A somewhat misleading title, since it is not actually a book for reference on factual and constructional information beyond the theoretical and simple stage. Rather is it an introduction, an ABC. There are useful bits, -- definitions, a few tables -- but on the whole it is not the right sort of book to give a beginner the basic and fundamental principles, nor to interest the experienced person with useful working information. The important phases are elementary in treatment, and the explanations given are so far from being of assistance in actual practice, that even the beginner would be disillusioned as he advanced. For example, the building of a model transmitter is described -- which the veriest amateur does not need as it is sold in kit form at nominal cost, with complete instructions. However, the fact that the book has been revised by the radio editor of the N.Y. Sun indicates that it is basically sound, and the previous seven editions indicate that it has a place.