510 BELL SYSTEM TECHNICAL JOURNAL 



So 



Replacing d bv-y^and / by mil-r gives: 



h 



Si J-S2 



= F (9) 



Ci 



„,'^+,T('i)'l + i + ±-l-'i£L-£i=o (10) 



dt^ L\h/ Ci C2 Cs J h Cl C3 



Considering now the parallel mechanical electrical circuits, and 

 assuming as before sine functions for v, i, F, and E, we have : 



Mechanical Case, substituting ^^1 = ] co Si, etc., in the last equations: 



COCl 1-2 OJCl 



L \ /« / COCl WC2 COC3 J 



+Jl — ^+J— r =0, 



/2 WCi OJCs 



j^+-4'-s-j^)=o. 



C0C3 \ WC3 1 



. N2 



Electrical Case, with ideal transformer of turns ratio jj-: 



C0C3 \ wC :;/ 



The analogy between the two sets of equations is quite obvious. 

 It will be noticed that the effect of the lever arm is to introduce an 

 equivalent transformer of a turns ratio which is the reciprocal of 

 the corresponding lengths of the arms. 



The general method of deducing the equivnlent electric circuits 

 should be clear from the above illustrations of the air-chamber and 



