Tidal Investigations 



7b 



A good result can be obtained from these observations for the range of ihe 

 tide, as shown in the tabulated statfement for this locality. The range at Spring 

 tides is again found to be not over one foot. The extreme difference of level 

 during the period is 2 .40 feet; but this appears to be due, in part at least, to a 

 general raising or lowering of the water by the influence of the wind; and it is 

 thus much greater than the true amplitude of the tidal undulation. 



Summary of Results. 



Locality. 



Spring 

 range. 



Neap 

 range. 



Establishment 

 (Local time.) 



CoUinson point 



Martin point 



Demarcation point. . . 



Cape Kellett 



Bernard harbour 



Prince of Wales strait 



0-60 foot. 



0-72 

 0-43 

 1-46 

 0-95 



0-26 foot. 

 0-29 " 



0-40 " 



0-20 " 



Oh. 18 m. 



12 h. 14 m. 

 9 h. 50 m.* 

 6 h. 46 m. 

 Ih. 15 m. 



*Thi3 value is only roughly approximate. 



TIDAL OBSERVATIONS OBTAINED IN 1916. 



These were taken at three localities in the region still further north; but 

 they were limited to little over a day at each place. The dates selected in each 

 instance for the observations were just after the new or full moon, in the 

 endeavour to obtain data for the Spring tides. The time was taken with watches; 

 but their face readings differed by two to four hours, and their actual errors 

 have never been deduced from the astronomical observations taken for the 

 purpose. It is doubtful, however, when the series of observations is so short, 

 whether they would be adequate for the determination of an Establishment, 

 even if the time errors could be correctly allowed for. The position of the 

 localities is shown on the map.' 



Cape Isachsen. — Tidal observations were obtained at this cape, at the 

 extreme northwest end of Ellef Ringnes land, during a full day on June 2 to 3, 

 1916. Readings were taken on a scale to the nearest half inch, every fifteen 

 minutes continuously, for twenty-five hours. 



The astronomical conditions were as follows, the hours being in Standard 

 time for the 120th Meridian West: New moon. May 31 at 11 h. Moon maximum 

 North, June 1 at 10 h. Moon in Apogee, June 3 at 13 h. The tides were thus 

 at the apogee Springs, with the maximum of diurnal inequality. 



The range of the tide was from '27 to 0-92 of a foot; the mean of the four 

 consecutive ranges being 0-57 foot. This may be taken as the Spring range 

 with the moon in apogee. 



Hassel sound. — The tidal observations were obtained at the south end of 

 this sound, at the cape on the west side of the entrance. They comprised twenty 

 hours on July 18 and 19, 1916. Readings were taken on a scale to the nearest 

 quarter of an inch, at intervals of five to fifteen minutes during this period. 



The astronomical conditions were as follows; Full moon and Perigee on 

 July 14. Moon on equator, July 18. The observations were thus two or 

 three days after the Spring tides, but near perigee; and the diurnal inequality 

 was inappreciable. 



