INDEX 



361 



E.m.f., instantaneous value of de- 

 veloped (alternator), 293 

 virtual, or effective, value of, 294, 



346 

 wave form, 291, 346 



Empirical formulas, impossible to 

 avoid, 3 



Enamelled wires, 38 



End connections (armature), length 

 of, 98 



End flux cut by commutated coil, 

 155 



English language, importance of 

 thorough knowledge of, 5 



Equalizing connections for dyna- 

 mos, 90 



Equivalent sine waves, 295, 348 

 slot flux, 161, 164, 285 



ESTERLINE, PROP. J. W., referred 

 to, 101 



Excitation (see Ampere-turns). 



Exciting current, usual values of 

 (dynamos), 192 



Face conductors (definition), 72 (see 



also Armature conductors). 

 Factor of safety, calculation of, in 



magnet design, 63 

 Fans, power required to drive venti- 

 lating, 107, 318 



FIELD, PROP. A. B., referred to, 319 

 Field distortion in relation to com- 

 mutation, 169 



magnet design, 185, 228, 299 

 with distributed windings, 270 



272, 335 

 rheostat, 191 

 windings, design of, 191, 231, 299, 



351 

 FLEMING AND JOHNSON, referred to, 



192 

 Flux density (definition), 13 



in air gap of alternators, 251, 



325 



of dynamos, 75, 132 

 of magnets, 50, 54, 63, 65 

 in armature cores, 104, 210, 266, 

 330 



Flux density in armature teeth, 102, 

 104, 119, 122, 197, 209, 214, 251, 



266 

 in commutating zone, 165, 167, 



224 



in pole core, 213 

 in rotor teeth, 335 

 distribution, effect of armature 



current on, 135 

 effect of neighboring poles on, 



126, 130 



effect of tooth saturation on, 132 

 over armature surface, 124, 129, 



213, 221, 342 

 leakage (see Leakage). 

 Form factor, 294 

 Frequency of alternators, 238 



of D.C. dynamos, 78 

 Friction coefficient (between met- 

 als), 52 



of brushes, 182 

 losses (alternators), 317 

 (brushes), 181, 227, 318 

 (dynamos), 196 



G 



Gauss (definition), 13 

 Generator (see Alternator; dynamo). 

 Gilbert, 11; definition, 12 

 GRAY, PROF. A., referred to, 309 



HAWKINS AND WALLIS, referred to, 99 

 HAY, DR. A., referred to, 116, 132 

 Heating coefficient (see Cooling 



coefficient). 



intermittent, of magnet coils, 46 

 of armatures, coils, etc. (see 



Temperature rise). 

 HELE-SHAW, H. S., referred to, 116 

 HOBART AND PUNGA, referred to, 307 

 Homopolar machines (reference 



only), 83 



Horsepower transmitted by mag- 

 netic clutch, 52 



Horseshoe lifting magnet, design of 

 53 



