RATE OF WEARIXG OF JJJ/j j<j j L .-^ 



45 



they pursue their devious way down the coast, but bv many 

 other even more instructive examples of this work. It not 

 infrequently happens that vessels loaded with brick, coal, iron 

 ores, and other hard substances are cast away on the exposed 

 beaches of the Atlantic Ocean, and their cargoes delivered to 

 the shore waves. In a few months we find the waste scat- 



Eastern Side of Cape Ann, Massacnuseits 



Bowlder beach of the rudest type, showing large stones plucked from the neighboring coas-. 

 beaten against each other when heavy surges roll against the shore. 



tered, it may be for miles, in the direction in which the 

 materials of the beach are moving. In some cases hard-burned 

 brick or anthracite coal will journey on a sand beach for a 

 distance of five miles before the bits are entirely worn out, 

 and they may endure for a year before they are quite ground 

 to dust. If the shore be pebbly and well exposed to the sea, 

 all the fragments, save those which find protection in some 



