148 Mr Barlow's Remarks on the Dip and Intensity of the 



tion, but also to the intensities in different parts of the world, as 

 will be seen by comparing them with the results obtained by 

 Captain Sabine in various parts of the northern hemisphere, 

 and with those of Captain Parry and Lieutenant Foster, at Port 

 Bowen, and other stations ; and, as the general results in Han- 

 steen''s table of intensities, as well as those from observation, ap- 

 pear to be all consistent with the above explanation, we are jus- 

 tified, I think, in concluding, that the discrepance between the 

 intensities, as observed, and as computed from the formula 



I = A V 4 Q • "§> arises from the unequal temperature of the 



different regions ; and, consequently, that the hypothesis of a 

 pole of intensity, distinct from that of direction, is unsatisfactory 

 and untenable. 



Tli£ Jbllowing are the dips and intensities, as observed by 

 Captain Sabine, and as computed by thejbrmida I = A 



4 — 3 sin § 



With respect to the intensity of the horizontal needle, it will 

 be obviously subject to different laws, because it will be less 

 as the dip is greater, and greater as the general intensity is 



