MAGNETIC OBSERVATIONS. 



87 



Netlik, Whale Sound. 



(For result by declinometer see further on.) 



Observations of magnetic declination, August 4 (5tli A.M.), 1861. S. J. McCormick, observer. 



Bearing of the sun. 

 Observed time, pocket chronometer, 2"^ 20" 44' 

 Chronometer correction A r — 4 41 54 



= 11° Ol'.i 



21 38 50 

 — 5 41 



y = 



6 = 



1/= 

 A = 



S 



4" 45" 28' 

 16° 54' 21" 



— 2 26 51 

 3 magnetic bear 



20 45.8 

 -39 57 

 68 00 W. 



Mean time of observation (4th), 

 Equation of time U 



Hour angle t 



Magnetic declination, + 107 57 or -f 107° 37' when corrected 



for diurnal variation. 

 For a second determination see further on. 



Port Foulke, Smith Strait, July, 1861. 



Observations for magnetic declination at the Observatory. H. G. Radcliff, observer. 



Instruments used : Portable declinometer and theodolite. 



Observations for azimuth of marks B and C. July 9 P. M., 1861. 



The horizontal circle of the theodolite reads in a direction from south towards east. 



We have from the astronomical paper the chronometer correction of 2007 on 

 mean time, July 9, 1861 = — 'P' 47"° 17", and from the chronometer comparison, 

 pocket chronometer, 2'^ OS"' 35\8 = 2'' 3" by chronometer 2007; hence AT= 

 — ^h ^'^m 53. . .^yg h.(l^fe also the observed times of the sun's centre, from the above : 

 6^ 05" 12', 6>' 23'" 22% 6*^ 32" 20% and 6" 43°' 58= by chronometer. The correspond- 

 ing derived hour angles are P 12"' 25% 1^ 30-° 35% 1" 39"' 32% and 1" SP 10% and 

 the computed azimuths, 20° 08'. 3, 25° 08'. 5, 27° 35'. 8, and 30° 46'.5 (all west of 

 south) ; hence by means of the corresponding circle readings 57° 07'. 7, 52° 07'. 9, 

 49° 43'. 4, and 46° 28.'5, in connection with the mean reading of B 40° 01'. 6, and 

 of C 167° 25'. 4 we obtain the 



Azimuth of B. 



37° 14'.9 



37 14.8 



37 17.6 



37 13.4 



Mean, 37 15 2 W. of S. 



Azimuth of C. 



87° 15'. 2 azimuth of B 

 127 23.8 angular difference 



90 OS. 6 E. of S. 



