TIDAL PHENOMENA OF THE ST. JOHN RIVER. 78 



Mr. D. L. Hutchinson. Tal)le II is similar to Table T, except 

 that it is calculated from the less reliable I'esults obtained during 

 windy weather. The following are the more important jioints 

 l)rought out by these tables : 



(1) The Time of lliyh Wdter at Springhill. Just at high 

 water or low water at any place the level changes very slowly. 

 Hence it is difficult to be quite certain of the exact moment of 

 change. Remembering that this remark applies to both the St. 

 John and the Springhill records, the close agreement among the 

 results of column 5, which gives the interval between high 

 water at Springhill and liigh water at St. John, must be considered 

 very satisfactory. The mean interval is nine hours and twenty 

 minutes, the greatest divergence from the mean is ten minutes, 

 and the next greatest five minutes. The " probable error " is 

 only one and a half inches. The second series being made in 

 windy weather, do not agree so well among one another, but give 

 a mean of nine hours and sixteen minutes, differing by less than 

 one per cent fiom the preceding. The mean tidal range at St. 

 John was twenty feet in Series I and sixteen feet in Series II. 

 Hence the former results may be taken as fairly representative 

 of spring tides and the latter as neap tides. The mean tidal 

 I'ange is twenty-five per cent greater in Series I than in Series II, 

 and yet the time of passage of high water from St. John differs 

 by less than one per cent. We seem justified in concluding that 

 the interval between high water at St. John and high water at 

 Springhill is practically independent of the tidal range. This 

 should be remembered in connection with the results obtained at 

 other points on the river. 



(^,i) Amonnt of Tide at Springhill. From Series I we see 

 that when the mean range of tide at St. John is twenty feet, 

 that at Springhill is four inches or 1.63 per cent or about one- 

 sixtieth of the range at St. John. Moreover, the range at 

 Springhill is (allowing for wind disturbances) proportional to that 

 at St. John. This is otherwise evident from the principle of the 

 superposition of small motions. 



