bowlders were studied, and hundreds of specimens were 
collected. Work was resumed the next spring, and five 
additional trenches were opened across widely separated 
portions of the quarries. Much additional information 
was collected, and many specimens were added to the collec¬ 
tion, The chipped stones, the refuse and rejectage of the 
chipping work, occur in millions, hut no single example of 
a typical finished implement was found. It is especially 
worthy of note that nature has no means of fracturing such 
hard and tough bowlders as make up the bowlder deposits; 
in the whole of Piney Branch and even in Rock Creek Valley 
there is not a chipped bowlder of average hardness that has 
not been held in the hand of an Indian workman. In June 
work was commenced on another group of quarries situated 
north of the new Haval Observatory, on the western side of 
i 
Rock Creek. Very extensive quarrying and implement-making 
had been carried on at this place. The conditions and 
phenomena were practically identical with those of the Piney 
Branch site* and the same is doubtless true of many other 
sites within the city limits. The bowlder beds are of 
wide distribution and are the result of wear along the beach 
lines of river or bay when the water stood at the particular 
level. 
See my two volumes. Bulletin 60 and Volume'' 
of the Bureau of Ethnology. 
