Variable-speed drive for United States Army air corps wind tunnel at wright field, Dayton, Ohio

THE machinery manufacturers are being required to solve many design and production problems in connection with our national-defense program. All electrical manufacturing companies are exerting maximum effort to produce generators, motors, conversion apparatus, and other electrical equipment which are needed in meeting the requirements of a large and rapidly expanding industrial activity. There is a further need for machines of greater capacity, new combinations of apparatus and control devices, and more information on machine characteristics to accomplish new and difficult objectives.