 He contributed three papers on the subject to "Revue Générale de l'Electricité" in 1930, which included some practical applications.The main one was the use of the constant-current output for the control of traction motors on electric vehicles and the operation of cranes, areas in which he had some practical experience, following trials in conjunction with the Alsthom Company in France.In 1930, he made a trip to Britain, and the Metropolitan-Vickers company took his ideas and developed a working system.