AND THE FORMATION OF VALLEYS. 93 



road from Ross to Waterford runs, evidently con- 

 sisted at first of various straight lines joining into 

 one another ; the top of the southward escarpment 

 still in a great measure showing their old directions, 

 while the bottom of the slopes, joining into the 

 river alluvium, forms more or less regular curves. 

 At each alteration in the bearing of the valley there 

 is a more or less well-marked lateral valley, showing 

 that the changes in direction are due to transverse 

 breaks, probably lines of fault ; but on account of the 

 depth of the meteoric drift this could not be proved ; 

 but in the valleys of the Barrow and associated 

 rivers, such relations are quite apparent. 



Various changes in the level of S.E. Ireland have 

 taken place in very recent times, the last having 

 been a rise of from five to ten feet, by which the 

 land acquired its present elevation. 



Before this change the tide in the estuaries of the 



drift cliffs, averaging from 20 to 40 feet in height, while in or about 

 that year the sea was cut off from them, when the " North mud-lands " 

 were reclaimed. Now (1873) the cliffs have changed more or less into 

 slopes. In a few places this has been done artificially for agricultural 

 purposes, in sandy portions rabbits have materially assisted in the 

 work ; but in general the process consists of the formation of small 

 landslips, associated with ordinary meteoric waste. In some places 

 where the drift is a sand and associated with springs, small bays are 

 being formed in the line of escarpment, the sand during winter being 

 carried out in large quantities on to the flat. This work has been 

 accomplished in twenty-five years. Rock cliffs, under ordinary cir- 

 cumstances, will also be modified into slopes; these, however, may 

 take centuries, instead of years, to undergo appreciable change. 



