Abstract :
Discussion of paper 42–138 by T. R. Rhea and H. H. Zielinski, presented at the AIEE summer convention, Chicago, Ill., June 22–26, 1942, and at the AIEE Pacific Coast convention, Vancouver, B. C., Canada, September 9–11, 1942, and published in AIEE TRANSACTIONS, 1942, October section, pages 733–41. The following discussion was presented at the 1942 summer convention.