30 Staff-Commander E. W. Creak on the Magnetical [May 8, 



observed at various stations round the harbour of Grodhavn, showed 

 considerable differences, evidently caused by local magnetic dis- 

 turbance. 



Proceeding northward to winter quarters a few results in declina- 

 tion were obtained at intermediate stations. 



On the 1st September, 1875, the " Alert " reached her winter 

 quarters at Moeberg Beach, latitude 82° 27' K, longitude 61° 22' W. 

 The magnetic observatory, constructed entirely of snow, was situated 

 at a distance of 200 yards from the ship. It was divided into three 

 distinct houses 27 feet apart, and in these the horizontal force mag- 

 netometer, Barrow's dip-circle, and the differential declination mag- 

 netometer were secured to snow pedestals. As no stove was used the 

 range of the thermometer registered was from — 10° to +4°. 



Here the series of observations, the results of which are given in 

 the following pages, were made during the winter. The mean values 

 of the several elements obtained are : — 



o / 



Absolute declination 97 57 W. 



„ inclination 84 42 IN". 



„ horizontal force (unifilar) 1-137 Total force = 12'309 



Total force (Lloyd's needles) =12-258 



Horizontal force (ditto) 1'134 



In his sledging journey to the extreme northerly position attained 

 in the expedition (lat. 83° 20' 26" N.), Commander Markham made 

 observations of the declination, and with the Fox circle. 



The "Discovery" took up winter quarters at Discovery Bay, 53 

 miles S.W. of the " Alert," in latitude 81° 44' R, longitude 65° 3' W., 

 on the 26th August, 1875. 



The magnetic observatory house was constructed of wood, and stood 

 on the shore 197 yards from the ship, and the pedestals formed of the 

 ship's binnacles sunk into the ground were found to be very firm. 

 For the differential declination magnetometer an ice-house was built 

 on the ice-floe 90 yards from the ship, the magnetometer being frozen 

 on to a pedestal of ice. The mean value of the several elements ob- 

 served at this station are : — 



o / 



Absolute declination. . . „ , 101 44 W. 



inclination 84 50 IS". 



„ horizontal force (unifilar) 1-131 .... Total force = 12-559 



Total force (Lloyd's needles) =12-225 



Horizontal force (ditto) T107 



One of the chief subjects of interest in the magnetical results of the 

 observations at the winter quarters observatories is that of the diurnal 

 variation or inequality of the declination, and frequent magnetic dis- 

 turbances, the latter especially, as the ships wintered in a region 



