66 MAGNETIC INTENSITY, FERN ROCK OBSERVATORY. 



Table of Results of log. — , log. in X, of m the Magnetic Moment of Magnet A. 67, and of the 

 Horizontal Intensity A', at Van Rensselaer Harbor. 



Recapitulation of \''alues of X 



January 31, 1854 

 February 20, " 

 June 15, " 

 May 18, 1855 



A'=1.11'7 

 Lilt 

 1.121 

 1.203 



1.139 

 izontal force during the whole 



Mean corresponding to June, 1 854 



Taking the above vahie 1.139 for the mean hor 

 period, and multiplying it by sec. 84° 45'.8, the total force at Van Rensselaer 

 Harbor during the same period becomes ^= 12.479. 



By means of the known value of m the horizontal intensity at the stations 

 Hakluyt Island and coast near Cape York has been computed as follows: — 

 Hakluyt Island, June 21, 1855 . . X= 1.344 

 Coast near Cape York, July 19, 1855 . X 1.573 



' I redetermined m at Washington, D. C, in Marcli, 185.x, and 

 l)nt a small loss of magnetism during nearly four years. 



it o(|ual to (1.311, cxliiliitini] 



