aECTwcnT/iY 



-TV eF A^uEO SCitNCE. 



L:.:..QCT. ; ? 





LIST OF PRINCIPAL SYMBOLS 



The following list comprises most of the symbols used in the text. Those 

 not occurring here are explained where they appear. When, also, a symbol 

 has a use different from that stated below, the correct meaning is given 

 where the symbol occurs. 



Symbol. Meaning. l':a- v. h< P- .1. rm, <i 



a Air-gap 90 



a Width of commutator segment 237 



A Area 11 



A a Area of flux per tooth pitch in the air 101 



Ai Area of flux per tooth pitch in the iron K U 



(AC) Number of ampere-conductors per centimeter 165 



f> Thickness of transformer coil J 1 1 



b Width of brush 



6' Thickness of mica 236 



B Flux density 11 



Hm Maximum value of the flux density 81 



Cj X umber of secondary conductors 



Cpp Conductors per pole per phase J 1 ' . 



d Duct width 94 



e, E Electromotive force 



/ Frequency I ^ 



P Mechanical force J7 1 



PI Tension per square centimeter 



/ Compression per square centimeter J 1 \ 



// Magnetic intensity 



// Maximum value of the magnetic intensity 81 



Electric current 80, MM 



Magnet i/.inn current . 81 



/i Current per armature branch 

 



A- a Air-nap factor '' 



Breadth f > 88 



k, .s 



k w \\ m.lmu-pitch fad,,, 88 



/ LCIIK" U 



XV 



