xvi CONTENTS. 



CHAPTER IV. 



ELECTRIC TELEGRAPHY (continued}. 



PAGE 



I. Writing Telegraphs. The Morse and Morse-Digney Telegraph . . 575 



II. Printing Telegraphs. Hughes's System 583 



III. Wheatstone's Automatic High-Speed Printing Telegraph .... 591 



IV. Autographic Telegraphs Caselli's and Meyer's System .... 597 



CHAPTER V. 



TELEGRAPHIC LINES. 



I. Air Lines. Subterranean Lines 607 



II. Submarine and Transoceanic Telegraph Lines 611 



III. The Batteries employed in Telegraphy 620 



IV. The Alarums 622 



V. The Lightning Conductors ....... 624 



VI. Duplex Telegraphy "... 629 



VII. The Universal Telegraphic Network 630 



CHAPTER VI. 



ELECTRIC HOROLOGY. 



I. Electric Regulators 633 



II. Electric Clocks, properly so called 639 



III. Electric Time Signals 645 



IV. Chronographs and Chronoscopes 647 



CHAPTER VII. 



ELECTRIC MOTORS AND ELECTRO-MAGNETIC MACHINES. 



I. Oscillating Electric Motors 651 



II. Electro-Motors with Constant Rotation 654 



III. Various Applications of Electro-motors 657 



IV. Magneto-Electric Machines 660 



