270 BELL SYSTEM TECHNICAL JOURNAL 



Bicircular Coordinates 



(x + coth m)2 + y2 = csch^ u; x^ + (y — cot0)2 = csc^G 

 u = log (rj/ri) 



Using the bicircular system of coordinates facilitates finding the distribution of electric 

 charge on two parallel conductors, and thence their capacity. Rotating the bicircular 

 system about the vertical axis generates a toroidal coordinate system which faciUtates 

 determining the capacity of a torus. 



