INDEX. 



227 



Lightning conductors, joints of, 220. 



, material lor, 219. 



.points lor, 217. 



, silent discharge of, 222. 



, space protected by, 217, 218. 



, test of copper tape, 221, 222. 

 Lines of force, 55. 



M 



Machine, Armstrong's hydro-electric, 105- 



107. 



described by Xoad, 100. 

 , frictional, 96-100. 

 . the Holtz, 108-110. 

 , the Topler, 110-122. 

 Machines compared, Iloltz and Topler, 122- 



1-24. 



, influence, 108. 



Measurement of energy, 100-102. 

 Medical treatment by electricity, 142, 143. 

 Metals electrified by friction, 4,5, 132. 

 Metal screen, inductive action of, 152, 153. 

 Mode of action of the f rictional machine, 99, 



100. 



of the Holtz machine, 122, 123. 

 of the Topler machine, 115-124. 

 Multiplication of charge in Toplei machine, 

 121, 122. 



N 



Nature of electricity, 23-42. 

 Negative charge, 22. 



potential, 12, 13, 21. 



sign, 13. 



Non-conductors, 4, 5, 6. 

 Non electrics, 4. 



O 



O/one, generation of, 131. 



I'ail experiment, CO-65. 

 Pane, the charged, 72-74. 

 Plates, image, 103. 104. 

 Points, air current from, 104, 105. 



, influence of, C9, 70. 

 Polarized light and electricity, 28-31, 

 Proof plnne, 58, 59. 

 Positive and negative, 12, 13, 21. 



sign, 13. 



Potential, atmospheric, 177-180. 

 and earth currents, 175-189. 

 , el.-ctric, 10-22, 

 , difference of, 11, 12. 

 , difference of, between atmospheric 



strata, 179, 180. 

 , diurnal and seasonal variation of, 177- 



179. 



of jar P, in Topler machine. 139, 140. 

 . reversal of, in Tbpler machine, 120, 140. 

 , zero, 13, 65, 66. 



Power, transmission of, by static electricity, 

 128,129. 



Q 



Quadrant electrometer, Thomson's, 169-174. 

 Quantity and intensity, 6-8. 



Radiant energy, 31. 

 matter, 154. 



Replenisher for electrometer, 164. 



Repulsion, 1-4, 15, 16, 1C9. 



Residual charge, 84, 85. 



Reversal of potential in Topler machine, 120, 

 140. 



Rotation of Topler machine, direct and re- 

 versed, 138, 139. 



Rotary movement in A r acua, 149-151. 



s 



Silent discharge, 89. 



Source of electric supply of the Topler ma- 

 chine, 129-132. 



Spark, the, its direction, subdivision, and 

 color, 133-138. 



, and snap, 39, 40. 

 Specific inductive capacity, 51-54. 

 Spheres, electrified, 68, 69. 

 Spheroid, electrified, 70, 71. 

 Spontaneous discharge, 88. 

 Static electricity defined, 8, 9. 

 Surface condensation , 55-58. 



, thickness of electrified, 66. 



transmission , 58. 



Telegraph lines, observations on, 186-183, 204, 



205 

 Tides, electric, 183, 184. 



