502 



ATLANTIC COAST TIDES 



dissected. For each of the 159 tidal stations in this area the 

 lunitidal intervals have been taken from the tide tables of the 

 U. S. Coast Survey, and referred to the time of high water at 

 St Johns, Newfoundland. The datum resulting is the mean 

 solar time interval between high water at St Johns and local 

 high water. It is corrected for difference of longitude and the 

 mooii's motion. It differs from a cotidal hour such as Whewell 

 used in being referred to another station than Greenwich and by 



[^-o-r^gc3 g, 



being expressed in mean solar instead of lunar time. All the 

 stations have been examined, and on the American coast, where 

 stations are very numerous, a few have been selected that agree 

 well with those in their neighborhood. These, with all the sta- 

 tions on the New Brunswick and Nova Scotia coasts, appear on 

 the accompanying map. 



On looking over the mean tidal ranges throughout the gulf, 

 we observe that this is the area of greatest tides of our whole 

 coast, ranges of 10 or 12 feet prevailing. The least range on the 

 mainland is about 8 feet, near Newburyport, increasing south- 



