228 



INDEX. 



Time of electric discharge, 126-123. 

 Thermopile, illustrations from the, 175, 176. 

 Thickness of electrified surface, 66. 

 Thunder, 211, 214. 



clouds, formation of, 207-208. 

 Topler machine, the, 110-122. 



, the four-plate, 114. 



, experiments with, 125-145. 



, mode of action of, 115-124. 

 Tornadoes, 223. 

 Torsion balance, Coulomb's, 156-161. 



, inaccuracy of the, 159 101. 

 Transmission, electric, in vacua, 146-154. 



of power by static electricity, 118, 12'J. 



, surface, 58. 

 Tubes, Geissler, 147, 148. 

 Tube, vacuum, 146, 147. 



u 



Universal discharger, 87, 88. 

 Unit jar, Lane's, 101, 102. 



Vacua, electric transmission in, 32, 146-154. 



, electric transmission in low, 146-149. 



, electric transmission in high, 149-154. 



, rotary movement in high, 149-151. 

 Vacuum tube, 146, 147. 



w 



Wave theory, the, 31-37. 

 Whirl, the electric, 104. 

 Wind, electric, 104, 105, 143. 



Zero potential. 13. C5, 66. 



