CORRECTION. 



On page 150, Vol. iii, No. 2, November 20, 1920, line 18, for The resistance 

 after, etc, read The resistance due to A and M after, etc.; line 20, of the same 

 page, equation (4) should read as follows: 



Resistance = 2,475.22 ('^^^Ve"^'^^- T^'^'^V 70.69 (e-^^'^\ + 10 (4) 



page 151, line 11, equation (5) should read as follows: 



/ Kn \ / -KnT -KoT\ -KoT 



line 16, of the same page, for the value of O is 92.57 read the value of O is 82.57; 

 lines 16 and 17, of the same page, for (92.57 - 10) -^ (100 - 10) = 0.917 read 

 (82.57) -r (90) = 0.917. 



