[w. BELL DAWSON] TIDES IN GULF AND RIVER bT. LAWRENCE S3 



given are in absolute time ; as the time of the tide throughout is reduced 

 to Standard time for the 60th meridian, four hours slower than Green- 

 wich Mean Time. In the differences between Anticosti, Father Point, and 

 Quebec, the ten highest and ten lowest values in each year are omitted, 

 and the values given are the averages of the next three highest and 

 lowest. These extreme values are omitted to allow for irregularity due 

 to wind disturbance, which is considerable in so long an estuary, especially 

 when the winter months are included in the observations. The omissions 

 thus amoiint to about two per month on the average. 



St. Paul island, Cabot strait ; to S. W. Point, Anticosti. — Distance, 240 



miles. 



From simultaneous observations of November and December, 1894, and July to 



October, 1896. 

 Difference in the time of H. W. ranges from 4h. 19m. to 6h. 56m. 

 Range in the difference, 2h. 37m. Average difference =5h. ;35m. 



S. W. Point, Anticosti to Quebec. — Distance, 450 miles. 



From one year's observations ; November, 1894, to October, 1895. 

 Difference in time of H. W. ranges from 4h. oOm. to 6h. 01m. 

 Range in the difference, Ih. 11m. Average difi'erence=5h. 26m. 



From one year's observations ; November, 1895, to October, 1896. 

 Difference in time of H. W. ranges from 4h. 37m. to 6h. OOm. 

 Range in the difference, Ih. 23m. Average difference=5h. 21m. 



Father Point to Quebec. — Distance, 195 miles. 



From one year's observations ; December, 1894, to January, 1896. 

 Dift'erence in time of H. W. ranges from 3h. 46m. to 4h. 42m. 

 Range in the difference. Oh. 56m. Average difference = 4h. 21m. 



From one year's observations ; January, 1896, to February, 1897. 

 Difference in time of H. W. ranges from 3h. 45m. to 4h. 41m. 

 Range in the difference. Oh. .56m. Average difference=4h. 19m. 



We thus find that the variation in the period of time which the tidal 

 undulation occupies in crossing the open Gulf, is twice as great as the 

 variation in its period between Anticosti and Quebec, where the distance 

 is double as far. The reason of this irregularity in the Gulf we will 

 refer to again. 



It is to be expected in the long estuary of the Lower St. Lawrence 

 that the spring tides, because of their gi-eater amplitude, would travel 

 faster than the neaps. The tides at Quebec accord with this principle ; 

 as the high waters follow each other at closer intervals, Avhile the ampli- 

 tude of the tide is increasing, and fall off again through longer intervals 

 towards the neap tides. To test the effect of this upon the differences in 

 the time of high water between Anticosti and Quebec, these differences 

 Avere tabulated according to the synodical lunar month, or the period of 

 the moon's phases ; but they failed to show any regular variation 



