594 Proceedings of the Royal Irish Academy. 



■n-orthy of attention. Thus, it may be obserYed from the elevation of 

 the north side of the cromlech, that the stones of this southern wall 

 form at their junction or overlap a U-shaped void or opening with 

 rounded surfaces ; these are smooth and, as it were, water-worn ; this 

 result might possibly arise from a very simple and natural cause, that 

 is, the habit of the cattle grazing about rubbing their dewlaps on these 

 surfaces, the height of the opening and its size allowing of their doing 

 so ; nevertheless, the fact that these smooth surfaces are not con- 

 tinuous horizontally, but extend downwards on the faces of the stones 

 beyond the parts of these accessible to the cattle, tends to show that 

 originally these surfaces were smooth. Lastly, on the inside of the 

 south -westei-n supporting stone (C), and at a height of about 1 m. from 

 the floor, there may be recognized, on careful examination by the 

 hand, small patches of the surface perfectly smooth and, as it were,. 

 ground fine. One spot in particular struck me much, as it shows a 

 cross-section of a mica crystal perfectly smooth, and such as to imply 

 water grinding, say with fine sand, on a hard, smooth surface, the 

 result being therefore quite distinct from any possible result of 

 weathering. These patches I look on as the remains of a polished 

 glaciated surface, and am led to conclude that the stone in its original 

 state was a glacial boulder, highly ground and polished on one face at 

 least, probably having been found in the neighbouring stream, and 

 was used by the builders of the cromlech precisely on account of 

 its highly polished surface, to which some particular signification was 

 attached. If my observations and conclusions are correct, some very 

 interesting points of view would thus be opened up both as to the 

 choice of the material used in these monuments, and as to their age, 

 since the lapse of time necessary to allow of the removal by atmo- 

 spheric action of the polished surface has been in some way proportional 

 to their age. There is also thus raised the question, were not the 

 other stones of the chamber polished boulders, including the cap 

 itself? This would be at least probable. The cap is undoubtedly a glacial 

 boulder, and may have been more or less polished on its under surface. 

 As to the other stones, no trace apparently remains of any former smooth 

 surface. However, the northern stone (F) presents a character which 

 merits attention ; it is its relative thinness and extent. Stones of granite 

 which have undergone very great pressures by superimposed matter, 

 and were subjected at the same time to motion in a given direction, 

 as also to low temperature with water present would undergo, at least 

 in the portions near the contact surface, molecular derangements such 

 that subsequent relief of the pressures and low temperatures would 



