CHAPTER  UL— (Continued.)

a  Steady  Current  in  an  Inductive  Circuit ;  Time  Constant  of  an
Inductive  Circuit — §  17,  Logarithmic  Curves  ;  Law  of  Growth
of  Current  in  Inductive  Circuit — §  18.  Instantaneous  Value  of
Simple  Periodic  Current ;  Solution  of  Current  Equation  ;  Impe-
dance of  Inductive  Circuit;  Relations  of  Impressed  Electromotive
Force,  Current  and  Impedance. — §  19.  G^metrical  Illustrations;
Clock  Diagrams. — §  20.  Graphical  Representation  of  Periodic
Currents  ;  Laws  of  Vector  Addition. — §  21.  Impressed  and
Effective  Electromotive  Forces  ;  Clock  Diagram  of  Electromotive
Forces  in  Inductive  Circuit ;  Triangle  Representing  Resistance^
Impedance,  and  Reactance  of  Circuit.— §  22.  The  Mean  Value
of  the  Power  of  a  Periodic  Current ;  Geometrical  Theorem. —
§  23.  Power  Curves  for  Inductive  and  Non-inductive  Circuits. —
§  24.  The  Experimental  Measuremeut  of  Periodic  Currents  and
Electromotive  Forces  ;  Mean -Square  Value.— §  25.  Method  of
Measuriug  the  True  Mean  Power  Given  to  an  Inductive  Circuit ;
Theory  of  the  Wattmeter  ;  Divided  Circuits  ;  Important  Trigo-
nometrical Lemma. — §  26.  Irape<lance  df  Branched  Circuits. —
S  27.  Wattmeter  Measurement  of  Periodic  Power. — §  28.  Correct-
ing Factor  of  a  Wattmeter. —§  29.  Mutual  Induction  of  Two
Circuits  of  Constant  Inductance ;  Effect  of  Closed  Secondary
OQ  the  Resistance  and  Inductance  of  a  Primary  Circuit. — §  30.
Tlie  Flow  of  Simple  Periodic  Currents  into  a  Condenser  ;  Time-
Constant  of  a  Condenser  :  Charging  a  Condenser  Through  a
Resistance  ;  Admittance  ;  Coudenser  Equation. — §31.  A  Shunted
Condenser  in  Series  with  an  Inductive  Resistance  ;  Annulment
of  Inductance  by  Capacity. — §  32.  Representation  of  Periodic
Currents  by  Polar  Diagrams  ;  Determination  of  Mean -Square
Value  of  a  Periodic  Quantity  from  the  Polar  Diagram. ->§  33.
