Currents along a Number of Parallel Wires. 5G5 



It is easily deduced by the method of the former paper 

 that the equation giving c is 



f liqir Aiqrr 



£ s =A + «"S~B u + « * B 13 4- 



2fn — l)iqn 



,•....+■«— s—Bu; 



compare equation ('28), loc. cit. 



2% 

 Putting A = log — — log a, 



B 12 = log log b 12 &c, 



the term log — is multiplied by a series whose sum is zero 



and disappears from the equation. 



Also 



b 12 — b ln = 2r sin - , 



n 



2tt 

 b u = b lt n _i = 2r sin — &c 



n 7 7 



where r is the radius of the circumscribing circle. 

 — — — log a —2 cos -J— loff ( 2r sin — ) 



-2 cos ^ logf 2f sin 2 ^) - &c. 



The terms run on until the coefficient of 2r is sin ^ when 



. n — 1 7r . • i i T • i 



n is even, or sin . ~ when ft is odd. In either case the 



n w 



coefficient of log 2r sums up to unity. And we have 



? = Kg - + log [(sm n ) (»-) •*•••], 



we have 



/ 1 27-7/ 



-o = lOff 



If n is even the last factor in the expression for rj is 



/ 7r\~ 2 c03 1" 



