A. B. Wynne — Striated Pebble from the Salt Range. 493 



even. On the largest surface the striation is fine, nearly in the 

 direction of the longest axis of the pebble, on other surfaces they 

 cross this direction at various acute angles, ranging from 5° to 25° 

 and upwards. 



An enlarged photograph of the pebble, showing its principal face 

 and the well-marked striation of this, was exhibited. Some of the 

 planes show small cavities, once apparently filled by crystals of 

 pyrites, which, being dislodged and forced, always in similar 

 parallel directions, became the graving-tools by which the stone was 

 scored. 



Projection of some of the faces of the pebble, by Prof. O'Keilly, El. Col. Sc. Dub. 

 Reduced to two-thirds nat. size. 



In this figure the pebble's principal face is shown to the left, and the others con- 

 secutively in contact in one direction as they adjoin each other on the specimen ; 

 the figures denoting the angle between each face. 



From the position of a group of the facets, all contiguous and of 

 unequal size, together with the slight difference of direction in their 

 striation, it appears that this pebble made about a half revolution 

 nearly around its major axis by six separate stages, being ground and 

 polished at each stage to a degree closely simulating the most 

 artificial accuracy. 



The conditions which would permit of this result become a question 

 for consideration. Supposing the pebble to have been grasped by ice, 

 whatever its bulk, having an effective hold of but two inches ; 

 this being the utmost amount to which it could have been imbedded 

 while any of these surfaces was exposed : will this account for the 

 sculpture of the specimens ? 



Other questions which the pebble suggested were : — 



1. How it became so frequently shifted in the matrix which 

 produced the resistance that not alone was one-half of it subjected 



