pliocene age. The 

 interval still unaccounted for between the oldest of those and the 

 palseolithic era of post glacial man, according to any chronology 

 hitherto applied, is indeed enormous. Yet such . a series of stages 

 of progi-ession helps the imagination to realize in some degree the 

 remoter past. But in the assumed revelations of palaeolithic art in 

 the North American drift, we pass abruptly from the savage Indian 



