26 AKT. r,. — IT. NAGAOKA : TUE INDUCTANCE 



The two expressions (21) and (22) for S in terras of q and q^ 

 resp. will enable ns to calculate the self-inductance L by the 

 formula (18) with any desirable accuracy, while for practical 

 purposes, the simpler expressions (21') and (22') will generally 

 suffice. 



§ 22. The application of quadric transformation to the 

 elliptic integrals which enter into ^ will lead to an expression, 

 which is expedient for the evaluation of the coefficient, but for 

 the use of physicists and engineers, those already given would be 

 efficient for numerical calculation. It would however not be out 

 of place to notice the different gates, which are open for expres- 

 sing S in a convenient manner. 



§ 23. The following numerical examples are given for the 

 sake of comparison of formulœ (20) and (21) 



For «=45°, formula (20) gives 



The fourth figure is slightly in error as formula (21) will 

 show. 



For « = 45°, ^ = 0.04321392; by formula (21) 



