108 



PROF. T. H. CORE ON THE MAGNETIC DIP, 



The mean aunual decrease ill the dip, of i8i minute, 

 corresponds very well with that of 2'o2 as found from the 

 Kew observations from 1857 to 1874 inclusive, and I'-go 

 from the Stonyhurst observations from 1871 to 1874 

 inclusive. 



Table II. — Horizontal Force. 



The values of the horizontal force corresponding to the 

 middle of each of the four years, and the annual increase 

 for each year, are as follows : — 



