194 Proceedings of the Royal Irish Academy. 



Point. On this beach Greenore and Carnsore rock fragments are not 

 uncommon ; but in the two small bays to the north of the Point, the 

 gravel and shingle is made up almost solely of the local rocks, many of 

 the fragments being more or less angular. In connexion with these 

 two bays are interesting phenomena to be mentioned hereafter in con- 

 nexion with the wind waves. 



Prom Arklow to "Wicklow Head the general driftage of the beaches 

 is northward ; but in connexion with most of the headlands there are 

 *' half counter-tides" for a few hours before high water, especially dur- 

 ing springs.'' The debris from the shipping at Arklow is principally^ 

 beached on the strand S.W. of Mizen Head ; off Wicklow Head 

 there are short " counter- tides " forming two or more races, the 

 principal one being Bride's Pace. 



North of Wicklow Head a current from the S.E. strikes the 

 coast line at Six-mile-Point, and there divides, part going northward, 

 but a considerable portion southward, to form the counter-tide that 

 carries the beach with it towards Wicklow. To its meeting with a 

 current from the south is due the just-mentioned Bride's Pace. Irt 

 connexion with Wicklow Head there is, before high water, a " half 

 counter- tide " running east to Wicklow town, which prevents the 

 "full" beach extending south-eastward to the head. The current 

 going north from Six-mile-Point is deflected by the land drainage 

 from The Breaches; and at the colliding of these, the "Breaches 

 Shoal" has accumulated. IS^orth of The Breaches a current runs 

 northward to opposite Delgany, where it is met by a " counter-tide," 

 and in the dead water produced at their junction the Mouldditck 

 Bank has been formed. 



Parther north a current from the south-eastward impinges 

 on the coast near Greystones, a part going south to form the just- 

 mentioned "counter-tide," and the rest northward to Bray Head, off 

 which it is met by a " counter-tide," and at their meeting a race is 

 formed. 



To the north of Bray Head a current fi-om the S.E. strikes 

 the coast line at the tower ISTo. 4, near the middle of Killiney Bay : 

 here it divides, apart constituting the "counter-tide" that runs S., 

 carrying the beach with it to Bray, and from thence running to Bray 

 Head to form the previously-mentioned race. Here, as at Wicklow, 

 there is a little before high water, a current running E. from the 

 Head to the S. end of the strand, which prevents the "fuU" beach 

 extending to the high ground of the hill. Another similarity between 

 these two beaches is, that from tower No. 4 to Bray, and from Six- 

 mile Point to Wicklow, the pebbles forming the beaches gradually 



® These currents seem to occur at every rocky headland immediately before 

 high water, especially during springs. They are of such short duration that usually 

 they pass unobserved — yet they are important, as to them is due that the beach is 

 kept back from reaching to the Heads. 



