[w. BELL DAWSON] TIDES IN GULF AND RIVER ST. LAWRENCE 



S& 



The nature of these complications in the Gulf is further shown by 

 the following comparisons of the times of the tide, based upon the differ- 

 ences of time as now determined : — 



Progress of H. W. at Spring Tidks. 



Locality. Time of H. W. 



St. Paul Island Sh. 41m. 



Anticosti 14/t. 16/n. 



Neguac in Miramichi Bay. .. 17/i. 47?h. 



St. Paul Island 21/i. 08?». 



Progress of the Following L.W. 



TimeofL.W. 



Locality. 



14/i. o4»i St. Paul Island. 



17/i 41«i, ^^' ^- ^^ ^^^ middle of the 

 ■ I, open Gulf. 



20/i. 29m Anticosti, 



Thus by the time the tidal undulation reaches Miramichi bay, along 

 the course described, and causes high water there, the next following low- 

 water has entered Cabot strait and is already half way across the Gulf on 

 its way to the entrance to the St. Lawrence. We thus have high watei- 

 on the southwestern side of the Gulf at the same moment that a low- 

 water depression is in the middle of the Gulf in the offing. This account» 

 for the etfucement of the tide at the Magdalen islands in the middle of 

 the Gulf. A tidal station was originally established there ; but it proved 

 useless, as often for days together the variation in level was so slight that 

 the time of the tide could not be made out. It was only at the spi-ings 

 that the tide was at all distinct. 



In Northumberland strait the tide progresses regularly ; although on 

 the Nova .Scotia side it is nearly simultaneous in time for the greater part 

 of the distance. The différences in the time of high water with St. Paul 

 island are not constant, however ; although the greatest difference is on 

 the average only 2'' 21™ later. This appears to result from a variation in 

 the amount of the diurnal inequality, with the progress of the tide. 

 Thus, in the difference between Pictou or Charlottetown and St. Paul 

 island, there is still an inequality or outstanding variation which follows 

 the moons declination. At Charlottetown the case is further complicated 

 either by the effect of the wind, or by some form of tidal interference ^ 

 but this we will refer to again. 



The southwestern half of the Gulf of St. Lawrence, in which all the 

 more important Canadian harbours of the Gulf are found, may thus be 

 divided into three regions, with respect to the tidal stations to which the 

 tides can be referred. The region of the Lower St. Lawrence, already 

 referred to Quebec, can be extended to include Chaleurs bay. The open 



