SURF AROUND HEADLANDS 



163 



this effect is not often of practical importance otherwise, because the 

 bottom usually does shoal toward either side of a bay, whether the 

 latter be broad or narrow, so the waves, being refracted around, break 

 all along the shore and lose in height more than they gain in their 

 run up the bay. 



Figube 48. — Chart of St. Mary Bay, Nova Scotia. Soundings in fathoms. 



SURF AROUND HEADLANDS 



It has been stated that when the waves are advancing directly 

 toward a promontory in the direction of its main axis, they are focused 

 more or less on its tip, so that the surf is more severe there (figs. 49, 50) 

 than it would be on a straight coast line, with waves of the same size, 

 and coming in parallel with the coast. But this is true only where 

 the water off the headland in question is so shallow, and the waves 

 running at the time are so long, that they are refracted enough to make 

 them advance upon it from the two sides, as well as against its tip. 

 Sand spits illustrate this, as do higher headlands that are fronted by 

 sloping beaches or by boulder zones, as many are. And it is seldom, 



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