100 



STONE ART. 



[ETH. ANN. 13 



the ordinary sinker or club-liead, so that no dividing line is possible. 

 Theories constructed on a basis of their use may be far from correct. 



They present various forms and degrees of finish; many have the 

 natural surface on botli sides with the edge worked off by grinding or 

 pecking, the latter being produced probably by use as a hammer; the 

 sides may be ground down while the edge remains untouched; or the 

 sides may be pecked and the edge ground, being probably of a thick 

 pebble originally. Some of the finer grades, as chalcedony and quartz, 

 that have received the highest finish, appear to have had all the work 

 done by grinding or rubbing, as even those only slightly worked bear 

 no signs of hammering or pecking. When of the harder materials 

 they are generally made of water worn pebbles as nearly the desired 

 form as can be found; in fact, some specimens which are in their nat- 

 ural state, entirely unworked, require a very close examination to dis- 



FlG. 95 Discoidal atone. 



tinguisli them from others whose whole surface has been artificially pro- 

 duced. In the jasper conglomerates from Arkansas, however, there is a 

 regular series ft'om a roughly chipped disk to one of the highest polish 

 and symmetry. The larger ones of quartz, particularly those with con- 

 cavities in the sides, must liave been patiently wrought for years before 

 brought to their present state. Many of the smaller ones, especially 

 sandstone, seem to have been designed for grinding or polishing. 



The following groups are represented in the collection : 



A, Sides hollowed out, edge convex; 2 to 6 inches diameter, seven- 

 eighth.: to 2f thick. 



1. Edges of concavity sharp. 



a. Cavity a regular curve from side to side. The type (figure 95) is of 

 quartz, from Cherokee county, Georgia. There are also, from Kanawha 

 valley, West Virginia, one of sandstone, of wliich one side has been 

 worked out by a fiint, the little pits being distinctly visible, while the 

 other side has natural surface; from Loudon county, Tennessee, one of 



