11. 



ELECTEICAL KHEOMETRY. 



47 



log. ill' 



log. 7t^ . . 



39" 



. = 3.2622488 

 = 3.2636092 



log. I? ... 

 log. c . . . 



c = sin. 6 = sm. 86° 47 

 log. h = log. cos. d 

 log.lr . . . 



. = 9.9986396 

 = 9.9993198 



= 8.7475917 

 . = 7.4951834 



the denominator, h^ I? &. 



log. h^ . . . 

 log. li ... 





= 3.2636092 

 . = 1.6318046 



log. 



W 



log. 



I? 



log. 



(? 



WW 



For the numerator. 

 + h^ . 



E' + h' 



Log. R^ + h^ . 



log. (? 



log. E' 86°.792 



log. 2 U 

 log. F' . 

 log. l? . 

 log. 2 h^ W F' 



{B^ + U) (? E' 



— 2h}E'- . 



+ 2h} W F' . 

 Numerator 

 log. 58.4437 



— log. W I? & 



4.8954138 

 7.4951834 

 9.9986 396 

 2.3892368 



= 506.25 

 = 457.288 

 = 963.538 



= 2.9838684 

 = 9.9986396 

 = 0.0025472 



Log.{R' + h')c^E' 



. = 2.9850552 



log. 2 A^ ... 

 log. E^ .... 



= 2.9612203 

 . = 0.0025472 



log. 2h'E' 



= 2.9637675 



= 2.9612203 

 = 0.6308795 

 = 7.4951834 

 = 1.0872732 



= 966.174 

 = 919.956 

 = 12.2257 



= 58.4437 

 = 1.7667378 

 = 2.3892368 



%• / {'^,P) = ^og. f (/t,, 30°) . . = 9.3775010 

 But from a preceding calculation made for the needle in the centre under the 

 same deviation 30°, we found 



Log.f{c, 30°) = 8.8445407; 

 hence the ratio of the forces will be obtained — 



