EQUATION GIVEN BY DEFLEXIONS. 61 



The comparison of these (0 having such a sign that the 

 forces are opposed) gives the equation 



c^.AB + c-*. K=EB. sin0 ; 



in which it is to be remembered that the second term 

 on the left side is small. 



27. Experimental determination continued. Second 

 process, the disturbing magnet applied end-on. 



Here the form of the apparatus must be slightly 

 varied. The reversed Telescope CD, and the telescope 

 H, must occupy the same position as before : but the 

 magnet A must be carried upon an arm F at right angles 

 to F\ see Figures 26, 27. For the same reasons as in 



Fig. 26. 



last Article, the magnet A will be used in the two 

 positions shewn in these Figures, and also in two corre- 

 sponding positions on the opposite half of the transversal 



