Century has added to the world’s wealth of ideas and material resources. In acknowledging the many obligations to friends who have aided me in the work, my thanks are due first to the Editors of the _Scientific American_ for aid rendered in the preparation of the work; also to courteous officials in the Government Departments, and to many progressive manufacturers throughout the country. E. W. B. _Washington, D. C., October, 1900._ TABLE OF CONTENTS. CHAPTER I. THE PERSPECTIVE VIEW. CHAPTER II. CHRONOLOGY OF LEADING INVENTIONS OF THE NINETEENTH CENTURY. CHAPTER III. THE ELECTRIC TELEGRAPH. The Voltaic Pile. Daniell’s Battery. Use of Conducting Wire by Weber. Steinheil Employs Earth as Return Circuit. Prof. Henry’s Electro- Magnet, and First Telegraphic Experiment. Prof. Morse’s Telegraphic Code and Register. First Line Between Washington and Baltimore. Bain’s Chemical Telegraph. Gintl’s Duplex Telegraph. Edison’s Quadruplex. House’s Printing Telegraph. Fac Simile Telegraphs. Channing and Farmer Fire Alarm. Telegraphing by Induction. Wireless Telegraphy by Marconi. Statistics. CHAPTER IV. THE ATLANTIC CABLE. Difficulties of Laying. Congratulatory Messages Between Queen Victoria and President Buchanan. The Siphon Recorder. Statistics. CHAPTER V. THE DYNAMO AND ITS APPLICATIONS. Observations of Faraday and Henry. Magneto-Electric Machines of Pixii, and of Saxton. Hjorth’s Dynamo of 1855. Wilde’s Machine of 1866. Siemens’ of 1867. Gramme’s of 1870. Tesla’s Polyphase Currents. CHAPTER VI. THE ELECTRIC MOTOR. Barlow’s Spur Wheel. Dal Negro’s Electric Pendulum. Prof. Henry’s Electric Motor. Jacobi’s Electric Boat. Davenport’s Motor. The Neff Motor. Dr. Page’s Electric Locomotive. Dr. Siemens’ First Electric Railway at Berlin, 1879. First Electric Railway in United States, between Baltimore and Hampden, 1885. Third Rail System. Statistics. Electric Railways, and General Electric Company. Distribution Electric Current in Principal Cities. CHAPTER VII. THE ELECTRIC LIGHT. Voltaic Arc by Sir Humphrey Davy. The Jablochkoff Candle. Patents of Brush, Weston, and Others. Search Lights. Grove’s First Incandescent Lamp. Starr-King Lamp. Moses Farmer Lights First Dwelling with Electric Lamps. Sawyer-Man Lamp. Edison’s Incandescent Lamp. Edison’s Three-Wire System of Circuits. Statistics. CHAPTER VIII. THE TELEPHONE. Preliminary Suggestions and Experiments of Bourseul, Reis, and Drawbaugh. First Speaking Telephone by Prof. Bell. Differences between Reis’ and Bell’s Telephones. The Blake Transmitter. Berliner’s Variation of Resistance and Electric Undulations, by Variation of Pressure. Edison’s Carbon Microphone. The Telephone Exchange. Statistics. CHAPTER IX. ELECTRICITY, MISCELLANEOUS.