Abstract :
This paper is not intended to be a theoretical discussion of the principles of unipolar machines; neither is it a purely descriptive article. It is rather a record of engineering experiences obtained, and difficulties overcome, in the practical development of a large machine of the unipolar type. For those who are interested in the designs and development of electrical machinery there may be many points of very considerable interest in this record. Some of the conditions of operation, with their attendant difficulties, proved to be so unusual that it is believed that a straightforward story of these troubles, and the methods for correcting them, will be of some value as a published record.