226 



INDEX. 



Electric movement, 13-16. 



potential, 10-11. 



transmission in vacua, 146-154. 



wind, 104, 105, 143. 

 Electrometers, 155-174. 



, attracted disc, 161. 

 Electrometer, Thomson's absolute, 161-1C9. 



, mode of using the absolute, 166-169. 



, Thomson's quadrant, 109-174. 



, mode of using the quadrant, 173, 174. 

 Klectrophorus, the, 92-96. 

 Electroscope, the gold leaf, 16-18. 



, the pith ball, 2 3. 



, charged by induction, 44. 

 Energy, the conservation of, 23-26. 



, radiant, 31. 

 Ether, 31-33. 

 Equipotential, 55. 

 Experiments with the Topler machine ,125-145. 



F 



Farad iy's hollow cube, 65. 

 Faradic current, 141. 

 Figures, Lichtenberg's, 89-91. 

 Force, 1. 



, lines of, 55. 

 Form, influence of, 67. 

 Formulae for charged surfaces, 167. 



, application of, to measurement by elec- 

 trometer, 167-169. 

 Fracture of Leyden jar, 88, 140. 

 Friction, mutual effects of, 18-21. 

 Frictional electricity, 8, 9. 



machine, 96-100. 



G 



Gauge, idiostatic, for electrometer, 63. 

 Gas lighting, 143-145. 

 Geissler tubes, 147, 148. 

 Generators, electric, 92-124. 

 Glass for Leydeu jars, 77. 



illuminated by electricity, 151. 



, required thickness of, for insulation, 74. 



, specific inductive capacity of, 53, 54. 

 Gravity and electiicity compared, 13, 14. 

 Gunpowder, method of exploding by elec- 

 tricity, 87. 



IT 



Heat and electricity compared, 13, 14, 33, 37, 



Heat, light, and electricity compared, 26-31. 

 Heat lightning, 223. 



Heating effects of electricity in high vacua, 



153, 154. 



Hollow conductors, 58-66. 

 Hollow cube, Faraday's, 65. 

 Holtz machine, the, 108-110, 122-124. 

 Holtz and Topler machines compared, 122- 



124. 



Holtz, Dr. W., correspondence with, 123, 124. 

 Hydro-electro machine, Armstrong's, 105- 



107. 



Idiostatic gauge for electrometer, 163. 

 Image plates, 103, 104. 

 Induction, 43-54. 



, theory of, 48, 49. 



varies inversely as square of distance, 46, 



47. 

 Inductive capacity, specific, 51-54. 



influence of dielectric, 49-51. 

 Influence machines, 108. 

 Insulator defined, 6. 

 Intensity, electric, 6-8. 



Jar, the Leyden, 75-91. 



Jar D,in Topler machine, higher potential of, 

 139, 140. 



Leyden jar, the, 75-91. 



, charged by cascade, 77-79. 



, discharged through book, 81-84. 



, electromotive force of, 77. 



, fractured by overcharge, 88, 140. 



, glass suitable for, 77. 



, Lane's unit, 101, 102. 



, residual charge of, 84, 85. 



, spontaneous discharge of, 88. 



, the atmosphere as a, 180, 181. 



, with movable coatings, 85, 86. 

 Leyden battery, the, 79, 80. 



, Tyndall's experience with, 87. 

 Lichtenberg's figures, 89-91. 

 Light, heat, and electricity compared, 26-31, 

 138. 



, polarized and electricity, 28-31, 3fi. 

 Lightning and thunder, 207-223. 

 Lightning conductors, 216-221. 



, attachment of, 218. 



, earth connection of, 221. 



, form Of, 219, 220. 



, inspection of, C21. 



