■602 Proceedings of the Royal Irish Academy. 



■stone (E), relatively small in size, presents the same fashioned and 

 mitred extremity. The stone situated het-n^een these two (P), though 

 still smaller in size, presents characteristics -which render it very inte- 

 resting. Its edges are relatively sharp, and the stone is so disposed 

 tliat one of the faces, the northern one, gives a due east and -west 

 direction -within a degree of error. Its form presents the further 

 singularity, and is such, that an edge on the upper siu-face furnishes a 

 ■direction, as shown on the plan, looking to the winter solstice, that is 

 -west 23° 28' south. This direction would, in tlie east, give the rising 

 of the summer sun at the solstice. Xow it is interesting to remark 

 that the position of the cromlech is at such a height above the sea 

 level, and the slope towards the sea such, as to afford a clear view on 

 the horizon of Dublin Bay, a condition favourable to an exact obser- 

 vation of this nature. 



It may be suggested that the eastern and western stones already 

 mentioned were formerly set up where they now are, so as to give 

 with the face or edge of this remarkable stone, east and west points of 

 bearing that is to mark out more distinctly the required directions. 

 Considering tlie weight of the larger of these stones (7 tons), I certainly 

 have doubts as to their having ever formed supports for the cap stone 

 The orientation of the bed of the cromlech is roughly north-west and 

 south-east. 



Druid's Chaie, Killixet. 



As bearing on the orientation of the stone just described, I submit 

 a plan of two of the stones fonning the group known as the " Druid's 

 Chair," Killiney. One of these, the most westerly of the set, pre- 

 sents on its southern face two deep circular incisions which have 

 suggested that they were made with a -view of obtaining two mill- 

 stones from this rock. Its upper edge or face is partly fashioned 

 into two circular surfaces, so that the north-eastern side of the rock 

 presents the outline shown in the accompanying elevation. Between 

 this rock and the " Druid's Chair" lies a single stone somewhat dis- 

 posed as that just described for the Mount Yenus cromlech, and so 

 markedly oriented east and west. At the Druid's Chair the stone in 

 question has a face practically due north and south (north, 0° 35' 

 west). There exists thus a due north and south line of direction, and 

 it was to be presumed that means had been secured of determining an 

 east and west line of direction. Now, as a matter of fact, a line di'awn 

 from the southern corner of this stone to the south-western corner of 

 the mill-stone rock, gives a due east and west direction. 



