O'Reilly — On the Orientation of Some Cromlechs. 599 



fashion into shape. That the middle stone was roughly fashioned 

 seems to me quite evident. As in the case of the Brennanstown 

 monument, these two stones (the left-hand one and the mitred) are 

 closely approximated. If therefore it he assumed that in this latter 

 case the mitred stone was intended to help in an astronomical observa- 

 tion it should follow by analogy that in the Howth monument some 

 such object was sought. As a matter of fact it is found that on 

 standing on the inside or chamber side of the mitred stone, and looking 

 over it towards the quartzite cliff (" Much Hill "), the sky-line of this 

 stands out clearly, and the view of the sky in that direction is open. 

 This peculiar relation, one to the other, of these three end stones seems 

 to connect these two monuments; but was that of Howth intended in 

 this respect for solar or stellar observation ? This question is to some 

 extent answered by pointing out that the left-hand stone (D) or most 

 south-westerly has a direction east 27° 45' south, and west 27° 45' north, 

 or roughly is in the direction of the summer setting Sun at the period 

 of solstice. It is quite true that the present value of the declination 

 is only 23° 27', but it is recorded by Bailly, in his " Histoire cle 

 r Astronomic," that higher values were used amongst the ancients. 

 At present owing to the dismantled state of the monument this appli- 

 cation of it is not at all evident, but when the supporting stones were 

 all upright and in their original positions, the rays of the setting Sun 

 at the period of the summer solstice, could traverse the chamber and 

 pass out between the mitred stone and the adjacent south-western 

 pillar, it being borne in mind that the monument stands at a level so 

 as to dominate the horizon to the west, and not taking into account 

 the present tree growth which of course now interrupts the clear view 

 in that direction. Judging from the nature of the contact now existing 

 between what I may call the middle-stone on the south-west side of the 

 chamber (J.), and the under surface of the cap, I am inclined to believe 

 that this stone has been twisted in its fall towards the north, and that 

 originally it stood in about the same direction as the south-western 

 pillar-stone, and did not obstruct the passage of any light coming from 

 the north-western end of the chamber, as its presumed position would 

 apparently indicate. 



In any case it will not be forcing the data presented by the plan 

 to say that the original direction of the chamber was about west 

 26°-27° south, and east 26°-27°. Lastly, there is a singular similarity 

 in the relations of the left-hand stones of the Shanganagh and Howth 

 cromlechs with the adjacent stones in that they make at their con- 

 tact nearly equal horizontal angles, that is, about 55° to 60°. 



