VARIED EFFECTS OF TIDES 



IZ 



of the tide. Thus in passing north from Cape Florida to 

 the St. Lawrence, the well-trained student of the tides would 

 be able to determine in a general way the shape of the shore 

 by the rise and fall of the sea. 



It is easy to conceive how the energy of the tidal currents 



^^:^. 





Seashore View 









Showing the position of the mantle of sea-weed which protects the rocks from the action of frost and. in 

 a measure, from the assaults of the waves. Note that the smaller fragments which may be tossed about 

 are destitute of the covering. The lower portion of the stone in the foreground against which the boy is 

 leaning shows the scouring action of the waves which they effect by means of the sand which they impel 



depends, in the most intimate way, upon the altitude the 

 wave attains in tlie diurnal movement. When, as on 

 the coast of Florida, the rise and fall is probabl}- not on the 

 average much more than one foot, we may have but feeble 

 movements created by the tidal swing ; in the region about 

 the Bay of Fundy, where the rise is fifty feet or more, 



