INDEX. 



Ab-ampere, definition of the, 16 

 Ab-ohra, definition of the, 20 

 Absorption of light, influence of, on illu- 

 mination, 324 



Ab-volt, definition of the, 24 

 All-day efficiency, definition of, 469 

 Alternating- current arc, the, 334 

 Alternator, the, 36 

 Aluminum wire, weights and resistances 



of, 307 

 Ammeters, 200 



errors of, 479 



Ampere, definition of the, 16 

 Ampere-turn, the, 356 

 Angle of lead of brushes, 94 

 Anti-parallel wiring scheme (see return 



loop). 



Arc, the electric, characteristics of, 330 

 alternating-current, 334 

 direct-current, 332 

 lamp, the, 327 

 rating, 337 

 Arc lamps on constant-voltage mains, 336 



series grouping of, 338 

 lighting, constant-current series sys- 

 tem, 339 



Armature, closed-coil and open -coil, 40 

 coil or section, 420 

 core loss, calculation of, 382 

 cross-magnetizing action of, 151 

 definition of, 36, 38 

 demagnetizing action of, 151 

 faults, testing for, 182 

 inductors, 420 



loss in generators and motors, 129 

 neutral axis of, 93 

 reaction, 151 



compensation of, 160 

 winding, dependence of brushes 



upon, 432 

 the disk, 419 



Armature winding, the drum, 418 



element of, 420 



the helical, 418 



lap, 423 



modified multiplex, 445 



multi-circuit, 431 



open-coil and closed-coil, 419 



parallel grouping of, see lap. 



reentrancy of, 428 



the ring, 418 



table of conditions, 436 



two-circuit, 431 



simplex and multiplex, 429 



series grouping of, see wave. 



wave, 426 

 Armature windings, 418 



examples of, 436 



Armatures, smooth and slotted, 67 

 Axis of commutation, 93 



neutral, of armature, 93 



Balancer, the motor-generator, 274 



the three-wire, 273 



Battery, the storage (see storage bat- 

 tery). 



the voltaic or primary, 239 

 Bipolar versus multipolar dynamos, 65 

 Booster, the compound, 261 



the differential, 261 



the negative, 259 



the shunt, 257 



with carbon rheostat control, 261 

 Boosters, automatic, 258 

 Brush arc-lighting generator, the, 342 



contact resistance, 472-473 



holders, 63 



lead, 91 

 Brushes, 63 



number of on a dynamo, 432 

 Building-up of a generator, 80 

 Bunsen photometer, the, 313 



