174 



BREAKER DIRECTION AND HEIGHT 



one is inside the lagoon, no matter how heavy the breakers may be on 

 the exposed faces of the reefs outside, provided only that the contour 

 of the lagoon falls away sharply inside the entrance. If only the one 

 side falls away, this will be the more quiet side, the other the least so. 

 The measurements of waves that have been made in Duluth Harbor 

 (p. 168) suggest, for example, that sidewise expansion would not only 

 reduce waves that were 15 feet high outside to only about 2 feet high 



56' 



58' 



53' 



3° 

 51' 



49' 



155' 



— r 





53 



3° 

 51' 



- 49' 



56' 



58' 



155' 



Figure 56. — Chart of Nukuoro Atoll, Caroline Group, western tropical Pacific. 



Soundings in fathoms. 



at a distance of a quarter of a mile inwards from the entrance of an 

 atoll as nearly circular as the one charted in figure 56, but would 

 render them imperceptible by the time they had crossed the lagoon , 

 if the latter were so much as y 2 mile across. And the waves running 

 in through the passage would be drained of so much of their energy as 

 they broke along its sides that their heights would already be reduced 

 considerably, before ever they reached the lagoon at all. 



