Tl'LE RIVER ROCK-PAINTING. 



235 



breaking of the large rock, small depressions were found which had 

 been used as mortars for grinding and mixing the colors. These de- 

 pressions average 2 inches in diameter and about 1 inch in depth. 

 Traces of color still remain, mixed with a thin layer of a shining sub- 

 stance resembling a coating of varnish, though of a flinty hardness. 



I 



This coating is so thin that it cannot be removed with a steel instru- 

 ment, and appears to have become part of the rock itself. 



From the animals depicted upon the ceilingit seems that both beaver 

 and deer were found in the country, and as the beaver tail and the hoofs 

 of deer and antelope arc boiled to procure glue, it is probable that the 



