INDEX 



363 



Maxwell, 11; definition, 13 

 MENGES, C. L. R. E., referred to, 155 

 Mesh connection, 244 

 Mica, commutator, thickness of, 94, 



177 

 MOORE, PROP. C. R., referred to, 



101, 132 

 MORDEY flat coil alternator referred 



to, 239 



MORTENSEN, S. H., referred to, 307 

 Moss, E. W., referred to, 84 

 Motors, continuous current, 70, 235 

 MOULD, J., referred to, 84 

 Multiple, or lap, winding, 86 

 Multiplex armature windings, 86 



N 



Neutral field, or zone (definition), 



146, 283 

 NOEGQERATH, J. E., referred to, 84 



Oersted (definition), 13 

 Open-circuit characteristic curve 



(see Saturation curve). 

 Output formula for D.C. dynamos, 

 73, 76 



of three-phase generator, 247 



PARSHALL AND HOBART, referred to, 



101 



PELTON water-wheel, referred to, 241 

 Peripheral loading (see Specific load- 

 ing). 



velocity of alternator rotors, 238 

 of commutators, 184 

 of dynamo armatures, 77 

 Permeability, 11, 15; definition, 13 

 Permeance, 11; definition, 13 

 between concentric cylinders, 26 

 flat surfaces, 24 

 parallel cylinders, 27 

 curve, 123, 130 

 of air gap (slotted armatures), 



116, 272 



of leakage paths (formulas), 23 

 Phases, number of, 239 



Plunger magnet, 49 



Polar coordinates, use of, for plot- 

 ting irregular waves, 294, 347 



Pole arc, 74, 76, 204, 249 



Pole-face windings, 170, 279, 322, 

 336 



Pole, length of, 186, 227 



Pole pitch (definition), 74; usual 



values, 80, 249 



factors determining width of, 

 78, 248 



Pole shoes, 188, 269 



Poles, number of, 80, 204, 241 



POWELL, P. H., referred to, 116 



Pressure rise when switching off 

 magnet coil, 33 



Pressures, usual, in commercial 

 designs, 33, 248 



Properties of materials, 32 



Pull exerted by magnets, 29, 50 



Q 



Quantity of air required with 



forced ventilation, 112 

 of electricity, 70 



R 



Reactance, armature, 304 



coils, use of, 355 

 Reactive voltage drop (slots), 288; 



(ends), 266, 304, 332 

 Regulation, effect of flux distribu- 

 tion on, 311 



inherent (definition), 252 

 of alternators, 252, 301, 312, 352 

 on any power factor, 309 

 on zero power factor, 305 

 Reluctance, magnetic, 11; definition, 



13 



Resistance of armature windings, 97 

 of copper wires, 36 

 variation of, with temperature, 36 

 Rheostat, shunt field, 191 

 Rise of pressure on switching-off coil, 



33 

 of temperature (see Temperature 



rise). 



Rotor of turbo-alternators, 270, 272, 

 326, 335 



