ELECTRICAL MACHINE DESIGN- THE DESIGN AND SPECIFICATION OF DIRECT AND ALTERNATING CURRENT MACHINERY by ALEXANDER GRAY. Originally published in 1913. PREFACE: The following work was compiled as a course of lectures on Electrical Machine Design delivered at Mo Gill University. Since the design of electrical machinery is as much an art as it is science no list of formula or collection of data is sufficient to enable one to become a successful designer. There is a certain amount of data, however, sifted from the mass of material on the subject, which every designer finds convenient to compile for ready reference. This work contains data that the author found necessary to tabulate during several years of experience as a designer of electrical apparatus. A study of design Is of the utmost importance to all students, because only by such a study can a knowledge of the limitations of machines be acquired. The machines discussed are those which have become more or less standard, namely, direct-cur rent generators and motors, alternating current generators, syn chronous motors, polyphase induction motors, and transformers; other apparatus seldom offers an electrical problem that is not discussed under one or more of the above headings. The principle followed throughout the work is to build up the design for the given rating by the use of a few fundamental formula*, and design constants, the meaning and limits of which are discussed thoroughly, and the same procedure has been followed for the several pieces of apparatus.