INDEX. 



513 



Efficiency, electrical, of a generator, 135 

 of a generator, calculation of, 132 

 of generator, variation of with out- 

 put, 136 

 of lamps, 326 



mechanical, of a motor, 141 

 of a motor, calculation of, 138 



Siemens' law, 99 

 variation of, with output, 141 

 Electric arc, the, characteristics of, 330 

 current, see current, 

 distribution, size of wires for, 275 

 lamp, the, 325 

 lighting, 308 

 strength of air between parallel wires, 



302 



of cable insulation, 301 

 of insulation, dependence of size 



of wires upon, 299 



Electrical efficiency of a generator, 135 

 power, cost of, 223 



systems of selling, 232 

 resistance, see resistance. 

 Electromotive force, definition of, 22 



induced, 30 

 Electrolysis, 238 

 Electrolyte, definition of, 238 

 Electromagnets, 351 

 Enclosed-arc lamp, the, 336 

 End-cell control, 256 

 Equalizing arrangement, the, 184 

 Expansion, coefficients of linear, 283 

 Exciter dynamo, the, 38 

 External characteristic of series generator, 



386 

 of shunt generator, 397 



Faults in armatures, testing for, 182 

 Feeder control, 195 

 Field excitation of generators, 44, 87 

 of motors, 48 

 separate, 44 



loss in generators and motors, 127 



magnet, definition of, 36, 38 



magnetic, 4 



rheostat, the, 88 



switch, non-sparking, 188 



33 



Fire risks, 219 



Flat-compounding of a generator, 86 

 " Floating battery," the, 258 

 Flux density in iron, 361 



magnetic, definition of, 8 



of light required for illumination, 324 

 Foucault currents (see eddy currents). 

 Fuses and circuit breakers, 205 



Galvanized wire, weight of, 283 

 Generator, the, 35 



the compound, 47, 86 

 adjustment of, 90 

 connections of, 79 

 the double -current, 273 

 efficiency, calculation of, 132 

 electromotive force of, 82 

 the flat-compound, 86 

 and motor efficiencies, 127 



losses, 127 

 output of, 8 1 

 the over-compound, 86 

 separately excited, the, 85 

 the series, 46 

 series, connections of, 78 

 the shunt, 45 

 shunt, connections of, 79 

 the split-pole, 272 



Generators, characteristic curves of, 75 

 characteristic curves of, 386-407 

 for Edison three-wire system, 271 

 field excitation of, 44, 87 

 and motors, diseases of, 1 75 

 management of, 172 

 starting of, 174 

 operation of, in parallel, 184 

 rating of, 82 

 voltage control of, 88 

 voltage regulation of, 88 

 Gilbert, the definition of, 356 

 Glare of a lamp, definition of, 322 

 Globes, lamp, 338 

 Glow lamp, the carbon- filament, 343 



metal-filament, 348 

 Grounds and ground detectors, 209 

 Guarantees and ratings, 145 

 standard, 164 



