( 348 ) 

 By (7) we see that 



These relations would hold for all electrified systems, vüiratino' 

 in the magnetic field. 



§ 8. We shall begin by examining the viliralions, (lepcniliiig on 

 harmonies of the first order. 



Let the fundamental harmonics be 



i^n ^^ ^ ■'• > -^i~* ^= -^ .'/ ' ^' 13 ^^ ^ : » 



Then : 



aji = «23 = «33 = Vs ^ «^ ^1' 



fljo = «23 = «o] = 0, 



?-H =: Z<22 = ^33 = V'i Jia~ By = % 71 (J, 



''J2 = ^23 = ^31 = 0, 



h2 = V-i n Ha , fi3 = «23 = , 



and, if we rei)lace «ii, ^'ii and '12 by «1, />i, f 1 , 



/^l7M = — «l/'l + 'l/'2' (8) 



/'A i"2 = — «j/'i — '^l/'l ' (^) 



ft\ ï'z = — "\Pi' 



From these equations we conclude that, for // r= and f 1 = 0, 

 all vibrations have the frequency «1, given by 



which follows also from (3). 



When there is a magnetic field, the vibrations corresponding to 

 r, will still have this frequency »*], but besides these there will be 

 two motions with a modified time of vibration. In order to find 

 them, wo may suppose that p^ and pc, contain the factor e'»' multi- 



