MAX AND THE GLACIAL PERIOD. 659 



descending drainage. Their immense and continually increas- 

 ing numbers seemed to warrant the belief that they had re- 

 sulted from systematic operations of some sort, once conducted, 

 for unknown purposes, upon this particular spot. A portion 

 of the studied specimens subsequently yielded evidence of 

 having received shape from human hands, and therefore it 

 was assumed provisionally that the site of exposure represented 

 a prehistoric workshop. 



" Prolonged investigation ensued ; and investigation estab- 

 lished the hitherto unsuspected fact that no quartz chips nor 

 fragments were inclosed in the upper part of the gravel and 

 sand terrace at the notch, nor within a considerable distance 

 at either hand, though they were sought with careful scrutiny. 

 . . . Ultimately it was ascertained that the notch quartzes had 

 dropped to the level at which they were seen from a thin layer 

 of them once lying from ten inches to two feet above it, and 

 subsequently broken up through the wearing away of the sand 

 underneath by drainage. This layer or stratum was still intact 

 on the north and south and partially so on the east, in which 

 direction it had, however, at certain points, suffered some dis- 

 placement by wagoning. It extended in a nearly horizontal 

 plane into the terrace, in the sloping edge of which the notch, 

 opening into its west bank and truncated at its edge, is cut. 

 . . . The quartz-bearing layer averaged a few inches only in 

 thickness, varying a little as the included pieces happened to 

 be of smaller or larger size. The contents were commonly 

 closely compacted, so much so that one might sometimes ex- 

 tract hundreds of fragments, many of them very small ones, 

 of course, from an area of considerably less than a square yard. 



" The quartz bed, so far as examined, rested upon a few 

 inches of sandy soil, which passed downward into a coarse 

 water-worn gravel, immediately overlying till. Above the 

 quartz chips, stratified gravel and sand extended up to the sur- 

 face of the terrace. The pebbles of the gravel lying directly 

 on the quartz-bearing stratum were small and well rounded, 

 and were noticeably less angular than those of the gravel below. 

 The stratum of quartz chips lay at a level some twelve or fif- 

 teen feet lower than the plane of the terrace-top. 



" These observations show that the quartz chips were spread 



