HYDRAULICS. 



tion is ~ (a -f- 6) 2 , and the space which the wave 



o 



86 



appears to pass over in a second, is 



Examen Maritime, vol. i. 816. 



In these theorems, 8 is put for V 2g-, to which it is 

 nearly equal. 



If a he neglected, the velocity of the wave becomes 

 - > which is the velocity as determined by 



7F 



NEWTON, Principia, lib. u. prop. 46. See also Bos- 

 SUT, Hydrod. torn. i. 312. 



304. While the depth of the water is sufficient 

 to allow the oscillation to proceed undisturbed, 

 the waves have no progressive motion, and are 

 kept, each in its place, by the action of the waves 

 that surround it. But if by a rock rising near to 

 the surface, or by the shelving of the shore, the 

 oscillation is prevented, or much retarded, the 

 waves in the deep water are not balanced by those 

 in the shallower, and therefore acquire a progres- 

 sive motion toward the latter, and form break- 

 ers. Hence it is, that waves always break against 

 the shore, whatever be the direction of the 

 wind. 



Breakers 



