CONTENTS. 



CHAPTER PAOB 



INTRODUCTION v 



I. THE AUTHOR'S DESIGN 1 



II. HISTORY OF ELECTRICAL SCIENCE.. 6 



III. HISTORY OF MAGNETISM 20 



IV. THEORY AND NATURE OF MAGNETISM 25 

 V. THEORY OF ELECTRICITY 39 



VI. ELECTRICAL CURRENTS 49 



VII. ELECTRIC GENERATORS 62 



VIII. ATMOSPHERIC ELECTRICITY 77 



IX. ELECTRICAL MEASUREMENT 83 



X THE ELECTRIC TELEGRAPH 88 



XI. RECEIVING MESSAGES 103 



XII. MISCELLANEOUS METHODS 108 



XIII. MULTIPLE TRANSMISSION 114 



XIV. WAY DUPLEX SYSTEM 129 



XV. THE TELEPHONE 134 



XVI. How THE TELEPHONE TALKS 145 



XVII. SUBMARINE TELEGRAPHY 154 



XVIII. SimiM-LiM. TI.I I.<;I:M'HS 159 



XIX Tin: Tl.l. U-TOGRAPH 165 



X.\ I'fHUKITIES 171 



XXI. \Vll;l.J.l.>- Tl.l I.i.i: M'HY 176 



iii 



