188(3.] On Local Magnetic Disturbance in Islands. 91 



Kerguelen Island. 





Declination. 



Inclination. 



Total force. Observer. 



Christmas Harbour . . 

 Howe's Foreland .... 



33° 38' W. 

 34 35 



70° 50' S. 

 72 



70 53 



11 -032 

 11-003 



H.M.S. " Chal- 

 lenger," 1874. 





33 = 34' W. 

 34 

 34 57 



71° 47' S. 

 71 7 



11-422 

 11 '087 



H.M.S. " Chal- 

 lenger," 1874. 



Observatory Bay .... 

 Swain's Haulover. . . . 



35° 48' TV. 



35 54 

 35 20 



71° 56' S. 

 71 

 71 7 



71 21 



11-143 "I 



10- 288 I 



11- 171 \ 



Perry, 1 Jan., 

 1875. 



H.M.S. "Chal- 

 lenger," 1874. 

 1 Jan., 1875. 



The "Challenger" was not swung in the neighbourhood of Ker- 

 guelen Island, and the normal values have therefore been derived from 

 the results of single observations made at sea between the swinging, 

 at the Cape of Good Hope, and that in lat. 63° 30' S., long. 90° 47' E. 

 They are therefore less exact, but sufficiently so for the purpose of 

 showing that the disturbances on the island proceed from red 

 magnetism. 



Thus, at Christmas Harbour, Accessible Bay, and Betsy Cove r 

 where there was high land to the westward of each observing station, 

 the westerly declination is about 1° less than the normal. At Howe's 

 Foreland and Betsy Cove the inclination is increased, and at the latter 

 place the total force is considerably above the normal. At Observatory 

 Bay and the adjacent stations the disturbance is comparatively of a 

 moderate amount, except in the total force at Swain's Haulover, 

 which shows an unusually large diminution. 



Jnan Fernandez. 





Declination. 



Inclination. 



Total force. 



Observer. 



Near Fort St. Juan 



16° '40' E. 



39° 40' S. 



37 54 



8-138 



7-860 



H.M.S. 

 " Challenger," 

 1875. 







The sea observations from which the normal values have been 

 deduced were made at two positions — one before, the other after the 

 ship's arrival at Juan Fernandez. 



