MOMENTARY CONTACTS. 



231 



which gives 



^ 

 pi 



7T 2 

 ^T 2 



This current is represented by the curve B (Fig. 61). It is a 



di 

 maximum when = 0, that is to say, when 



u- 



an equation which gives sensibly 



/3\s 

 =(-), or /=3. 



W 



239. Finally, in order to shorten the arrival waves, and to 

 discharge the wire, the origin of the wire may be put alternately at 

 equal potentials and opposite signs, during equal or unequal times, 

 by connecting it with one of the poles of a battery. 



Fig. 62. 



Curves I, II, and III of Fig. 62, represent the arrival waves of 

 the alternative successive contacts : 



Curves. 



I 



II 

 III 



Duration of contact. 



4* 

 3*' 



