In this work the author makes no attempt to romanti cize the history of radio. Rather, radio is treated as a great new utility created by men Of genius who hearkened less to outside inspiration than to voices within themselves: men (and boys) of pioneering spirit who through enthu siasm and diligence studied and experimented, Often with meager equipment, until desired results were attained. The work supplies a readable record Of radio achievement having somewhat chronological treatment, which will en able radio workers to live over again days and nights Of attachment to a labor that held their interest constant. The book, without mathematics, presents a narrative of experimental achievement which boys and young men will find stimulating, while at the same time they acquire a knowledge of how radio started and how it grew. The layman, also, by perusing this work may learn how radio operates, since the knowledge Of its construction and work ing today is built up from its elementary beginning. And, because Of the manner in which the various scientists, engineers, and experimenters are identified, the reader may recognize the many consecutive contributions as achieve ments Of real people.