O'Reilly — Old Churches of Dalkei/ Toicn and Idand. 221 



to that still existing in the church of Dalkey Town, it may be 

 presumed that it was designed to fulfil the same objects — that is, 

 to admit sunlight and mark the arrival of some certain pei-iod of the 

 year or festival day, or even that of the equinox. Tliis double mode 

 of observation of the latter — that is, by direct observation towards the 

 horizon from the height of the belfry, on the one hand, and by the 

 incidence of the sunbeams through the compartment of the window, 

 on the other — in no way contradict, but rather supplement one 

 another ; since in our climate the horizon may be covered at sunrise, 

 and the sky quite clear at mid-day. Enough, however, has been said 

 to point out the interest that the forms, positions, and dimensions of 

 the different openings of this class of ancient church in Ireland 

 present, and to justify the proposition that a more careful examination 

 and measurement of the still existing " cilU " or oratories should be 

 made in the expectation of very interesting and instructive results 

 being fui'nished thereby. As the church on Dalkey Island is stated 

 to have been dedicated to St. Begnet, as well as that of Dalkey Town, 

 it might be expected that its orientation would in some way concord 

 with such dedication. As already mentioned, however, the orientation 

 in this case is nearly due east and west, the difference or error 

 of direction therefrom being about 3°, as determined by a hand- 

 compass. It might be asked is this error due to defective observation, 

 or to imperfect means of tracing the east and west line, or rather was 

 the direction as existing so intended from the foundation. It has 

 been already remarked that the position of the building is such that 

 the eastern horizon cannot be seen from its actual site, on account of 

 the ground rising towards the east, as shown in the section (PL XVI., 

 fig. 6) ; hence, if the orientation were made by actual observation of the 

 sun on the true equinoctial day, and if his appearance above the ridge 

 of rocks lying to the east of the site were aAvaited for the tracing of 

 the line of orientation, there should be an error of at least some degrees 

 to the south of the correct east and west direction intended ; and such 

 is actually the case. Hence, it is reasonable to presume that a true 

 east and west orientation was intended ; and the error of about 3° is 

 quite in harmony with this view. "Were the error to the north, it 

 would be more difficult to reconcile with such intention, and there 

 would be grounds for assuming that it was designed to refer to some 

 feast-day happening close to the equinox (such as that of St. Benedict, 

 the patriarch of the western monks), 21st March. 



The presumption that the orientation was intended to be duo east 

 and west, and that the observation of the sun for equinox was one 



