334 POPULAR SCIENCE MONTHLY. 



Tlie presence of these artiiieial flakes, blades, and other forms 

 of simple implements can only he explained hv considering them 

 as a constituent part of the containing bed, having been brought 

 liither by the same agency that brought the sand, pebbles, and clay. 

 AVhen standing before a newly made section of this implement-bear- 

 ing deposit it is easy to picture the slow progress of its accumula- 

 tion. The broad plain has been subjected to overflow, now of water 

 bearing only sand, and then of muddy water; no^v with current 

 strong enough to roll small pebbles from some distant jDoint, and 

 then periods when the sun shone on the new deposit, dried it, and 

 the loose sand was rippled by the wind. Floods of greater volume 

 occasionally swept across the plain, and ice-incased pel)bles were 

 dropped upon its surface, and with this building up of the plateau 

 to a higher level there were also brought to it traces of man's handi- 

 work. Of this, I think, there can be no doubt now. Years ago 

 T endeavored to show from the distribution of rude argillite imple- 

 ments of specializ.ed forms, as arrow points and small blades, trimmed 

 flakes and scrapers, that these objects were older, as a class, than 

 jasper and quartz implements and weapons, and that pottery was 

 made only in the rudest way before " flint " chipping — jasper and 

 quartz — was established. The more exhaustively this subject was 

 followed up, the proi)osition became more evidently true, and to-day 

 it is unqualifiedly confirmed by the results obtained from system- 

 atically digging deeply over wide areas of country. The fact that 

 argillite continued in use until the very last does not affect this con- 

 elusion. 



As the high land, now forty or more feet above the river and 

 beyond the reach of its floods of greatest magnitude, was once con- 

 tinually overflowed and gradually built up by the materials the 

 water spread upon it, it is evident that the conditions were mate- 

 rially different when such things haj)iiened from what now obtains, 

 and the whole configuration of the country to-day points to but the 

 one conc!usi((n : that these ])!arc;iu-buil(ling floods occurred so long 

 ago as when the river fiowed at a higher h'vel and possessed a greater 

 transporting jjowei- tlian at pi-esent. 'ilii-. it is true, was long after 

 the coarse gravel and imge bowlders wei-e ri'ansported from the hill- 

 sides of the ii|i|iei' \alley. l)iit it \va> bel'oi'e the river was confined 

 to its present ehanuel, and more <ignilicant]y before what may be 

 called the soil-making period, itself of long duration ard the tinu' of 

 the Indian as such. Xot an argillite ehip from the >an(ls beneath the 

 soil but sjieaks ol the distant day when tlii- plateau was an almost 

 l)ari'en plain, and man saw it, roanieij (i\-er it, and perhaps dwelt upon 

 it, when l>ui the scantiest vegetation dotted its surface, and only 

 upon the hills beyond its boundary were there trees and herbage. 



