Abstract :
THE subject of this paper has been suggested to the U. S. Committee, by the Council of the I. E. C., as suitable for a report at this 1926 meeting, and has been assigned to the writer for preparation. The writer does not claim any authorization from the U. S. National Committee to present its views officially on the subject. He merely submits the paper as expressing personal opinions, aided, however, by the records and reports of a certain group of engineers who have given special attention to the thermal constants of electric machines, and who are mentioned in the following text.
