12 SEA AND LAND 



student perceives that in a single very great storm the face 

 of the chff ma)' be worn back to the average distance of some 

 inches, and that the retreat of the upper part goes on 

 more steadfastly, but in an inevitable way, as the stones of 

 the overhanging precipice are loosened by frost and decay. 

 We can often trace the distance to which the sea has cut 

 back from tlic j^lace where it was left at the last change in the 

 level of the land, by the broad rocky shelf leading off to 

 the edge of the deeper water. Sometimes, as in the coast of 

 Yorkshire just south of Whitby, this extends as a flat table 

 of stone at about the level of low tide, to a distance of a mile 

 or more from the base of the cliffs. On this Yorkshire coast 

 the cliffs rise in places to the height of six or eight hundred 

 feet, and are so steep that it is impossible to climb them. 

 Shipwrecked mariners and persons who have been imprisoned 

 against their base by the swift rising tide have to be rescued, 

 if they are saved at all, by means of baskets or ladders 

 lowered from the summit of the escarpment. A similar, 

 thouofh less extensive, wave-worn shelf extends alonof the 

 southern shore of the island of Anticosti, in the Gulf of St. 

 Lawrence, for the distance of more than one hundred miles. 

 There as elsewhere ships are apt to strike against the margin 

 of the wave-shelf and to go to pieces or fall away and sink in 

 the deep water which borders the ledge. The great distance 

 to the shore, and the wild tumble of waters which a great 

 storm produces on the rocky table, make shipwreck in these 

 conditions peculiarly hopeless for the mariner. Shores of this 

 nature are always formed where the open sea is bordered by 

 hard rocks and has remained for a loner creoloofic time at the 

 same elevation with reference to the assault of the waves. 

 Where a rocky shore does not exhibit these features we may 



