6b Canadian Arctic Expedition, 1913-18 



shows the large error that may result in the determination of the Establishment 

 in these regions, if care is not taken to balance the values for both the tides 

 in the twenty-four hours, which occur at the opposite transits of the moon. 

 Possibly some of the apparent discrepancies in Arctic values may thus be 

 accounted for, if they are based on unbalanced observations. 



Because of these variations and uncertainties, the luni-tidal intervals at 

 both Spring and Neap tides are included; since the change during the course 

 of the month is not likely to be as much as these known amounts between 

 successive transits. The primary values taken as a basis for averages, are in 

 all cases the mean of two successive luni-tidal intervals, at the opposite transits 

 of the moon; to eliminate the inequality. For the two localities taken together, 

 as they are both near Cape Kellett, the result is as follows: — 



At Springs^ — Mean of two luni-tidal intervals; Jan. 15-16. . 10 h. 15 m. 



At Neaps — Average of two mean values; Jan. 24-26 8 h. 05 m. 



At Neaps — Average of three mean values; Jan. 23-25 — 11 h. 05 m. 



Resulting approximate Establishment 9 h. 50 m. 



Bernard harbour. On the south side of Dolphin and Union strait. Longi- 

 tude 7 h. 39 m. 22 s. West. — The tidal observations here, were obtained in 

 June and December of 1915. The first series, from June 6 to 23, were taken 

 with a registering tide gauge; but the record is very broken and imperfect 

 owing to the instrument not working properly; and there are no comparisons 

 to show that the time is correct. The second series, from December 4 to 12, 

 are readings on a tide scale, taken to the hundredth of a foot; and the watch 

 time error runs from to 18 m. fast on chronometer, not on local, during the 

 seven days of observation. The readings were taken by Mr. G. H. Wilkins 

 in June, 1915; and by Messrs. K. G. Chipman, J. R. Cox, F. Johansen, W. V. 

 Bruce and Drs. J. J. O'Neill and R. M. Anderson, working in turn throughout 

 the twenty-four hours during the December period. 



The best result that can be obtained from the first series, is the Spring 

 range about the date of the new moon on June 12; as the observations did not 

 cover the following Neap tides. The result, averaged with the later observations 

 of December, shows the Spring range to be nearly Ij feet, which is the greatest 

 range measured at any of these tidal stations in the region of Beaufort sea. 



A good determination of the Establishment was obtained from the December 

 series; as the chronometer error was ultimately ascertained, and the greater 

 range of the tide makes the time of high water more definite than elsewhere. 

 The result, together with the best value for the Spring range, is given in the 

 table appended. It will be noticed that at times the luni-tidal intervals have 

 an alternation of a full hour in their values; which again shows that results 

 should be based on successive transits taken in pairs. 



Prince of Wales strait. — This was made winter quarters for the Polar Bear, 

 which was laid up in the strait near Armstrong point on Victoria island. Tidal 

 observations were obtained here for a month, from October 8 to November 8, 

 1915. The height was read on a scale to the nearest quarter inch, at short 

 intervals day and night; and these readings when plotted, gave a continuous 

 tide curve for the period. The time was kept by a watch, and its error was 

 obtained by comparison with a chronometer. (See Supplementary Note.) 

 The resulting Establishment as given in the table opposite, is based on the 

 luni-tidal intervals at three Spring tides. There are allso complete meteoro- 

 logical observations covering this period of a month. 



