INTRODUCTION. 3 



some would wish us to believe, how is it that it has 

 accomplished in these countries so little work since 

 the glacial period, while the effect of marine de- 

 nudation in the rearranged drift is so apparent? 

 Many rocks, exposed ever since the glacial period to 

 meteoric action, have not as yet lost their glacial 

 dressing or striae ; while very little of the drift in the 

 valleys above marine influences has been removed, 

 and in other places no traces of this continuous de- 

 nudation can be detected. 



In the Esker gravels of the central plain of Ireland, 

 but especially in the King's County, there are deep 

 bowl-shaped hollows. The vegetable soil or decomposed 

 drift on these gravels is always shallow, often only a 

 few inches in depth. This, in ordinary cases, might be 

 accounted for by its being washed away nearly as 

 fast as it was formed, by rain and runlets, the slopes 

 of these hills being always more or less steep. If such 

 was the case in the bowl-shaped hollows, there ought 

 to be at the bottom much more soil than on the slopes, 

 the continual waste of the land carrying down the soil 

 to the lowest level ; yet such does not appear to be the 

 case, the depth of the soil on the slopes and on the 

 bottom of the bowls being nearly equal, except when 

 the hollows are tilled. In these hollows, on account 

 of the nature of the drift, water rarely, if ever, lodges. 

 In the County Wexford much of the low country is 

 covered by a drift composed of either marl or clay, in 



