218 



ON TIDES AND TIDAL ACTION IN HARBORS. 



required for tbe transmission of the impulse from one end to the other, 

 and during its transmission the particles will successively approach to 

 each other, by which an infinitesimal elevation and subsidence, after 

 the manner of a wave, will be produced. In the same way the trans- 



riMES AND HEIGHTS OF TIDES ON ATLANTIC COAST OF UNITED STATES 



TJEWYORK, 



Jl 



mission of the movement through the incompressible water of the sea 

 is attended with an infinitesimal elevation and recession ; but when the 

 movement reaches shallow water, in approaching the shores, the hori- 

 zontal motion is partly translated into vertical motion upon the sloping 

 bottom 5 audit is thus that the tides attain sensible vertical height. 



