Dedicated to the scientists, engineers, and inventors who through their labor and genius in perfecting the art of radio communication have placed at the disposal of mankind one of the most useful and powerful instrumentalities of the age FOREWORD The authors of this book have made what they believe is the first attempt to outline the practical, commercial, and romantic sides of radio telephone and telegraph communication. In preparing the manuscript they visualized a book that would instruct and entertain the layman. The practical information has been made as readable as possible and the subject matter has been carefully chosen so as to include the many problems that confront the beginner in either the construction or operation of a radiophone receiver or transmitter. The story of radio, its development and application, forms one of the most interesting chapters in the history of science. Few people realize the importance of this new art in our every-day life or what the future holds for it. The Radio Age is here, with all of its wonders and all of its possibilities. The authors wish to thank Mr. L. M. Clement and Mr. H. Houck for their kindness in reading the manuscript. They also wish to thank Miss Mary Texanna Loomis, principal of the Loomis Radio School, Washington, D. C, for her cooperation in supplying the records of the work of Dr. M. Loomis. They take this opportunity to thank Miss Virginia Waterson for her effort in collecting the biographical material and Mrs. R. F. Yates for her work in typing the complete manuscript. Raymond Francis Yates Louis Gerard Pacent