432 CERTAIN OBJECTS OF UNKNOWN SIGNIFICANCE, 



former are most convenient mill-stones; the latter quite unsuit- 

 able. But the insuperable objection to the grinder theory is the 

 total absence of all the signs of wear which must necessarily have 

 appeared upon stones put to such a use.* 



Stones of this shape might have been used as grinders or 

 pounders in three different ways — (1) held by one end and rubbed 

 backwards and forwards; (2) held by the apex in a 'perpendicular 

 fashion and used as a pestle; (3) held by the apex whilst the 

 substance to be pounded was struck at an angle. 



No. 4 stone shows us what to expect if the first method had 

 been adopted ; all the markings would have been obliterated. 

 The state of the concave, radiated or ribbed bases, proves the 

 second impossible. The third is an attempt to explain why the 

 signs of wear appear only at the foot of the " stones " and nowhere 



else.f 



I believe that when we can say positively what has caused this 

 peculiar wear, we shall ha^•e solved the mystery, and no explana- 

 tion which does not account for it can be satisfactory. But 

 surely this idea of its origin is far-fetched. 



If the angle was at all high, the base must have suffered con- 

 siderably; if at all low, then the wear must have extended much 

 further up the stone than is actually the case. 



Again, judging from the length and composition of the objects, 

 they would probably have all broken in the middle if so used; the 

 clay specimen (No. 7) would certainly have done so. But even 

 supposing everything to progress happily — the proper angle always 

 maintained, and the pounder carefully twisted so that the wear 

 might be fairly equal all the way round — then it is still certain 

 that the blacks would not have gone to the, comparatively speak- 



* I am not forgetful of No. 4, but the condition of tlie remaining eii'ht 

 specimens forbids our basing any tlieory applicable to all upon the state of 

 this stone, which has evidently been put to uses quite foreign to those for 

 which it was originally intended. 



t Excluding the flaws and fractures at the ypex of several specimens, 

 which, in all probability, were accidental. 



