676 Prof. J. J. Tlioiii.son on the Magnetic Properties of 



— in tor — t(w -2)a) ? 



^^i^,o.-.,./A'-Yiy^"'i!:,.. 



Avhen tliis substitution is made (2) will give the z component 

 of the magnetic force. 



The .r component « is, on the assumption that the motion 

 is steady, given by the equation 



.d 1 



u = eaQ) cos a ^' J 



hence writing cot for 6 and proceeding as before, we find 

 that when the acceleration of the particle is taken into 

 account 



o(,=.\ea(o 



dz\ r + T ""V d^ r 



2twr 



\d^ dr)) r ^ dr) r J 



_{n—l)(i)r 



_ (n — l)i(or 



W^/ ^7;V./|^ 2 drj) r J 



The value of ij3 can be got in a similar way by multiplying 



3. These expressions consist of two parts : (1) periodic 

 terms proportional to some power of e'*^^, and (2) terms in- 

 dependent of the time; in considering the magnetic force 

 due to the particles we shall take these terms separately, 

 retaining in each only the lowest power of a. 



