ee ROYAL SOCIETY OF CANADA 



We thus tind that the tides throughout the greater part of the- 

 southwestern half of the Gulf of St. Lawrence, can be referred directly 

 or indirectly to the tidal station at St. Paul island, which is an import- 

 ant result ; and the leading tidal ditïerences for the purpose have also 

 been obtained. 



The tidal data for St. Paul Island are according]}' being worked out, 

 by the harmonic analysis of the tidal record during one complete year ; 

 which form the best continuous observations that it has yet been possible- 

 to obtain. When these data ai^e computed, closer results for Pictou and 

 the dependent ports in Northumberland strait, can be obtained. The- 

 tidal differences throughout this portion of the Grulf will also become 

 available. 



As the range in the différence between Charlottetown and Pictou is 

 60 great, a further endeavour was made to arrive at a more satisfactory 

 result. Declination curves, obtained by the method above described,, 

 Avere prepared from the differences with both Halifax and Quebec ; but 

 the outstanding errors in the time of the tide were found to be quite a* 

 trreat as when the average difference with Pictou was used as a constant 

 quantit}'. It appears, therefore, to be impracticable to obtain bettei- 

 results than by following up the lines already suggested. It would no- 

 doubt be possible to obtain good results from long continued obser- 

 vations, by the establishment of thoroughly equipjDed stations at indi- 

 vidual harbours, if their iaiportance would warrant the expenditure 

 required in doing so. But the endeavour of the Tidal Survey is to make 

 it possible to refer the tides to the existing principal stations. 



NOTE. 



(Tide and current in tlie Strait of Belle Isle). — As the wide range in the- 

 difference in the time of the tide between this strait and Halifax appears to be 

 largely due to diurnal inequality, the differences were tried a second time in the 

 opposite sense ; that is, the difference between the time of high water in the strait 

 and the next folloiciny high water at Halifax. This amounts to a reversal of the- 

 diurnal inequality at the two places with respect to each other ; and although the 

 difference itself is greater, the inequalities, and consequently the range in the differ- 

 ence, are much reduced, which is more satisfactory. The result for a period of four 

 months, namely. May 1 to August ;^1, 1896, is as follows : 



Difference in time of H. W. ranges from 9h. 16m. to Uh. 21m. 

 Range in the difference, 2h. 0.5m, Average difference ; tide at 

 Forteau bay, lOh. 16m. earlier than next following tide at Halifax. 



A careful elimination of wind disturbance would further reduce this range and 

 bring the average difference to a reliable value for purposes of computation. 



AVith regard to the relation of the current to the tide in this strait; the variation 

 appears less irregular than above stated in the part of the comparison for which the 

 better-observed tides of September, in 1894, are used, when the tides wei-e obtained 

 on the recording gauge. Further observations of the turn of the current in the 

 strait are, however, desirable. 



