Transcriber's note: Italic text has been marked with _underscores_. Subscript numbers are displayed as _{2} as in the equation in Chapter VII. Please see the end of this book for further notes. [Illustration: WILBUR WRIGHT Who with his younger brother, Orville Wright, invented the first practical aeroplane. Wilbur Wright's death of typhoid fever in the summer of 1912 was an irreparable loss to aviation.] THE BOY'S BOOK OF NEW INVENTIONS BY HARRY E. MAULE [Illustration] MANY ILLUSTRATIONS GARDEN CITY NEW YORK DOUBLEDAY, PAGE & COMPANY 1912 _Copyright, 1912, by_ DOUBLEDAY, PAGE & COMPANY _All rights reserved including that of translation into foreign languages, including the Scandinavian_ TO MY MOTHER In Appreciation of Her Broad Interest In All the Activities of the World _ACKNOWLEDGMENTS_ _The thanks of the publishers and author are due a great many individuals and publications for aid in securing photographs and data used in the preparation of this volume._ _Although space prevents giving the names of all, opportunity is here taken to express to each the heartiest appreciation of their generous help and valuable suggestions._ _More than to all of these are my thanks due my wife, Edna O'Dell Maule, for her constant aid and coöperation._ PREFACE In the preparation of this book the author has tried to give an interesting account of the invention and workings of a few of the machines and mechanical processes that are making the history of our time more wonderful and more dramatic than that of any other age since the world began. For heroic devotion to science in the face of danger and the scorn of their fellowmen, there is no class who have made a better record than inventors. Most inventions, too, are far more than scientific calculation, and it is the human story of the various factors in this great age of invention that is here set forth for boy readers. New discoveries, or new applications of forces known to exist, illustrating some broad principle of science, have been the chief concern of the author in choosing the subjects to be taken up in the various chapters, so that it has been necessary to limit the scope of the book, except in one or two instances, to inventions that have come into general use within the last ten years. In "The Boy's Book of Inventions," "The Second Boy's Book of Inventions," and "Stories of Invention," Mr. Baker and Mr. Doubleday have told the stories of many of the greatest inventions up to 1904, including those of the gasoline motor, the wireless telegraph, the dirigible balloon, photography, the phonograph, submarine boats, etc. Consequently for the most part the important developments in some of these machines are treated briefly in the final chapters, while the earlier chapters are devoted to new inventions, which, if made before 1904, did not receive general notice until after that time.