AND CAHOBE SHINGLE BEACH, CO. WEXEOKD. 39 



Admiralty Chart would seem to that there are currents on either 



suggest that there is a current side of the long banks running 



hugging the west shore of Lyme direct from Greenore to Cahore. 



Bay from Start Point to Berry 



Head, and running from this part 



of the bay direct onto the Chesil 



beach. 



From a consideration of this comparison, it will be evident that 

 there is a strikiug agreement in the circumstances of the beaches 

 at Chesil and Cahore. The most distinctive differences are : — 1. The 

 great length of the Chesil beach. 2. The regular gradation in the 

 size of the pebbles forming this beach. 3. The great height to 

 which the beach is piled up near its eastern termination. These 

 peculiarities may be explained by the circumstances under which it 

 was formed and is kept up. Chesil beach is open to the incoming 

 tidal current and to winds which are not only the prevailing, but 

 also the most effective winds, and which, at the same time, come in 

 a direction similar to that of the incoming tidal current, and thereby 

 considerably augment it. The Cahore beach is protected from 

 the landward currents from the incoming tidal stream by the off- 

 shore banks in Wexford Bay. The prevailing winds (S.W. winds) 

 have no effect ; the more effective winds in regard to the driftage, 

 come from the S.E. ; but the more prevailing winds that effect the 

 driftage on the coast are from the N.E.; and these considerably 

 change and modify the tidal driftage. Take, for instance, their 

 effects on the mouth of Wexford Harbour. The tidal driftage tends 

 to extend the Dogger bank towards the N.E. Continued winds 

 from the north-east, however, will stop this driftage, and force the 

 sand into the N.E. channel, and thus raise the " bar," so that at 

 times it is scarcely passable*. These winds, while they last, have 

 considerable effect on the Cahore beach, pushing it towards the 

 S.S.W., and modifying the arrangement of the fragments so that 

 the pebbles in it are arranged more like those in the Chesil beach 

 after continued winds from the S.E., than at any other time. The 

 off-shore banks in Wexford Bay are probably due, in part, to the 

 frail nature of the shore-cliffs t ; it is likely, however, that they may 

 be due in part to the circumstance of the wind-waves rarely con- 

 spiring with the tidal current, which consequently seldom acts to 

 the most advantage. The efflux out of Wexford Harbour also 

 has a considerable effect on the banks ; the Lucifer bank, since 

 the intaking of a considerable portion of the tidal muds of the 

 lagoon, is gradually being carried away, as is apparent on a com- 

 parison of the chart of 1847 with that of 1873. These banks, 



* Wexford Bay during this winter, 1875-76, has been so silted up that the 

 regular traders from the port can scarcely get in or out. 



t Land-wind driftage must also considerably augment them, as during the 

 continued winds from the north-eastward clouds of sand are carried for miles 

 southward, along the coast-line into Wexford Bay ; part to be lodged by the 

 water on the banks, and part to be carried again northward by the tidal stream. 



