24 LANDSCAPE IN HISTORY 



workmanship, found imbedded in the sands and silts 

 of this marine terrace, show that the upheaval has 

 taken place since some part of Neolithic time. The 

 addition of these strips of level ground to the margin 

 of the land has had an important influence on the 

 human population of these districts, for it has pro- 

 vided many hundreds of square miles of arable ground, 

 comprising admirable sites for dozens of villages and 

 towns as well as for excellent coast-roads. 



On the other hand, a long tract of land, extending 

 from Cork across the Bristol Channel and the southern 

 counties to the coast of Yorkshire, has sunk fifty feet 

 or more since the Neolithic period. The result of this 

 depression has been to allow the sea to ascend far up 

 many of the estuaries which had previously been river- 

 valleys, and thus to create, or at least to deepen and 

 widen, the numerous natural harbours which indent 

 the south coasts of England, Wales and Ireland. 

 Not improbably the downward movement, by helping 

 to lower the narrow isthmus which in the earlier 

 ages of the human period connected Kent with the 

 north-west of France, contributed not a little to the 

 insulation of England from the continent. 



Earthquake-shocks, though generally feeble, have 

 been of severity enough to damage public buildings. 

 The cathedral of St. David's in its uneven floor 

 and dislocated walls, still bears witness to the shock 

 which six hundred years ago did so much injury to 

 the churches of the west of England. But though a 

 formidable catalogue has been drawn up of the earth- 

 quakes experienced within the limits of these islands, 

 it is not to that kind of underground disturbance that 



