26 



BELL SYSTEM TECHNICAL JOURNAL 



Fig. 1 — Spherical coordinates. The positive directions of r-, 9-, and vp-coniponents 

 of a vector are, respectively, the directions of increasing r, 6, and tp. 



and the impedance in the direction of increasing (p are 



' ~ ~ir~H:' 



7 _ ^r _ _ jEfl 



In cyHndrical coordinates we have (Fig. 2) : 



^^ //. /J' 



7 = 





Z. = 





IT. 



Fig. 2 — Cylindrical coordinates. The positive directions of p-, v?-, and s-coniponents 

 of a vector are, respectively, the directions of increasing p, <f>, and z. 



