Abstract :
Summary form only given, as follows. This, the 57th volume of the TRANSACTIONS of the AIEE, is the first to be published under the revised publication policy adopted during 1937. Under this policy, the TRANSACTIONS contains only finally reviewed papers and correlated discussions approved by the AIEE technical program committee for presentation at national conventions or District meetings. Because of the transition from the former to the new publication policy, the content of this volume is somewhat less than normal. Included in this volume are papers and related discussions presented at the following AIEE meetings and conventions: 1. 1938 winter convention, New York, NY, January 24-28: all papers presented except those published in the 1937 volume under the former publication policy. 2. North Eastern District meeting, Lenox, Mass., May 18-20: all papers approved for presentation. 3. 1938 summer convention, Washington, DC, June 20-24: all papers presented, except nine that will appear in the 1939 volume, and two that were published in the 1937 volume under the former publication policy. 4. 1938 Pacific Coast convention, Portland, Ore., August 9-12: one paper; others will appear in the 1939 volume. The present publication policy also provides for the publication of a large proportion of the approved TRANSACTIONS papers and discussions month by month in a segregated TRANSACTIONS section of the monthly issues of ELECTRICAL ENGINEERING; extra sheets are printed at the same time for ultimate binding in the annual TRANSACTIONS volume. The papers and discussions so published during the year 1938 comprise pages 1 to 712, inclusive, of this volume; pages 713 to 796, inclusive, did not appear in ELECTRICAL ENGINEERING. Since the adoption of the new publication policy involved a change from a program in which all papers were published in advance of presentation at an Institute meeting or convention to a program in which they all were published after such presentation, there wa- of necessity a transition period of several months during which papers and discussions were not completely correlated. Therefore, the first portion of this volume, up to page 492, contains: (1) discussions of some papers that were published in the 1937 TRANSACTIONS volume under the previous publication policy; (2) papers published before the related discussions became available, in order to maintain a TRANSACTIONS section of reasonable proportions in the monthly issues of ELECTRICAL ENGINEERING; and (3) discussions of these papers published separately in subsequent pages. From page 493 on, all discussions published have been correlated with their respective papers. Continuing the practice of recent years, full correlation of all material in this volume has been accomplished through the medium of the multientry reference index beginning on page 797. A reference to any of the several subject entries for any technical paper will lead directly to the paper and to any discussion on- that paper published during 1938.
