116 TEUftESTRTAL MAGNETISM. 



II. In the Southern Hemisphere. 



Holarton, Van Diemen Island. From hourly observa- 

 tions during six years with horizontal and vertical force 

 magnetometers, the principal maximum (of south dip) occurs 

 at 11 J A.M.; the principal minimum at 6 A.M. ;" a secondary 

 maximum at 10 P.M.; and a secondary minimum at 5 P.M. 

 (Sabine, Hobarton, Vol. i. p. Ixvii.) The south dip is greater 

 in the six months when the Sun is in the southern signs 

 ( 70 36'-60) than when in the northern signs 

 ( - 70 35'-42). The intensity of the total force is also 

 greater at Hobarton from December to February than 

 from June to August. (Hobarton Obs. Vol. ii. p. xlvi.) 



Cape of Good Hope. From hourly observations during 

 4 1 years with horizontal and vertical force magnetometers, 

 a single progression is found. Maximum at 8 h. 34 m. A.M. ; 

 minimum at '*34 P.M. ; with a very small intervening 

 fluctuation between 7 A.M. and 9 A.M. 



In comparing the two stations of Toronto and Hobarton, 

 situated in corresponding latitudes on either side of the 

 equator, we notice remarkable correspondencies in respect 

 to the turning hours ; thus 



10 to 11J A.M. is the epoch of principal minimum at 

 Toronto, and of principal maximum at Hobarton. 



4 P.M. is the epoch of principal maximum at Toronto, 

 and 5 P.M. of secondary minimum at Hobarton. 



6 A.M. is the epoch of principal minimum at Hobarton, 

 and of secondary minimum at Toronto ; and from 



