This volume comprises the non-mathematical portions of a course of lectures, entitled "Electric Waves and their Application to Wireless Telegraphy," which for several years have been given by the author to classes at Harvard University. In giving the lectures and in preparing this volume, the design has been: - First, to present, in as elementary a form as possible, the course of reasoning and experimentation that has led to the conception of electric waves; second, to follow this with a discussion of the properties of electric waves and electric oscillations; third, to give a history of the application of electric waves to wireless telegraphy; and fourth, to elaborate the general principles and methods of electric-wave telegraphy in sufficient detail to be of possible use to elementary students of electricity and to amateur and professional electricians engaged in operating and constructing wireless telegraphic apparatus.
The author wishes to express his sincere thanks to Commander S. S. Robison of the United States Navy, to Mr. Elliott Woods of Washington, and to Chief Inspector D. M. Mahood of the New York Navy Yard for their kindness in supplying photographs for some of the illustrations. Also, the author is grateful to the Editors of the Physical Review for the loan of Plates I and II, and to Mr. Greenleaf Whittier Pickard for the privilege of consulting his manuscript account of experiments on the effects of daylight on transmission. Finally, the author takes great pleasure in expressing his gratitude to his friend Mr. George Francis Arnold, who has kindly read the proofs and made many valuable suggestions.