The Tides. 355 



the tides, if the sea were, in all parts, of the 

 same depth ; but the shoals in certain parts, and 

 the narrowness of some of the streights and 

 channels, cause a great variety in the height of 

 the tides ; of which it is impossible to give an 

 account, without an exact knowledge of all these 

 irregularities, the relative situation of the shores, 

 the depth of the channels, &c. 



At the mouths of rivers, the flood tide and 

 the tide of ebb exhibit different phsenomena. 

 The current of the river resists the flux of the 

 sea, but aids its motion at the reflux; whence 

 the tide of ebb lasts considerably longer than 

 the tide of flood. This is the reason, too, why 

 high water takes place at a later hour in great 

 rivers than elsewhere. But the diversities of 

 ebb and flow in different localities are too 

 numerous to be traced in our narrow limits. 



END OF VOL. I. 



UNIVERSITY 







