241 



Edison, Thomas, railway telegraphy, 131. 



electromotograph, 175. 

 'Electric currents, rh. VI. 4!) 



not currents but atomic motion, 54. 



induction of, .">>. 



guarded against, 1G9. 



at Niagara, 193. 

 -Sled: i tors, ( h. VII, 62. 



frictional, 49. 



galvanic batteries, 62. 



storage-batteries, 64. 



dynamos. ;?, I'.tL*. 



metal heating, 74. 

 Electricity, science of, 6. 



achievements of, 16. 



eras in science of, 18. 



theory of, Ch. V, 39. 



not a fluid, a form of energy, 40. 



static and dynamic, 46. 



measurement of, Ch. IX, 83. 

 Electric light, cause of, 50. 

 Electric machines. 49. 



frictional, 51. 



galvanic or chemical, 51. 



chanical, 70. 

 Electromagnet invented by Faraday, 14. 



commercial value, 23. 



theory of (soft iron), 26. 



permanent I steel), 28. 



condition of use, 30. 



the earth a, 32. 



germ of, 93. 



differential. 1 15. 

 Electromotograph, 175. 



>rth, Miss, sends first telegraphic message, 



Sther, lines of force, 31. 

 nature of, 40. 



